drivers/firewire/ohci.c

   1 /*
   2  * Driver for OHCI 1394 controllers
   3  *
   4  * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include <linux/bitops.h>
  22 #include <linux/bug.h>
  23 #include <linux/compiler.h>
  24 #include <linux/delay.h>
  25 #include <linux/device.h>
  26 #include <linux/dma-mapping.h>
  27 #include <linux/firewire.h>
  28 #include <linux/firewire-constants.h>
  29 #include <linux/init.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/io.h>
  32 #include <linux/kernel.h>
  33 #include <linux/list.h>
  34 #include <linux/mm.h>
  35 #include <linux/module.h>
  36 #include <linux/moduleparam.h>
  37 #include <linux/mutex.h>
  38 #include <linux/pci.h>
  39 #include <linux/pci_ids.h>
  40 #include <linux/slab.h>
  41 #include <linux/spinlock.h>
  42 #include <linux/string.h>
  43 #include <linux/time.h>
  44 #include <linux/vmalloc.h>
  45
  46 #include <asm/byteorder.h>
  47 #include <asm/page.h>
  48 #include <asm/system.h>
  49
  50 #ifdef CONFIG_PPC_PMAC
  51 #include <asm/pmac_feature.h>
  52 #endif
  53
  54 #include "core.h"
  55 #include "ohci.h"
  56
  57 #define DESCRIPTOR_OUTPUT_MORE          0
  58 #define DESCRIPTOR_OUTPUT_LAST          (1 << 12)
  59 #define DESCRIPTOR_INPUT_MORE           (2 << 12)
  60 #define DESCRIPTOR_INPUT_LAST           (3 << 12)
  61 #define DESCRIPTOR_STATUS               (1 << 11)
  62 #define DESCRIPTOR_KEY_IMMEDIATE        (2 << 8)
  63 #define DESCRIPTOR_PING                 (1 << 7)
  64 #define DESCRIPTOR_YY                   (1 << 6)
  65 #define DESCRIPTOR_NO_IRQ               (0 << 4)
  66 #define DESCRIPTOR_IRQ_ERROR            (1 << 4)
  67 #define DESCRIPTOR_IRQ_ALWAYS           (3 << 4)
  68 #define DESCRIPTOR_BRANCH_ALWAYS        (3 << 2)
  69 #define DESCRIPTOR_WAIT                 (3 << 0)
  70
  71 struct descriptor {
  72         __le16 req_count;
  73         __le16 control;
  74         __le32 data_address;
  75         __le32 branch_address;
  76         __le16 res_count;
  77         __le16 transfer_status;
  78 } __attribute__((aligned(16)));
  79
  80 #define CONTROL_SET(regs)       (regs)
  81 #define CONTROL_CLEAR(regs)     ((regs) + 4)
  82 #define COMMAND_PTR(regs)       ((regs) + 12)
  83 #define CONTEXT_MATCH(regs)     ((regs) + 16)
  84
  85 #define AR_BUFFER_SIZE  (32*1024)
  86 #define AR_BUFFERS_MIN  DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
  87 /* we need at least two pages for proper list management */
  88 #define AR_BUFFERS      (AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
  89
  90 #define MAX_ASYNC_PAYLOAD       4096
  91 #define MAX_AR_PACKET_SIZE      (16 + MAX_ASYNC_PAYLOAD + 4)
  92 #define AR_WRAPAROUND_PAGES     DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
  93
  94 struct ar_context {
  95         struct fw_ohci *ohci;
  96         struct page *pages[AR_BUFFERS];
  97         void *buffer;
  98         struct descriptor *descriptors;
  99         dma_addr_t descriptors_bus;
 100         void *pointer;
 101         unsigned int last_buffer_index;
 102         u32 regs;
 103         struct tasklet_struct tasklet;
 104 };
 105
 106 struct context;
 107
 108 typedef int (*descriptor_callback_t)(struct context *ctx,
 109                                      struct descriptor *d,
 110                                      struct descriptor *last);
 111
 112 /*
 113  * A buffer that contains a block of DMA-able coherent memory used for
 114  * storing a portion of a DMA descriptor program.
 115  */
 116 struct descriptor_buffer {
 117         struct list_head list;
 118         dma_addr_t buffer_bus;
 119         size_t buffer_size;
 120         size_t used;
 121         struct descriptor buffer[0];
 122 };
 123
 124 struct context {
 125         struct fw_ohci *ohci;
 126         u32 regs;
 127         int total_allocation;
 128         bool running;
 129         bool flushing;
 130
 131         /*
 132          * List of page-sized buffers for storing DMA descriptors.
 133          * Head of list contains buffers in use and tail of list contains
 134          * free buffers.
 135          */
 136         struct list_head buffer_list;
 137
 138         /*
 139          * Pointer to a buffer inside buffer_list that contains the tail
 140          * end of the current DMA program.
 141          */
 142         struct descriptor_buffer *buffer_tail;
 143
 144         /*
 145          * The descriptor containing the branch address of the first
 146          * descriptor that has not yet been filled by the device.
 147          */
 148         struct descriptor *last;
 149
 150         /*
 151          * The last descriptor in the DMA program.  It contains the branch
 152          * address that must be updated upon appending a new descriptor.
 153          */
 154         struct descriptor *prev;
 155
 156         descriptor_callback_t callback;
 157
 158         struct tasklet_struct tasklet;
 159 };
 160
 161 #define IT_HEADER_SY(v)          ((v) <<  0)
 162 #define IT_HEADER_TCODE(v)       ((v) <<  4)
 163 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
 164 #define IT_HEADER_TAG(v)         ((v) << 14)
 165 #define IT_HEADER_SPEED(v)       ((v) << 16)
 166 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
 167
 168 struct iso_context {
 169         struct fw_iso_context base;
 170         struct context context;
 171         int excess_bytes;
 172         void *header;
 173         size_t header_length;
 174
 175         u8 sync;
 176         u8 tags;
 177 };
 178
 179 #define CONFIG_ROM_SIZE 1024
 180
 181 struct fw_ohci {
 182         struct fw_card card;
 183
 184         __iomem char *registers;
 185         int node_id;
 186         int generation;
 187         int request_generation; /* for timestamping incoming requests */
 188         unsigned quirks;
 189         unsigned int pri_req_max;
 190         u32 bus_time;
 191         bool is_root;
 192         bool csr_state_setclear_abdicate;
 193         int n_ir;
 194         int n_it;
 195         /*
 196          * Spinlock for accessing fw_ohci data.  Never call out of
 197          * this driver with this lock held.
 198          */
 199         spinlock_t lock;
 200
 201         struct mutex phy_reg_mutex;
 202
 203         void *misc_buffer;
 204         dma_addr_t misc_buffer_bus;
 205
 206         struct ar_context ar_request_ctx;
 207         struct ar_context ar_response_ctx;
 208         struct context at_request_ctx;
 209         struct context at_response_ctx;
 210
 211         u32 it_context_support;
 212         u32 it_context_mask;     /* unoccupied IT contexts */
 213         struct iso_context *it_context_list;
 214         u64 ir_context_channels; /* unoccupied channels */
 215         u32 ir_context_support;
 216         u32 ir_context_mask;     /* unoccupied IR contexts */
 217         struct iso_context *ir_context_list;
 218         u64 mc_channels; /* channels in use by the multichannel IR context */
 219         bool mc_allocated;
 220
 221         __be32    *config_rom;
 222         dma_addr_t config_rom_bus;
 223         __be32    *next_config_rom;
 224         dma_addr_t next_config_rom_bus;
 225         __be32     next_header;
 226
 227         __le32    *self_id_cpu;
 228         dma_addr_t self_id_bus;
 229         struct tasklet_struct bus_reset_tasklet;
 230
 231         u32 self_id_buffer[512];
 232 };
 233
 234 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
 235 {
 236         return container_of(card, struct fw_ohci, card);
 237 }
 238
 239 #define IT_CONTEXT_CYCLE_MATCH_ENABLE   0x80000000
 240 #define IR_CONTEXT_BUFFER_FILL          0x80000000
 241 #define IR_CONTEXT_ISOCH_HEADER         0x40000000
 242 #define IR_CONTEXT_CYCLE_MATCH_ENABLE   0x20000000
 243 #define IR_CONTEXT_MULTI_CHANNEL_MODE   0x10000000
 244 #define IR_CONTEXT_DUAL_BUFFER_MODE     0x08000000
 245
 246 #define CONTEXT_RUN     0x8000
 247 #define CONTEXT_WAKE    0x1000
 248 #define CONTEXT_DEAD    0x0800
 249 #define CONTEXT_ACTIVE  0x0400
 250
 251 #define OHCI1394_MAX_AT_REQ_RETRIES     0xf
 252 #define OHCI1394_MAX_AT_RESP_RETRIES    0x2
 253 #define OHCI1394_MAX_PHYS_RESP_RETRIES  0x8
 254
 255 #define OHCI1394_REGISTER_SIZE          0x800
 256 #define OHCI_LOOP_COUNT                 500
 257 #define OHCI1394_PCI_HCI_Control        0x40
 258 #define SELF_ID_BUF_SIZE                0x800
 259 #define OHCI_TCODE_PHY_PACKET           0x0e
 260 #define OHCI_VERSION_1_1                0x010010
 261
 262 static char ohci_driver_name[] = KBUILD_MODNAME;
 263
 264 #define PCI_DEVICE_ID_AGERE_FW643       0x5901
 265 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW 0x2380
 266 #define PCI_DEVICE_ID_TI_TSB12LV22      0x8009
 267
 268 #define QUIRK_CYCLE_TIMER               1
 269 #define QUIRK_RESET_PACKET              2
 270 #define QUIRK_BE_HEADERS                4
 271 #define QUIRK_NO_1394A                  8
 272 #define QUIRK_NO_MSI                    16
 273
 274 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
 275 static const struct {
 276         unsigned short vendor, device, revision, flags;
 277 } ohci_quirks[] = {
 278         {PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
 279                 QUIRK_CYCLE_TIMER},
 280
 281         {PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
 282                 QUIRK_BE_HEADERS},
 283
 284         {PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
 285                 QUIRK_NO_MSI},
 286
 287         {PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
 288                 QUIRK_NO_MSI},
 289
 290         {PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
 291                 QUIRK_CYCLE_TIMER},
 292
 293         {PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
 294                 QUIRK_CYCLE_TIMER},
 295
 296         {PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
 297                 QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
 298
 299         {PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
 300                 QUIRK_RESET_PACKET},
 301
 302         {PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
 303                 QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
 304 };
 305
 306 /* This overrides anything that was found in ohci_quirks[]. */
 307 static int param_quirks;
 308 module_param_named(quirks, param_quirks, int, 0644);
 309 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
 310         ", nonatomic cycle timer = "    __stringify(QUIRK_CYCLE_TIMER)
 311         ", reset packet generation = "  __stringify(QUIRK_RESET_PACKET)
 312         ", AR/selfID endianess = "      __stringify(QUIRK_BE_HEADERS)
 313         ", no 1394a enhancements = "    __stringify(QUIRK_NO_1394A)
 314         ", disable MSI = "              __stringify(QUIRK_NO_MSI)
 315         ")");
 316
 317 #define OHCI_PARAM_DEBUG_AT_AR          1
 318 #define OHCI_PARAM_DEBUG_SELFIDS        2
 319 #define OHCI_PARAM_DEBUG_IRQS           4
 320 #define OHCI_PARAM_DEBUG_BUSRESETS      8 /* only effective before chip init */
 321
 322 #ifdef CONFIG_FIREWIRE_OHCI_DEBUG
 323
 324 static int param_debug;
 325 module_param_named(debug, param_debug, int, 0644);
 326 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
 327         ", AT/AR events = "     __stringify(OHCI_PARAM_DEBUG_AT_AR)
 328         ", self-IDs = "         __stringify(OHCI_PARAM_DEBUG_SELFIDS)
 329         ", IRQs = "             __stringify(OHCI_PARAM_DEBUG_IRQS)
 330         ", busReset events = "  __stringify(OHCI_PARAM_DEBUG_BUSRESETS)
 331         ", or a combination, or all = -1)");
 332
 333 static void log_irqs(u32 evt)
 334 {
 335         if (likely(!(param_debug &
 336                         (OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
 337                 return;
 338
 339         if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
 340             !(evt & OHCI1394_busReset))
 341                 return;
 342
 343         fw_notify("IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
 344             evt & OHCI1394_selfIDComplete       ? " selfID"             : "",
 345             evt & OHCI1394_RQPkt                ? " AR_req"             : "",
 346             evt & OHCI1394_RSPkt                ? " AR_resp"            : "",
 347             evt & OHCI1394_reqTxComplete        ? " AT_req"             : "",
 348             evt & OHCI1394_respTxComplete       ? " AT_resp"            : "",
 349             evt & OHCI1394_isochRx              ? " IR"                 : "",
 350             evt & OHCI1394_isochTx              ? " IT"                 : "",
 351             evt & OHCI1394_postedWriteErr       ? " postedWriteErr"     : "",
 352             evt & OHCI1394_cycleTooLong         ? " cycleTooLong"       : "",
 353             evt & OHCI1394_cycle64Seconds       ? " cycle64Seconds"     : "",
 354             evt & OHCI1394_cycleInconsistent    ? " cycleInconsistent"  : "",
 355             evt & OHCI1394_regAccessFail        ? " regAccessFail"      : "",
 356             evt & OHCI1394_unrecoverableError   ? " unrecoverableError" : "",
 357             evt & OHCI1394_busReset             ? " busReset"           : "",
 358             evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
 359                     OHCI1394_RSPkt | OHCI1394_reqTxComplete |
 360                     OHCI1394_respTxComplete | OHCI1394_isochRx |
 361                     OHCI1394_isochTx | OHCI1394_postedWriteErr |
 362                     OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
 363                     OHCI1394_cycleInconsistent |
 364                     OHCI1394_regAccessFail | OHCI1394_busReset)
 365                                                 ? " ?"                  : "");
 366 }
 367
 368 static const char *speed[] = {
 369         [0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
 370 };
 371 static const char *power[] = {
 372         [0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
 373         [4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
 374 };
 375 static const char port[] = { '.', '-', 'p', 'c', };
 376
 377 static char _p(u32 *s, int shift)
 378 {
 379         return port[*s >> shift & 3];
 380 }
 381
 382 static void log_selfids(int node_id, int generation, int self_id_count, u32 *s)
 383 {
 384         if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
 385                 return;
 386
 387         fw_notify("%d selfIDs, generation %d, local node ID %04x\n",
 388                   self_id_count, generation, node_id);
 389
 390         for (; self_id_count--; ++s)
 391                 if ((*s & 1 << 23) == 0)
 392                         fw_notify("selfID 0: %08x, phy %d [%c%c%c] "
 393                             "%s gc=%d %s %s%s%s\n",
 394                             *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
 395                             speed[*s >> 14 & 3], *s >> 16 & 63,
 396                             power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
 397                             *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
 398                 else
 399                         fw_notify("selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
 400                             *s, *s >> 24 & 63,
 401                             _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
 402                             _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
 403 }
 404
 405 static const char *evts[] = {
 406         [0x00] = "evt_no_status",       [0x01] = "-reserved-",
 407         [0x02] = "evt_long_packet",     [0x03] = "evt_missing_ack",
 408         [0x04] = "evt_underrun",        [0x05] = "evt_overrun",
 409         [0x06] = "evt_descriptor_read", [0x07] = "evt_data_read",
 410         [0x08] = "evt_data_write",      [0x09] = "evt_bus_reset",
 411         [0x0a] = "evt_timeout",         [0x0b] = "evt_tcode_err",
 412         [0x0c] = "-reserved-",          [0x0d] = "-reserved-",
 413         [0x0e] = "evt_unknown",         [0x0f] = "evt_flushed",
