arch/ia64/sn/kernel/irq.c

   1 /*
   2  * Platform dependent support for SGI SN
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (c) 2000-2006 Silicon Graphics, Inc.  All Rights Reserved.
   9  */
  10
  11 #include <linux/irq.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/init.h>
  14 #include <asm/sn/addrs.h>
  15 #include <asm/sn/arch.h>
  16 #include <asm/sn/intr.h>
  17 #include <asm/sn/pcibr_provider.h>
  18 #include <asm/sn/pcibus_provider_defs.h>
  19 #include <asm/sn/pcidev.h>
  20 #include <asm/sn/shub_mmr.h>
  21 #include <asm/sn/sn_sal.h>
  22
  23 static void force_interrupt(int irq);
  24 static void register_intr_pda(struct sn_irq_info *sn_irq_info);
  25 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info);
  26
  27 int sn_force_interrupt_flag = 1;
  28 extern int sn_ioif_inited;
  29 struct list_head **sn_irq_lh;
  30 static DEFINE_SPINLOCK(sn_irq_info_lock); /* non-IRQ lock */
  31
  32 u64 sn_intr_alloc(nasid_t local_nasid, int local_widget,
  33                                      struct sn_irq_info *sn_irq_info,
  34                                      int req_irq, nasid_t req_nasid,
  35                                      int req_slice)
  36 {
  37         struct ia64_sal_retval ret_stuff;
  38         ret_stuff.status = 0;
  39         ret_stuff.v0 = 0;
  40
  41         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  42                         (u64) SAL_INTR_ALLOC, (u64) local_nasid,
  43                         (u64) local_widget, __pa(sn_irq_info), (u64) req_irq,
  44                         (u64) req_nasid, (u64) req_slice);
  45
  46         return ret_stuff.status;
  47 }
  48
  49 void sn_intr_free(nasid_t local_nasid, int local_widget,
  50                                 struct sn_irq_info *sn_irq_info)
  51 {
  52         struct ia64_sal_retval ret_stuff;
  53         ret_stuff.status = 0;
  54         ret_stuff.v0 = 0;
  55
  56         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  57                         (u64) SAL_INTR_FREE, (u64) local_nasid,
  58                         (u64) local_widget, (u64) sn_irq_info->irq_irq,
  59                         (u64) sn_irq_info->irq_cookie, 0, 0);
  60 }
  61
  62 u64 sn_intr_redirect(nasid_t local_nasid, int local_widget,
  63                       struct sn_irq_info *sn_irq_info,
  64                       nasid_t req_nasid, int req_slice)
  65 {
  66         struct ia64_sal_retval ret_stuff;
  67         ret_stuff.status = 0;
  68         ret_stuff.v0 = 0;
  69
  70         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  71                         (u64) SAL_INTR_REDIRECT, (u64) local_nasid,
  72                         (u64) local_widget, __pa(sn_irq_info),
  73                         (u64) req_nasid, (u64) req_slice, 0);
  74
  75         return ret_stuff.status;
  76 }
  77
  78 static unsigned int sn_startup_irq(unsigned int irq)
  79 {
  80         return 0;
  81 }
  82
  83 static void sn_shutdown_irq(unsigned int irq)
  84 {
  85 }
  86
  87 static void sn_disable_irq(unsigned int irq)
  88 {
  89 }
  90
  91 static void sn_enable_irq(unsigned int irq)
  92 {
  93 }
  94
  95 static void sn_ack_irq(unsigned int irq)
  96 {
  97         u64 event_occurred, mask;
  98
  99         irq = irq & 0xff;
 100         event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED));
 101         mask = event_occurred & SH_ALL_INT_MASK;
 102         HUB_S((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS), mask);
 103         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
 104
 105         move_native_irq(irq);
 106 }
 107
 108 static void sn_end_irq(unsigned int irq)
 109 {
 110         int ivec;
 111         u64 event_occurred;
 112
 113         ivec = irq & 0xff;
 114         if (ivec == SGI_UART_VECTOR) {
 115                 event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR (SH_EVENT_OCCURRED));
 116                 /* If the UART bit is set here, we may have received an
 117                  * interrupt from the UART that the driver missed.  To
 118                  * make sure, we IPI ourselves to force us to look again.
