drivers/dma/ioat_dma.c

   1 /*
   2  * Intel I/OAT DMA Linux driver
   3  * Copyright(c) 2004 - 2009 Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * The full GNU General Public License is included in this distribution in
  19  * the file called "COPYING".
  20  *
  21  */
  22
  23 /*
  24  * This driver supports an Intel I/OAT DMA engine, which does asynchronous
  25  * copy operations.
  26  */
  27
  28 #include <linux/init.h>
  29 #include <linux/module.h>
  30 #include <linux/pci.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/dmaengine.h>
  33 #include <linux/delay.h>
  34 #include <linux/dma-mapping.h>
  35 #include <linux/workqueue.h>
  36 #include <linux/i7300_idle.h>
  37 #include "ioatdma.h"
  38 #include "ioatdma_registers.h"
  39 #include "ioatdma_hw.h"
  40
  41 #define to_ioat_chan(chan) container_of(chan, struct ioat_dma_chan, common)
  42 #define to_ioatdma_device(dev) container_of(dev, struct ioatdma_device, common)
  43 #define to_ioat_desc(lh) container_of(lh, struct ioat_desc_sw, node)
  44 #define tx_to_ioat_desc(tx) container_of(tx, struct ioat_desc_sw, async_tx)
  45
  46 #define chan_num(ch) ((int)((ch)->reg_base - (ch)->device->reg_base) / 0x80)
  47 static int ioat_pending_level = 4;
  48 module_param(ioat_pending_level, int, 0644);
  49 MODULE_PARM_DESC(ioat_pending_level,
  50                  "high-water mark for pushing ioat descriptors (default: 4)");
  51
  52 #define RESET_DELAY  msecs_to_jiffies(100)
  53 #define WATCHDOG_DELAY  round_jiffies(msecs_to_jiffies(2000))
  54 static void ioat_dma_chan_reset_part2(struct work_struct *work);
  55 static void ioat_dma_chan_watchdog(struct work_struct *work);
  56
  57 /*
  58  * workaround for IOAT ver.3.0 null descriptor issue
  59  * (channel returns error when size is 0)
  60  */
  61 #define NULL_DESC_BUFFER_SIZE 1
  62
  63 /* internal functions */
  64 static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan);
  65 static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan);
  66
  67 static struct ioat_desc_sw *
  68 ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan);
  69 static struct ioat_desc_sw *
  70 ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan);
  71
  72 static inline struct ioat_dma_chan *ioat_lookup_chan_by_index(
  73                                                 struct ioatdma_device *device,
  74                                                 int index)
  75 {
  76         return device->idx[index];
  77 }
  78
  79 /**
  80  * ioat_dma_do_interrupt - handler used for single vector interrupt mode
  81  * @irq: interrupt id
  82  * @data: interrupt data
  83  */
  84 static irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
  85 {
  86         struct ioatdma_device *instance = data;
  87         struct ioat_dma_chan *ioat_chan;
  88         unsigned long attnstatus;
  89         int bit;
  90         u8 intrctrl;
  91
  92         intrctrl = readb(instance->reg_base + IOAT_INTRCTRL_OFFSET);
  93
  94         if (!(intrctrl & IOAT_INTRCTRL_MASTER_INT_EN))
  95                 return IRQ_NONE;
  96
  97         if (!(intrctrl & IOAT_INTRCTRL_INT_STATUS)) {
  98                 writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
  99                 return IRQ_NONE;
 100         }
 101
 102         attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET);
 103         for_each_bit(bit, &attnstatus, BITS_PER_LONG) {
 104                 ioat_chan = ioat_lookup_chan_by_index(instance, bit);
 105                 tasklet_schedule(&ioat_chan->cleanup_task);
 106         }
 107
 108         writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
 109         return IRQ_HANDLED;
 110 }
 111
 112 /**
 113  * ioat_dma_do_interrupt_msix - handler used for vector-per-channel interrupt mode
 114  * @irq: interrupt id
 115  * @data: interrupt data
 116  */
 117 static irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
 118 {
 119         struct ioat_dma_chan *ioat_chan = data;
 120
 121         tasklet_schedule(&ioat_chan->cleanup_task);
 122
 123         return IRQ_HANDLED;
 124 }
 125
 126 static void ioat_dma_cleanup_tasklet(unsigned long data);
 127
 128 /**
 129  * ioat_dma_enumerate_channels - find and initialize the device's channels
 130  * @device: the device to be enumerated
 131  */
 132 static int ioat_dma_enumerate_channels(struct ioatdma_device *device)
 133 {
 134         u8 xfercap_scale;
 135         u32 xfercap;
 136         int i;
 137         struct ioat_dma_chan *ioat_chan;
 138
 139         /*
 140          * IOAT ver.3 workarounds
 141          */
 142         if (device->version == IOAT_VER_3_0) {
 143                 u32 chan_err_mask;
 144                 u16 dev_id;
 145                 u32 dmauncerrsts;
 146
 147                 /*
 148                  * Write CHANERRMSK_INT with 3E07h to mask out the errors
 149                  * that can cause stability issues for IOAT ver.3
 150                  */
 151                 chan_err_mask = 0x3E07;
 152                 pci_write_config_dword(device->pdev,
 153                         IOAT_PCI_CHANERRMASK_INT_OFFSET,
 154                         chan_err_mask);
 155
 156                 /*
 157                  * Clear DMAUNCERRSTS Cfg-Reg Parity Error status bit
 158                  * (workaround for spurious config parity error after restart)
 159                  */
 160                 pci_read_config_word(device->pdev,
 161                         IOAT_PCI_DEVICE_ID_OFFSET,
 162                         &dev_id);
 163                 if (dev_id == PCI_DEVICE_ID_INTEL_IOAT_TBG0) {
 164                         dmauncerrsts = 0x10;
 165                         pci_write_config_dword(device->pdev,
 166                                 IOAT_PCI_DMAUNCERRSTS_OFFSET,
 167                                 dmauncerrsts);
 168                 }
 169         }
 170
 171         device->common.chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET);
 172         xfercap_scale = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
 173         xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));
 174
 175 #ifdef  CONFIG_I7300_IDLE_IOAT_CHANNEL
 176         if (i7300_idle_platform_probe(NULL, NULL) == 0) {
 177                 device->common.chancnt--;
 178         }
 179 #endif
 180         for (i = 0; i < device->common.chancnt; i++) {
 181                 ioat_chan = kzalloc(sizeof(*ioat_chan), GFP_KERNEL);
 182                 if (!ioat_chan) {
 183                         device->common.chancnt = i;
 184                         break;
 185                 }
 186
 187                 ioat_chan->device = device;
 188                 ioat_chan->reg_base = device->reg_base + (0x80 * (i + 1));
 189                 ioat_chan->xfercap = xfercap;
 190                 ioat_chan->desccount = 0;
 191                 INIT_DELAYED_WORK(&ioat_chan->work, ioat_dma_chan_reset_part2);
 192                 if (ioat_chan->device->version == IOAT_VER_2_0)
 193                         writel(IOAT_DCACTRL_CMPL_WRITE_ENABLE |
 194                                IOAT_DMA_DCA_ANY_CPU,
 195                                ioat_chan->reg_base + IOAT_DCACTRL_OFFSET);
 196                 else if (ioat_chan->device->version == IOAT_VER_3_0)
 197                         writel(IOAT_DMA_DCA_ANY_CPU,
 198                                ioat_chan->reg_base + IOAT_DCACTRL_OFFSET);
 199                 spin_lock_init(&ioat_chan->cleanup_lock);
 200                 spin_lock_init(&ioat_chan->desc_lock);
 201                 INIT_LIST_HEAD(&ioat_chan->free_desc);
 202                 INIT_LIST_HEAD(&ioat_chan->used_desc);
 203                 /* This should be made common somewhere in dmaengine.c */
 204                 ioat_chan->common.device = &device->common;
 205                 list_add_tail(&ioat_chan->common.device_node,
 206                               &device->common.channels);
 207                 device->idx[i] = ioat_chan;
 208                 tasklet_init(&ioat_chan->cleanup_task,
 209                              ioat_dma_cleanup_tasklet,
 210                              (unsigned long) ioat_chan);
 211                 tasklet_disable(&ioat_chan->cleanup_task);
 212         }
 213         return device->common.chancnt;
 214 }
 215
 216 /**
 217  * ioat_dma_memcpy_issue_pending - push potentially unrecognized appended