 414         [0x10] = "-reserved-",          [0x11] = "ack_complete",
 415         [0x12] = "ack_pending ",        [0x13] = "-reserved-",
 416         [0x14] = "ack_busy_X",          [0x15] = "ack_busy_A",
 417         [0x16] = "ack_busy_B",          [0x17] = "-reserved-",
 418         [0x18] = "-reserved-",          [0x19] = "-reserved-",
 419         [0x1a] = "-reserved-",          [0x1b] = "ack_tardy",
 420         [0x1c] = "-reserved-",          [0x1d] = "ack_data_error",
 421         [0x1e] = "ack_type_error",      [0x1f] = "-reserved-",
 422         [0x20] = "pending/cancelled",
 423 };
 424 static const char *tcodes[] = {
 425         [0x0] = "QW req",               [0x1] = "BW req",
 426         [0x2] = "W resp",               [0x3] = "-reserved-",
 427         [0x4] = "QR req",               [0x5] = "BR req",
 428         [0x6] = "QR resp",              [0x7] = "BR resp",
 429         [0x8] = "cycle start",          [0x9] = "Lk req",
 430         [0xa] = "async stream packet",  [0xb] = "Lk resp",
 431         [0xc] = "-reserved-",           [0xd] = "-reserved-",
 432         [0xe] = "link internal",        [0xf] = "-reserved-",
 433 };
 434
 435 static void log_ar_at_event(char dir, int speed, u32 *header, int evt)
 436 {
 437         int tcode = header[0] >> 4 & 0xf;
 438         char specific[12];
 439
 440         if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
 441                 return;
 442
 443         if (unlikely(evt >= ARRAY_SIZE(evts)))
 444                         evt = 0x1f;
 445
 446         if (evt == OHCI1394_evt_bus_reset) {
 447                 fw_notify("A%c evt_bus_reset, generation %d\n",
 448                     dir, (header[2] >> 16) & 0xff);
 449                 return;
 450         }
 451
 452         switch (tcode) {
 453         case 0x0: case 0x6: case 0x8:
 454                 snprintf(specific, sizeof(specific), " = %08x",
 455                          be32_to_cpu((__force __be32)header[3]));
 456                 break;
 457         case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
 458                 snprintf(specific, sizeof(specific), " %x,%x",
 459                          header[3] >> 16, header[3] & 0xffff);
 460                 break;
 461         default:
 462                 specific[0] = '\0';
 463         }
 464
 465         switch (tcode) {
 466         case 0xa:
 467                 fw_notify("A%c %s, %s\n", dir, evts[evt], tcodes[tcode]);
 468                 break;
 469         case 0xe:
 470                 fw_notify("A%c %s, PHY %08x %08x\n",
 471                           dir, evts[evt], header[1], header[2]);
 472                 break;
 473         case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
 474                 fw_notify("A%c spd %x tl %02x, "
 475                     "%04x -> %04x, %s, "
 476                     "%s, %04x%08x%s\n",
 477                     dir, speed, header[0] >> 10 & 0x3f,
 478                     header[1] >> 16, header[0] >> 16, evts[evt],
 479                     tcodes[tcode], header[1] & 0xffff, header[2], specific);
 480                 break;
 481         default:
 482                 fw_notify("A%c spd %x tl %02x, "
 483                     "%04x -> %04x, %s, "
 484                     "%s%s\n",
 485                     dir, speed, header[0] >> 10 & 0x3f,
 486                     header[1] >> 16, header[0] >> 16, evts[evt],
 487                     tcodes[tcode], specific);
 488         }
 489 }
 490
 491 #else
 492
 493 #define param_debug 0
 494 static inline void log_irqs(u32 evt) {}
 495 static inline void log_selfids(int node_id, int generation, int self_id_count, u32 *s) {}
 496 static inline void log_ar_at_event(char dir, int speed, u32 *header, int evt) {}
 497
 498 #endif /* CONFIG_FIREWIRE_OHCI_DEBUG */
 499
 500 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
 501 {
 502         writel(data, ohci->registers + offset);
 503 }
 504
 505 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
 506 {
 507         return readl(ohci->registers + offset);
 508 }
 509
 510 static inline void flush_writes(const struct fw_ohci *ohci)
 511 {
 512         /* Do a dummy read to flush writes. */
 513         reg_read(ohci, OHCI1394_Version);
 514 }
 515
 516 static int read_phy_reg(struct fw_ohci *ohci, int addr)
 517 {
 518         u32 val;
 519         int i;
 520
 521         reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
 522         for (i = 0; i < 3 + 100; i++) {
 523                 val = reg_read(ohci, OHCI1394_PhyControl);
 524                 if (val & OHCI1394_PhyControl_ReadDone)
 525                         return OHCI1394_PhyControl_ReadData(val);
 526
 527                 /*
 528                  * Try a few times without waiting.  Sleeping is necessary
 529                  * only when the link/PHY interface is busy.
 530                  */
 531                 if (i >= 3)
 532                         msleep(1);
 533         }
 534         fw_error("failed to read phy reg\n");
 535
 536         return -EBUSY;
 537 }
 538
 539 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
 540 {
 541         int i;
 542
 543         reg_write(ohci, OHCI1394_PhyControl,
 544                   OHCI1394_PhyControl_Write(addr, val));
 545         for (i = 0; i < 3 + 100; i++) {
 546                 val = reg_read(ohci, OHCI1394_PhyControl);
 547                 if (!(val & OHCI1394_PhyControl_WritePending))
 548                         return 0;
 549
 550                 if (i >= 3)
 551                         msleep(1);
 552         }
 553         fw_error("failed to write phy reg\n");
 554
 555         return -EBUSY;
 556 }
 557
 558 static int update_phy_reg(struct fw_ohci *ohci, int addr,
 559                           int clear_bits, int set_bits)
 560 {
 561         int ret = read_phy_reg(ohci, addr);
 562         if (ret < 0)
 563                 return ret;
 564
 565         /*
 566          * The interrupt status bits are cleared by writing a one bit.
 567          * Avoid clearing them unless explicitly requested in set_bits.
 568          */
 569         if (addr == 5)
 570                 clear_bits |= PHY_INT_STATUS_BITS;
 571
 572         return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
 573 }
 574
 575 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
 576 {
 577         int ret;
 578
 579         ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
 580         if (ret < 0)
 581                 return ret;
 582
 583         return read_phy_reg(ohci, addr);
 584 }
 585
 586 static int ohci_read_phy_reg(struct fw_card *card, int addr)
 587 {
 588         struct fw_ohci *ohci = fw_ohci(card);
 589         int ret;
 590
 591         mutex_lock(&ohci->phy_reg_mutex);
 592         ret = read_phy_reg(ohci, addr);
 593         mutex_unlock(&ohci->phy_reg_mutex);
 594
 595         return ret;
 596 }
 597
 598 static int ohci_update_phy_reg(struct fw_card *card, int addr,
 599                                int clear_bits, int set_bits)
 600 {
 601         struct fw_ohci *ohci = fw_ohci(card);
 602         int ret;
 603
 604         mutex_lock(&ohci->phy_reg_mutex);
 605         ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
 606         mutex_unlock(&ohci->phy_reg_mutex);
 607
 608         return ret;
 609 }
 610
 611 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
 612 {
 613         return page_private(ctx->pages[i]);
 614 }
 615
 616 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
 617 {
 618         struct descriptor *d;
 619
 620         d = &ctx->descriptors[index];
 621         d->branch_address  &= cpu_to_le32(~0xf);
 622         d->res_count       =  cpu_to_le16(PAGE_SIZE);
 623         d->transfer_status =  0;
 624
 625         wmb(); /* finish init of new descriptors before branch_address update */
 626         d = &ctx->descriptors[ctx->last_buffer_index];
 627         d->branch_address  |= cpu_to_le32(1);
 628
 629         ctx->last_buffer_index = index;
 630
 631         reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
 632         flush_writes(ctx->ohci);
 633 }
 634
 635 static void ar_context_release(struct ar_context *ctx)
 636 {
 637         unsigned int i;
 638
 639         if (ctx->buffer)
 640                 vm_unmap_ram(ctx->buffer, AR_BUFFERS + AR_WRAPAROUND_PAGES);
 641
 642         for (i = 0; i < AR_BUFFERS; i++)
 643                 if (ctx->pages[i]) {
 644                         dma_unmap_page(ctx->ohci->card.device,
 645                                        ar_buffer_bus(ctx, i),
 646                                        PAGE_SIZE, DMA_FROM_DEVICE);
 647                         __free_page(ctx->pages[i]);
 648                 }
 649 }
 650
 651 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
 652 {
 653         if (reg_read(ctx->ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
 654                 reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
 655                 flush_writes(ctx->ohci);
 656
 657                 fw_error("AR error: %s; DMA stopped\n", error_msg);
 658         }
 659         /* FIXME: restart? */
 660 }
 661
 662 static inline unsigned int ar_next_buffer_index(unsigned int index)
 663 {
 664         return (index + 1) % AR_BUFFERS;
 665 }
 666
 667 static inline unsigned int ar_prev_buffer_index(unsigned int index)
 668 {
 669         return (index - 1 + AR_BUFFERS) % AR_BUFFERS;
 670 }
 671
 672 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
 673 {
 674         return ar_next_buffer_index(ctx->last_buffer_index);
 675 }
 676
 677 /*
 678  * We search for the buffer that contains the last AR packet DMA data written
 679  * by the controller.
 680  */
 681 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
 682                                                  unsigned int *buffer_offset)
 683 {
 684         unsigned int i, next_i, last = ctx->last_buffer_index;
 685         __le16 res_count, next_res_count;
 686
 687         i = ar_first_buffer_index(ctx);
 688         res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
 689
 690         /* A buffer that is not yet completely filled must be the last one. */
 691         while (i != last && res_count == 0) {
 692
 693                 /* Peek at the next descriptor. */
 694                 next_i = ar_next_buffer_index(i);
 695                 rmb(); /* read descriptors in order */
 696                 next_res_count = ACCESS_ONCE(
 697                                 ctx->descriptors[next_i].res_count);
 698                 /*
 699                  * If the next descriptor is still empty, we must stop at this
 700                  * descriptor.
 701                  */
 702                 if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
 703                         /*
 704                          * The exception is when the DMA data for one packet is
 705                          * split over three buffers; in this case, the middle
 706                          * buffer's descriptor might be never updated by the
 707                          * controller and look still empty, and we have to peek
 708                          * at the third one.
 709                          */
 710                         if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
 711                                 next_i = ar_next_buffer_index(next_i);
 712                                 rmb();
 713                                 next_res_count = ACCESS_ONCE(
 714                                         ctx->descriptors[next_i].res_count);
 715                                 if (next_res_count != cpu_to_le16(PAGE_SIZE))
 716                                         goto next_buffer_is_active;
 717                         }
 718
 719                         break;
 720                 }
 721
 722 next_buffer_is_active:
 723                 i = next_i;
 724                 res_count = next_res_count;
 725         }
 726
 727         rmb(); /* read res_count before the DMA data */
 728
 729         *buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
 730         if (*buffer_offset > PAGE_SIZE) {
 731                 *buffer_offset = 0;
 732                 ar_context_abort(ctx, "corrupted descriptor");
 733         }
 734
 735         return i;
 736 }
 737
 738 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
 739                                     unsigned int end_buffer_index,
 740                                     unsigned int end_buffer_offset)
 741 {
 742         unsigned int i;
 743
 744         i = ar_first_buffer_index(ctx);
 745         while (i != end_buffer_index) {
 746                 dma_sync_single_for_cpu(ctx->ohci->card.device,
 747                                         ar_buffer_bus(ctx, i),
 748                                         PAGE_SIZE, DMA_FROM_DEVICE);
 749                 i = ar_next_buffer_index(i);
 750         }
 751         if (end_buffer_offset > 0)
 752                 dma_sync_single_for_cpu(ctx->ohci->card.device,
 753                                         ar_buffer_bus(ctx, i),
 754                                         end_buffer_offset, DMA_FROM_DEVICE);
 755 }
 756
 757 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
 758 #define cond_le32_to_cpu(v) \
 759         (ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
 760 #else
 761 #define cond_le32_to_cpu(v) le32_to_cpu(v)
 762 #endif
 763
 764 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
 765 {
 766         struct fw_ohci *ohci = ctx->ohci;
 767         struct fw_packet p;
 768         u32 status, length, tcode;
 769         int evt;
 770
 771         p.header[0] = cond_le32_to_cpu(buffer[0]);
 772         p.header[1] = cond_le32_to_cpu(buffer[1]);
 773         p.header[2] = cond_le32_to_cpu(buffer[2]);
 774
 775         tcode = (p.header[0] >> 4) & 0x0f;
 776         switch (tcode) {
 777         case TCODE_WRITE_QUADLET_REQUEST:
 778         case TCODE_READ_QUADLET_RESPONSE:
 779                 p.header[3] = (__force __u32) buffer[3];
 780                 p.header_length = 16;
 781                 p.payload_length = 0;
 782                 break;
 783
 784         case TCODE_READ_BLOCK_REQUEST :
 785                 p.header[3] = cond_le32_to_cpu(buffer[3]);
 786                 p.header_length = 16;
 787                 p.payload_length = 0;
 788                 break;
 789
 790         case TCODE_WRITE_BLOCK_REQUEST:
 791         case TCODE_READ_BLOCK_RESPONSE:
 792         case TCODE_LOCK_REQUEST:
 793         case TCODE_LOCK_RESPONSE:
 794                 p.header[3] = cond_le32_to_cpu(buffer[3]);
 795                 p.header_length = 16;
 796                 p.payload_length = p.header[3] >> 16;
 797                 if (p.payload_length > MAX_ASYNC_PAYLOAD) {
 798                         ar_context_abort(ctx, "invalid packet length");
 799                         return NULL;
 800                 }
 801                 break;
 802
 803         case TCODE_WRITE_RESPONSE:
 804         case TCODE_READ_QUADLET_REQUEST:
 805         case OHCI_TCODE_PHY_PACKET:
 806                 p.header_length = 12;
 807                 p.payload_length = 0;
 808                 break;
 809
 810         default:
 811                 ar_context_abort(ctx, "invalid tcode");
 812                 return NULL;
 813         }
 814
 815         p.payload = (void *) buffer + p.header_length;
 816
 817         /* FIXME: What to do about evt_* errors? */
 818         length = (p.header_length + p.payload_length + 3) / 4;
 819         status = cond_le32_to_cpu(buffer[length]);
 820         evt    = (status >> 16) & 0x1f;
 821
 822         p.ack        = evt - 16;
 823         p.speed      = (status >> 21) & 0x7;
 824         p.timestamp  = status & 0xffff;
 825         p.generation = ohci->request_generation;
 826
 827         log_ar_at_event('R', p.speed, p.header, evt);
 828
 829         /*
 830          * Several controllers, notably from NEC and VIA, forget to
 831          * write ack_complete status at PHY packet reception.