 119                  */
 120                 if (event_occurred & SH_EVENT_OCCURRED_UART_INT_MASK) {
 121                         platform_send_ipi(smp_processor_id(), SGI_UART_VECTOR,
 122                                           IA64_IPI_DM_INT, 0);
 123                 }
 124         }
 125         __clear_bit(ivec, (volatile void *)pda->sn_in_service_ivecs);
 126         if (sn_force_interrupt_flag)
 127                 force_interrupt(irq);
 128 }
 129
 130 static void sn_irq_info_free(struct rcu_head *head);
 131
 132 struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info,
 133                                        nasid_t nasid, int slice)
 134 {
 135         int vector;
 136         int cpuid;
 137 #ifdef CONFIG_SMP
 138         int cpuphys;
 139 #endif
 140         int64_t bridge;
 141         int local_widget, status;
 142         nasid_t local_nasid;
 143         struct sn_irq_info *new_irq_info;
 144         struct sn_pcibus_provider *pci_provider;
 145
 146         bridge = (u64) sn_irq_info->irq_bridge;
 147         if (!bridge) {
 148                 return NULL; /* irq is not a device interrupt */
 149         }
 150
 151         local_nasid = NASID_GET(bridge);
 152
 153         if (local_nasid & 1)
 154                 local_widget = TIO_SWIN_WIDGETNUM(bridge);
 155         else
 156                 local_widget = SWIN_WIDGETNUM(bridge);
 157         vector = sn_irq_info->irq_irq;
 158
 159         /* Make use of SAL_INTR_REDIRECT if PROM supports it */
 160         status = sn_intr_redirect(local_nasid, local_widget, sn_irq_info, nasid, slice);
 161         if (!status) {
 162                 new_irq_info = sn_irq_info;
 163                 goto finish_up;
 164         }
 165
 166         /*
 167          * PROM does not support SAL_INTR_REDIRECT, or it failed.
 168          * Revert to old method.
 169          */
 170         new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 171         if (new_irq_info == NULL)
 172                 return NULL;
 173
 174         memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
 175
 176         /* Free the old PROM new_irq_info structure */
 177         sn_intr_free(local_nasid, local_widget, new_irq_info);
 178         unregister_intr_pda(new_irq_info);
 179
 180         /* allocate a new PROM new_irq_info struct */
 181         status = sn_intr_alloc(local_nasid, local_widget,
 182                                new_irq_info, vector,
 183                                nasid, slice);
 184
 185         /* SAL call failed */
 186         if (status) {
 187                 kfree(new_irq_info);
 188                 return NULL;
 189         }
 190
 191         register_intr_pda(new_irq_info);
 192         spin_lock(&sn_irq_info_lock);
 193         list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
 194         spin_unlock(&sn_irq_info_lock);
 195         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 196
 197
 198 finish_up:
 199         /* Update kernels new_irq_info with new target info */
 200         cpuid = nasid_slice_to_cpuid(new_irq_info->irq_nasid,
 201                                      new_irq_info->irq_slice);
 202         new_irq_info->irq_cpuid = cpuid;
 203
 204         pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 205
 206         /*
 207          * If this represents a line interrupt, target it.  If it's
 208          * an msi (irq_int_bit < 0), it's already targeted.