 218  *                                 descriptors to hw
 219  * @chan: DMA channel handle
 220  */
 221 static inline void __ioat1_dma_memcpy_issue_pending(
 222                                                 struct ioat_dma_chan *ioat_chan)
 223 {
 224         ioat_chan->pending = 0;
 225         writeb(IOAT_CHANCMD_APPEND, ioat_chan->reg_base + IOAT1_CHANCMD_OFFSET);
 226 }
 227
 228 static void ioat1_dma_memcpy_issue_pending(struct dma_chan *chan)
 229 {
 230         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 231
 232         if (ioat_chan->pending > 0) {
 233                 spin_lock_bh(&ioat_chan->desc_lock);
 234                 __ioat1_dma_memcpy_issue_pending(ioat_chan);
 235                 spin_unlock_bh(&ioat_chan->desc_lock);
 236         }
 237 }
 238
 239 static inline void __ioat2_dma_memcpy_issue_pending(
 240                                                 struct ioat_dma_chan *ioat_chan)
 241 {
 242         ioat_chan->pending = 0;
 243         writew(ioat_chan->dmacount,
 244                ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
 245 }
 246
 247 static void ioat2_dma_memcpy_issue_pending(struct dma_chan *chan)
 248 {
 249         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 250
 251         if (ioat_chan->pending > 0) {
 252                 spin_lock_bh(&ioat_chan->desc_lock);
 253                 __ioat2_dma_memcpy_issue_pending(ioat_chan);
 254                 spin_unlock_bh(&ioat_chan->desc_lock);
 255         }
 256 }
 257
 258
 259 /**
 260  * ioat_dma_chan_reset_part2 - reinit the channel after a reset
 261  */
 262 static void ioat_dma_chan_reset_part2(struct work_struct *work)
 263 {
 264         struct ioat_dma_chan *ioat_chan =
 265                 container_of(work, struct ioat_dma_chan, work.work);
 266         struct ioat_desc_sw *desc;
 267
 268         spin_lock_bh(&ioat_chan->cleanup_lock);
 269         spin_lock_bh(&ioat_chan->desc_lock);
 270
 271         ioat_chan->completion_virt->low = 0;
 272         ioat_chan->completion_virt->high = 0;
 273         ioat_chan->pending = 0;
 274
 275         /*
 276          * count the descriptors waiting, and be sure to do it
 277          * right for both the CB1 line and the CB2 ring
 278          */
 279         ioat_chan->dmacount = 0;
 280         if (ioat_chan->used_desc.prev) {
 281                 desc = to_ioat_desc(ioat_chan->used_desc.prev);
 282                 do {
 283                         ioat_chan->dmacount++;
 284                         desc = to_ioat_desc(desc->node.next);
 285                 } while (&desc->node != ioat_chan->used_desc.next);
 286         }
 287
 288         /*
 289          * write the new starting descriptor address
 290          * this puts channel engine into ARMED state
 291          */
 292         desc = to_ioat_desc(ioat_chan->used_desc.prev);
 293         switch (ioat_chan->device->version) {
 294         case IOAT_VER_1_2:
 295                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
 296                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_LOW);
 297                 writel(((u64) desc->async_tx.phys) >> 32,
 298                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_HIGH);
 299
 300                 writeb(IOAT_CHANCMD_START, ioat_chan->reg_base
 301                         + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
 302                 break;
 303         case IOAT_VER_2_0:
 304                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
 305                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_LOW);
 306                 writel(((u64) desc->async_tx.phys) >> 32,
 307                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_HIGH);
 308
 309                 /* tell the engine to go with what's left to be done */
 310                 writew(ioat_chan->dmacount,
 311                        ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
 312
 313                 break;
 314         }
 315         dev_err(&ioat_chan->device->pdev->dev,
 316                 "chan%d reset - %d descs waiting, %d total desc\n",
 317                 chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount);
 318
 319         spin_unlock_bh(&ioat_chan->desc_lock);
 320         spin_unlock_bh(&ioat_chan->cleanup_lock);
 321 }
 322
 323 /**
 324  * ioat_dma_reset_channel - restart a channel
 325  * @ioat_chan: IOAT DMA channel handle
 326  */
 327 static void ioat_dma_reset_channel(struct ioat_dma_chan *ioat_chan)
 328 {
 329         u32 chansts, chanerr;
 330
 331         if (!ioat_chan->used_desc.prev)
 332                 return;
 333
 334         chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 335         chansts = (ioat_chan->completion_virt->low
 336                                         & IOAT_CHANSTS_DMA_TRANSFER_STATUS);
 337         if (chanerr) {
 338                 dev_err(&ioat_chan->device->pdev->dev,
 339                         "chan%d, CHANSTS = 0x%08x CHANERR = 0x%04x, clearing\n",
 340                         chan_num(ioat_chan), chansts, chanerr);
 341                 writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 342         }
 343
 344         /*
 345          * whack it upside the head with a reset
 346          * and wait for things to settle out.
 347          * force the pending count to a really big negative
 348          * to make sure no one forces an issue_pending
 349          * while we're waiting.
 350          */
 351
 352         spin_lock_bh(&ioat_chan->desc_lock);
 353         ioat_chan->pending = INT_MIN;
 354         writeb(IOAT_CHANCMD_RESET,
 355                ioat_chan->reg_base
 356                + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
 357         spin_unlock_bh(&ioat_chan->desc_lock);
 358
 359         /* schedule the 2nd half instead of sleeping a long time */
 360         schedule_delayed_work(&ioat_chan->work, RESET_DELAY);
 361 }
 362
 363 /**
 364  * ioat_dma_chan_watchdog - watch for stuck channels
 365  */
 366 static void ioat_dma_chan_watchdog(struct work_struct *work)
 367 {
 368         struct ioatdma_device *device =
 369                 container_of(work, struct ioatdma_device, work.work);
 370         struct ioat_dma_chan *ioat_chan;
 371         int i;
 372
 373         union {
 374                 u64 full;
 375                 struct {
 376                         u32 low;
 377                         u32 high;
 378                 };
 379         } completion_hw;
 380         unsigned long compl_desc_addr_hw;
 381
 382         for (i = 0; i < device->common.chancnt; i++) {
 383                 ioat_chan = ioat_lookup_chan_by_index(device, i);
 384
 385                 if (ioat_chan->device->version == IOAT_VER_1_2
 386                         /* have we started processing anything yet */
 387                     && ioat_chan->last_completion
 388                         /* have we completed any since last watchdog cycle? */
 389                     && (ioat_chan->last_completion ==
 390                                 ioat_chan->watchdog_completion)
 391                         /* has TCP stuck on one cookie since last watchdog? */
 392                     && (ioat_chan->watchdog_tcp_cookie ==
 393                                 ioat_chan->watchdog_last_tcp_cookie)
 394                     && (ioat_chan->watchdog_tcp_cookie !=
 395                                 ioat_chan->completed_cookie)
 396                         /* is there something in the chain to be processed? */
 397                         /* CB1 chain always has at least the last one processed */
 398                     && (ioat_chan->used_desc.prev != ioat_chan->used_desc.next)
 399                     && ioat_chan->pending == 0) {
 400
 401                         /*
 402                          * check CHANSTS register for completed
 403                          * descriptor address.
 404                          * if it is different than completion writeback,
 405                          * it is not zero
 406                          * and it has changed since the last watchdog
 407                          *     we can assume that channel
 408                          *     is still working correctly
 409                          *     and the problem is in completion writeback.