 832          */
 833         if (evt == OHCI1394_evt_no_status &&
 834             (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
 835                 p.ack = ACK_COMPLETE;
 836
 837         /*
 838          * The OHCI bus reset handler synthesizes a PHY packet with
 839          * the new generation number when a bus reset happens (see
 840          * section 8.4.2.3).  This helps us determine when a request
 841          * was received and make sure we send the response in the same
 842          * generation.  We only need this for requests; for responses
 843          * we use the unique tlabel for finding the matching
 844          * request.
 845          *
 846          * Alas some chips sometimes emit bus reset packets with a
 847          * wrong generation.  We set the correct generation for these
 848          * at a slightly incorrect time (in bus_reset_tasklet).
 849          */
 850         if (evt == OHCI1394_evt_bus_reset) {
 851                 if (!(ohci->quirks & QUIRK_RESET_PACKET))
 852                         ohci->request_generation = (p.header[2] >> 16) & 0xff;
 853         } else if (ctx == &ohci->ar_request_ctx) {
 854                 fw_core_handle_request(&ohci->card, &p);
 855         } else {
 856                 fw_core_handle_response(&ohci->card, &p);
 857         }
 858
 859         return buffer + length + 1;
 860 }
 861
 862 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
 863 {
 864         void *next;
 865
 866         while (p < end) {
 867                 next = handle_ar_packet(ctx, p);
 868                 if (!next)
 869                         return p;
 870                 p = next;
 871         }
 872
 873         return p;
 874 }
 875
 876 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
 877 {
 878         unsigned int i;
 879
 880         i = ar_first_buffer_index(ctx);
 881         while (i != end_buffer) {
 882                 dma_sync_single_for_device(ctx->ohci->card.device,
 883                                            ar_buffer_bus(ctx, i),
 884                                            PAGE_SIZE, DMA_FROM_DEVICE);
 885                 ar_context_link_page(ctx, i);
 886                 i = ar_next_buffer_index(i);
 887         }
 888 }
 889
 890 static void ar_context_tasklet(unsigned long data)
 891 {
 892         struct ar_context *ctx = (struct ar_context *)data;
 893         unsigned int end_buffer_index, end_buffer_offset;
 894         void *p, *end;
 895
 896         p = ctx->pointer;
 897         if (!p)
 898                 return;
 899
 900         end_buffer_index = ar_search_last_active_buffer(ctx,
 901                                                         &end_buffer_offset);
 902         ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
 903         end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
 904
 905         if (end_buffer_index < ar_first_buffer_index(ctx)) {
 906                 /*
 907                  * The filled part of the overall buffer wraps around; handle
 908                  * all packets up to the buffer end here.  If the last packet
 909                  * wraps around, its tail will be visible after the buffer end
 910                  * because the buffer start pages are mapped there again.
 911                  */
 912                 void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
 913                 p = handle_ar_packets(ctx, p, buffer_end);
 914                 if (p < buffer_end)
 915                         goto error;
 916                 /* adjust p to point back into the actual buffer */
 917                 p -= AR_BUFFERS * PAGE_SIZE;
 918         }
 919
 920         p = handle_ar_packets(ctx, p, end);
 921         if (p != end) {
 922                 if (p > end)
 923                         ar_context_abort(ctx, "inconsistent descriptor");
 924                 goto error;
 925         }
 926
 927         ctx->pointer = p;
 928         ar_recycle_buffers(ctx, end_buffer_index);
 929
 930         return;
 931
 932 error:
 933         ctx->pointer = NULL;
 934 }
 935
 936 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
 937                            unsigned int descriptors_offset, u32 regs)
 938 {
 939         unsigned int i;
 940         dma_addr_t dma_addr;
 941         struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
 942         struct descriptor *d;
 943
 944         ctx->regs        = regs;
 945         ctx->ohci        = ohci;
 946         tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
 947
 948         for (i = 0; i < AR_BUFFERS; i++) {
 949                 ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
 950                 if (!ctx->pages[i])
 951                         goto out_of_memory;
 952                 dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
 953                                         0, PAGE_SIZE, DMA_FROM_DEVICE);
 954                 if (dma_mapping_error(ohci->card.device, dma_addr)) {
 955                         __free_page(ctx->pages[i]);
 956                         ctx->pages[i] = NULL;
 957                         goto out_of_memory;
 958                 }
 959                 set_page_private(ctx->pages[i], dma_addr);
 960         }
 961
 962         for (i = 0; i < AR_BUFFERS; i++)
 963                 pages[i]              = ctx->pages[i];
 964         for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
 965                 pages[AR_BUFFERS + i] = ctx->pages[i];
 966         ctx->buffer = vm_map_ram(pages, AR_BUFFERS + AR_WRAPAROUND_PAGES,
 967                                  -1, PAGE_KERNEL);
 968         if (!ctx->buffer)
 969                 goto out_of_memory;
 970
 971         ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
 972         ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
 973
 974         for (i = 0; i < AR_BUFFERS; i++) {
 975                 d = &ctx->descriptors[i];
 976                 d->req_count      = cpu_to_le16(PAGE_SIZE);
 977                 d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
 978                                                 DESCRIPTOR_STATUS |
 979                                                 DESCRIPTOR_BRANCH_ALWAYS);
 980                 d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
 981                 d->branch_address = cpu_to_le32(ctx->descriptors_bus +
 982                         ar_next_buffer_index(i) * sizeof(struct descriptor));
 983         }
 984
 985         return 0;
 986
 987 out_of_memory:
 988         ar_context_release(ctx);
 989
 990         return -ENOMEM;
 991 }
 992
 993 static void ar_context_run(struct ar_context *ctx)
 994 {
 995         unsigned int i;
 996
 997         for (i = 0; i < AR_BUFFERS; i++)
 998                 ar_context_link_page(ctx, i);
 999
1000         ctx->pointer = ctx->buffer;
1001
1002         reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1003         reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1004         flush_writes(ctx->ohci);
1005 }
1006
1007 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1008 {
1009         int b, key;
1010
1011         b   = (le16_to_cpu(d->control) & DESCRIPTOR_BRANCH_ALWAYS) >> 2;
1012         key = (le16_to_cpu(d->control) & DESCRIPTOR_KEY_IMMEDIATE) >> 8;
1013
1014         /* figure out which descriptor the branch address goes in */
1015         if (z == 2 && (b == 3 || key == 2))
1016                 return d;
1017         else
1018                 return d + z - 1;
1019 }
1020
1021 static void context_tasklet(unsigned long data)
1022 {
1023         struct context *ctx = (struct context *) data;
1024         struct descriptor *d, *last;
1025         u32 address;
1026         int z;
1027         struct descriptor_buffer *desc;
1028
1029         desc = list_entry(ctx->buffer_list.next,
1030                         struct descriptor_buffer, list);
1031         last = ctx->last;
1032         while (last->branch_address != 0) {
1033                 struct descriptor_buffer *old_desc = desc;
1034                 address = le32_to_cpu(last->branch_address);
1035                 z = address & 0xf;
1036                 address &= ~0xf;
1037
1038                 /* If the branch address points to a buffer outside of the
1039                  * current buffer, advance to the next buffer. */
1040                 if (address < desc->buffer_bus ||
1041                                 address >= desc->buffer_bus + desc->used)
1042                         desc = list_entry(desc->list.next,
1043                                         struct descriptor_buffer, list);
1044                 d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1045                 last = find_branch_descriptor(d, z);
1046
1047                 if (!ctx->callback(ctx, d, last))
1048                         break;
1049
1050                 if (old_desc != desc) {
1051                         /* If we've advanced to the next buffer, move the
1052                          * previous buffer to the free list. */
1053                         unsigned long flags;
1054                         old_desc->used = 0;
1055                         spin_lock_irqsave(&ctx->ohci->lock, flags);
1056                         list_move_tail(&old_desc->list, &ctx->buffer_list);
1057                         spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1058                 }
1059                 ctx->last = last;
1060         }
1061 }
1062
1063 /*
1064  * Allocate a new buffer and add it to the list of free buffers for this
1065  * context.  Must be called with ohci->lock held.
1066  */
1067 static int context_add_buffer(struct context *ctx)
1068 {
1069         struct descriptor_buffer *desc;
1070         dma_addr_t uninitialized_var(bus_addr);
1071         int offset;
1072
1073         /*
1074          * 16MB of descriptors should be far more than enough for any DMA
1075          * program.  This will catch run-away userspace or DoS attacks.
1076          */
1077         if (ctx->total_allocation >= 16*1024*1024)
1078                 return -ENOMEM;
1079
1080         desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1081                         &bus_addr, GFP_ATOMIC);
1082         if (!desc)
1083                 return -ENOMEM;
1084
1085         offset = (void *)&desc->buffer - (void *)desc;
1086         desc->buffer_size = PAGE_SIZE - offset;
1087         desc->buffer_bus = bus_addr + offset;
1088         desc->used = 0;
1089
1090         list_add_tail(&desc->list, &ctx->buffer_list);
1091         ctx->total_allocation += PAGE_SIZE;
1092
1093         return 0;
1094 }
1095
1096 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1097                         u32 regs, descriptor_callback_t callback)
1098 {
1099         ctx->ohci = ohci;
1100         ctx->regs = regs;
1101         ctx->total_allocation = 0;
1102
1103         INIT_LIST_HEAD(&ctx->buffer_list);
1104         if (context_add_buffer(ctx) < 0)
1105                 return -ENOMEM;
1106
1107         ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1108                         struct descriptor_buffer, list);
1109
1110         tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1111         ctx->callback = callback;
1112
1113         /*
1114          * We put a dummy descriptor in the buffer that has a NULL
1115          * branch address and looks like it's been sent.  That way we
1116          * have a descriptor to append DMA programs to.
1117          */
1118         memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1119         ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1120         ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1121         ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1122         ctx->last = ctx->buffer_tail->buffer;
1123         ctx->prev = ctx->buffer_tail->buffer;
1124
1125         return 0;
1126 }
1127
1128 static void context_release(struct context *ctx)
1129 {
1130         struct fw_card *card = &ctx->ohci->card;
1131         struct descriptor_buffer *desc, *tmp;
1132
1133         list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1134                 dma_free_coherent(card->device, PAGE_SIZE, desc,
1135                         desc->buffer_bus -
1136                         ((void *)&desc->buffer - (void *)desc));
1137 }
1138
1139 /* Must be called with ohci->lock held */
1140 static struct descriptor *context_get_descriptors(struct context *ctx,
1141                                                   int z, dma_addr_t *d_bus)
1142 {
1143         struct descriptor *d = NULL;
1144         struct descriptor_buffer *desc = ctx->buffer_tail;
1145
1146         if (z * sizeof(*d) > desc->buffer_size)
1147                 return NULL;
1148
1149         if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1150                 /* No room for the descriptor in this buffer, so advance to the
1151                  * next one. */
1152
1153                 if (desc->list.next == &ctx->buffer_list) {
1154                         /* If there is no free buffer next in the list,
1155                          * allocate one. */
1156                         if (context_add_buffer(ctx) < 0)
1157                                 return NULL;
1158                 }
1159                 desc = list_entry(desc->list.next,
1160                                 struct descriptor_buffer, list);
1161                 ctx->buffer_tail = desc;
1162         }
1163
1164         d = desc->buffer + desc->used / sizeof(*d);
1165         memset(d, 0, z * sizeof(*d));
1166         *d_bus = desc->buffer_bus + desc->used;
1167
1168         return d;
1169 }
1170
1171 static void context_run(struct context *ctx, u32 extra)
1172 {
1173         struct fw_ohci *ohci = ctx->ohci;
1174
1175         reg_write(ohci, COMMAND_PTR(ctx->regs),
1176                   le32_to_cpu(ctx->last->branch_address));
1177         reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1178         reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1179         ctx->running = true;
1180         flush_writes(ohci);
1181 }
1182
1183 static void context_append(struct context *ctx,
1184                            struct descriptor *d, int z, int extra)
1185 {
1186         dma_addr_t d_bus;
1187         struct descriptor_buffer *desc = ctx->buffer_tail;
1188
1189         d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1190
1191         desc->used += (z + extra) * sizeof(*d);
1192
1193         wmb(); /* finish init of new descriptors before branch_address update */
1194         ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1195         ctx->prev = find_branch_descriptor(d, z);
1196
1197         reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1198         flush_writes(ctx->ohci);
1199 }
1200
1201 static void context_stop(struct context *ctx)
1202 {
1203         u32 reg;
1204         int i;
1205
1206         reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1207         ctx->running = false;
1208         flush_writes(ctx->ohci);
1209
1210         for (i = 0; i < 10; i++) {
1211                 reg = reg_read(ctx->ohci, CONTROL_SET(ctx->regs));
1212                 if ((reg & CONTEXT_ACTIVE) == 0)
1213                         return;
1214
1215                 mdelay(1);
1216         }
1217         fw_error("Error: DMA context still active (0x%08x)\n", reg);
1218 }
1219
1220 struct driver_data {
1221         struct fw_packet *packet;
1222 };
1223
1224 /*
1225  * This function apppends a packet to the DMA queue for transmission.
1226  * Must always be called with the ochi->lock held to ensure proper
1227  * generation handling and locking around packet queue manipulation.
1228  */
1229 static int at_context_queue_packet(struct context *ctx,
1230                                    struct fw_packet *packet)
1231 {
1232         struct fw_ohci *ohci = ctx->ohci;
1233         dma_addr_t d_bus, uninitialized_var(payload_bus);
1234         struct driver_data *driver_data;
1235         struct descriptor *d, *last;
1236         __le32 *header;
1237         int z, tcode;
1238
1239         d = context_get_descriptors(ctx, 4, &d_bus);
1240         if (d == NULL) {
1241                 packet->ack = RCODE_SEND_ERROR;
1242                 return -1;
1243         }
1244
1245         d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1246         d[0].res_count = cpu_to_le16(packet->timestamp);
1247
1248         /*
1249          * The DMA format for asyncronous link packets is different
1250          * from the IEEE1394 layout, so shift the fields around
1251          * accordingly.
