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 #include <asm/sn/sn_feature_sets.h>
  23
  24 static void force_interrupt(int irq);
  25 static void register_intr_pda(struct sn_irq_info *sn_irq_info);
  26 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info);
  27
  28 int sn_force_interrupt_flag = 1;
  29 extern int sn_ioif_inited;
  30 struct list_head **sn_irq_lh;
  31 static DEFINE_SPINLOCK(sn_irq_info_lock); /* non-IRQ lock */
  32
  33 u64 sn_intr_alloc(nasid_t local_nasid, int local_widget,
  34                                      struct sn_irq_info *sn_irq_info,
  35                                      int req_irq, nasid_t req_nasid,
  36                                      int req_slice)
  37 {
  38         struct ia64_sal_retval ret_stuff;
  39         ret_stuff.status = 0;
  40         ret_stuff.v0 = 0;
  41
  42         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  43                         (u64) SAL_INTR_ALLOC, (u64) local_nasid,
  44                         (u64) local_widget, __pa(sn_irq_info), (u64) req_irq,
  45                         (u64) req_nasid, (u64) req_slice);
  46
  47         return ret_stuff.status;
  48 }
  49
  50 void sn_intr_free(nasid_t local_nasid, int local_widget,
  51                                 struct sn_irq_info *sn_irq_info)
  52 {
  53         struct ia64_sal_retval ret_stuff;
  54         ret_stuff.status = 0;
  55         ret_stuff.v0 = 0;
  56
  57         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  58                         (u64) SAL_INTR_FREE, (u64) local_nasid,
  59                         (u64) local_widget, (u64) sn_irq_info->irq_irq,
  60                         (u64) sn_irq_info->irq_cookie, 0, 0);
  61 }
  62
  63 u64 sn_intr_redirect(nasid_t local_nasid, int local_widget,
  64                       struct sn_irq_info *sn_irq_info,
  65                       nasid_t req_nasid, int req_slice)
  66 {
  67         struct ia64_sal_retval ret_stuff;
  68         ret_stuff.status = 0;
  69         ret_stuff.v0 = 0;
  70
  71         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  72                         (u64) SAL_INTR_REDIRECT, (u64) local_nasid,
  73                         (u64) local_widget, __pa(sn_irq_info),
  74                         (u64) req_nasid, (u64) req_slice, 0);
  75
  76         return ret_stuff.status;
  77 }
  78
  79 static unsigned int sn_startup_irq(unsigned int irq)
  80 {
  81         return 0;
  82 }
  83
  84 static void sn_shutdown_irq(unsigned int irq)
  85 {
  86 }
  87
  88 static void sn_disable_irq(unsigned int irq)
  89 {
  90 }
  91
  92 static void sn_enable_irq(unsigned int irq)
  93 {
  94 }
  95
  96 static void sn_ack_irq(unsigned int irq)
  97 {
  98         u64 event_occurred, mask;
  99
 100         irq = irq & 0xff;
 101         event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED));
 102         mask = event_occurred & SH_ALL_INT_MASK;
 103         HUB_S((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS), mask);
 104         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
 105
 106         move_native_irq(irq);
 107 }
 108
 109 static void sn_end_irq(unsigned int irq)
 110 {
 111         int ivec;
 112         u64 event_occurred;
 113
 114         ivec = irq & 0xff;
 115         if (ivec == SGI_UART_VECTOR) {
 116                 event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR (SH_EVENT_OCCURRED));
 117                 /* If the UART bit is set here, we may have received an
 118                  * interrupt from the UART that the driver missed.  To
 119                  * make sure, we IPI ourselves to force us to look again.