 410                          *     update completion writeback
 411                          *     with actual CHANSTS value
 412                          * else
 413                          *     try resetting the channel
 414                          */
 415
 416                         completion_hw.low = readl(ioat_chan->reg_base +
 417                                 IOAT_CHANSTS_OFFSET_LOW(ioat_chan->device->version));
 418                         completion_hw.high = readl(ioat_chan->reg_base +
 419                                 IOAT_CHANSTS_OFFSET_HIGH(ioat_chan->device->version));
 420 #if (BITS_PER_LONG == 64)
 421                         compl_desc_addr_hw =
 422                                 completion_hw.full
 423                                 & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
 424 #else
 425                         compl_desc_addr_hw =
 426                                 completion_hw.low & IOAT_LOW_COMPLETION_MASK;
 427 #endif
 428
 429                         if ((compl_desc_addr_hw != 0)
 430                            && (compl_desc_addr_hw != ioat_chan->watchdog_completion)
 431                            && (compl_desc_addr_hw != ioat_chan->last_compl_desc_addr_hw)) {
 432                                 ioat_chan->last_compl_desc_addr_hw = compl_desc_addr_hw;
 433                                 ioat_chan->completion_virt->low = completion_hw.low;
 434                                 ioat_chan->completion_virt->high = completion_hw.high;
 435                         } else {
 436                                 ioat_dma_reset_channel(ioat_chan);
 437                                 ioat_chan->watchdog_completion = 0;
 438                                 ioat_chan->last_compl_desc_addr_hw = 0;
 439                         }
 440
 441                 /*
 442                  * for version 2.0 if there are descriptors yet to be processed
 443                  * and the last completed hasn't changed since the last watchdog
 444                  *      if they haven't hit the pending level
 445                  *          issue the pending to push them through
 446                  *      else
 447                  *          try resetting the channel
 448                  */
 449                 } else if (ioat_chan->device->version == IOAT_VER_2_0
 450                     && ioat_chan->used_desc.prev
 451                     && ioat_chan->last_completion
 452                     && ioat_chan->last_completion == ioat_chan->watchdog_completion) {
 453
 454                         if (ioat_chan->pending < ioat_pending_level)
 455                                 ioat2_dma_memcpy_issue_pending(&ioat_chan->common);
 456                         else {
 457                                 ioat_dma_reset_channel(ioat_chan);
 458                                 ioat_chan->watchdog_completion = 0;
 459                         }
 460                 } else {
 461                         ioat_chan->last_compl_desc_addr_hw = 0;
 462                         ioat_chan->watchdog_completion
 463                                         = ioat_chan->last_completion;
 464                 }
 465
 466                 ioat_chan->watchdog_last_tcp_cookie =
 467                         ioat_chan->watchdog_tcp_cookie;
 468         }
 469
 470         schedule_delayed_work(&device->work, WATCHDOG_DELAY);
 471 }
 472
 473 static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx)
 474 {
 475         struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan);
 476         struct ioat_desc_sw *first = tx_to_ioat_desc(tx);
 477         struct ioat_desc_sw *prev, *new;
 478         struct ioat_dma_descriptor *hw;
 479         dma_cookie_t cookie;
 480         LIST_HEAD(new_chain);
 481         u32 copy;
 482         size_t len;
 483         dma_addr_t src, dst;
 484         unsigned long orig_flags;
 485         unsigned int desc_count = 0;
 486
 487         /* src and dest and len are stored in the initial descriptor */
 488         len = first->len;
 489         src = first->src;
 490         dst = first->dst;
 491         orig_flags = first->async_tx.flags;
 492         new = first;
 493
 494         spin_lock_bh(&ioat_chan->desc_lock);
 495         prev = to_ioat_desc(ioat_chan->used_desc.prev);
 496         prefetch(prev->hw);
 497         do {
 498                 copy = min_t(size_t, len, ioat_chan->xfercap);
 499
 500                 async_tx_ack(&new->async_tx);
 501
 502                 hw = new->hw;
 503                 hw->size = copy;
 504                 hw->ctl = 0;
 505                 hw->src_addr = src;
 506                 hw->dst_addr = dst;
 507                 hw->next = 0;
 508
 509                 /* chain together the physical address list for the HW */
 510                 wmb();
 511                 prev->hw->next = (u64) new->async_tx.phys;
 512
 513                 len -= copy;
 514                 dst += copy;
 515                 src += copy;
 516
 517                 list_add_tail(&new->node, &new_chain);
 518                 desc_count++;
 519                 prev = new;
 520         } while (len && (new = ioat1_dma_get_next_descriptor(ioat_chan)));
 521
 522         if (!new) {
 523                 dev_err(&ioat_chan->device->pdev->dev,
 524                         "tx submit failed\n");
 525                 spin_unlock_bh(&ioat_chan->desc_lock);
 526                 return -ENOMEM;
 527         }
 528
 529         hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
 530         if (first->async_tx.callback) {
 531                 hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN;
 532                 if (first != new) {
 533                         /* move callback into to last desc */
 534                         new->async_tx.callback = first->async_tx.callback;
 535                         new->async_tx.callback_param
 536                                         = first->async_tx.callback_param;
 537                         first->async_tx.callback = NULL;
 538                         first->async_tx.callback_param = NULL;
 539                 }
 540         }
 541
 542         new->tx_cnt = desc_count;
 543         new->async_tx.flags = orig_flags; /* client is in control of this ack */
 544
 545         /* store the original values for use in later cleanup */
 546         if (new != first) {
 547                 new->src = first->src;
 548                 new->dst = first->dst;
 549                 new->len = first->len;
 550         }
 551
 552         /* cookie incr and addition to used_list must be atomic */
 553         cookie = ioat_chan->common.cookie;
 554         cookie++;
 555         if (cookie < 0)
 556                 cookie = 1;
 557         ioat_chan->common.cookie = new->async_tx.cookie = cookie;
 558
 559         /* write address into NextDescriptor field of last desc in chain */
 560         to_ioat_desc(ioat_chan->used_desc.prev)->hw->next =
 561                                                         first->async_tx.phys;
 562         list_splice_tail(&new_chain, &ioat_chan->used_desc);
 563
 564         ioat_chan->dmacount += desc_count;
 565         ioat_chan->pending += desc_count;
 566         if (ioat_chan->pending >= ioat_pending_level)
 567                 __ioat1_dma_memcpy_issue_pending(ioat_chan);
 568         spin_unlock_bh(&ioat_chan->desc_lock);
 569
 570         return cookie;
 571 }
 572
 573 static dma_cookie_t ioat2_tx_submit(struct dma_async_tx_descriptor *tx)
 574 {
 575         struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan);
 576         struct ioat_desc_sw *first = tx_to_ioat_desc(tx);
 577         struct ioat_desc_sw *new;
 578         struct ioat_dma_descriptor *hw;
 579         dma_cookie_t cookie;
 580         u32 copy;
 581         size_t len;
 582         dma_addr_t src, dst;
 583         unsigned long orig_flags;
 584         unsigned int desc_count = 0;
 585
 586         /* src and dest and len are stored in the initial descriptor */
 587         len = first->len;
 588         src = first->src;
 589         dst = first->dst;
 590         orig_flags = first->async_tx.flags;
 591         new = first;
 592
 593         /*
 594          * ioat_chan->desc_lock is still in force in version 2 path
 595          * it gets unlocked at end of this function
 596          */
 597         do {
 598                 copy = min_t(size_t, len, ioat_chan->xfercap);
 599
 600                 async_tx_ack(&new->async_tx);
 601
 602                 hw = new->hw;
 603                 hw->size = copy;
 604                 hw->ctl = 0;
 605                 hw->src_addr = src;
 606                 hw->dst_addr = dst;
 607
 608                 len -= copy;
 609                 dst += copy;
 610                 src += copy;
 611                 desc_count++;
 612         } while (len && (new = ioat2_dma_get_next_descriptor(ioat_chan)));
 613
 614         if (!new) {
 615                 dev_err(&ioat_chan->device->pdev->dev,
 616                         "tx submit failed\n");
 617                 spin_unlock_bh(&ioat_chan->desc_lock);
 618                 return -ENOMEM;
 619         }
 620
 621         hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
 622         if (first->async_tx.callback) {
 623                 hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN;
 624                 if (first != new) {
 625                         /* move callback into to last desc */
 626                         new->async_tx.callback = first->async_tx.callback;
 627                         new->async_tx.callback_param
 628                                         = first->async_tx.callback_param;
 629                         first->async_tx.callback = NULL;
 630                         first->async_tx.callback_param = NULL;
 631                 }
 632         }
 633
 634         new->tx_cnt = desc_count;
 635         new->async_tx.flags = orig_flags; /* client is in control of this ack */
 636
 637         /* store the original values for use in later cleanup */
 638         if (new != first) {
 639                 new->src = first->src;
 640                 new->dst = first->dst;
 641                 new->len = first->len;
 642         }
 643
 644         /* cookie incr and addition to used_list must be atomic */
 645         cookie = ioat_chan->common.cookie;
 646         cookie++;
 647         if (cookie < 0)
 648                 cookie = 1;
 649         ioat_chan->common.cookie = new->async_tx.cookie = cookie;
 650