 209          */
 210         if (new_irq_info->irq_int_bit >= 0 &&
 211             pci_provider && pci_provider->target_interrupt)
 212                 (pci_provider->target_interrupt)(new_irq_info);
 213
 214 #ifdef CONFIG_SMP
 215         cpuphys = cpu_physical_id(cpuid);
 216         set_irq_affinity_info((vector & 0xff), cpuphys, 0);
 217 #endif
 218
 219         return new_irq_info;
 220 }
 221
 222 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
 223 {
 224         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 225         nasid_t nasid;
 226         int slice;
 227
 228         nasid = cpuid_to_nasid(first_cpu(mask));
 229         slice = cpuid_to_slice(first_cpu(mask));
 230
 231         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 232                                  sn_irq_lh[irq], list)
 233                 (void)sn_retarget_vector(sn_irq_info, nasid, slice);
 234 }
 235
 236 static void
 237 sn_mask_irq(unsigned int irq)
 238 {
 239 }
 240
 241 static void
 242 sn_unmask_irq(unsigned int irq)
 243 {
 244 }
 245
 246 struct irq_chip irq_type_sn = {
 247         .name           = "SN hub",
 248         .startup        = sn_startup_irq,
 249         .shutdown       = sn_shutdown_irq,
 250         .enable         = sn_enable_irq,
 251         .disable        = sn_disable_irq,
 252         .ack            = sn_ack_irq,
 253         .end            = sn_end_irq,
 254         .mask           = sn_mask_irq,
 255         .unmask         = sn_unmask_irq,
 256         .set_affinity   = sn_set_affinity_irq
 257 };
 258
 259 ia64_vector sn_irq_to_vector(int irq)
 260 {
 261         if (irq >= IA64_NUM_VECTORS)
 262                 return 0;
 263         return (ia64_vector)irq;
 264 }
 265
 266 unsigned int sn_local_vector_to_irq(u8 vector)
 267 {
 268         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 269 }
 270
 271 void sn_irq_init(void)
 272 {
 273         int i;
 274         irq_desc_t *base_desc = irq_desc;
 275
 276         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 277         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 278
 279         for (i = 0; i < NR_IRQS; i++) {
 280                 if (base_desc[i].chip == &no_irq_type) {
 281                         base_desc[i].chip = &irq_type_sn;
 282                 }
 283         }
 284 }
 285
 286 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 287 {
 288         int irq = sn_irq_info->irq_irq;
 289         int cpu = sn_irq_info->irq_cpuid;
 290
 291         if (pdacpu(cpu)->sn_last_irq < irq) {
 292                 pdacpu(cpu)->sn_last_irq = irq;
 293         }
 294
 295         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 296                 pdacpu(cpu)->sn_first_irq = irq;
 297 }
 298
 299 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 300 {
 301         int irq = sn_irq_info->irq_irq;
 302         int cpu = sn_irq_info->irq_cpuid;
 303         struct sn_irq_info *tmp_irq_info;
 304         int i, foundmatch;
 305
 306         rcu_read_lock();
 307         if (pdacpu(cpu)->sn_last_irq == irq) {
 308                 foundmatch = 0;
 309                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 310                      i && !foundmatch; i--) {
 311                         list_for_each_entry_rcu(tmp_irq_info,
 312                                                 sn_irq_lh[i],
 313                                                 list) {
 314                                 if (tmp_irq_info->irq_cpuid == cpu) {
 315                                         foundmatch = 1;
 316                                         break;
 317                                 }
 318                         }
 319                 }
 320                 pdacpu(cpu)->sn_last_irq = i;
 321         }
 322
 323         if (pdacpu(cpu)->sn_first_irq == irq) {
 324                 foundmatch = 0;
 325                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 326                      i < NR_IRQS && !foundmatch; i++) {
 327                         list_for_each_entry_rcu(tmp_irq_info,
 328                                                 sn_irq_lh[i],
 329                                                 list) {
 330                                 if (tmp_irq_info->irq_cpuid == cpu) {
 331                                         foundmatch = 1;
 332                                         break;
 333                                 }
 334                         }
 335                 }
 336                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 337         }
 338         rcu_read_unlock();
 339 }
 340
 341 static void sn_irq_info_free(struct rcu_head *head)
 342 {
 343         struct sn_irq_info *sn_irq_info;
 344
 345         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 346         kfree(sn_irq_info);
 347 }
 348
 349 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 350 {
 351         nasid_t nasid = sn_irq_info->irq_nasid;
 352         int slice = sn_irq_info->irq_slice;
 353         int cpu = nasid_slice_to_cpuid(nasid, slice);
 354 #ifdef CONFIG_SMP
 355         int cpuphys;
 356 #endif
 357
 358         pci_dev_get(pci_dev);
 359         sn_irq_info->irq_cpuid = cpu;
 360         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 361
 362         /* link it into the sn_irq[irq] list */