 120                  */
 121                 if (event_occurred & SH_EVENT_OCCURRED_UART_INT_MASK) {
 122                         platform_send_ipi(smp_processor_id(), SGI_UART_VECTOR,
 123                                           IA64_IPI_DM_INT, 0);
 124                 }
 125         }
 126         __clear_bit(ivec, (volatile void *)pda->sn_in_service_ivecs);
 127         if (sn_force_interrupt_flag)
 128                 force_interrupt(irq);
 129 }
 130
 131 static void sn_irq_info_free(struct rcu_head *head);
 132
 133 struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info,
 134                                        nasid_t nasid, int slice)
 135 {
 136         int vector;
 137         int cpuid;
 138 #ifdef CONFIG_SMP
 139         int cpuphys;
 140 #endif
 141         int64_t bridge;
 142         int local_widget, status;
 143         nasid_t local_nasid;
 144         struct sn_irq_info *new_irq_info;
 145         struct sn_pcibus_provider *pci_provider;
 146
 147         bridge = (u64) sn_irq_info->irq_bridge;
 148         if (!bridge) {
 149                 return NULL; /* irq is not a device interrupt */
 150         }
 151
 152         local_nasid = NASID_GET(bridge);
 153
 154         if (local_nasid & 1)
 155                 local_widget = TIO_SWIN_WIDGETNUM(bridge);
 156         else
 157                 local_widget = SWIN_WIDGETNUM(bridge);
 158         vector = sn_irq_info->irq_irq;
 159
 160         /* Make use of SAL_INTR_REDIRECT if PROM supports it */
 161         status = sn_intr_redirect(local_nasid, local_widget, sn_irq_info, nasid, slice);
 162         if (!status) {
 163                 new_irq_info = sn_irq_info;
 164                 goto finish_up;
 165         }
 166
 167         /*
 168          * PROM does not support SAL_INTR_REDIRECT, or it failed.
 169          * Revert to old method.
 170          */
 171         new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 172         if (new_irq_info == NULL)
 173                 return NULL;
 174
 175         memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
 176
 177         /* Free the old PROM new_irq_info structure */
 178         sn_intr_free(local_nasid, local_widget, new_irq_info);
 179         unregister_intr_pda(new_irq_info);
 180
 181         /* allocate a new PROM new_irq_info struct */
 182         status = sn_intr_alloc(local_nasid, local_widget,
 183                                new_irq_info, vector,
 184                                nasid, slice);
 185
 186         /* SAL call failed */
 187         if (status) {
 188                 kfree(new_irq_info);
 189                 return NULL;
 190         }
 191
 192         register_intr_pda(new_irq_info);
 193         spin_lock(&sn_irq_info_lock);
 194         list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
 195         spin_unlock(&sn_irq_info_lock);
 196         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 197
 198
 199 finish_up:
 200         /* Update kernels new_irq_info with new target info */
 201         cpuid = nasid_slice_to_cpuid(new_irq_info->irq_nasid,
 202                                      new_irq_info->irq_slice);
 203         new_irq_info->irq_cpuid = cpuid;
 204
 205         pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 206
 207         /*
 208          * If this represents a line interrupt, target it.  If it's
 209          * an msi (irq_int_bit < 0), it's already targeted.
 210          */
 211         if (new_irq_info->irq_int_bit >= 0 &&
 212             pci_provider && pci_provider->target_interrupt)
 213                 (pci_provider->target_interrupt)(new_irq_info);
 214
 215 #ifdef CONFIG_SMP
 216         cpuphys = cpu_physical_id(cpuid);
 217         set_irq_affinity_info((vector & 0xff), cpuphys, 0);
 218 #endif
 219
 220         return new_irq_info;
 221 }
 222
 223 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
 224 {
 225         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 226         nasid_t nasid;
 227         int slice;
 228
 229         nasid = cpuid_to_nasid(first_cpu(mask));
 230         slice = cpuid_to_slice(first_cpu(mask));
 231
 232         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 233                                  sn_irq_lh[irq], list)
 234                 (void)sn_retarget_vector(sn_irq_info, nasid, slice);
 235 }
 236
 237 #ifdef CONFIG_SMP
 238 void sn_set_err_irq_affinity(unsigned int irq)
 239 {
 240         /*
 241          * On systems which support CPU disabling (SHub2), all error interrupts
 242          * are targetted at the boot CPU.