1252          */
1253
1254         tcode = (packet->header[0] >> 4) & 0x0f;
1255         header = (__le32 *) &d[1];
1256         switch (tcode) {
1257         case TCODE_WRITE_QUADLET_REQUEST:
1258         case TCODE_WRITE_BLOCK_REQUEST:
1259         case TCODE_WRITE_RESPONSE:
1260         case TCODE_READ_QUADLET_REQUEST:
1261         case TCODE_READ_BLOCK_REQUEST:
1262         case TCODE_READ_QUADLET_RESPONSE:
1263         case TCODE_READ_BLOCK_RESPONSE:
1264         case TCODE_LOCK_REQUEST:
1265         case TCODE_LOCK_RESPONSE:
1266                 header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1267                                         (packet->speed << 16));
1268                 header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1269                                         (packet->header[0] & 0xffff0000));
1270                 header[2] = cpu_to_le32(packet->header[2]);
1271
1272                 if (TCODE_IS_BLOCK_PACKET(tcode))
1273                         header[3] = cpu_to_le32(packet->header[3]);
1274                 else
1275                         header[3] = (__force __le32) packet->header[3];
1276
1277                 d[0].req_count = cpu_to_le16(packet->header_length);
1278                 break;
1279
1280         case TCODE_LINK_INTERNAL:
1281                 header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1282                                         (packet->speed << 16));
1283                 header[1] = cpu_to_le32(packet->header[1]);
1284                 header[2] = cpu_to_le32(packet->header[2]);
1285                 d[0].req_count = cpu_to_le16(12);
1286
1287                 if (is_ping_packet(&packet->header[1]))
1288                         d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1289                 break;
1290
1291         case TCODE_STREAM_DATA:
1292                 header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1293                                         (packet->speed << 16));
1294                 header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1295                 d[0].req_count = cpu_to_le16(8);
1296                 break;
1297
1298         default:
1299                 /* BUG(); */
1300                 packet->ack = RCODE_SEND_ERROR;
1301                 return -1;
1302         }
1303
1304         driver_data = (struct driver_data *) &d[3];
1305         driver_data->packet = packet;
1306         packet->driver_data = driver_data;
1307
1308         if (packet->payload_length > 0) {
1309                 payload_bus =
1310                         dma_map_single(ohci->card.device, packet->payload,
1311                                        packet->payload_length, DMA_TO_DEVICE);
1312                 if (dma_mapping_error(ohci->card.device, payload_bus)) {
1313                         packet->ack = RCODE_SEND_ERROR;
1314                         return -1;
1315                 }
1316                 packet->payload_bus     = payload_bus;
1317                 packet->payload_mapped  = true;
1318
1319                 d[2].req_count    = cpu_to_le16(packet->payload_length);
1320                 d[2].data_address = cpu_to_le32(payload_bus);
1321                 last = &d[2];
1322                 z = 3;
1323         } else {
1324                 last = &d[0];
1325                 z = 2;
1326         }
1327
1328         last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1329                                      DESCRIPTOR_IRQ_ALWAYS |
1330                                      DESCRIPTOR_BRANCH_ALWAYS);
1331
1332         /* FIXME: Document how the locking works. */
1333         if (ohci->generation != packet->generation) {
1334                 if (packet->payload_mapped)
1335                         dma_unmap_single(ohci->card.device, payload_bus,
1336                                          packet->payload_length, DMA_TO_DEVICE);
1337                 packet->ack = RCODE_GENERATION;
1338                 return -1;
1339         }
1340
1341         context_append(ctx, d, z, 4 - z);
1342
1343         if (!ctx->running)
1344                 context_run(ctx, 0);
1345
1346         return 0;
1347 }
1348
1349 static void at_context_flush(struct context *ctx)
1350 {
1351         tasklet_disable(&ctx->tasklet);
1352
1353         ctx->flushing = true;
1354         context_tasklet((unsigned long)ctx);
1355         ctx->flushing = false;
1356
1357         tasklet_enable(&ctx->tasklet);
1358 }
1359
1360 static int handle_at_packet(struct context *context,
1361                             struct descriptor *d,
1362                             struct descriptor *last)
1363 {
1364         struct driver_data *driver_data;
1365         struct fw_packet *packet;
1366         struct fw_ohci *ohci = context->ohci;
1367         int evt;
1368
1369         if (last->transfer_status == 0 && !context->flushing)
1370                 /* This descriptor isn't done yet, stop iteration. */
1371                 return 0;
1372
1373         driver_data = (struct driver_data *) &d[3];
1374         packet = driver_data->packet;
1375         if (packet == NULL)
1376                 /* This packet was cancelled, just continue. */
1377                 return 1;
1378
1379         if (packet->payload_mapped)
1380                 dma_unmap_single(ohci->card.device, packet->payload_bus,
1381                                  packet->payload_length, DMA_TO_DEVICE);
1382
1383         evt = le16_to_cpu(last->transfer_status) & 0x1f;
1384         packet->timestamp = le16_to_cpu(last->res_count);
1385
1386         log_ar_at_event('T', packet->speed, packet->header, evt);
1387
1388         switch (evt) {
1389         case OHCI1394_evt_timeout:
1390                 /* Async response transmit timed out. */
1391                 packet->ack = RCODE_CANCELLED;
1392                 break;
1393
1394         case OHCI1394_evt_flushed:
1395                 /*
1396                  * The packet was flushed should give same error as
1397                  * when we try to use a stale generation count.
1398                  */
1399                 packet->ack = RCODE_GENERATION;
1400                 break;
1401
1402         case OHCI1394_evt_missing_ack:
1403                 if (context->flushing)
1404                         packet->ack = RCODE_GENERATION;
1405                 else {
1406                         /*
1407                          * Using a valid (current) generation count, but the
1408                          * node is not on the bus or not sending acks.
1409                          */
1410                         packet->ack = RCODE_NO_ACK;
1411                 }
1412                 break;
1413
1414         case ACK_COMPLETE + 0x10:
1415         case ACK_PENDING + 0x10:
1416         case ACK_BUSY_X + 0x10:
1417         case ACK_BUSY_A + 0x10:
1418         case ACK_BUSY_B + 0x10:
1419         case ACK_DATA_ERROR + 0x10:
1420         case ACK_TYPE_ERROR + 0x10:
1421                 packet->ack = evt - 0x10;
1422                 break;
1423
1424         case OHCI1394_evt_no_status:
1425                 if (context->flushing) {
1426                         packet->ack = RCODE_GENERATION;
1427                         break;
1428                 }
1429                 /* fall through */
1430
1431         default:
1432                 packet->ack = RCODE_SEND_ERROR;
1433                 break;
1434         }
1435
1436         packet->callback(packet, &ohci->card, packet->ack);
1437
1438         return 1;
1439 }
1440
1441 #define HEADER_GET_DESTINATION(q)       (((q) >> 16) & 0xffff)
1442 #define HEADER_GET_TCODE(q)             (((q) >> 4) & 0x0f)
1443 #define HEADER_GET_OFFSET_HIGH(q)       (((q) >> 0) & 0xffff)
1444 #define HEADER_GET_DATA_LENGTH(q)       (((q) >> 16) & 0xffff)
1445 #define HEADER_GET_EXTENDED_TCODE(q)    (((q) >> 0) & 0xffff)
1446
1447 static void handle_local_rom(struct fw_ohci *ohci,
1448                              struct fw_packet *packet, u32 csr)
1449 {
1450         struct fw_packet response;
1451         int tcode, length, i;
1452
1453         tcode = HEADER_GET_TCODE(packet->header[0]);
1454         if (TCODE_IS_BLOCK_PACKET(tcode))
1455                 length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1456         else
1457                 length = 4;
1458
1459         i = csr - CSR_CONFIG_ROM;
1460         if (i + length > CONFIG_ROM_SIZE) {
1461                 fw_fill_response(&response, packet->header,
1462                                  RCODE_ADDRESS_ERROR, NULL, 0);
1463         } else if (!TCODE_IS_READ_REQUEST(tcode)) {
1464                 fw_fill_response(&response, packet->header,
1465                                  RCODE_TYPE_ERROR, NULL, 0);
1466         } else {
1467                 fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1468                                  (void *) ohci->config_rom + i, length);
1469         }
1470
1471         fw_core_handle_response(&ohci->card, &response);
1472 }
1473
1474 static void handle_local_lock(struct fw_ohci *ohci,
1475                               struct fw_packet *packet, u32 csr)
1476 {
1477         struct fw_packet response;
1478         int tcode, length, ext_tcode, sel, try;
1479         __be32 *payload, lock_old;
1480         u32 lock_arg, lock_data;
1481
1482         tcode = HEADER_GET_TCODE(packet->header[0]);
1483         length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1484         payload = packet->payload;
1485         ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1486
1487         if (tcode == TCODE_LOCK_REQUEST &&
1488             ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1489                 lock_arg = be32_to_cpu(payload[0]);
1490                 lock_data = be32_to_cpu(payload[1]);
1491         } else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1492                 lock_arg = 0;
1493                 lock_data = 0;
1494         } else {
1495                 fw_fill_response(&response, packet->header,
1496                                  RCODE_TYPE_ERROR, NULL, 0);
1497                 goto out;
1498         }
1499
1500         sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1501         reg_write(ohci, OHCI1394_CSRData, lock_data);
1502         reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1503         reg_write(ohci, OHCI1394_CSRControl, sel);
1504
1505         for (try = 0; try < 20; try++)
1506                 if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1507                         lock_old = cpu_to_be32(reg_read(ohci,
1508                                                         OHCI1394_CSRData));
1509                         fw_fill_response(&response, packet->header,
1510                                          RCODE_COMPLETE,
1511                                          &lock_old, sizeof(lock_old));
1512                         goto out;
1513                 }
1514
1515         fw_error("swap not done (CSR lock timeout)\n");
1516         fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1517
1518  out:
1519         fw_core_handle_response(&ohci->card, &response);
1520 }
1521
1522 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1523 {
1524         u64 offset, csr;
1525
1526         if (ctx == &ctx->ohci->at_request_ctx) {
1527                 packet->ack = ACK_PENDING;
1528                 packet->callback(packet, &ctx->ohci->card, packet->ack);
1529         }
1530
1531         offset =
1532                 ((unsigned long long)
1533                  HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1534                 packet->header[2];
1535         csr = offset - CSR_REGISTER_BASE;
1536
1537         /* Handle config rom reads. */
1538         if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1539                 handle_local_rom(ctx->ohci, packet, csr);
1540         else switch (csr) {
1541         case CSR_BUS_MANAGER_ID:
1542         case CSR_BANDWIDTH_AVAILABLE:
1543         case CSR_CHANNELS_AVAILABLE_HI:
1544         case CSR_CHANNELS_AVAILABLE_LO:
1545                 handle_local_lock(ctx->ohci, packet, csr);
1546                 break;
1547         default:
1548                 if (ctx == &ctx->ohci->at_request_ctx)
1549                         fw_core_handle_request(&ctx->ohci->card, packet);
1550                 else
1551                         fw_core_handle_response(&ctx->ohci->card, packet);
1552                 break;
1553         }
1554
1555         if (ctx == &ctx->ohci->at_response_ctx) {
1556                 packet->ack = ACK_COMPLETE;
1557                 packet->callback(packet, &ctx->ohci->card, packet->ack);
1558         }
1559 }
1560
1561 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1562 {
1563         unsigned long flags;
1564         int ret;
1565
1566         spin_lock_irqsave(&ctx->ohci->lock, flags);
1567
1568         if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1569             ctx->ohci->generation == packet->generation) {
1570                 spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1571                 handle_local_request(ctx, packet);
1572                 return;
1573         }
1574
1575         ret = at_context_queue_packet(ctx, packet);
1576         spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1577
1578         if (ret < 0)
1579                 packet->callback(packet, &ctx->ohci->card, packet->ack);
1580
1581 }
1582
1583 static void detect_dead_context(struct fw_ohci *ohci,
1584                                 const char *name, unsigned int regs)
1585 {
1586         u32 ctl;
1587
1588         ctl = reg_read(ohci, CONTROL_SET(regs));
1589         if (ctl & CONTEXT_DEAD) {
1590 #ifdef CONFIG_FIREWIRE_OHCI_DEBUG
1591                 fw_error("DMA context %s has stopped, error code: %s\n",
1592                          name, evts[ctl & 0x1f]);
1593 #else
1594                 fw_error("DMA context %s has stopped, error code: %#x\n",
1595                          name, ctl & 0x1f);
1596 #endif
1597         }
1598 }
1599
1600 static void handle_dead_contexts(struct fw_ohci *ohci)
1601 {
1602         unsigned int i;
1603         char name[8];
1604
1605         detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1606         detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1607         detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1608         detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1609         for (i = 0; i < 32; ++i) {
1610                 if (!(ohci->it_context_support & (1 << i)))
1611                         continue;
1612                 sprintf(name, "IT%u", i);
1613                 detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1614         }
1615         for (i = 0; i < 32; ++i) {
1616                 if (!(ohci->ir_context_support & (1 << i)))
1617                         continue;
1618                 sprintf(name, "IR%u", i);
1619                 detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1620         }
1621         /* TODO: maybe try to flush and restart the dead contexts */
1622 }
1623
1624 static u32 cycle_timer_ticks(u32 cycle_timer)
1625 {
1626         u32 ticks;
1627
1628         ticks = cycle_timer & 0xfff;
1629         ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1630         ticks += (3072 * 8000) * (cycle_timer >> 25);
1631
1632         return ticks;
1633 }
1634
1635 /*
1636  * Some controllers exhibit one or more of the following bugs when updating the
1637  * iso cycle timer register:
1638  *  - When the lowest six bits are wrapping around to zero, a read that happens
1639  *    at the same time will return garbage in the lowest ten bits.
1640  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1641  *    not incremented for about 60 ns.
1642  *  - Occasionally, the entire register reads zero.
1643  *
1644  * To catch these, we read the register three times and ensure that the
1645  * difference between each two consecutive reads is approximately the same, i.e.
1646  * less than twice the other.  Furthermore, any negative difference indicates an
1647  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1648  * execute, so we have enough precision to compute the ratio of the differences.)
1649  */
1650 static u32 get_cycle_time(struct fw_ohci *ohci)
1651 {
1652         u32 c0, c1, c2;
1653         u32 t0, t1, t2;
1654         s32 diff01, diff12;
1655         int i;
1656
1657         c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1658
1659         if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1660                 i = 0;
1661                 c1 = c2;
1662                 c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1663                 do {
1664                         c0 = c1;
1665                         c1 = c2;
1666                         c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1667                         t0 = cycle_timer_ticks(c0);
1668                         t1 = cycle_timer_ticks(c1);
1669                         t2 = cycle_timer_ticks(c2);
1670                         diff01 = t1 - t0;
1671                         diff12 = t2 - t1;
1672                 } while ((diff01 <= 0 || diff12 <= 0 ||
1673                           diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1674                          && i++ < 20);
1675         }
1676
1677         return c2;
1678 }
1679
1680 /*
1681  * This function has to be called at least every 64 seconds.  The bus_time
1682  * field stores not only the upper 25 bits of the BUS_TIME register but also
1683  * the most significant bit of the cycle timer in bit 6 so that we can detect
1684  * changes in this bit.
