arch/powerpc/platforms/iseries/irq.c

   1 /*
   2  * This module supports the iSeries PCI bus interrupt handling
   3  * Copyright (C) 20yy  <Robert L Holtorf> <IBM Corp>
   4  * Copyright (C) 2004-2005 IBM Corporation
   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:
  18  * Free Software Foundation, Inc.,
  19  * 59 Temple Place, Suite 330,
  20  * Boston, MA  02111-1307  USA
  21  *
  22  * Change Activity:
  23  *   Created, December 13, 2000 by Wayne Holm
  24  * End Change Activity
  25  */
  26 #include <linux/pci.h>
  27 #include <linux/init.h>
  28 #include <linux/threads.h>
  29 #include <linux/smp.h>
  30 #include <linux/param.h>
  31 #include <linux/string.h>
  32 #include <linux/bootmem.h>
  33 #include <linux/irq.h>
  34 #include <linux/spinlock.h>
  35
  36 #include <asm/paca.h>
  37 #include <asm/iseries/hv_types.h>
  38 #include <asm/iseries/hv_lp_event.h>
  39 #include <asm/iseries/hv_call_xm.h>
  40 #include <asm/iseries/it_lp_queue.h>
  41
  42 #include "irq.h"
  43 #include "pci.h"
  44 #include "call_pci.h"
  45 #include "smp.h"
  46
  47 #ifdef CONFIG_PCI
  48
  49 enum pci_event_type {
  50         pe_bus_created          = 0,    /* PHB has been created */
  51         pe_bus_error            = 1,    /* PHB has failed */
  52         pe_bus_failed           = 2,    /* Msg to Secondary, Primary failed bus */
  53         pe_node_failed          = 4,    /* Multi-adapter bridge has failed */
  54         pe_node_recovered       = 5,    /* Multi-adapter bridge has recovered */
  55         pe_bus_recovered        = 12,   /* PHB has been recovered */
  56         pe_unquiese_bus         = 18,   /* Secondary bus unqiescing */
  57         pe_bridge_error         = 21,   /* Bridge Error */
  58         pe_slot_interrupt       = 22    /* Slot interrupt */
  59 };
  60
  61 struct pci_event {
  62         struct HvLpEvent event;
  63         union {
  64                 u64 __align;            /* Align on an 8-byte boundary */
  65                 struct {
  66                         u32             fisr;
  67                         HvBusNumber     bus_number;
  68                         HvSubBusNumber  sub_bus_number;
  69                         HvAgentId       dev_id;
  70                 } slot;
  71                 struct {
  72                         HvBusNumber     bus_number;
  73                         HvSubBusNumber  sub_bus_number;
  74                 } bus;
  75                 struct {
  76                         HvBusNumber     bus_number;
  77                         HvSubBusNumber  sub_bus_number;
  78                         HvAgentId       dev_id;
  79                 } node;
  80         } data;
  81 };
  82
  83 static DEFINE_SPINLOCK(pending_irqs_lock);
  84 static int num_pending_irqs;
  85 static int pending_irqs[NR_IRQS];
  86
  87 static void int_received(struct pci_event *event)
  88 {
  89         int irq;
  90
  91         switch (event->event.xSubtype) {
  92         case pe_slot_interrupt:
  93                 irq = event->event.xCorrelationToken;
  94                 if (irq < NR_IRQS) {
  95                         spin_lock(&pending_irqs_lock);
  96                         pending_irqs[irq]++;
  97                         num_pending_irqs++;
  98                         spin_unlock(&pending_irqs_lock);
  99                 } else {
 100                         printk(KERN_WARNING "int_received: bad irq number %d\n",
 101                                         irq);
 102                         HvCallPci_eoi(event->data.slot.bus_number,
 103                                         event->data.slot.sub_bus_number,
 104                                         event->data.slot.dev_id);
 105                 }