 651         ioat_chan->dmacount += desc_count;
 652         ioat_chan->pending += desc_count;
 653         if (ioat_chan->pending >= ioat_pending_level)
 654                 __ioat2_dma_memcpy_issue_pending(ioat_chan);
 655         spin_unlock_bh(&ioat_chan->desc_lock);
 656
 657         return cookie;
 658 }
 659
 660 /**
 661  * ioat_dma_alloc_descriptor - allocate and return a sw and hw descriptor pair
 662  * @ioat_chan: the channel supplying the memory pool for the descriptors
 663  * @flags: allocation flags
 664  */
 665 static struct ioat_desc_sw *ioat_dma_alloc_descriptor(
 666                                         struct ioat_dma_chan *ioat_chan,
 667                                         gfp_t flags)
 668 {
 669         struct ioat_dma_descriptor *desc;
 670         struct ioat_desc_sw *desc_sw;
 671         struct ioatdma_device *ioatdma_device;
 672         dma_addr_t phys;
 673
 674         ioatdma_device = to_ioatdma_device(ioat_chan->common.device);
 675         desc = pci_pool_alloc(ioatdma_device->dma_pool, flags, &phys);
 676         if (unlikely(!desc))
 677                 return NULL;
 678
 679         desc_sw = kzalloc(sizeof(*desc_sw), flags);
 680         if (unlikely(!desc_sw)) {
 681                 pci_pool_free(ioatdma_device->dma_pool, desc, phys);
 682                 return NULL;
 683         }
 684
 685         memset(desc, 0, sizeof(*desc));
 686         dma_async_tx_descriptor_init(&desc_sw->async_tx, &ioat_chan->common);
 687         switch (ioat_chan->device->version) {
 688         case IOAT_VER_1_2:
 689                 desc_sw->async_tx.tx_submit = ioat1_tx_submit;
 690                 break;
 691         case IOAT_VER_2_0:
 692         case IOAT_VER_3_0:
 693                 desc_sw->async_tx.tx_submit = ioat2_tx_submit;
 694                 break;
 695         }
 696
 697         desc_sw->hw = desc;
 698         desc_sw->async_tx.phys = phys;
 699
 700         return desc_sw;
 701 }
 702
 703 static int ioat_initial_desc_count = 256;
 704 module_param(ioat_initial_desc_count, int, 0644);
 705 MODULE_PARM_DESC(ioat_initial_desc_count,
 706                  "initial descriptors per channel (default: 256)");
 707
 708 /**
 709  * ioat2_dma_massage_chan_desc - link the descriptors into a circle
 710  * @ioat_chan: the channel to be massaged
 711  */
 712 static void ioat2_dma_massage_chan_desc(struct ioat_dma_chan *ioat_chan)
 713 {
 714         struct ioat_desc_sw *desc, *_desc;
 715
 716         /* setup used_desc */
 717         ioat_chan->used_desc.next = ioat_chan->free_desc.next;
 718         ioat_chan->used_desc.prev = NULL;
 719
 720         /* pull free_desc out of the circle so that every node is a hw
 721          * descriptor, but leave it pointing to the list
 722          */
 723         ioat_chan->free_desc.prev->next = ioat_chan->free_desc.next;
 724         ioat_chan->free_desc.next->prev = ioat_chan->free_desc.prev;
 725
 726         /* circle link the hw descriptors */
 727         desc = to_ioat_desc(ioat_chan->free_desc.next);
 728         desc->hw->next = to_ioat_desc(desc->node.next)->async_tx.phys;
 729         list_for_each_entry_safe(desc, _desc, ioat_chan->free_desc.next, node) {
 730                 desc->hw->next = to_ioat_desc(desc->node.next)->async_tx.phys;
 731         }
 732 }
 733
 734 /**
 735  * ioat_dma_alloc_chan_resources - returns the number of allocated descriptors
 736  * @chan: the channel to be filled out
 737  */
 738 static int ioat_dma_alloc_chan_resources(struct dma_chan *chan)
 739 {
 740         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 741         struct ioat_desc_sw *desc;
 742         u16 chanctrl;
 743         u32 chanerr;
 744         int i;
 745         LIST_HEAD(tmp_list);
 746
 747         /* have we already been set up? */
 748         if (!list_empty(&ioat_chan->free_desc))
 749                 return ioat_chan->desccount;
 750
 751         /* Setup register to interrupt and write completion status on error */
 752         chanctrl = IOAT_CHANCTRL_ERR_INT_EN |
 753                 IOAT_CHANCTRL_ANY_ERR_ABORT_EN |
 754                 IOAT_CHANCTRL_ERR_COMPLETION_EN;
 755         writew(chanctrl, ioat_chan->reg_base + IOAT_CHANCTRL_OFFSET);
 756
 757         chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 758         if (chanerr) {
 759                 dev_err(&ioat_chan->device->pdev->dev,
 760                         "CHANERR = %x, clearing\n", chanerr);
 761                 writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 762         }
 763
 764         /* Allocate descriptors */
 765         for (i = 0; i < ioat_initial_desc_count; i++) {
 766                 desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_KERNEL);
 767                 if (!desc) {
 768                         dev_err(&ioat_chan->device->pdev->dev,
 769                                 "Only %d initial descriptors\n", i);
 770                         break;
 771                 }
 772                 list_add_tail(&desc->node, &tmp_list);
 773         }
 774         spin_lock_bh(&ioat_chan->desc_lock);
 775         ioat_chan->desccount = i;
 776         list_splice(&tmp_list, &ioat_chan->free_desc);
 777         if (ioat_chan->device->version != IOAT_VER_1_2)
 778                 ioat2_dma_massage_chan_desc(ioat_chan);
 779         spin_unlock_bh(&ioat_chan->desc_lock);
 780
 781         /* allocate a completion writeback area */
 782         /* doing 2 32bit writes to mmio since 1 64b write doesn't work */
 783         ioat_chan->completion_virt =
 784                 pci_pool_alloc(ioat_chan->device->completion_pool,
 785                                GFP_KERNEL,
 786                                &ioat_chan->completion_addr);
 787         memset(ioat_chan->completion_virt, 0,
 788                sizeof(*ioat_chan->completion_virt));
 789         writel(((u64) ioat_chan->completion_addr) & 0x00000000FFFFFFFF,
 790                ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
 791         writel(((u64) ioat_chan->completion_addr) >> 32,
 792                ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
 793
 794         tasklet_enable(&ioat_chan->cleanup_task);
 795         ioat_dma_start_null_desc(ioat_chan);  /* give chain to dma device */
 796         return ioat_chan->desccount;
 797 }
 798
 799 /**
 800  * ioat_dma_free_chan_resources - release all the descriptors
 801  * @chan: the channel to be cleaned
 802  */
 803 static void ioat_dma_free_chan_resources(struct dma_chan *chan)
 804 {
 805         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 806         struct ioatdma_device *ioatdma_device = to_ioatdma_device(chan->device);
 807         struct ioat_desc_sw *desc, *_desc;
 808         int in_use_descs = 0;
 809
 810         /* Before freeing channel resources first check
 811          * if they have been previously allocated for this channel.
 812          */
 813         if (ioat_chan->desccount == 0)
 814                 return;
 815
 816         tasklet_disable(&ioat_chan->cleanup_task);
 817         ioat_dma_memcpy_cleanup(ioat_chan);
 818
 819         /* Delay 100ms after reset to allow internal DMA logic to quiesce
 820          * before removing DMA descriptor resources.
 821          */
 822         writeb(IOAT_CHANCMD_RESET,
 823                ioat_chan->reg_base
 824                         + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
 825         mdelay(100);
 826
 827         spin_lock_bh(&ioat_chan->desc_lock);
 828         switch (ioat_chan->device->version) {
 829         case IOAT_VER_1_2:
 830                 list_for_each_entry_safe(desc, _desc,
 831                                          &ioat_chan->used_desc, node) {
 832                         in_use_descs++;
 833                         list_del(&desc->node);
 834                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 835                                       desc->async_tx.phys);
 836                         kfree(desc);
 837                 }
 838                 list_for_each_entry_safe(desc, _desc,
 839                                          &ioat_chan->free_desc, node) {
 840                         list_del(&desc->node);
 841                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 842                                       desc->async_tx.phys);
 843                         kfree(desc);
 844                 }
 845                 break;
 846         case IOAT_VER_2_0:
 847         case IOAT_VER_3_0:
 848                 list_for_each_entry_safe(desc, _desc,
 849                                          ioat_chan->free_desc.next, node) {
 850                         list_del(&desc->node);
 851                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 852                                       desc->async_tx.phys);
 853                         kfree(desc);
 854                 }
 855                 desc = to_ioat_desc(ioat_chan->free_desc.next);
 856                 pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 857                               desc->async_tx.phys);
 858                 kfree(desc);
 859                 INIT_LIST_HEAD(&ioat_chan->free_desc);
 860                 INIT_LIST_HEAD(&ioat_chan->used_desc);
 861                 break;
 862         }
 863         spin_unlock_bh(&ioat_chan->desc_lock);
 864
 865         pci_pool_free(ioatdma_device->completion_pool,
 866                       ioat_chan->completion_virt,
 867                       ioat_chan->completion_addr);
 868
 869         /* one is ok since we left it on there on purpose */
 870         if (in_use_descs > 1)
 871                 dev_err(&ioat_chan->device->pdev->dev,
 872                         "Freeing %d in use descriptors!\n",
 873                         in_use_descs - 1);
 874
 875         ioat_chan->last_completion = ioat_chan->completion_addr = 0;
 876         ioat_chan->pending = 0;
 877         ioat_chan->dmacount = 0;
 878         ioat_chan->desccount = 0;
 879         ioat_chan->watchdog_completion = 0;
 880         ioat_chan->last_compl_desc_addr_hw = 0;
 881         ioat_chan->watchdog_tcp_cookie =
 882                 ioat_chan->watchdog_last_tcp_cookie = 0;
 883 }
 884
 885 /**
 886  * ioat_dma_get_next_descriptor - return the next available descriptor
 887  * @ioat_chan: IOAT DMA channel handle
 888  *
 889  * Gets the next descriptor from the chain, and must be called with the
 890  * channel's desc_lock held.  Allocates more descriptors if the channel
 891  * has run out.