1685  */
1686 static u32 update_bus_time(struct fw_ohci *ohci)
1687 {
1688         u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1689
1690         if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1691                 ohci->bus_time += 0x40;
1692
1693         return ohci->bus_time | cycle_time_seconds;
1694 }
1695
1696 static void bus_reset_tasklet(unsigned long data)
1697 {
1698         struct fw_ohci *ohci = (struct fw_ohci *)data;
1699         int self_id_count, i, j, reg;
1700         int generation, new_generation;
1701         unsigned long flags;
1702         void *free_rom = NULL;
1703         dma_addr_t free_rom_bus = 0;
1704         bool is_new_root;
1705
1706         reg = reg_read(ohci, OHCI1394_NodeID);
1707         if (!(reg & OHCI1394_NodeID_idValid)) {
1708                 fw_notify("node ID not valid, new bus reset in progress\n");
1709                 return;
1710         }
1711         if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1712                 fw_notify("malconfigured bus\n");
1713                 return;
1714         }
1715         ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1716                                OHCI1394_NodeID_nodeNumber);
1717
1718         is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1719         if (!(ohci->is_root && is_new_root))
1720                 reg_write(ohci, OHCI1394_LinkControlSet,
1721                           OHCI1394_LinkControl_cycleMaster);
1722         ohci->is_root = is_new_root;
1723
1724         reg = reg_read(ohci, OHCI1394_SelfIDCount);
1725         if (reg & OHCI1394_SelfIDCount_selfIDError) {
1726                 fw_notify("inconsistent self IDs\n");
1727                 return;
1728         }
1729         /*
1730          * The count in the SelfIDCount register is the number of
1731          * bytes in the self ID receive buffer.  Since we also receive
1732          * the inverted quadlets and a header quadlet, we shift one
1733          * bit extra to get the actual number of self IDs.
1734          */
1735         self_id_count = (reg >> 3) & 0xff;
1736         if (self_id_count == 0 || self_id_count > 252) {
1737                 fw_notify("inconsistent self IDs\n");
1738                 return;
1739         }
1740         generation = (cond_le32_to_cpu(ohci->self_id_cpu[0]) >> 16) & 0xff;
1741         rmb();
1742
1743         for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1744                 if (ohci->self_id_cpu[i] != ~ohci->self_id_cpu[i + 1]) {
1745                         fw_notify("inconsistent self IDs\n");
1746                         return;
1747                 }
1748                 ohci->self_id_buffer[j] =
1749                                 cond_le32_to_cpu(ohci->self_id_cpu[i]);
1750         }
1751         rmb();
1752
1753         /*
1754          * Check the consistency of the self IDs we just read.  The
1755          * problem we face is that a new bus reset can start while we
1756          * read out the self IDs from the DMA buffer. If this happens,
1757          * the DMA buffer will be overwritten with new self IDs and we
1758          * will read out inconsistent data.  The OHCI specification
1759          * (section 11.2) recommends a technique similar to
1760          * linux/seqlock.h, where we remember the generation of the
1761          * self IDs in the buffer before reading them out and compare
1762          * it to the current generation after reading them out.  If
1763          * the two generations match we know we have a consistent set
1764          * of self IDs.
1765          */
1766
1767         new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1768         if (new_generation != generation) {
1769                 fw_notify("recursive bus reset detected, "
1770                           "discarding self ids\n");
1771                 return;
1772         }
1773
1774         /* FIXME: Document how the locking works. */
1775         spin_lock_irqsave(&ohci->lock, flags);
1776
1777         ohci->generation = -1; /* prevent AT packet queueing */
1778         context_stop(&ohci->at_request_ctx);
1779         context_stop(&ohci->at_response_ctx);
1780
1781         spin_unlock_irqrestore(&ohci->lock, flags);
1782
1783         /*
1784          * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
1785          * packets in the AT queues and software needs to drain them.
1786          * Some OHCI 1.1 controllers (JMicron) apparently require this too.
1787          */
1788         at_context_flush(&ohci->at_request_ctx);
1789         at_context_flush(&ohci->at_response_ctx);
1790
1791         spin_lock_irqsave(&ohci->lock, flags);
1792
1793         ohci->generation = generation;
1794         reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
1795
1796         if (ohci->quirks & QUIRK_RESET_PACKET)
1797                 ohci->request_generation = generation;
1798
1799         /*
1800          * This next bit is unrelated to the AT context stuff but we
1801          * have to do it under the spinlock also.  If a new config rom
1802          * was set up before this reset, the old one is now no longer
1803          * in use and we can free it. Update the config rom pointers
1804          * to point to the current config rom and clear the
1805          * next_config_rom pointer so a new update can take place.
1806          */
1807
1808         if (ohci->next_config_rom != NULL) {
1809                 if (ohci->next_config_rom != ohci->config_rom) {
1810                         free_rom      = ohci->config_rom;
1811                         free_rom_bus  = ohci->config_rom_bus;
1812                 }
1813                 ohci->config_rom      = ohci->next_config_rom;
1814                 ohci->config_rom_bus  = ohci->next_config_rom_bus;
1815                 ohci->next_config_rom = NULL;
1816
1817                 /*
1818                  * Restore config_rom image and manually update
1819                  * config_rom registers.  Writing the header quadlet
1820                  * will indicate that the config rom is ready, so we
1821                  * do that last.
1822                  */
1823                 reg_write(ohci, OHCI1394_BusOptions,
1824                           be32_to_cpu(ohci->config_rom[2]));
1825                 ohci->config_rom[0] = ohci->next_header;
1826                 reg_write(ohci, OHCI1394_ConfigROMhdr,
1827                           be32_to_cpu(ohci->next_header));
1828         }
1829
1830 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
1831         reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
1832         reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
1833 #endif
1834
1835         spin_unlock_irqrestore(&ohci->lock, flags);
1836
1837         if (free_rom)
1838                 dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
1839                                   free_rom, free_rom_bus);
1840
1841         log_selfids(ohci->node_id, generation,
1842                     self_id_count, ohci->self_id_buffer);
1843
1844         fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
1845                                  self_id_count, ohci->self_id_buffer,
1846                                  ohci->csr_state_setclear_abdicate);
1847         ohci->csr_state_setclear_abdicate = false;
1848 }
1849
1850 static irqreturn_t irq_handler(int irq, void *data)
1851 {
1852         struct fw_ohci *ohci = data;
1853         u32 event, iso_event;
1854         int i;
1855
1856         event = reg_read(ohci, OHCI1394_IntEventClear);
1857
1858         if (!event || !~event)
1859                 return IRQ_NONE;
1860
1861         /*
1862          * busReset and postedWriteErr must not be cleared yet
1863          * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
1864          */
1865         reg_write(ohci, OHCI1394_IntEventClear,
1866                   event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
1867         log_irqs(event);
1868
1869         if (event & OHCI1394_selfIDComplete)
1870                 tasklet_schedule(&ohci->bus_reset_tasklet);
1871
1872         if (event & OHCI1394_RQPkt)
1873                 tasklet_schedule(&ohci->ar_request_ctx.tasklet);
1874
1875         if (event & OHCI1394_RSPkt)
1876                 tasklet_schedule(&ohci->ar_response_ctx.tasklet);
1877
1878         if (event & OHCI1394_reqTxComplete)
1879                 tasklet_schedule(&ohci->at_request_ctx.tasklet);
1880
1881         if (event & OHCI1394_respTxComplete)
1882                 tasklet_schedule(&ohci->at_response_ctx.tasklet);
1883
1884         if (event & OHCI1394_isochRx) {
1885                 iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
1886                 reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
1887
1888                 while (iso_event) {
1889                         i = ffs(iso_event) - 1;
1890                         tasklet_schedule(
1891                                 &ohci->ir_context_list[i].context.tasklet);
1892                         iso_event &= ~(1 << i);
1893                 }
1894         }
1895
1896         if (event & OHCI1394_isochTx) {
1897                 iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
1898                 reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
1899
1900                 while (iso_event) {
1901                         i = ffs(iso_event) - 1;
1902                         tasklet_schedule(
1903                                 &ohci->it_context_list[i].context.tasklet);
1904                         iso_event &= ~(1 << i);
1905                 }
1906         }
1907
1908         if (unlikely(event & OHCI1394_regAccessFail))
1909                 fw_error("Register access failure - "
1910                          "please notify linux1394-devel@lists.sf.net\n");
1911
1912         if (unlikely(event & OHCI1394_postedWriteErr)) {
1913                 reg_read(ohci, OHCI1394_PostedWriteAddressHi);
1914                 reg_read(ohci, OHCI1394_PostedWriteAddressLo);
1915                 reg_write(ohci, OHCI1394_IntEventClear,
1916                           OHCI1394_postedWriteErr);
1917                 fw_error("PCI posted write error\n");
1918         }
1919
1920         if (unlikely(event & OHCI1394_cycleTooLong)) {
1921                 if (printk_ratelimit())
1922                         fw_notify("isochronous cycle too long\n");
1923                 reg_write(ohci, OHCI1394_LinkControlSet,
1924                           OHCI1394_LinkControl_cycleMaster);
1925         }
1926
1927         if (unlikely(event & OHCI1394_cycleInconsistent)) {
1928                 /*
1929                  * We need to clear this event bit in order to make
1930                  * cycleMatch isochronous I/O work.  In theory we should
1931                  * stop active cycleMatch iso contexts now and restart
1932                  * them at least two cycles later.  (FIXME?)
1933                  */
1934                 if (printk_ratelimit())
1935                         fw_notify("isochronous cycle inconsistent\n");
1936         }
1937
1938         if (unlikely(event & OHCI1394_unrecoverableError))
1939                 handle_dead_contexts(ohci);
1940
1941         if (event & OHCI1394_cycle64Seconds) {
1942                 spin_lock(&ohci->lock);
1943                 update_bus_time(ohci);
1944                 spin_unlock(&ohci->lock);
1945         } else
1946                 flush_writes(ohci);
1947
1948         return IRQ_HANDLED;
1949 }
1950
1951 static int software_reset(struct fw_ohci *ohci)
1952 {
1953         int i;
1954
1955         reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
1956
1957         for (i = 0; i < OHCI_LOOP_COUNT; i++) {
1958                 if ((reg_read(ohci, OHCI1394_HCControlSet) &
1959                      OHCI1394_HCControl_softReset) == 0)
1960                         return 0;
1961                 msleep(1);
1962         }
1963
1964         return -EBUSY;
1965 }
1966
1967 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
1968 {
1969         size_t size = length * 4;
1970
1971         memcpy(dest, src, size);
1972         if (size < CONFIG_ROM_SIZE)
1973                 memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
1974 }
1975
1976 static int configure_1394a_enhancements(struct fw_ohci *ohci)
1977 {
1978         bool enable_1394a;
1979         int ret, clear, set, offset;
1980
1981         /* Check if the driver should configure link and PHY. */
1982         if (!(reg_read(ohci, OHCI1394_HCControlSet) &
1983               OHCI1394_HCControl_programPhyEnable))
1984                 return 0;
1985
1986         /* Paranoia: check whether the PHY supports 1394a, too. */
1987         enable_1394a = false;
1988         ret = read_phy_reg(ohci, 2);
1989         if (ret < 0)
1990                 return ret;
1991         if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
1992                 ret = read_paged_phy_reg(ohci, 1, 8);
1993                 if (ret < 0)
1994                         return ret;
1995                 if (ret >= 1)
1996                         enable_1394a = true;
1997         }
1998
1999         if (ohci->quirks & QUIRK_NO_1394A)
2000                 enable_1394a = false;
2001
2002         /* Configure PHY and link consistently. */
2003         if (enable_1394a) {
2004                 clear = 0;
2005                 set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2006         } else {
2007                 clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2008                 set = 0;
2009         }
2010         ret = update_phy_reg(ohci, 5, clear, set);
2011         if (ret < 0)
2012                 return ret;
2013
2014         if (enable_1394a)
2015                 offset = OHCI1394_HCControlSet;
2016         else
2017                 offset = OHCI1394_HCControlClear;
2018         reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2019
2020         /* Clean up: configuration has been taken care of. */
2021         reg_write(ohci, OHCI1394_HCControlClear,
2022                   OHCI1394_HCControl_programPhyEnable);
2023
2024         return 0;
2025 }
2026
2027 static int ohci_enable(struct fw_card *card,
2028                        const __be32 *config_rom, size_t length)
2029 {
2030         struct fw_ohci *ohci = fw_ohci(card);
2031         struct pci_dev *dev = to_pci_dev(card->device);
2032         u32 lps, seconds, version, irqs;
2033         int i, ret;
2034
2035         if (software_reset(ohci)) {
2036                 fw_error("Failed to reset ohci card.\n");
2037                 return -EBUSY;
2038         }
2039
2040         /*
2041          * Now enable LPS, which we need in order to start accessing
2042          * most of the registers.  In fact, on some cards (ALI M5251),
2043          * accessing registers in the SClk domain without LPS enabled
2044          * will lock up the machine.  Wait 50msec to make sure we have
2045          * full link enabled.  However, with some cards (well, at least
2046          * a JMicron PCIe card), we have to try again sometimes.
2047          */
2048         reg_write(ohci, OHCI1394_HCControlSet,
2049                   OHCI1394_HCControl_LPS |
2050                   OHCI1394_HCControl_postedWriteEnable);
2051         flush_writes(ohci);
2052
2053         for (lps = 0, i = 0; !lps && i < 3; i++) {
2054                 msleep(50);
2055                 lps = reg_read(ohci, OHCI1394_HCControlSet) &
2056                       OHCI1394_HCControl_LPS;
2057         }
2058
2059         if (!lps) {
2060                 fw_error("Failed to set Link Power Status\n");
2061                 return -EIO;
2062         }
2063
2064         reg_write(ohci, OHCI1394_HCControlClear,
2065                   OHCI1394_HCControl_noByteSwapData);
2066
2067         reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2068         reg_write(ohci, OHCI1394_LinkControlSet,
2069                   OHCI1394_LinkControl_rcvSelfID |
2070                   OHCI1394_LinkControl_rcvPhyPkt |
2071                   OHCI1394_LinkControl_cycleTimerEnable |
2072                   OHCI1394_LinkControl_cycleMaster);
2073
2074         reg_write(ohci, OHCI1394_ATRetries,
2075                   OHCI1394_MAX_AT_REQ_RETRIES |
2076                   (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2077                   (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2078                   (200 << 16));
2079
2080         seconds = lower_32_bits(get_seconds());
2081         reg_write(ohci, OHCI1394_IsochronousCycleTimer, seconds << 25);
2082         ohci->bus_time = seconds & ~0x3f;
2083
2084         version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2085         if (version >= OHCI_VERSION_1_1) {
2086                 reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2087                           0xfffffffe);
2088                 card->broadcast_channel_auto_allocated = true;
2089         }
2090
2091         /* Get implemented bits of the priority arbitration request counter. */
2092         reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2093         ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2094         reg_write(ohci, OHCI1394_FairnessControl, 0);
2095         card->priority_budget_implemented = ohci->pri_req_max != 0;
2096
2097         ar_context_run(&ohci->ar_request_ctx);
2098         ar_context_run(&ohci->ar_response_ctx);
2099
2100         reg_write(ohci, OHCI1394_PhyUpperBound, 0x00010000);
2101         reg_write(ohci, OHCI1394_IntEventClear, ~0);
2102         reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2103
2104         ret = configure_1394a_enhancements(ohci);
2105         if (ret < 0)
2106                 return ret;
2107
2108         /* Activate link_on bit and contender bit in our self ID packets.*/
2109         ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2110         if (ret < 0)
2111                 return ret;
2112
2113         /*
2114          * When the link is not yet enabled, the atomic config rom
2115          * update mechanism described below in ohci_set_config_rom()
2116          * is not active.  We have to update ConfigRomHeader and
2117          * BusOptions manually, and the write to ConfigROMmap takes
2118          * effect immediately.  We tie this to the enabling of the
2119          * link, so we have a valid config rom before enabling - the
2120          * OHCI requires that ConfigROMhdr and BusOptions have valid
2121          * values before enabling.