 106                 break;
 107                 /* Ignore error recovery events for now */
 108         case pe_bus_created:
 109                 printk(KERN_INFO "int_received: system bus %d created\n",
 110                         event->data.bus.bus_number);
 111                 break;
 112         case pe_bus_error:
 113         case pe_bus_failed:
 114                 printk(KERN_INFO "int_received: system bus %d failed\n",
 115                         event->data.bus.bus_number);
 116                 break;
 117         case pe_bus_recovered:
 118         case pe_unquiese_bus:
 119                 printk(KERN_INFO "int_received: system bus %d recovered\n",
 120                         event->data.bus.bus_number);
 121                 break;
 122         case pe_node_failed:
 123         case pe_bridge_error:
 124                 printk(KERN_INFO
 125                         "int_received: multi-adapter bridge %d/%d/%d failed\n",
 126                         event->data.node.bus_number,
 127                         event->data.node.sub_bus_number,
 128                         event->data.node.dev_id);
 129                 break;
 130         case pe_node_recovered:
 131                 printk(KERN_INFO
 132                         "int_received: multi-adapter bridge %d/%d/%d recovered\n",
 133                         event->data.node.bus_number,
 134                         event->data.node.sub_bus_number,
 135                         event->data.node.dev_id);
 136                 break;
 137         default:
 138                 printk(KERN_ERR
 139                         "int_received: unrecognized event subtype 0x%x\n",
 140                         event->event.xSubtype);
 141                 break;
 142         }
 143 }
 144
 145 static void pci_event_handler(struct HvLpEvent *event)
 146 {
 147         if (event && (event->xType == HvLpEvent_Type_PciIo)) {
 148                 if (hvlpevent_is_int(event))
 149                         int_received((struct pci_event *)event);
 150                 else
 151                         printk(KERN_ERR
 152                                 "pci_event_handler: unexpected ack received\n");
 153         } else if (event)
 154                 printk(KERN_ERR
 155                         "pci_event_handler: Unrecognized PCI event type 0x%x\n",
 156                         (int)event->xType);
 157         else
 158                 printk(KERN_ERR "pci_event_handler: NULL event received\n");
 159 }
 160
 161 #define REAL_IRQ_TO_SUBBUS(irq) (((irq) >> 14) & 0xff)
 162 #define REAL_IRQ_TO_BUS(irq)    ((((irq) >> 6) & 0xff) + 1)
 163 #define REAL_IRQ_TO_IDSEL(irq)  ((((irq) >> 3) & 7) + 1)
 164 #define REAL_IRQ_TO_FUNC(irq)   ((irq) & 7)
 165
 166 /*
 167  * This will be called by device drivers (via enable_IRQ)
 168  * to enable INTA in the bridge interrupt status register.
 169  */
 170 static void iseries_enable_IRQ(struct irq_data *d)
 171 {
 172         u32 bus, dev_id, function, mask;
 173         const u32 sub_bus = 0;
 174         unsigned int rirq = (unsigned int)irq_map[d->irq].hwirq;
 175
 176         /* The IRQ has already been locked by the caller */
 177         bus = REAL_IRQ_TO_BUS(rirq);
 178         function = REAL_IRQ_TO_FUNC(rirq);
 179         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 180
 181         /* Unmask secondary INTA */
 182         mask = 0x80000000;
 183         HvCallPci_unmaskInterrupts(bus, sub_bus, dev_id, mask);
 184 }
 185
 186 /* This is called by iseries_activate_IRQs */
 187 static unsigned int iseries_startup_IRQ(struct irq_data *d)
 188 {
 189         u32 bus, dev_id, function, mask;
 190         const u32 sub_bus = 0;
 191         unsigned int rirq = (unsigned int)irq_map[d->irq].hwirq;