 892  */
 893 static struct ioat_desc_sw *
 894 ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
 895 {
 896         struct ioat_desc_sw *new;
 897
 898         if (!list_empty(&ioat_chan->free_desc)) {
 899                 new = to_ioat_desc(ioat_chan->free_desc.next);
 900                 list_del(&new->node);
 901         } else {
 902                 /* try to get another desc */
 903                 new = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
 904                 if (!new) {
 905                         dev_err(&ioat_chan->device->pdev->dev,
 906                                 "alloc failed\n");
 907                         return NULL;
 908                 }
 909         }
 910
 911         prefetch(new->hw);
 912         return new;
 913 }
 914
 915 static struct ioat_desc_sw *
 916 ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
 917 {
 918         struct ioat_desc_sw *new;
 919
 920         /*
 921          * used.prev points to where to start processing
 922          * used.next points to next free descriptor
 923          * if used.prev == NULL, there are none waiting to be processed
 924          * if used.next == used.prev.prev, there is only one free descriptor,
 925          *      and we need to use it to as a noop descriptor before
 926          *      linking in a new set of descriptors, since the device
 927          *      has probably already read the pointer to it
 928          */
 929         if (ioat_chan->used_desc.prev &&
 930             ioat_chan->used_desc.next == ioat_chan->used_desc.prev->prev) {
 931
 932                 struct ioat_desc_sw *desc;
 933                 struct ioat_desc_sw *noop_desc;
 934                 int i;
 935
 936                 /* set up the noop descriptor */
 937                 noop_desc = to_ioat_desc(ioat_chan->used_desc.next);
 938                 /* set size to non-zero value (channel returns error when size is 0) */
 939                 noop_desc->hw->size = NULL_DESC_BUFFER_SIZE;
 940                 noop_desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL;
 941                 noop_desc->hw->src_addr = 0;
 942                 noop_desc->hw->dst_addr = 0;
 943
 944                 ioat_chan->used_desc.next = ioat_chan->used_desc.next->next;
 945                 ioat_chan->pending++;
 946                 ioat_chan->dmacount++;
 947
 948                 /* try to get a few more descriptors */
 949                 for (i = 16; i; i--) {
 950                         desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
 951                         if (!desc) {
 952                                 dev_err(&ioat_chan->device->pdev->dev,
 953                                         "alloc failed\n");
 954                                 break;
 955                         }
 956                         list_add_tail(&desc->node, ioat_chan->used_desc.next);
 957
 958                         desc->hw->next
 959                                 = to_ioat_desc(desc->node.next)->async_tx.phys;
 960                         to_ioat_desc(desc->node.prev)->hw->next
 961                                 = desc->async_tx.phys;
 962                         ioat_chan->desccount++;
 963                 }
 964
 965                 ioat_chan->used_desc.next = noop_desc->node.next;
 966         }
 967         new = to_ioat_desc(ioat_chan->used_desc.next);
 968         prefetch(new);
 969         ioat_chan->used_desc.next = new->node.next;
 970
 971         if (ioat_chan->used_desc.prev == NULL)
 972                 ioat_chan->used_desc.prev = &new->node;
 973
 974         prefetch(new->hw);
 975         return new;
 976 }
 977
 978 static struct ioat_desc_sw *ioat_dma_get_next_descriptor(
 979                                                 struct ioat_dma_chan *ioat_chan)
 980 {
 981         if (!ioat_chan)
 982                 return NULL;
 983
 984         switch (ioat_chan->device->version) {
 985         case IOAT_VER_1_2:
 986                 return ioat1_dma_get_next_descriptor(ioat_chan);
 987         case IOAT_VER_2_0:
 988         case IOAT_VER_3_0:
 989                 return ioat2_dma_get_next_descriptor(ioat_chan);
 990         }
 991         return NULL;
 992 }
 993
 994 static struct dma_async_tx_descriptor *ioat1_dma_prep_memcpy(
 995                                                 struct dma_chan *chan,
 996                                                 dma_addr_t dma_dest,
 997                                                 dma_addr_t dma_src,
 998                                                 size_t len,
 999                                                 unsigned long flags)
1000 {
1001         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1002         struct ioat_desc_sw *new;
1003
1004         spin_lock_bh(&ioat_chan->desc_lock);
1005         new = ioat_dma_get_next_descriptor(ioat_chan);
1006         spin_unlock_bh(&ioat_chan->desc_lock);
1007
1008         if (new) {
1009                 new->len = len;
1010                 new->dst = dma_dest;
1011                 new->src = dma_src;
1012                 new->async_tx.flags = flags;
1013                 return &new->async_tx;
1014         } else {
1015                 dev_err(&ioat_chan->device->pdev->dev,
1016                         "chan%d - get_next_desc failed: %d descs waiting, %d total desc\n",
1017                         chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount);
1018                 return NULL;
1019         }
1020 }
1021
1022 static struct dma_async_tx_descriptor *ioat2_dma_prep_memcpy(
1023                                                 struct dma_chan *chan,
1024                                                 dma_addr_t dma_dest,
1025                                                 dma_addr_t dma_src,
1026                                                 size_t len,
1027                                                 unsigned long flags)
1028 {
1029         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1030         struct ioat_desc_sw *new;
1031
1032         spin_lock_bh(&ioat_chan->desc_lock);
1033         new = ioat2_dma_get_next_descriptor(ioat_chan);
1034
1035         /*
1036          * leave ioat_chan->desc_lock set in ioat 2 path
1037          * it will get unlocked at end of tx_submit
1038          */
1039
1040         if (new) {
1041                 new->len = len;
1042                 new->dst = dma_dest;
1043                 new->src = dma_src;
1044                 new->async_tx.flags = flags;
1045                 return &new->async_tx;
1046         } else {
1047                 spin_unlock_bh(&ioat_chan->desc_lock);
1048                 dev_err(&ioat_chan->device->pdev->dev,
1049                         "chan%d - get_next_desc failed: %d descs waiting, %d total desc\n",
1050                         chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount);
1051                 return NULL;
1052         }
1053 }
1054
1055 static void ioat_dma_cleanup_tasklet(unsigned long data)
1056 {
1057         struct ioat_dma_chan *chan = (void *)data;
1058         ioat_dma_memcpy_cleanup(chan);
1059         writew(IOAT_CHANCTRL_INT_DISABLE,
1060                chan->reg_base + IOAT_CHANCTRL_OFFSET);
1061 }
1062
1063 static void
1064 ioat_dma_unmap(struct ioat_dma_chan *ioat_chan, struct ioat_desc_sw *desc)
1065 {
1066         if (!(desc->async_tx.flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
1067                 if (desc->async_tx.flags & DMA_COMPL_DEST_UNMAP_SINGLE)
1068                         pci_unmap_single(ioat_chan->device->pdev,
1069                                          pci_unmap_addr(desc, dst),
1070                                          pci_unmap_len(desc, len),
1071                                          PCI_DMA_FROMDEVICE);
1072                 else
1073                         pci_unmap_page(ioat_chan->device->pdev,
1074                                        pci_unmap_addr(desc, dst),
1075                                        pci_unmap_len(desc, len),
1076                                        PCI_DMA_FROMDEVICE);
1077         }
1078
1079         if (!(desc->async_tx.flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
1080                 if (desc->async_tx.flags & DMA_COMPL_SRC_UNMAP_SINGLE)
1081                         pci_unmap_single(ioat_chan->device->pdev,
1082                                          pci_unmap_addr(desc, src),
1083                                          pci_unmap_len(desc, len),
1084                                          PCI_DMA_TODEVICE);
1085                 else
1086                         pci_unmap_page(ioat_chan->device->pdev,
1087                                        pci_unmap_addr(desc, src),
1088                                        pci_unmap_len(desc, len),
1089                                        PCI_DMA_TODEVICE);
1090         }
1091 }
1092
1093 /**
1094  * ioat_dma_memcpy_cleanup - cleanup up finished descriptors
1095  * @chan: ioat channel to be cleaned up
1096  */
1097 static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan)
1098 {
1099         unsigned long phys_complete;
1100         struct ioat_desc_sw *desc, *_desc;
1101         dma_cookie_t cookie = 0;
1102         unsigned long desc_phys;
1103         struct ioat_desc_sw *latest_desc;
1104
1105         prefetch(ioat_chan->completion_virt);
1106
1107         if (!spin_trylock_bh(&ioat_chan->cleanup_lock))
1108                 return;
1109
1110         /* The completion writeback can happen at any time,
1111            so reads by the driver need to be atomic operations
1112            The descriptor physical addresses are limited to 32-bits
1113            when the CPU can only do a 32-bit mov */
1114
1115 #if (BITS_PER_LONG == 64)
1116         phys_complete =
1117                 ioat_chan->completion_virt->full
1118                 & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
1119 #else
1120         phys_complete =
1121                 ioat_chan->completion_virt->low & IOAT_LOW_COMPLETION_MASK;
1122 #endif
1123
1124         if ((ioat_chan->completion_virt->full
1125                 & IOAT_CHANSTS_DMA_TRANSFER_STATUS) ==
1126                                 IOAT_CHANSTS_DMA_TRANSFER_STATUS_HALTED) {
1127                 dev_err(&ioat_chan->device->pdev->dev,
1128                         "Channel halted, chanerr = %x\n",
1129                         readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET));
1130
1131                 /* TODO do something to salvage the situation */
1132         }
1133
1134         if (phys_complete == ioat_chan->last_completion) {
1135                 spin_unlock_bh(&ioat_chan->cleanup_lock);
1136                 /*
1137                  * perhaps we're stuck so hard that the watchdog can't go off?