 243          */
 244         if (is_shub2() && sn_prom_feature_available(PRF_CPU_DISABLE_SUPPORT))
 245                 set_irq_affinity_info(irq, cpu_physical_id(0), 0);
 246 }
 247 #else
 248 void sn_set_err_irq_affinity(unsigned int irq) { }
 249 #endif
 250
 251 static void
 252 sn_mask_irq(unsigned int irq)
 253 {
 254 }
 255
 256 static void
 257 sn_unmask_irq(unsigned int irq)
 258 {
 259 }
 260
 261 struct irq_chip irq_type_sn = {
 262         .name           = "SN hub",
 263         .startup        = sn_startup_irq,
 264         .shutdown       = sn_shutdown_irq,
 265         .enable         = sn_enable_irq,
 266         .disable        = sn_disable_irq,
 267         .ack            = sn_ack_irq,
 268         .end            = sn_end_irq,
 269         .mask           = sn_mask_irq,
 270         .unmask         = sn_unmask_irq,
 271         .set_affinity   = sn_set_affinity_irq
 272 };
 273
 274 ia64_vector sn_irq_to_vector(int irq)
 275 {
 276         if (irq >= IA64_NUM_VECTORS)
 277                 return 0;
 278         return (ia64_vector)irq;
 279 }
 280
 281 unsigned int sn_local_vector_to_irq(u8 vector)
 282 {
 283         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 284 }
 285
 286 void sn_irq_init(void)
 287 {
 288         int i;
 289         irq_desc_t *base_desc = irq_desc;
 290
 291         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 292         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 293
 294         for (i = 0; i < NR_IRQS; i++) {
 295                 if (base_desc[i].chip == &no_irq_type) {
 296                         base_desc[i].chip = &irq_type_sn;
 297                 }
 298         }
 299 }
 300
 301 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 302 {
 303         int irq = sn_irq_info->irq_irq;
 304         int cpu = sn_irq_info->irq_cpuid;
 305
 306         if (pdacpu(cpu)->sn_last_irq < irq) {
 307                 pdacpu(cpu)->sn_last_irq = irq;
 308         }
 309
 310         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 311                 pdacpu(cpu)->sn_first_irq = irq;
 312 }
 313
 314 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 315 {
 316         int irq = sn_irq_info->irq_irq;
 317         int cpu = sn_irq_info->irq_cpuid;
 318         struct sn_irq_info *tmp_irq_info;
 319         int i, foundmatch;
 320
 321         rcu_read_lock();
 322         if (pdacpu(cpu)->sn_last_irq == irq) {
 323                 foundmatch = 0;
 324                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 325                      i && !foundmatch; i--) {
 326                         list_for_each_entry_rcu(tmp_irq_info,
 327                                                 sn_irq_lh[i],
 328                                                 list) {
 329                                 if (tmp_irq_info->irq_cpuid == cpu) {
 330                                         foundmatch = 1;
 331                                         break;
 332                                 }
 333                         }
 334                 }
 335                 pdacpu(cpu)->sn_last_irq = i;
 336         }
 337
 338         if (pdacpu(cpu)->sn_first_irq == irq) {
 339                 foundmatch = 0;
 340                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 341                      i < NR_IRQS && !foundmatch; i++) {
 342                         list_for_each_entry_rcu(tmp_irq_info,
 343                                                 sn_irq_lh[i],
 344                                                 list) {
 345                                 if (tmp_irq_info->irq_cpuid == cpu) {
 346                                         foundmatch = 1;
 347                                         break;
 348                                 }
 349                         }
 350                 }
 351                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 352         }
 353         rcu_read_unlock();
 354 }
 355
 356 static void sn_irq_info_free(struct rcu_head *head)
 357 {
 358         struct sn_irq_info *sn_irq_info;
 359
 360         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 361         kfree(sn_irq_info);
 362 }
 363
 364 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 365 {
 366         nasid_t nasid = sn_irq_info->irq_nasid;
 367         int slice = sn_irq_info->irq_slice;
 368         int cpu = nasid_slice_to_cpuid(nasid, slice);
 369 #ifdef CONFIG_SMP
 370         int cpuphys;
 371 #endif
 372
 373         pci_dev_get(pci_dev);
 374         sn_irq_info->irq_cpuid = cpu;
 375         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 376
 377         /* link it into the sn_irq[irq] list */
 378         spin_lock(&sn_irq_info_lock);
 379         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 380         reserve_irq_vector(sn_irq_info->irq_irq);
 381         spin_unlock(&sn_irq_info_lock);
 382
 383         register_intr_pda(sn_irq_info);
 384 #ifdef CONFIG_SMP
 385         cpuphys = cpu_physical_id(cpu);