2122          *
2123          * However, when the ConfigROMmap is written, some controllers
2124          * always read back quadlets 0 and 2 from the config rom to
2125          * the ConfigRomHeader and BusOptions registers on bus reset.
2126          * They shouldn't do that in this initial case where the link
2127          * isn't enabled.  This means we have to use the same
2128          * workaround here, setting the bus header to 0 and then write
2129          * the right values in the bus reset tasklet.
2130          */
2131
2132         if (config_rom) {
2133                 ohci->next_config_rom =
2134                         dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2135                                            &ohci->next_config_rom_bus,
2136                                            GFP_KERNEL);
2137                 if (ohci->next_config_rom == NULL)
2138                         return -ENOMEM;
2139
2140                 copy_config_rom(ohci->next_config_rom, config_rom, length);
2141         } else {
2142                 /*
2143                  * In the suspend case, config_rom is NULL, which
2144                  * means that we just reuse the old config rom.
2145                  */
2146                 ohci->next_config_rom = ohci->config_rom;
2147                 ohci->next_config_rom_bus = ohci->config_rom_bus;
2148         }
2149
2150         ohci->next_header = ohci->next_config_rom[0];
2151         ohci->next_config_rom[0] = 0;
2152         reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2153         reg_write(ohci, OHCI1394_BusOptions,
2154                   be32_to_cpu(ohci->next_config_rom[2]));
2155         reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2156
2157         reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2158
2159         if (!(ohci->quirks & QUIRK_NO_MSI))
2160                 pci_enable_msi(dev);
2161         if (request_irq(dev->irq, irq_handler,
2162                         pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
2163                         ohci_driver_name, ohci)) {
2164                 fw_error("Failed to allocate interrupt %d.\n", dev->irq);
2165                 pci_disable_msi(dev);
2166                 dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2167                                   ohci->config_rom, ohci->config_rom_bus);
2168                 return -EIO;
2169         }
2170
2171         irqs =  OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2172                 OHCI1394_RQPkt | OHCI1394_RSPkt |
2173                 OHCI1394_isochTx | OHCI1394_isochRx |
2174                 OHCI1394_postedWriteErr |
2175                 OHCI1394_selfIDComplete |
2176                 OHCI1394_regAccessFail |
2177                 OHCI1394_cycle64Seconds |
2178                 OHCI1394_cycleInconsistent |
2179                 OHCI1394_unrecoverableError |
2180                 OHCI1394_cycleTooLong |
2181                 OHCI1394_masterIntEnable;
2182         if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2183                 irqs |= OHCI1394_busReset;
2184         reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2185
2186         reg_write(ohci, OHCI1394_HCControlSet,
2187                   OHCI1394_HCControl_linkEnable |
2188                   OHCI1394_HCControl_BIBimageValid);
2189         flush_writes(ohci);
2190
2191         /* We are ready to go, reset bus to finish initialization. */
2192         fw_schedule_bus_reset(&ohci->card, false, true);
2193
2194         return 0;
2195 }
2196
2197 static int ohci_set_config_rom(struct fw_card *card,
2198                                const __be32 *config_rom, size_t length)
2199 {
2200         struct fw_ohci *ohci;
2201         unsigned long flags;
2202         __be32 *next_config_rom;
2203         dma_addr_t uninitialized_var(next_config_rom_bus);
2204
2205         ohci = fw_ohci(card);
2206
2207         /*
2208          * When the OHCI controller is enabled, the config rom update
2209          * mechanism is a bit tricky, but easy enough to use.  See
2210          * section 5.5.6 in the OHCI specification.
2211          *
2212          * The OHCI controller caches the new config rom address in a
2213          * shadow register (ConfigROMmapNext) and needs a bus reset
2214          * for the changes to take place.  When the bus reset is
2215          * detected, the controller loads the new values for the
2216          * ConfigRomHeader and BusOptions registers from the specified
2217          * config rom and loads ConfigROMmap from the ConfigROMmapNext
2218          * shadow register. All automatically and atomically.
2219          *
2220          * Now, there's a twist to this story.  The automatic load of
2221          * ConfigRomHeader and BusOptions doesn't honor the
2222          * noByteSwapData bit, so with a be32 config rom, the
2223          * controller will load be32 values in to these registers
2224          * during the atomic update, even on litte endian
2225          * architectures.  The workaround we use is to put a 0 in the
2226          * header quadlet; 0 is endian agnostic and means that the
2227          * config rom isn't ready yet.  In the bus reset tasklet we
2228          * then set up the real values for the two registers.
2229          *
2230          * We use ohci->lock to avoid racing with the code that sets
2231          * ohci->next_config_rom to NULL (see bus_reset_tasklet).
2232          */
2233
2234         next_config_rom =
2235                 dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2236                                    &next_config_rom_bus, GFP_KERNEL);
2237         if (next_config_rom == NULL)
2238                 return -ENOMEM;
2239
2240         spin_lock_irqsave(&ohci->lock, flags);
2241
2242         /*
2243          * If there is not an already pending config_rom update,
2244          * push our new allocation into the ohci->next_config_rom
2245          * and then mark the local variable as null so that we
2246          * won't deallocate the new buffer.
2247          *
2248          * OTOH, if there is a pending config_rom update, just
2249          * use that buffer with the new config_rom data, and
2250          * let this routine free the unused DMA allocation.
2251          */
2252
2253         if (ohci->next_config_rom == NULL) {
2254                 ohci->next_config_rom = next_config_rom;
2255                 ohci->next_config_rom_bus = next_config_rom_bus;
2256                 next_config_rom = NULL;
2257         }
2258
2259         copy_config_rom(ohci->next_config_rom, config_rom, length);
2260
2261         ohci->next_header = config_rom[0];
2262         ohci->next_config_rom[0] = 0;
2263
2264         reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2265
2266         spin_unlock_irqrestore(&ohci->lock, flags);
2267
2268         /* If we didn't use the DMA allocation, delete it. */
2269         if (next_config_rom != NULL)
2270                 dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2271                                   next_config_rom, next_config_rom_bus);
2272
2273         /*
2274          * Now initiate a bus reset to have the changes take
2275          * effect. We clean up the old config rom memory and DMA
2276          * mappings in the bus reset tasklet, since the OHCI
2277          * controller could need to access it before the bus reset
2278          * takes effect.
2279          */
2280
2281         fw_schedule_bus_reset(&ohci->card, true, true);
2282
2283         return 0;
2284 }
2285
2286 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2287 {
2288         struct fw_ohci *ohci = fw_ohci(card);
2289
2290         at_context_transmit(&ohci->at_request_ctx, packet);
2291 }
2292
2293 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2294 {
2295         struct fw_ohci *ohci = fw_ohci(card);
2296
2297         at_context_transmit(&ohci->at_response_ctx, packet);
2298 }
2299
2300 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2301 {
2302         struct fw_ohci *ohci = fw_ohci(card);
2303         struct context *ctx = &ohci->at_request_ctx;
2304         struct driver_data *driver_data = packet->driver_data;
2305         int ret = -ENOENT;
2306
2307         tasklet_disable(&ctx->tasklet);
2308
2309         if (packet->ack != 0)
2310                 goto out;
2311
2312         if (packet->payload_mapped)
2313                 dma_unmap_single(ohci->card.device, packet->payload_bus,
2314                                  packet->payload_length, DMA_TO_DEVICE);
2315
2316         log_ar_at_event('T', packet->speed, packet->header, 0x20);
2317         driver_data->packet = NULL;
2318         packet->ack = RCODE_CANCELLED;
2319         packet->callback(packet, &ohci->card, packet->ack);
2320         ret = 0;
2321  out:
2322         tasklet_enable(&ctx->tasklet);
2323
2324         return ret;
2325 }
2326
2327 static int ohci_enable_phys_dma(struct fw_card *card,
2328                                 int node_id, int generation)
2329 {
2330 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
2331         return 0;
2332 #else
2333         struct fw_ohci *ohci = fw_ohci(card);
2334         unsigned long flags;
2335         int n, ret = 0;
2336
2337         /*
2338          * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2339          * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2340          */
2341
2342         spin_lock_irqsave(&ohci->lock, flags);
2343
2344         if (ohci->generation != generation) {
2345                 ret = -ESTALE;
2346                 goto out;
2347         }
2348
2349         /*
2350          * Note, if the node ID contains a non-local bus ID, physical DMA is
2351          * enabled for _all_ nodes on remote buses.
2352          */
2353
2354         n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2355         if (n < 32)
2356                 reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2357         else
2358                 reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2359
2360         flush_writes(ohci);
2361  out:
2362         spin_unlock_irqrestore(&ohci->lock, flags);
2363
2364         return ret;
2365 #endif /* CONFIG_FIREWIRE_OHCI_REMOTE_DMA */
2366 }
2367
2368 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2369 {
2370         struct fw_ohci *ohci = fw_ohci(card);
2371         unsigned long flags;
2372         u32 value;
2373
2374         switch (csr_offset) {
2375         case CSR_STATE_CLEAR:
2376         case CSR_STATE_SET:
2377                 if (ohci->is_root &&
2378                     (reg_read(ohci, OHCI1394_LinkControlSet) &
2379                      OHCI1394_LinkControl_cycleMaster))
2380                         value = CSR_STATE_BIT_CMSTR;
2381                 else
2382                         value = 0;
2383                 if (ohci->csr_state_setclear_abdicate)
2384                         value |= CSR_STATE_BIT_ABDICATE;
2385
2386                 return value;
2387
2388         case CSR_NODE_IDS:
2389                 return reg_read(ohci, OHCI1394_NodeID) << 16;
2390
2391         case CSR_CYCLE_TIME:
2392                 return get_cycle_time(ohci);
2393
2394         case CSR_BUS_TIME:
2395                 /*
2396                  * We might be called just after the cycle timer has wrapped
2397                  * around but just before the cycle64Seconds handler, so we
2398                  * better check here, too, if the bus time needs to be updated.
2399                  */
2400                 spin_lock_irqsave(&ohci->lock, flags);
2401                 value = update_bus_time(ohci);
2402                 spin_unlock_irqrestore(&ohci->lock, flags);
2403                 return value;
2404
2405         case CSR_BUSY_TIMEOUT:
2406                 value = reg_read(ohci, OHCI1394_ATRetries);
2407                 return (value >> 4) & 0x0ffff00f;
2408
2409         case CSR_PRIORITY_BUDGET:
2410                 return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2411                         (ohci->pri_req_max << 8);
2412
2413         default:
2414                 WARN_ON(1);
2415                 return 0;
2416         }
2417 }
2418
2419 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2420 {
2421         struct fw_ohci *ohci = fw_ohci(card);
2422         unsigned long flags;
2423
2424         switch (csr_offset) {
2425         case CSR_STATE_CLEAR:
2426                 if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2427                         reg_write(ohci, OHCI1394_LinkControlClear,
2428                                   OHCI1394_LinkControl_cycleMaster);
2429                         flush_writes(ohci);
2430                 }
2431                 if (value & CSR_STATE_BIT_ABDICATE)
2432                         ohci->csr_state_setclear_abdicate = false;
2433                 break;
2434
2435         case CSR_STATE_SET:
2436                 if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2437                         reg_write(ohci, OHCI1394_LinkControlSet,
2438                                   OHCI1394_LinkControl_cycleMaster);
2439                         flush_writes(ohci);
2440                 }
2441                 if (value & CSR_STATE_BIT_ABDICATE)
2442                         ohci->csr_state_setclear_abdicate = true;
2443                 break;
2444
2445         case CSR_NODE_IDS:
2446                 reg_write(ohci, OHCI1394_NodeID, value >> 16);
2447                 flush_writes(ohci);
2448                 break;
2449
2450         case CSR_CYCLE_TIME:
2451                 reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2452                 reg_write(ohci, OHCI1394_IntEventSet,
2453                           OHCI1394_cycleInconsistent);
2454                 flush_writes(ohci);
2455                 break;
2456
2457         case CSR_BUS_TIME:
2458                 spin_lock_irqsave(&ohci->lock, flags);
2459                 ohci->bus_time = (ohci->bus_time & 0x7f) | (value & ~0x7f);
2460                 spin_unlock_irqrestore(&ohci->lock, flags);
2461                 break;
2462
2463         case CSR_BUSY_TIMEOUT:
2464                 value = (value & 0xf) | ((value & 0xf) << 4) |
2465                         ((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2466                 reg_write(ohci, OHCI1394_ATRetries, value);
2467                 flush_writes(ohci);
2468                 break;
2469
2470         case CSR_PRIORITY_BUDGET:
2471                 reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2472                 flush_writes(ohci);
2473                 break;
2474
2475         default:
2476                 WARN_ON(1);
2477                 break;
2478         }
2479 }
2480
2481 static void copy_iso_headers(struct iso_context *ctx, void *p)
2482 {
2483         int i = ctx->header_length;
2484
2485         if (i + ctx->base.header_size > PAGE_SIZE)
2486                 return;
2487
2488         /*
2489          * The iso header is byteswapped to little endian by
2490          * the controller, but the remaining header quadlets
2491          * are big endian.  We want to present all the headers
2492          * as big endian, so we have to swap the first quadlet.