1138                  * try to catch it after 2 seconds
1139                  */
1140                 if (ioat_chan->device->version != IOAT_VER_3_0) {
1141                         if (time_after(jiffies,
1142                                        ioat_chan->last_completion_time + HZ*WATCHDOG_DELAY)) {
1143                                 ioat_dma_chan_watchdog(&(ioat_chan->device->work.work));
1144                                 ioat_chan->last_completion_time = jiffies;
1145                         }
1146                 }
1147                 return;
1148         }
1149         ioat_chan->last_completion_time = jiffies;
1150
1151         cookie = 0;
1152         if (!spin_trylock_bh(&ioat_chan->desc_lock)) {
1153                 spin_unlock_bh(&ioat_chan->cleanup_lock);
1154                 return;
1155         }
1156
1157         switch (ioat_chan->device->version) {
1158         case IOAT_VER_1_2:
1159                 list_for_each_entry_safe(desc, _desc,
1160                                          &ioat_chan->used_desc, node) {
1161
1162                         /*
1163                          * Incoming DMA requests may use multiple descriptors,
1164                          * due to exceeding xfercap, perhaps. If so, only the
1165                          * last one will have a cookie, and require unmapping.
1166                          */
1167                         if (desc->async_tx.cookie) {
1168                                 cookie = desc->async_tx.cookie;
1169                                 ioat_dma_unmap(ioat_chan, desc);
1170                                 if (desc->async_tx.callback) {
1171                                         desc->async_tx.callback(desc->async_tx.callback_param);
1172                                         desc->async_tx.callback = NULL;
1173                                 }
1174                         }
1175
1176                         if (desc->async_tx.phys != phys_complete) {
1177                                 /*
1178                                  * a completed entry, but not the last, so clean
1179                                  * up if the client is done with the descriptor
1180                                  */
1181                                 if (async_tx_test_ack(&desc->async_tx)) {
1182                                         list_move_tail(&desc->node,
1183                                                        &ioat_chan->free_desc);
1184                                 } else
1185                                         desc->async_tx.cookie = 0;
1186                         } else {
1187                                 /*
1188                                  * last used desc. Do not remove, so we can
1189                                  * append from it, but don't look at it next
1190                                  * time, either
1191                                  */
1192                                 desc->async_tx.cookie = 0;
1193
1194                                 /* TODO check status bits? */
1195                                 break;
1196                         }
1197                 }
1198                 break;
1199         case IOAT_VER_2_0:
1200         case IOAT_VER_3_0:
1201                 /* has some other thread has already cleaned up? */
1202                 if (ioat_chan->used_desc.prev == NULL)
1203                         break;
1204
1205                 /* work backwards to find latest finished desc */
1206                 desc = to_ioat_desc(ioat_chan->used_desc.next);
1207                 latest_desc = NULL;
1208                 do {
1209                         desc = to_ioat_desc(desc->node.prev);
1210                         desc_phys = (unsigned long)desc->async_tx.phys
1211                                        & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
1212                         if (desc_phys == phys_complete) {
1213                                 latest_desc = desc;
1214                                 break;
1215                         }
1216                 } while (&desc->node != ioat_chan->used_desc.prev);
1217
1218                 if (latest_desc != NULL) {
1219
1220                         /* work forwards to clear finished descriptors */
1221                         for (desc = to_ioat_desc(ioat_chan->used_desc.prev);
1222                              &desc->node != latest_desc->node.next &&
1223                              &desc->node != ioat_chan->used_desc.next;
1224                              desc = to_ioat_desc(desc->node.next)) {
1225                                 if (desc->async_tx.cookie) {
1226                                         cookie = desc->async_tx.cookie;
1227                                         desc->async_tx.cookie = 0;
1228                                         ioat_dma_unmap(ioat_chan, desc);
1229                                         if (desc->async_tx.callback) {
1230                                                 desc->async_tx.callback(desc->async_tx.callback_param);
1231                                                 desc->async_tx.callback = NULL;
1232                                         }
1233                                 }
1234                         }
1235
1236                         /* move used.prev up beyond those that are finished */
1237                         if (&desc->node == ioat_chan->used_desc.next)
1238                                 ioat_chan->used_desc.prev = NULL;
1239                         else
1240                                 ioat_chan->used_desc.prev = &desc->node;
1241                 }
1242                 break;
1243         }
1244
1245         spin_unlock_bh(&ioat_chan->desc_lock);
1246
1247         ioat_chan->last_completion = phys_complete;
1248         if (cookie != 0)
1249                 ioat_chan->completed_cookie = cookie;
1250
1251         spin_unlock_bh(&ioat_chan->cleanup_lock);
1252 }
1253
1254 /**
1255  * ioat_dma_is_complete - poll the status of a IOAT DMA transaction
1256  * @chan: IOAT DMA channel handle
1257  * @cookie: DMA transaction identifier
1258  * @done: if not %NULL, updated with last completed transaction
1259  * @used: if not %NULL, updated with last used transaction
1260  */
1261 static enum dma_status ioat_dma_is_complete(struct dma_chan *chan,
1262                                             dma_cookie_t cookie,
1263                                             dma_cookie_t *done,
1264                                             dma_cookie_t *used)
1265 {
1266         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1267         dma_cookie_t last_used;
1268         dma_cookie_t last_complete;
1269         enum dma_status ret;
1270
1271         last_used = chan->cookie;
1272         last_complete = ioat_chan->completed_cookie;
1273         ioat_chan->watchdog_tcp_cookie = cookie;
1274
1275         if (done)
1276                 *done = last_complete;
1277         if (used)
1278                 *used = last_used;
1279
1280         ret = dma_async_is_complete(cookie, last_complete, last_used);
1281         if (ret == DMA_SUCCESS)
1282                 return ret;
1283
1284         ioat_dma_memcpy_cleanup(ioat_chan);
1285
1286         last_used = chan->cookie;
1287         last_complete = ioat_chan->completed_cookie;
1288
1289         if (done)
1290                 *done = last_complete;
1291         if (used)
1292                 *used = last_used;
1293
1294         return dma_async_is_complete(cookie, last_complete, last_used);
1295 }
1296
1297 static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan)
1298 {
1299         struct ioat_desc_sw *desc;
1300
1301         spin_lock_bh(&ioat_chan->desc_lock);
1302
1303         desc = ioat_dma_get_next_descriptor(ioat_chan);
1304
1305         if (!desc) {
1306                 dev_err(&ioat_chan->device->pdev->dev,
1307                         "Unable to start null desc - get next desc failed\n");
1308                 spin_unlock_bh(&ioat_chan->desc_lock);
1309                 return;
1310         }
1311
1312         desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL
1313                                 | IOAT_DMA_DESCRIPTOR_CTL_INT_GN
1314                                 | IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
1315         /* set size to non-zero value (channel returns error when size is 0) */
1316         desc->hw->size = NULL_DESC_BUFFER_SIZE;
1317         desc->hw->src_addr = 0;
1318         desc->hw->dst_addr = 0;
1319         async_tx_ack(&desc->async_tx);
1320         switch (ioat_chan->device->version) {
1321         case IOAT_VER_1_2:
1322                 desc->hw->next = 0;
1323                 list_add_tail(&desc->node, &ioat_chan->used_desc);
1324
1325                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
1326                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_LOW);
1327                 writel(((u64) desc->async_tx.phys) >> 32,
1328                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_HIGH);
1329
1330                 writeb(IOAT_CHANCMD_START, ioat_chan->reg_base
1331                         + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
1332                 break;
1333         case IOAT_VER_2_0:
1334         case IOAT_VER_3_0:
1335                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
1336                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_LOW);
1337                 writel(((u64) desc->async_tx.phys) >> 32,
1338                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_HIGH);
1339
1340                 ioat_chan->dmacount++;
1341                 __ioat2_dma_memcpy_issue_pending(ioat_chan);
1342                 break;
1343         }
1344         spin_unlock_bh(&ioat_chan->desc_lock);
1345 }
1346
1347 /*
1348  * Perform a IOAT transaction to verify the HW works.