 192
 193         bus = REAL_IRQ_TO_BUS(rirq);
 194         function = REAL_IRQ_TO_FUNC(rirq);
 195         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 196
 197         /* Link the IRQ number to the bridge */
 198         HvCallXm_connectBusUnit(bus, sub_bus, dev_id, d->irq);
 199
 200         /* Unmask bridge interrupts in the FISR */
 201         mask = 0x01010000 << function;
 202         HvCallPci_unmaskFisr(bus, sub_bus, dev_id, mask);
 203         iseries_enable_IRQ(d);
 204         return 0;
 205 }
 206
 207 /*
 208  * This is called out of iSeries_fixup to activate interrupt
 209  * generation for usable slots
 210  */
 211 void __init iSeries_activate_IRQs()
 212 {
 213         int irq;
 214         unsigned long flags;
 215
 216         for_each_irq (irq) {
 217                 struct irq_desc *desc = irq_to_desc(irq);
 218                 struct irq_chip *chip;
 219
 220                 if (!desc)
 221                         continue;
 222
 223                 chip = irq_desc_get_chip(desc);
 224                 if (chip && chip->irq_startup) {
 225                         raw_spin_lock_irqsave(&desc->lock, flags);
 226                         chip->irq_startup(&desc->irq_data);
 227                         raw_spin_unlock_irqrestore(&desc->lock, flags);
 228                 }
 229         }
 230 }
 231
 232 /*  this is not called anywhere currently */
 233 static void iseries_shutdown_IRQ(struct irq_data *d)
 234 {
 235         u32 bus, dev_id, function, mask;
 236         const u32 sub_bus = 0;
 237         unsigned int rirq = (unsigned int)irq_map[d->irq].hwirq;
 238
 239         /* irq should be locked by the caller */
 240         bus = REAL_IRQ_TO_BUS(rirq);
 241         function = REAL_IRQ_TO_FUNC(rirq);
 242         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 243
 244         /* Invalidate the IRQ number in the bridge */
 245         HvCallXm_connectBusUnit(bus, sub_bus, dev_id, 0);
 246
 247         /* Mask bridge interrupts in the FISR */
 248         mask = 0x01010000 << function;
 249         HvCallPci_maskFisr(bus, sub_bus, dev_id, mask);
 250 }
 251
 252 /*
 253  * This will be called by device drivers (via disable_IRQ)
 254  * to disable INTA in the bridge interrupt status register.
 255  */
 256 static void iseries_disable_IRQ(struct irq_data *d)
 257 {
 258         u32 bus, dev_id, function, mask;
 259         const u32 sub_bus = 0;
 260         unsigned int rirq = (unsigned int)irq_map[d->irq].hwirq;
 261
 262         /* The IRQ has already been locked by the caller */
 263         bus = REAL_IRQ_TO_BUS(rirq);
 264         function = REAL_IRQ_TO_FUNC(rirq);
 265         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 266
 267         /* Mask secondary INTA   */
 268         mask = 0x80000000;
 269         HvCallPci_maskInterrupts(bus, sub_bus, dev_id, mask);
 270 }
 271
 272 static void iseries_end_IRQ(struct irq_data *d)
 273 {
 274         unsigned int rirq = (unsigned int)irq_map[d->irq].hwirq;
 275
 276         HvCallPci_eoi(REAL_IRQ_TO_BUS(rirq), REAL_IRQ_TO_SUBBUS(rirq),
 277                 (REAL_IRQ_TO_IDSEL(rirq) << 4) + REAL_IRQ_TO_FUNC(rirq));
 278 }
 279
 280 static struct irq_chip iseries_pic = {
 281         .name           = "iSeries",
 282         .irq_startup    = iseries_startup_IRQ,
 283         .irq_shutdown   = iseries_shutdown_IRQ,
 284         .irq_unmask     = iseries_enable_IRQ,
 285         .irq_mask       = iseries_disable_IRQ,
 286         .irq_eoi        = iseries_end_IRQ
 287 };
 288
 289 /*
 290  * This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
 291  * It calculates the irq value for the slot.
 292  * Note that sub_bus is always 0 (at the moment at least).