 386         set_irq_affinity_info(sn_irq_info->irq_irq, cpuphys, 0);
 387 #endif
 388 }
 389
 390 void sn_irq_unfixup(struct pci_dev *pci_dev)
 391 {
 392         struct sn_irq_info *sn_irq_info;
 393
 394         /* Only cleanup IRQ stuff if this device has a host bus context */
 395         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 396                 return;
 397
 398         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 399         if (!sn_irq_info)
 400                 return;
 401         if (!sn_irq_info->irq_irq) {
 402                 kfree(sn_irq_info);
 403                 return;
 404         }
 405
 406         unregister_intr_pda(sn_irq_info);
 407         spin_lock(&sn_irq_info_lock);
 408         list_del_rcu(&sn_irq_info->list);
 409         spin_unlock(&sn_irq_info_lock);
 410         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 411                 free_irq_vector(sn_irq_info->irq_irq);
 412         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 413         pci_dev_put(pci_dev);
 414
 415 }
 416
 417 static inline void
 418 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 419 {
 420         struct sn_pcibus_provider *pci_provider;
 421
 422         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 423
 424         /* Don't force an interrupt if the irq has been disabled */
 425         if (!(irq_desc[sn_irq_info->irq_irq].status & IRQ_DISABLED) &&
 426             pci_provider && pci_provider->force_interrupt)
 427                 (*pci_provider->force_interrupt)(sn_irq_info);
 428 }
 429
 430 static void force_interrupt(int irq)
 431 {
 432         struct sn_irq_info *sn_irq_info;
 433
 434         if (!sn_ioif_inited)
 435                 return;
 436
 437         rcu_read_lock();
 438         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 439                 sn_call_force_intr_provider(sn_irq_info);
 440
 441         rcu_read_unlock();
 442 }
 443
 444 /*
 445  * Check for lost interrupts.  If the PIC int_status reg. says that
 446  * an interrupt has been sent, but not handled, and the interrupt
 447  * is not pending in either the cpu irr regs or in the soft irr regs,
 448  * and the interrupt is not in service, then the interrupt may have
 449  * been lost.  Force an interrupt on that pin.  It is possible that
 450  * the interrupt is in flight, so we may generate a spurious interrupt,
 451  * but we should never miss a real lost interrupt.
 452  */
 453 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 454 {
 455         u64 regval;
 456         struct pcidev_info *pcidev_info;
 457         struct pcibus_info *pcibus_info;
 458
 459         /*
 460          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 461          * since they do not target Shub II interrupt registers.  If that
 462          * ever changes, this check needs to accomodate.
 463          */
 464         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 465                 return;
 466
 467         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 468         if (!pcidev_info)
 469                 return;
 470
 471         pcibus_info =
 472             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 473             pdi_pcibus_info;
 474         regval = pcireg_intr_status_get(pcibus_info);
 475
 476         if (!ia64_get_irr(irq_to_vector(irq))) {
 477                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 478                         regval &= 0xff;
 479                         if (sn_irq_info->irq_int_bit & regval &
 480                             sn_irq_info->irq_last_intr) {
 481                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 482                                 sn_call_force_intr_provider(sn_irq_info);
 483                         }
 484                 }
 485         }
 486         sn_irq_info->irq_last_intr = regval;
 487 }
 488
 489 void sn_lb_int_war_check(void)
 490 {
 491         struct sn_irq_info *sn_irq_info;
 492         int i;
 493
 494         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 495                 return;
 496
 497         rcu_read_lock();
 498         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 499                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 500                         sn_check_intr(i, sn_irq_info);
 501                 }
 502         }
 503         rcu_read_unlock();
 504 }
 505
 506 void __init sn_irq_lh_init(void)
 507 {
 508         int i;
 509
 510         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 511         if (!sn_irq_lh)
 512                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 513
 514         for (i = 0; i < NR_IRQS; i++) {
 515                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 516                 if (!sn_irq_lh[i])
 517                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 518
 519                 INIT_LIST_HEAD(sn_irq_lh[i]);
 520         }
 521 }