1349  */
1350 #define IOAT_TEST_SIZE 2000
1351
1352 static void ioat_dma_test_callback(void *dma_async_param)
1353 {
1354         struct completion *cmp = dma_async_param;
1355
1356         complete(cmp);
1357 }
1358
1359 /**
1360  * ioat_dma_self_test - Perform a IOAT transaction to verify the HW works.
1361  * @device: device to be tested
1362  */
1363 static int ioat_dma_self_test(struct ioatdma_device *device)
1364 {
1365         int i;
1366         u8 *src;
1367         u8 *dest;
1368         struct dma_chan *dma_chan;
1369         struct dma_async_tx_descriptor *tx;
1370         dma_addr_t dma_dest, dma_src;
1371         dma_cookie_t cookie;
1372         int err = 0;
1373         struct completion cmp;
1374         unsigned long tmo;
1375         unsigned long flags;
1376
1377         src = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
1378         if (!src)
1379                 return -ENOMEM;
1380         dest = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
1381         if (!dest) {
1382                 kfree(src);
1383                 return -ENOMEM;
1384         }
1385
1386         /* Fill in src buffer */
1387         for (i = 0; i < IOAT_TEST_SIZE; i++)
1388                 src[i] = (u8)i;
1389
1390         /* Start copy, using first DMA channel */
1391         dma_chan = container_of(device->common.channels.next,
1392                                 struct dma_chan,
1393                                 device_node);
1394         if (device->common.device_alloc_chan_resources(dma_chan) < 1) {
1395                 dev_err(&device->pdev->dev,
1396                         "selftest cannot allocate chan resource\n");
1397                 err = -ENODEV;
1398                 goto out;
1399         }
1400
1401         dma_src = dma_map_single(dma_chan->device->dev, src, IOAT_TEST_SIZE,
1402                                  DMA_TO_DEVICE);
1403         dma_dest = dma_map_single(dma_chan->device->dev, dest, IOAT_TEST_SIZE,
1404                                   DMA_FROM_DEVICE);
1405         flags = DMA_COMPL_SRC_UNMAP_SINGLE | DMA_COMPL_DEST_UNMAP_SINGLE;
1406         tx = device->common.device_prep_dma_memcpy(dma_chan, dma_dest, dma_src,
1407                                                    IOAT_TEST_SIZE, flags);
1408         if (!tx) {
1409                 dev_err(&device->pdev->dev,
1410                         "Self-test prep failed, disabling\n");
1411                 err = -ENODEV;
1412                 goto free_resources;
1413         }
1414
1415         async_tx_ack(tx);
1416         init_completion(&cmp);
1417         tx->callback = ioat_dma_test_callback;
1418         tx->callback_param = &cmp;
1419         cookie = tx->tx_submit(tx);
1420         if (cookie < 0) {
1421                 dev_err(&device->pdev->dev,
1422                         "Self-test setup failed, disabling\n");
1423                 err = -ENODEV;
1424                 goto free_resources;
1425         }
1426         device->common.device_issue_pending(dma_chan);
1427
1428         tmo = wait_for_completion_timeout(&cmp, msecs_to_jiffies(3000));
1429
1430         if (tmo == 0 ||
1431             device->common.device_is_tx_complete(dma_chan, cookie, NULL, NULL)
1432                                         != DMA_SUCCESS) {
1433                 dev_err(&device->pdev->dev,
1434                         "Self-test copy timed out, disabling\n");
1435                 err = -ENODEV;
1436                 goto free_resources;
1437         }
1438         if (memcmp(src, dest, IOAT_TEST_SIZE)) {
1439                 dev_err(&device->pdev->dev,
1440                         "Self-test copy failed compare, disabling\n");
1441                 err = -ENODEV;
1442                 goto free_resources;
1443         }
1444
1445 free_resources:
1446         device->common.device_free_chan_resources(dma_chan);
1447 out:
1448         kfree(src);
1449         kfree(dest);
1450         return err;
1451 }
1452
1453 static char ioat_interrupt_style[32] = "msix";
1454 module_param_string(ioat_interrupt_style, ioat_interrupt_style,
1455                     sizeof(ioat_interrupt_style), 0644);
1456 MODULE_PARM_DESC(ioat_interrupt_style,
1457                  "set ioat interrupt style: msix (default), "
1458                  "msix-single-vector, msi, intx)");
1459
1460 /**
1461  * ioat_dma_setup_interrupts - setup interrupt handler
1462  * @device: ioat device
1463  */
1464 static int ioat_dma_setup_interrupts(struct ioatdma_device *device)
1465 {
1466         struct ioat_dma_chan *ioat_chan;
1467         int err, i, j, msixcnt;
1468         u8 intrctrl = 0;
1469
1470         if (!strcmp(ioat_interrupt_style, "msix"))
1471                 goto msix;
1472         if (!strcmp(ioat_interrupt_style, "msix-single-vector"))
1473                 goto msix_single_vector;
1474         if (!strcmp(ioat_interrupt_style, "msi"))
1475                 goto msi;
1476         if (!strcmp(ioat_interrupt_style, "intx"))
1477                 goto intx;
1478         dev_err(&device->pdev->dev, "invalid ioat_interrupt_style %s\n",
1479                 ioat_interrupt_style);
1480         goto err_no_irq;
1481
1482 msix:
1483         /* The number of MSI-X vectors should equal the number of channels */
1484         msixcnt = device->common.chancnt;
1485         for (i = 0; i < msixcnt; i++)
1486                 device->msix_entries[i].entry = i;
1487
1488         err = pci_enable_msix(device->pdev, device->msix_entries, msixcnt);
1489         if (err < 0)
1490                 goto msi;
1491         if (err > 0)
1492                 goto msix_single_vector;
1493
1494         for (i = 0; i < msixcnt; i++) {
1495                 ioat_chan = ioat_lookup_chan_by_index(device, i);
1496                 err = request_irq(device->msix_entries[i].vector,
1497                                   ioat_dma_do_interrupt_msix,
1498                                   0, "ioat-msix", ioat_chan);
1499                 if (err) {
1500                         for (j = 0; j < i; j++) {
1501                                 ioat_chan =
1502                                         ioat_lookup_chan_by_index(device, j);
1503                                 free_irq(device->msix_entries[j].vector,
1504                                          ioat_chan);
1505                         }
1506                         goto msix_single_vector;
1507                 }
1508         }
1509         intrctrl |= IOAT_INTRCTRL_MSIX_VECTOR_CONTROL;
1510         device->irq_mode = msix_multi_vector;
1511         goto done;
1512
1513 msix_single_vector:
1514         device->msix_entries[0].entry = 0;
1515         err = pci_enable_msix(device->pdev, device->msix_entries, 1);
1516         if (err)
1517                 goto msi;
1518
1519         err = request_irq(device->msix_entries[0].vector, ioat_dma_do_interrupt,
1520                           0, "ioat-msix", device);
1521         if (err) {
1522                 pci_disable_msix(device->pdev);
1523                 goto msi;
1524         }
1525         device->irq_mode = msix_single_vector;
1526         goto done;
1527
1528 msi:
1529         err = pci_enable_msi(device->pdev);
1530         if (err)
1531                 goto intx;
1532
1533         err = request_irq(device->pdev->irq, ioat_dma_do_interrupt,
1534                           0, "ioat-msi", device);
1535         if (err) {
1536                 pci_disable_msi(device->pdev);
1537                 goto intx;
1538         }
1539         /*
1540          * CB 1.2 devices need a bit set in configuration space to enable MSI
1541          */
1542         if (device->version == IOAT_VER_1_2) {
1543                 u32 dmactrl;
1544                 pci_read_config_dword(device->pdev,