2493          */
2494         if (ctx->base.header_size > 0)
2495                 *(u32 *) (ctx->header + i) = __swab32(*(u32 *) (p + 4));
2496         if (ctx->base.header_size > 4)
2497                 *(u32 *) (ctx->header + i + 4) = __swab32(*(u32 *) p);
2498         if (ctx->base.header_size > 8)
2499                 memcpy(ctx->header + i + 8, p + 8, ctx->base.header_size - 8);
2500         ctx->header_length += ctx->base.header_size;
2501 }
2502
2503 static int handle_ir_packet_per_buffer(struct context *context,
2504                                        struct descriptor *d,
2505                                        struct descriptor *last)
2506 {
2507         struct iso_context *ctx =
2508                 container_of(context, struct iso_context, context);
2509         struct descriptor *pd;
2510         __le32 *ir_header;
2511         void *p;
2512
2513         for (pd = d; pd <= last; pd++)
2514                 if (pd->transfer_status)
2515                         break;
2516         if (pd > last)
2517                 /* Descriptor(s) not done yet, stop iteration */
2518                 return 0;
2519
2520         p = last + 1;
2521         copy_iso_headers(ctx, p);
2522
2523         if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
2524                 ir_header = (__le32 *) p;
2525                 ctx->base.callback.sc(&ctx->base,
2526                                       le32_to_cpu(ir_header[0]) & 0xffff,
2527                                       ctx->header_length, ctx->header,
2528                                       ctx->base.callback_data);
2529                 ctx->header_length = 0;
2530         }
2531
2532         return 1;
2533 }
2534
2535 /* d == last because each descriptor block is only a single descriptor. */
2536 static int handle_ir_buffer_fill(struct context *context,
2537                                  struct descriptor *d,
2538                                  struct descriptor *last)
2539 {
2540         struct iso_context *ctx =
2541                 container_of(context, struct iso_context, context);
2542
2543         if (!last->transfer_status)
2544                 /* Descriptor(s) not done yet, stop iteration */
2545                 return 0;
2546
2547         if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS)
2548                 ctx->base.callback.mc(&ctx->base,
2549                                       le32_to_cpu(last->data_address) +
2550                                       le16_to_cpu(last->req_count) -
2551                                       le16_to_cpu(last->res_count),
2552                                       ctx->base.callback_data);
2553
2554         return 1;
2555 }
2556
2557 static int handle_it_packet(struct context *context,
2558                             struct descriptor *d,
2559                             struct descriptor *last)
2560 {
2561         struct iso_context *ctx =
2562                 container_of(context, struct iso_context, context);
2563         int i;
2564         struct descriptor *pd;
2565
2566         for (pd = d; pd <= last; pd++)
2567                 if (pd->transfer_status)
2568                         break;
2569         if (pd > last)
2570                 /* Descriptor(s) not done yet, stop iteration */
2571                 return 0;
2572
2573         i = ctx->header_length;
2574         if (i + 4 < PAGE_SIZE) {
2575                 /* Present this value as big-endian to match the receive code */
2576                 *(__be32 *)(ctx->header + i) = cpu_to_be32(
2577                                 ((u32)le16_to_cpu(pd->transfer_status) << 16) |
2578                                 le16_to_cpu(pd->res_count));
2579                 ctx->header_length += 4;
2580         }
2581         if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
2582                 ctx->base.callback.sc(&ctx->base, le16_to_cpu(last->res_count),
2583                                       ctx->header_length, ctx->header,
2584                                       ctx->base.callback_data);
2585                 ctx->header_length = 0;
2586         }
2587         return 1;
2588 }
2589
2590 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2591 {
2592         u32 hi = channels >> 32, lo = channels;
2593
2594         reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2595         reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2596         reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2597         reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2598         mmiowb();
2599         ohci->mc_channels = channels;
2600 }
2601
2602 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2603                                 int type, int channel, size_t header_size)
2604 {
2605         struct fw_ohci *ohci = fw_ohci(card);
2606         struct iso_context *uninitialized_var(ctx);
2607         descriptor_callback_t uninitialized_var(callback);
2608         u64 *uninitialized_var(channels);
2609         u32 *uninitialized_var(mask), uninitialized_var(regs);
2610         unsigned long flags;
2611         int index, ret = -EBUSY;
2612
2613         spin_lock_irqsave(&ohci->lock, flags);
2614
2615         switch (type) {
2616         case FW_ISO_CONTEXT_TRANSMIT:
2617                 mask     = &ohci->it_context_mask;
2618                 callback = handle_it_packet;
2619                 index    = ffs(*mask) - 1;
2620                 if (index >= 0) {
2621                         *mask &= ~(1 << index);
2622                         regs = OHCI1394_IsoXmitContextBase(index);
2623                         ctx  = &ohci->it_context_list[index];
2624                 }
2625                 break;
2626
2627         case FW_ISO_CONTEXT_RECEIVE:
2628                 channels = &ohci->ir_context_channels;
2629                 mask     = &ohci->ir_context_mask;
2630                 callback = handle_ir_packet_per_buffer;
2631                 index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2632                 if (index >= 0) {
2633                         *channels &= ~(1ULL << channel);
2634                         *mask     &= ~(1 << index);
2635                         regs = OHCI1394_IsoRcvContextBase(index);
2636                         ctx  = &ohci->ir_context_list[index];
2637                 }
2638                 break;
2639
2640         case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2641                 mask     = &ohci->ir_context_mask;
2642                 callback = handle_ir_buffer_fill;
2643                 index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2644                 if (index >= 0) {
2645                         ohci->mc_allocated = true;
2646                         *mask &= ~(1 << index);
2647                         regs = OHCI1394_IsoRcvContextBase(index);
2648                         ctx  = &ohci->ir_context_list[index];
2649                 }
2650                 break;
2651
2652         default:
2653                 index = -1;
2654                 ret = -ENOSYS;
2655         }
2656
2657         spin_unlock_irqrestore(&ohci->lock, flags);
2658
2659         if (index < 0)
2660                 return ERR_PTR(ret);
2661
2662         memset(ctx, 0, sizeof(*ctx));
2663         ctx->header_length = 0;
2664         ctx->header = (void *) __get_free_page(GFP_KERNEL);
2665         if (ctx->header == NULL) {
2666                 ret = -ENOMEM;
2667                 goto out;
2668         }
2669         ret = context_init(&ctx->context, ohci, regs, callback);
2670         if (ret < 0)
2671                 goto out_with_header;
2672
2673         if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL)
2674                 set_multichannel_mask(ohci, 0);
2675
2676         return &ctx->base;
2677
2678  out_with_header:
2679         free_page((unsigned long)ctx->header);
2680  out:
2681         spin_lock_irqsave(&ohci->lock, flags);
2682
2683         switch (type) {
2684         case FW_ISO_CONTEXT_RECEIVE:
2685                 *channels |= 1ULL << channel;
2686                 break;
2687
2688         case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2689                 ohci->mc_allocated = false;
2690                 break;
2691         }
2692         *mask |= 1 << index;
2693
2694         spin_unlock_irqrestore(&ohci->lock, flags);
2695
2696         return ERR_PTR(ret);
2697 }
2698
2699 static int ohci_start_iso(struct fw_iso_context *base,
2700                           s32 cycle, u32 sync, u32 tags)
2701 {
2702         struct iso_context *ctx = container_of(base, struct iso_context, base);
2703         struct fw_ohci *ohci = ctx->context.ohci;
2704         u32 control = IR_CONTEXT_ISOCH_HEADER, match;
2705         int index;
2706
2707         /* the controller cannot start without any queued packets */
2708         if (ctx->context.last->branch_address == 0)
2709                 return -ENODATA;
2710
2711         switch (ctx->base.type) {
2712         case FW_ISO_CONTEXT_TRANSMIT:
2713                 index = ctx - ohci->it_context_list;
2714                 match = 0;
2715                 if (cycle >= 0)
2716                         match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
2717                                 (cycle & 0x7fff) << 16;
2718
2719                 reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
2720                 reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
2721                 context_run(&ctx->context, match);
2722                 break;
2723
2724         case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2725                 control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
2726                 /* fall through */
2727         case FW_ISO_CONTEXT_RECEIVE:
2728                 index = ctx - ohci->ir_context_list;
2729                 match = (tags << 28) | (sync << 8) | ctx->base.channel;
2730                 if (cycle >= 0) {
2731                         match |= (cycle & 0x07fff) << 12;
2732                         control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
2733                 }
2734
2735                 reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
2736                 reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
2737                 reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
2738                 context_run(&ctx->context, control);
2739
2740                 ctx->sync = sync;
2741                 ctx->tags = tags;
2742
2743                 break;
2744         }
2745
2746         return 0;
2747 }
2748
2749 static int ohci_stop_iso(struct fw_iso_context *base)
2750 {
2751         struct fw_ohci *ohci = fw_ohci(base->card);
2752         struct iso_context *ctx = container_of(base, struct iso_context, base);
2753         int index;
2754
2755         switch (ctx->base.type) {
2756         case FW_ISO_CONTEXT_TRANSMIT:
2757                 index = ctx - ohci->it_context_list;
2758                 reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
2759                 break;
2760
2761         case FW_ISO_CONTEXT_RECEIVE:
2762         case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2763                 index = ctx - ohci->ir_context_list;
2764                 reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
2765                 break;
2766         }
2767         flush_writes(ohci);
2768         context_stop(&ctx->context);
2769         tasklet_kill(&ctx->context.tasklet);
2770
2771         return 0;
2772 }
2773
2774 static void ohci_free_iso_context(struct fw_iso_context *base)
2775 {
2776         struct fw_ohci *ohci = fw_ohci(base->card);
2777         struct iso_context *ctx = container_of(base, struct iso_context, base);
2778         unsigned long flags;
2779         int index;
2780
2781         ohci_stop_iso(base);
2782         context_release(&ctx->context);
2783         free_page((unsigned long)ctx->header);
2784
2785         spin_lock_irqsave(&ohci->lock, flags);
2786
2787         switch (base->type) {
2788         case FW_ISO_CONTEXT_TRANSMIT:
2789                 index = ctx - ohci->it_context_list;
2790                 ohci->it_context_mask |= 1 << index;
2791                 break;
2792
2793         case FW_ISO_CONTEXT_RECEIVE:
2794                 index = ctx - ohci->ir_context_list;
2795                 ohci->ir_context_mask |= 1 << index;
2796                 ohci->ir_context_channels |= 1ULL << base->channel;
2797                 break;
2798
2799         case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2800                 index = ctx - ohci->ir_context_list;
2801                 ohci->ir_context_mask |= 1 << index;
2802                 ohci->ir_context_channels |= ohci->mc_channels;
2803                 ohci->mc_channels = 0;
2804                 ohci->mc_allocated = false;
2805                 break;
2806         }
2807
2808         spin_unlock_irqrestore(&ohci->lock, flags);
2809 }
2810
2811 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
2812 {
2813         struct fw_ohci *ohci = fw_ohci(base->card);
2814         unsigned long flags;
2815         int ret;
2816
2817         switch (base->type) {
2818         case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2819
2820                 spin_lock_irqsave(&ohci->lock, flags);
2821
2822                 /* Don't allow multichannel to grab other contexts' channels. */
2823                 if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
2824                         *channels = ohci->ir_context_channels;
2825                         ret = -EBUSY;
2826                 } else {
2827                         set_multichannel_mask(ohci, *channels);
2828                         ret = 0;
2829                 }
2830
2831                 spin_unlock_irqrestore(&ohci->lock, flags);
2832
2833                 break;
2834         default:
2835                 ret = -EINVAL;
2836         }
2837
2838         return ret;
2839 }
2840
2841 #ifdef CONFIG_PM
2842 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
2843 {
2844         int i;
2845         struct iso_context *ctx;
2846
2847         for (i = 0 ; i < ohci->n_ir ; i++) {
2848                 ctx = &ohci->ir_context_list[i];
2849                 if (ctx->context.running)
2850                         ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
2851         }
2852
2853         for (i = 0 ; i < ohci->n_it ; i++) {
2854                 ctx = &ohci->it_context_list[i];
2855                 if (ctx->context.running)
2856                         ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
2857         }
2858 }
2859 #endif
2860
2861 static int queue_iso_transmit(struct iso_context *ctx,
2862                               struct fw_iso_packet *packet,
2863                               struct fw_iso_buffer *buffer,
2864                               unsigned long payload)
2865 {
2866         struct descriptor *d, *last, *pd;
2867         struct fw_iso_packet *p;
2868         __le32 *header;
2869         dma_addr_t d_bus, page_bus;
2870         u32 z, header_z, payload_z, irq;
2871         u32 payload_index, payload_end_index, next_page_index;
2872         int page, end_page, i, length, offset;
2873
2874         p = packet;
2875         payload_index = payload;
2876
2877         if (p->skip)
2878                 z = 1;
2879         else
2880                 z = 2;
2881         if (p->header_length > 0)
2882                 z++;
2883
2884         /* Determine the first page the payload isn't contained in. */
2885         end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
2886         if (p->payload_length > 0)
2887                 payload_z = end_page - (payload_index >> PAGE_SHIFT);
2888         else
2889                 payload_z = 0;
2890
2891         z += payload_z;
2892
2893         /* Get header size in number of descriptors. */
2894         header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
2895
2896         d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
2897         if (d == NULL)
2898                 return -ENOMEM;
2899
2900         if (!p->skip) {
2901                 d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
2902                 d[0].req_count = cpu_to_le16(8);
2903                 /*
2904                  * Link the skip address to this descriptor itself.  This causes
2905                  * a context to skip a cycle whenever lost cycles or FIFO
2906                  * overruns occur, without dropping the data.  The application
2907                  * should then decide whether this is an error condition or not.
2908                  * FIXME:  Make the context's cycle-lost behaviour configurable?
2909                  */
2910                 d[0].branch_address = cpu_to_le32(d_bus | z);
2911
2912                 header = (__le32 *) &d[1];
2913                 header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
2914                                         IT_HEADER_TAG(p->tag) |
2915                                         IT_HEADER_TCODE(TCODE_STREAM_DATA) |
2916                                         IT_HEADER_CHANNEL(ctx->base.channel) |
2917                                         IT_HEADER_SPEED(ctx->base.speed));
2918                 header[1] =
2919                         cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
2920                                                           p->payload_length));
2921         }
2922
2923         if (p->header_length > 0) {
2924                 d[2].req_count    = cpu_to_le16(p->header_length);
2925                 d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
2926                 memcpy(&d[z], p->header, p->header_length);
2927         }
2928
2929         pd = d + z - payload_z;
2930         payload_end_index = payload_index + p->payload_length;
2931         for (i = 0; i < payload_z; i++) {
2932                 page               = payload_index >> PAGE_SHIFT;
2933                 offset             = payload_index & ~PAGE_MASK;
2934                 next_page_index    = (page + 1) << PAGE_SHIFT;
2935                 length             =
2936                         min(next_page_index, payload_end_index) - payload_index;
2937                 pd[i].req_count    = cpu_to_le16(length);
2938
2939                 page_bus = page_private(buffer->pages[page]);
2940                 pd[i].data_address = cpu_to_le32(page_bus + offset);
2941
2942                 payload_index += length;
2943         }
2944
2945         if (p->interrupt)
2946                 irq = DESCRIPTOR_IRQ_ALWAYS;
2947         else
2948                 irq = DESCRIPTOR_NO_IRQ;
2949
2950         last = z == 2 ? d : d + z - 1;
2951         last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
2952                                      DESCRIPTOR_STATUS |
2953                                      DESCRIPTOR_BRANCH_ALWAYS |
2954                                      irq);
2955
2956         context_append(&ctx->context, d, z, header_z);
2957
2958         return 0;
2959 }
2960
2961 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
2962                                        struct fw_iso_packet *packet,
2963                                        struct fw_iso_buffer *buffer,
2964                                        unsigned long payload)
2965 {
2966         struct descriptor *d, *pd;
2967         dma_addr_t d_bus, page_bus;
2968         u32 z, header_z, rest;
2969         int i, j, length;
2970         int page, offset, packet_count, header_size, payload_per_buffer;
2971
2972         /*
2973          * The OHCI controller puts the isochronous header and trailer in the
2974          * buffer, so we need at least 8 bytes.