 363         spin_lock(&sn_irq_info_lock);
 364         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 365         reserve_irq_vector(sn_irq_info->irq_irq);
 366         spin_unlock(&sn_irq_info_lock);
 367
 368         register_intr_pda(sn_irq_info);
 369 #ifdef CONFIG_SMP
 370         cpuphys = cpu_physical_id(cpu);
 371         set_irq_affinity_info(sn_irq_info->irq_irq, cpuphys, 0);
 372 #endif
 373 }
 374
 375 void sn_irq_unfixup(struct pci_dev *pci_dev)
 376 {
 377         struct sn_irq_info *sn_irq_info;
 378
 379         /* Only cleanup IRQ stuff if this device has a host bus context */
 380         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 381                 return;
 382
 383         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 384         if (!sn_irq_info)
 385                 return;
 386         if (!sn_irq_info->irq_irq) {
 387                 kfree(sn_irq_info);
 388                 return;
 389         }
 390
 391         unregister_intr_pda(sn_irq_info);
 392         spin_lock(&sn_irq_info_lock);
 393         list_del_rcu(&sn_irq_info->list);
 394         spin_unlock(&sn_irq_info_lock);
 395         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 396                 free_irq_vector(sn_irq_info->irq_irq);
 397         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 398         pci_dev_put(pci_dev);
 399
 400 }
 401
 402 static inline void
 403 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 404 {
 405         struct sn_pcibus_provider *pci_provider;
 406
 407         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 408
 409         /* Don't force an interrupt if the irq has been disabled */
 410         if (!(irq_desc[sn_irq_info->irq_irq].status & IRQ_DISABLED) &&
 411             pci_provider && pci_provider->force_interrupt)
 412                 (*pci_provider->force_interrupt)(sn_irq_info);
 413 }
 414
 415 static void force_interrupt(int irq)
 416 {
 417         struct sn_irq_info *sn_irq_info;
 418
 419         if (!sn_ioif_inited)
 420                 return;
 421
 422         rcu_read_lock();
 423         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 424                 sn_call_force_intr_provider(sn_irq_info);
 425
 426         rcu_read_unlock();
 427 }
 428
 429 /*
 430  * Check for lost interrupts.  If the PIC int_status reg. says that
 431  * an interrupt has been sent, but not handled, and the interrupt
 432  * is not pending in either the cpu irr regs or in the soft irr regs,
 433  * and the interrupt is not in service, then the interrupt may have
 434  * been lost.  Force an interrupt on that pin.  It is possible that
 435  * the interrupt is in flight, so we may generate a spurious interrupt,
 436  * but we should never miss a real lost interrupt.
 437  */
 438 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 439 {
 440         u64 regval;
 441         struct pcidev_info *pcidev_info;
 442         struct pcibus_info *pcibus_info;
 443
 444         /*
 445          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 446          * since they do not target Shub II interrupt registers.  If that
 447          * ever changes, this check needs to accomodate.
 448          */
 449         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 450                 return;
 451
 452         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 453         if (!pcidev_info)
 454                 return;
 455
 456         pcibus_info =
 457             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 458             pdi_pcibus_info;
 459         regval = pcireg_intr_status_get(pcibus_info);
 460
 461         if (!ia64_get_irr(irq_to_vector(irq))) {
 462                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 463                         regval &= 0xff;
 464                         if (sn_irq_info->irq_int_bit & regval &
 465                             sn_irq_info->irq_last_intr) {
 466                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 467                                 sn_call_force_intr_provider(sn_irq_info);
 468                         }
 469                 }
 470         }
 471         sn_irq_info->irq_last_intr = regval;
 472 }
 473
 474 void sn_lb_int_war_check(void)
 475 {
 476         struct sn_irq_info *sn_irq_info;
 477         int i;
 478
 479         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 480                 return;
 481
 482         rcu_read_lock();
 483         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 484                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 485                         sn_check_intr(i, sn_irq_info);
 486                 }
 487         }
 488         rcu_read_unlock();
 489 }
 490
 491 void __init sn_irq_lh_init(void)
 492 {
 493         int i;
 494
 495         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 496         if (!sn_irq_lh)
 497                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 498
 499         for (i = 0; i < NR_IRQS; i++) {
 500                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 501                 if (!sn_irq_lh[i])
 502                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 503
 504                 INIT_LIST_HEAD(sn_irq_lh[i]);
 505         }
 506 }