 293  */
 294 int __init iSeries_allocate_IRQ(HvBusNumber bus,
 295                 HvSubBusNumber sub_bus, u32 bsubbus)
 296 {
 297         unsigned int realirq;
 298         u8 idsel = ISERIES_GET_DEVICE_FROM_SUBBUS(bsubbus);
 299         u8 function = ISERIES_GET_FUNCTION_FROM_SUBBUS(bsubbus);
 300
 301         realirq = (((((sub_bus << 8) + (bus - 1)) << 3) + (idsel - 1)) << 3)
 302                 + function;
 303
 304         return irq_create_mapping(NULL, realirq);
 305 }
 306
 307 #endif /* CONFIG_PCI */
 308
 309 /*
 310  * Get the next pending IRQ.
 311  */
 312 unsigned int iSeries_get_irq(void)
 313 {
 314         int irq = NO_IRQ_IGNORE;
 315
 316 #ifdef CONFIG_SMP
 317         if (get_lppaca()->int_dword.fields.ipi_cnt) {
 318                 get_lppaca()->int_dword.fields.ipi_cnt = 0;
 319                 iSeries_smp_message_recv();
 320         }
 321 #endif /* CONFIG_SMP */
 322         if (hvlpevent_is_pending())
 323                 process_hvlpevents();
 324
 325 #ifdef CONFIG_PCI
 326         if (num_pending_irqs) {
 327                 spin_lock(&pending_irqs_lock);
 328                 for (irq = 0; irq < NR_IRQS; irq++) {
 329                         if (pending_irqs[irq]) {
 330                                 pending_irqs[irq]--;
 331                                 num_pending_irqs--;
 332                                 break;
 333                         }
 334                 }
 335                 spin_unlock(&pending_irqs_lock);
 336                 if (irq >= NR_IRQS)
 337                         irq = NO_IRQ_IGNORE;
 338         }
 339 #endif
 340
 341         return irq;
 342 }
 343
 344 #ifdef CONFIG_PCI
 345
 346 static int iseries_irq_host_map(struct irq_host *h, unsigned int virq,
 347                                 irq_hw_number_t hw)
 348 {
 349         irq_set_chip_and_handler(virq, &iseries_pic, handle_fasteoi_irq);
 350
 351         return 0;
 352 }
 353
 354 static int iseries_irq_host_match(struct irq_host *h, struct device_node *np)
 355 {
 356         /* Match all */
 357         return 1;
 358 }
 359
 360 static struct irq_host_ops iseries_irq_host_ops = {
 361         .map = iseries_irq_host_map,
 362         .match = iseries_irq_host_match,
 363 };
 364
 365 /*
 366  * This is called by init_IRQ.  set in ppc_md.init_IRQ by iSeries_setup.c
 367  * It must be called before the bus walk.
 368  */
 369 void __init iSeries_init_IRQ(void)
 370 {
 371         /* Register PCI event handler and open an event path */
 372         struct irq_host *host;
 373         int ret;
 374
 375         /*
 376          * The Hypervisor only allows us up to 256 interrupt
 377          * sources (the irq number is passed in a u8).
 378          */
 379         irq_set_virq_count(256);
 380
 381         /* Create irq host. No need for a revmap since HV will give us
 382          * back our virtual irq number
 383          */
 384         host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
 385                               &iseries_irq_host_ops, 0);
 386         BUG_ON(host == NULL);
 387         irq_set_default_host(host);
 388
 389         ret = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
 390                         &pci_event_handler);
 391         if (ret == 0) {
 392                 ret = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
 393                 if (ret != 0)
 394                         printk(KERN_ERR "iseries_init_IRQ: open event path "
 395                                         "failed with rc 0x%x\n", ret);
 396         } else
 397                 printk(KERN_ERR "iseries_init_IRQ: register handler "
 398                                 "failed with rc 0x%x\n", ret);
 399 }
 400
 401 #endif  /* CONFIG_PCI */