2975          */
2976         packet_count = packet->header_length / ctx->base.header_size;
2977         header_size  = max(ctx->base.header_size, (size_t)8);
2978
2979         /* Get header size in number of descriptors. */
2980         header_z = DIV_ROUND_UP(header_size, sizeof(*d));
2981         page     = payload >> PAGE_SHIFT;
2982         offset   = payload & ~PAGE_MASK;
2983         payload_per_buffer = packet->payload_length / packet_count;
2984
2985         for (i = 0; i < packet_count; i++) {
2986                 /* d points to the header descriptor */
2987                 z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
2988                 d = context_get_descriptors(&ctx->context,
2989                                 z + header_z, &d_bus);
2990                 if (d == NULL)
2991                         return -ENOMEM;
2992
2993                 d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
2994                                               DESCRIPTOR_INPUT_MORE);
2995                 if (packet->skip && i == 0)
2996                         d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
2997                 d->req_count    = cpu_to_le16(header_size);
2998                 d->res_count    = d->req_count;
2999                 d->transfer_status = 0;
3000                 d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3001
3002                 rest = payload_per_buffer;
3003                 pd = d;
3004                 for (j = 1; j < z; j++) {
3005                         pd++;
3006                         pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3007                                                   DESCRIPTOR_INPUT_MORE);
3008
3009                         if (offset + rest < PAGE_SIZE)
3010                                 length = rest;
3011                         else
3012                                 length = PAGE_SIZE - offset;
3013                         pd->req_count = cpu_to_le16(length);
3014                         pd->res_count = pd->req_count;
3015                         pd->transfer_status = 0;
3016
3017                         page_bus = page_private(buffer->pages[page]);
3018                         pd->data_address = cpu_to_le32(page_bus + offset);
3019
3020                         offset = (offset + length) & ~PAGE_MASK;
3021                         rest -= length;
3022                         if (offset == 0)
3023                                 page++;
3024                 }
3025                 pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3026                                           DESCRIPTOR_INPUT_LAST |
3027                                           DESCRIPTOR_BRANCH_ALWAYS);
3028                 if (packet->interrupt && i == packet_count - 1)
3029                         pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3030
3031                 context_append(&ctx->context, d, z, header_z);
3032         }
3033
3034         return 0;
3035 }
3036
3037 static int queue_iso_buffer_fill(struct iso_context *ctx,
3038                                  struct fw_iso_packet *packet,
3039                                  struct fw_iso_buffer *buffer,
3040                                  unsigned long payload)
3041 {
3042         struct descriptor *d;
3043         dma_addr_t d_bus, page_bus;
3044         int page, offset, rest, z, i, length;
3045
3046         page   = payload >> PAGE_SHIFT;
3047         offset = payload & ~PAGE_MASK;
3048         rest   = packet->payload_length;
3049
3050         /* We need one descriptor for each page in the buffer. */
3051         z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3052
3053         if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3054                 return -EFAULT;
3055
3056         for (i = 0; i < z; i++) {
3057                 d = context_get_descriptors(&ctx->context, 1, &d_bus);
3058                 if (d == NULL)
3059                         return -ENOMEM;
3060
3061                 d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3062                                          DESCRIPTOR_BRANCH_ALWAYS);
3063                 if (packet->skip && i == 0)
3064                         d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3065                 if (packet->interrupt && i == z - 1)
3066                         d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3067
3068                 if (offset + rest < PAGE_SIZE)
3069                         length = rest;
3070                 else
3071                         length = PAGE_SIZE - offset;
3072                 d->req_count = cpu_to_le16(length);
3073                 d->res_count = d->req_count;
3074                 d->transfer_status = 0;
3075
3076                 page_bus = page_private(buffer->pages[page]);
3077                 d->data_address = cpu_to_le32(page_bus + offset);
3078
3079                 rest -= length;
3080                 offset = 0;
3081                 page++;
3082
3083                 context_append(&ctx->context, d, 1, 0);
3084         }
3085
3086         return 0;
3087 }
3088
3089 static int ohci_queue_iso(struct fw_iso_context *base,
3090                           struct fw_iso_packet *packet,
3091                           struct fw_iso_buffer *buffer,
3092                           unsigned long payload)
3093 {
3094         struct iso_context *ctx = container_of(base, struct iso_context, base);
3095         unsigned long flags;
3096         int ret = -ENOSYS;
3097
3098         spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3099         switch (base->type) {
3100         case FW_ISO_CONTEXT_TRANSMIT:
3101                 ret = queue_iso_transmit(ctx, packet, buffer, payload);
3102                 break;
3103         case FW_ISO_CONTEXT_RECEIVE:
3104                 ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3105                 break;
3106         case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3107                 ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3108                 break;
3109         }
3110         spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3111
3112         return ret;
3113 }
3114
3115 static const struct fw_card_driver ohci_driver = {
3116         .enable                 = ohci_enable,
3117         .read_phy_reg           = ohci_read_phy_reg,
3118         .update_phy_reg         = ohci_update_phy_reg,
3119         .set_config_rom         = ohci_set_config_rom,
3120         .send_request           = ohci_send_request,
3121         .send_response          = ohci_send_response,
3122         .cancel_packet          = ohci_cancel_packet,
3123         .enable_phys_dma        = ohci_enable_phys_dma,
3124         .read_csr               = ohci_read_csr,
3125         .write_csr              = ohci_write_csr,
3126
3127         .allocate_iso_context   = ohci_allocate_iso_context,
3128         .free_iso_context       = ohci_free_iso_context,
3129         .set_iso_channels       = ohci_set_iso_channels,
3130         .queue_iso              = ohci_queue_iso,
3131         .start_iso              = ohci_start_iso,
3132         .stop_iso               = ohci_stop_iso,
3133 };
3134
3135 #ifdef CONFIG_PPC_PMAC
3136 static void pmac_ohci_on(struct pci_dev *dev)
3137 {
3138         if (machine_is(powermac)) {
3139                 struct device_node *ofn = pci_device_to_OF_node(dev);
3140
3141                 if (ofn) {
3142                         pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3143                         pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3144                 }
3145         }
3146 }
3147
3148 static void pmac_ohci_off(struct pci_dev *dev)
3149 {
3150         if (machine_is(powermac)) {
3151                 struct device_node *ofn = pci_device_to_OF_node(dev);
3152
3153                 if (ofn) {
3154                         pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3155                         pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3156                 }
3157         }
3158 }
3159 #else
3160 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3161 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3162 #endif /* CONFIG_PPC_PMAC */
3163
3164 static int __devinit pci_probe(struct pci_dev *dev,
3165                                const struct pci_device_id *ent)
3166 {
3167         struct fw_ohci *ohci;
3168         u32 bus_options, max_receive, link_speed, version;
3169         u64 guid;
3170         int i, err;
3171         size_t size;
3172
3173         ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3174         if (ohci == NULL) {
3175                 err = -ENOMEM;
3176                 goto fail;
3177         }
3178
3179         fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3180
3181         pmac_ohci_on(dev);
3182
3183         err = pci_enable_device(dev);
3184         if (err) {
3185                 fw_error("Failed to enable OHCI hardware\n");
3186                 goto fail_free;
3187         }
3188
3189         pci_set_master(dev);
3190         pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3191         pci_set_drvdata(dev, ohci);
3192
3193         spin_lock_init(&ohci->lock);
3194         mutex_init(&ohci->phy_reg_mutex);
3195
3196         tasklet_init(&ohci->bus_reset_tasklet,
3197                      bus_reset_tasklet, (unsigned long)ohci);
3198
3199         err = pci_request_region(dev, 0, ohci_driver_name);
3200         if (err) {
3201                 fw_error("MMIO resource unavailable\n");
3202                 goto fail_disable;
3203         }
3204
3205         ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3206         if (ohci->registers == NULL) {
3207                 fw_error("Failed to remap registers\n");
3208                 err = -ENXIO;
3209                 goto fail_iomem;
3210         }
3211
3212         for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3213                 if ((ohci_quirks[i].vendor == dev->vendor) &&
3214                     (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3215                      ohci_quirks[i].device == dev->device) &&
3216                     (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3217                      ohci_quirks[i].revision >= dev->revision)) {
3218                         ohci->quirks = ohci_quirks[i].flags;
3219                         break;
3220                 }
3221         if (param_quirks)
3222                 ohci->quirks = param_quirks;
3223
3224         /*
3225          * Because dma_alloc_coherent() allocates at least one page,
3226          * we save space by using a common buffer for the AR request/
3227          * response descriptors and the self IDs buffer.
3228          */
3229         BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3230         BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3231         ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3232                                                PAGE_SIZE,
3233                                                &ohci->misc_buffer_bus,
3234                                                GFP_KERNEL);
3235         if (!ohci->misc_buffer) {
3236                 err = -ENOMEM;
3237                 goto fail_iounmap;
3238         }
3239
3240         err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3241                               OHCI1394_AsReqRcvContextControlSet);
3242         if (err < 0)
3243                 goto fail_misc_buf;
3244
3245         err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3246                               OHCI1394_AsRspRcvContextControlSet);
3247         if (err < 0)
3248                 goto fail_arreq_ctx;
3249
3250         err = context_init(&ohci->at_request_ctx, ohci,
3251                            OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3252         if (err < 0)
3253                 goto fail_arrsp_ctx;
3254
3255         err = context_init(&ohci->at_response_ctx, ohci,
3256                            OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3257         if (err < 0)
3258                 goto fail_atreq_ctx;
3259
3260         reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3261         ohci->ir_context_channels = ~0ULL;
3262         ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3263         reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3264         ohci->ir_context_mask = ohci->ir_context_support;
3265         ohci->n_ir = hweight32(ohci->ir_context_mask);
3266         size = sizeof(struct iso_context) * ohci->n_ir;
3267         ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3268
3269         reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3270         ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3271         reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3272         ohci->it_context_mask = ohci->it_context_support;
3273         ohci->n_it = hweight32(ohci->it_context_mask);
3274         size = sizeof(struct iso_context) * ohci->n_it;
3275         ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3276
3277         if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3278                 err = -ENOMEM;
3279                 goto fail_contexts;
3280         }
3281
3282         ohci->self_id_cpu = ohci->misc_buffer     + PAGE_SIZE/2;
3283         ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3284
3285         bus_options = reg_read(ohci, OHCI1394_BusOptions);
3286         max_receive = (bus_options >> 12) & 0xf;
3287         link_speed = bus_options & 0x7;
3288         guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3289                 reg_read(ohci, OHCI1394_GUIDLo);
3290
3291         err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3292         if (err)
3293                 goto fail_contexts;
3294
3295         version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3296         fw_notify("Added fw-ohci device %s, OHCI v%x.%x, "
3297                   "%d IR + %d IT contexts, quirks 0x%x\n",
3298                   dev_name(&dev->dev), version >> 16, version & 0xff,
3299                   ohci->n_ir, ohci->n_it, ohci->quirks);
3300
3301         return 0;
3302
3303  fail_contexts:
3304         kfree(ohci->ir_context_list);
3305         kfree(ohci->it_context_list);
3306         context_release(&ohci->at_response_ctx);
3307  fail_atreq_ctx:
3308         context_release(&ohci->at_request_ctx);
3309  fail_arrsp_ctx:
3310         ar_context_release(&ohci->ar_response_ctx);
3311  fail_arreq_ctx:
3312         ar_context_release(&ohci->ar_request_ctx);
3313  fail_misc_buf:
3314         dma_free_coherent(ohci->card.device, PAGE_SIZE,
3315                           ohci->misc_buffer, ohci->misc_buffer_bus);
3316  fail_iounmap:
3317         pci_iounmap(dev, ohci->registers);
3318  fail_iomem:
3319         pci_release_region(dev, 0);
3320  fail_disable:
3321         pci_disable_device(dev);
3322  fail_free:
3323         kfree(ohci);
3324         pmac_ohci_off(dev);
3325  fail:
3326         if (err == -ENOMEM)
3327                 fw_error("Out of memory\n");
3328
3329         return err;
3330 }
3331
3332 static void pci_remove(struct pci_dev *dev)
3333 {
3334         struct fw_ohci *ohci;
3335
3336         ohci = pci_get_drvdata(dev);
3337         reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3338         flush_writes(ohci);
3339         fw_core_remove_card(&ohci->card);
3340
3341         /*
3342          * FIXME: Fail all pending packets here, now that the upper
3343          * layers can't queue any more.
3344          */
3345
3346         software_reset(ohci);
3347         free_irq(dev->irq, ohci);
3348
3349         if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3350                 dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3351                                   ohci->next_config_rom, ohci->next_config_rom_bus);
3352         if (ohci->config_rom)
3353                 dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3354                                   ohci->config_rom, ohci->config_rom_bus);
3355         ar_context_release(&ohci->ar_request_ctx);
3356         ar_context_release(&ohci->ar_response_ctx);
3357         dma_free_coherent(ohci->card.device, PAGE_SIZE,
3358                           ohci->misc_buffer, ohci->misc_buffer_bus);
3359         context_release(&ohci->at_request_ctx);
3360         context_release(&ohci->at_response_ctx);
3361         kfree(ohci->it_context_list);
3362         kfree(ohci->ir_context_list);
3363         pci_disable_msi(dev);
3364         pci_iounmap(dev, ohci->registers);
3365         pci_release_region(dev, 0);
3366         pci_disable_device(dev);
3367         kfree(ohci);
3368         pmac_ohci_off(dev);
3369
3370         fw_notify("Removed fw-ohci device.\n");
3371 }
3372
3373 #ifdef CONFIG_PM
3374 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3375 {
3376         struct fw_ohci *ohci = pci_get_drvdata(dev);
3377         int err;
3378
3379         software_reset(ohci);
3380         free_irq(dev->irq, ohci);
3381         pci_disable_msi(dev);
3382         err = pci_save_state(dev);
3383         if (err) {
3384                 fw_error("pci_save_state failed\n");
3385                 return err;
3386         }
3387         err = pci_set_power_state(dev, pci_choose_state(dev, state));
3388         if (err)
3389                 fw_error("pci_set_power_state failed with %d\n", err);
3390         pmac_ohci_off(dev);
3391
3392         return 0;
3393 }
3394
3395 static int pci_resume(struct pci_dev *dev)
3396 {
3397         struct fw_ohci *ohci = pci_get_drvdata(dev);
3398         int err;
3399
3400         pmac_ohci_on(dev);
3401         pci_set_power_state(dev, PCI_D0);
3402         pci_restore_state(dev);
3403         err = pci_enable_device(dev);
3404         if (err) {
3405                 fw_error("pci_enable_device failed\n");
3406                 return err;
3407         }
3408
3409         /* Some systems don't setup GUID register on resume from ram  */
3410         if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3411                                         !reg_read(ohci, OHCI1394_GUIDHi)) {
3412                 reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3413                 reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3414         }
3415
3416         err = ohci_enable(&ohci->card, NULL, 0);
3417         if (err)
3418                 return err;
3419
3420         ohci_resume_iso_dma(ohci);
3421
3422         return 0;
3423 }
3424 #endif
3425
3426 static const struct pci_device_id pci_table[] = {
3427         { PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3428         { }
3429 };
3430
3431 MODULE_DEVICE_TABLE(pci, pci_table);
3432
3433 static struct pci_driver fw_ohci_pci_driver = {
3434         .name           = ohci_driver_name,
3435         .id_table       = pci_table,
3436         .probe          = pci_probe,
3437         .remove         = pci_remove,
3438 #ifdef CONFIG_PM
3439         .resume         = pci_resume,
3440         .suspend        = pci_suspend,
3441 #endif
3442 };
3443
3444 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3445 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3446 MODULE_LICENSE("GPL");
3447
3448 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3449 #ifndef CONFIG_IEEE1394_OHCI1394_MODULE
3450 MODULE_ALIAS("ohci1394");
3451 #endif
3452
3453 static int __init fw_ohci_init(void)
3454 {
3455         return pci_register_driver(&fw_ohci_pci_driver);
3456 }
3457
3458 static void __exit fw_ohci_cleanup(void)
3459 {
3460         pci_unregister_driver(&fw_ohci_pci_driver);
3461 }
3462
3463 module_init(fw_ohci_init);
3464 module_exit(fw_ohci_cleanup);