1545                                       IOAT_PCI_DMACTRL_OFFSET, &dmactrl);
1546                 dmactrl |= IOAT_PCI_DMACTRL_MSI_EN;
1547                 pci_write_config_dword(device->pdev,
1548                                        IOAT_PCI_DMACTRL_OFFSET, dmactrl);
1549         }
1550         device->irq_mode = msi;
1551         goto done;
1552
1553 intx:
1554         err = request_irq(device->pdev->irq, ioat_dma_do_interrupt,
1555                           IRQF_SHARED, "ioat-intx", device);
1556         if (err)
1557                 goto err_no_irq;
1558         device->irq_mode = intx;
1559
1560 done:
1561         intrctrl |= IOAT_INTRCTRL_MASTER_INT_EN;
1562         writeb(intrctrl, device->reg_base + IOAT_INTRCTRL_OFFSET);
1563         return 0;
1564
1565 err_no_irq:
1566         /* Disable all interrupt generation */
1567         writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
1568         dev_err(&device->pdev->dev, "no usable interrupts\n");
1569         device->irq_mode = none;
1570         return -1;
1571 }
1572
1573 /**
1574  * ioat_dma_remove_interrupts - remove whatever interrupts were set
1575  * @device: ioat device
1576  */
1577 static void ioat_dma_remove_interrupts(struct ioatdma_device *device)
1578 {
1579         struct ioat_dma_chan *ioat_chan;
1580         int i;
1581
1582         /* Disable all interrupt generation */
1583         writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
1584
1585         switch (device->irq_mode) {
1586         case msix_multi_vector:
1587                 for (i = 0; i < device->common.chancnt; i++) {
1588                         ioat_chan = ioat_lookup_chan_by_index(device, i);
1589                         free_irq(device->msix_entries[i].vector, ioat_chan);
1590                 }
1591                 pci_disable_msix(device->pdev);
1592                 break;
1593         case msix_single_vector:
1594                 free_irq(device->msix_entries[0].vector, device);
1595                 pci_disable_msix(device->pdev);
1596                 break;
1597         case msi:
1598                 free_irq(device->pdev->irq, device);
1599                 pci_disable_msi(device->pdev);
1600                 break;
1601         case intx:
1602                 free_irq(device->pdev->irq, device);
1603                 break;
1604         case none:
1605                 dev_warn(&device->pdev->dev,
1606                          "call to %s without interrupts setup\n", __func__);
1607         }
1608         device->irq_mode = none;
1609 }
1610
1611 struct ioatdma_device *ioat_dma_probe(struct pci_dev *pdev,
1612                                       void __iomem *iobase)
1613 {
1614         int err;
1615         struct ioatdma_device *device;
1616
1617         device = kzalloc(sizeof(*device), GFP_KERNEL);
1618         if (!device) {
1619                 err = -ENOMEM;
1620                 goto err_kzalloc;
1621         }
1622         device->pdev = pdev;
1623         device->reg_base = iobase;
1624         device->version = readb(device->reg_base + IOAT_VER_OFFSET);
1625
1626         /* DMA coherent memory pool for DMA descriptor allocations */
1627         device->dma_pool = pci_pool_create("dma_desc_pool", pdev,
1628                                            sizeof(struct ioat_dma_descriptor),
1629                                            64, 0);
1630         if (!device->dma_pool) {
1631                 err = -ENOMEM;
1632                 goto err_dma_pool;
1633         }
1634
1635         device->completion_pool = pci_pool_create("completion_pool", pdev,
1636                                                   sizeof(u64), SMP_CACHE_BYTES,
1637                                                   SMP_CACHE_BYTES);
1638         if (!device->completion_pool) {
1639                 err = -ENOMEM;
1640                 goto err_completion_pool;
1641         }
1642
1643         INIT_LIST_HEAD(&device->common.channels);
1644         ioat_dma_enumerate_channels(device);
1645
1646         device->common.device_alloc_chan_resources =
1647                                                 ioat_dma_alloc_chan_resources;
1648         device->common.device_free_chan_resources =
1649                                                 ioat_dma_free_chan_resources;
1650         device->common.dev = &pdev->dev;
1651
1652         dma_cap_set(DMA_MEMCPY, device->common.cap_mask);
1653         device->common.device_is_tx_complete = ioat_dma_is_complete;
1654         switch (device->version) {
1655         case IOAT_VER_1_2:
1656                 device->common.device_prep_dma_memcpy = ioat1_dma_prep_memcpy;
1657                 device->common.device_issue_pending =
1658                                                 ioat1_dma_memcpy_issue_pending;
1659                 break;
1660         case IOAT_VER_2_0:
1661         case IOAT_VER_3_0:
1662                 device->common.device_prep_dma_memcpy = ioat2_dma_prep_memcpy;
1663                 device->common.device_issue_pending =
1664                                                 ioat2_dma_memcpy_issue_pending;
1665                 break;
1666         }
1667
1668         dev_err(&device->pdev->dev,
1669                 "Intel(R) I/OAT DMA Engine found,"
1670                 " %d channels, device version 0x%02x, driver version %s\n",
1671                 device->common.chancnt, device->version, IOAT_DMA_VERSION);
1672
1673         if (!device->common.chancnt) {
1674                 dev_err(&device->pdev->dev,
1675                         "Intel(R) I/OAT DMA Engine problem found: "
1676                         "zero channels detected\n");
1677                 goto err_setup_interrupts;
1678         }
1679
1680         err = ioat_dma_setup_interrupts(device);
1681         if (err)
1682                 goto err_setup_interrupts;
1683
1684         err = ioat_dma_self_test(device);
1685         if (err)
1686                 goto err_self_test;
1687
1688         ioat_set_tcp_copy_break(device);
1689
1690         dma_async_device_register(&device->common);
1691
1692         if (device->version != IOAT_VER_3_0) {
1693                 INIT_DELAYED_WORK(&device->work, ioat_dma_chan_watchdog);
1694                 schedule_delayed_work(&device->work,
1695                                       WATCHDOG_DELAY);
1696         }
1697
1698         return device;
1699
1700 err_self_test:
1701         ioat_dma_remove_interrupts(device);
1702 err_setup_interrupts:
1703         pci_pool_destroy(device->completion_pool);
1704 err_completion_pool:
1705         pci_pool_destroy(device->dma_pool);
1706 err_dma_pool:
1707         kfree(device);
1708 err_kzalloc:
1709         dev_err(&pdev->dev,
1710                 "Intel(R) I/OAT DMA Engine initialization failed\n");
1711         return NULL;
1712 }
1713
1714 void ioat_dma_remove(struct ioatdma_device *device)
1715 {
1716         struct dma_chan *chan, *_chan;
1717         struct ioat_dma_chan *ioat_chan;
1718
1719         if (device->version != IOAT_VER_3_0)
1720                 cancel_delayed_work(&device->work);
1721
1722         ioat_dma_remove_interrupts(device);
1723
1724         dma_async_device_unregister(&device->common);
1725
1726         pci_pool_destroy(device->dma_pool);
1727         pci_pool_destroy(device->completion_pool);
1728
1729         iounmap(device->reg_base);
1730         pci_release_regions(device->pdev);
1731         pci_disable_device(device->pdev);
1732
1733         list_for_each_entry_safe(chan, _chan,
1734                                  &device->common.channels, device_node) {
1735                 ioat_chan = to_ioat_chan(chan);
1736                 list_del(&chan->device_node);
1737                 kfree(ioat_chan);
1738         }
1739         kfree(device);
1740 }
1741