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 unsigned int sn_local_vector_to_irq(u8 vector)
 260 {
 261         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 262 }
 263
 264 void sn_irq_init(void)
 265 {
 266         int i;
 267         irq_desc_t *base_desc = irq_desc;
 268
 269         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 270         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 271
 272         for (i = 0; i < NR_IRQS; i++) {
 273                 if (base_desc[i].chip == &no_irq_type) {
 274                         base_desc[i].chip = &irq_type_sn;
 275                 }
 276         }
 277 }
 278
 279 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 280 {
 281         int irq = sn_irq_info->irq_irq;
 282         int cpu = sn_irq_info->irq_cpuid;
 283
 284         if (pdacpu(cpu)->sn_last_irq < irq) {
 285                 pdacpu(cpu)->sn_last_irq = irq;
 286         }
 287
 288         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 289                 pdacpu(cpu)->sn_first_irq = irq;
 290 }
 291
 292 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 293 {
 294         int irq = sn_irq_info->irq_irq;
 295         int cpu = sn_irq_info->irq_cpuid;
 296         struct sn_irq_info *tmp_irq_info;
 297         int i, foundmatch;
 298
 299         rcu_read_lock();
 300         if (pdacpu(cpu)->sn_last_irq == irq) {
 301                 foundmatch = 0;
 302                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 303                      i && !foundmatch; i--) {
 304                         list_for_each_entry_rcu(tmp_irq_info,
 305                                                 sn_irq_lh[i],
 306                                                 list) {
 307                                 if (tmp_irq_info->irq_cpuid == cpu) {
 308                                         foundmatch = 1;
 309                                         break;
 310                                 }
 311                         }
 312                 }
 313                 pdacpu(cpu)->sn_last_irq = i;
 314         }
 315
 316         if (pdacpu(cpu)->sn_first_irq == irq) {
 317                 foundmatch = 0;
 318                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 319                      i < NR_IRQS && !foundmatch; i++) {
 320                         list_for_each_entry_rcu(tmp_irq_info,
 321                                                 sn_irq_lh[i],
 322                                                 list) {
 323                                 if (tmp_irq_info->irq_cpuid == cpu) {
 324                                         foundmatch = 1;
 325                                         break;
 326                                 }
 327                         }
 328                 }
 329                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 330         }
 331         rcu_read_unlock();
 332 }
 333
 334 static void sn_irq_info_free(struct rcu_head *head)
 335 {
 336         struct sn_irq_info *sn_irq_info;
 337
 338         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 339         kfree(sn_irq_info);
 340 }
 341
 342 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 343 {
 344         nasid_t nasid = sn_irq_info->irq_nasid;
 345         int slice = sn_irq_info->irq_slice;
 346         int cpu = nasid_slice_to_cpuid(nasid, slice);
 347 #ifdef CONFIG_SMP
 348         int cpuphys;
 349 #endif
 350
 351         pci_dev_get(pci_dev);
 352         sn_irq_info->irq_cpuid = cpu;
 353         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 354
 355         /* link it into the sn_irq[irq] list */
 356         spin_lock(&sn_irq_info_lock);
 357         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 358         reserve_irq_vector(sn_irq_info->irq_irq);
 359         spin_unlock(&sn_irq_info_lock);
 360
 361         register_intr_pda(sn_irq_info);
 362 #ifdef CONFIG_SMP
 363         cpuphys = cpu_physical_id(cpu);
 364         set_irq_affinity_info(sn_irq_info->irq_irq, cpuphys, 0);
 365 #endif
 366 }
 367
 368 void sn_irq_unfixup(struct pci_dev *pci_dev)
 369 {
 370         struct sn_irq_info *sn_irq_info;
 371
 372         /* Only cleanup IRQ stuff if this device has a host bus context */
 373         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 374                 return;
 375
 376         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 377         if (!sn_irq_info)
 378                 return;
 379         if (!sn_irq_info->irq_irq) {
 380                 kfree(sn_irq_info);
 381                 return;
 382         }
 383
 384         unregister_intr_pda(sn_irq_info);
 385         spin_lock(&sn_irq_info_lock);
 386         list_del_rcu(&sn_irq_info->list);
 387         spin_unlock(&sn_irq_info_lock);
 388         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 389                 free_irq_vector(sn_irq_info->irq_irq);
 390         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 391         pci_dev_put(pci_dev);
 392
 393 }
 394
 395 static inline void
 396 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 397 {
 398         struct sn_pcibus_provider *pci_provider;
 399
 400         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 401         if (pci_provider && pci_provider->force_interrupt)
 402                 (*pci_provider->force_interrupt)(sn_irq_info);
 403 }
 404
 405 static void force_interrupt(int irq)
 406 {
 407         struct sn_irq_info *sn_irq_info;
 408
 409         if (!sn_ioif_inited)
 410                 return;
 411
 412         rcu_read_lock();
 413         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 414                 sn_call_force_intr_provider(sn_irq_info);
 415
 416         rcu_read_unlock();
 417 }
 418
 419 /*
 420  * Check for lost interrupts.  If the PIC int_status reg. says that
 421  * an interrupt has been sent, but not handled, and the interrupt
 422  * is not pending in either the cpu irr regs or in the soft irr regs,
 423  * and the interrupt is not in service, then the interrupt may have
 424  * been lost.  Force an interrupt on that pin.  It is possible that
 425  * the interrupt is in flight, so we may generate a spurious interrupt,
 426  * but we should never miss a real lost interrupt.
 427  */
 428 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 429 {
 430         u64 regval;
 431         struct pcidev_info *pcidev_info;
 432         struct pcibus_info *pcibus_info;
 433
 434         /*
 435          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 436          * since they do not target Shub II interrupt registers.  If that
 437          * ever changes, this check needs to accomodate.
 438          */
 439         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 440                 return;
 441
 442         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 443         if (!pcidev_info)
 444                 return;
 445
 446         pcibus_info =
 447             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 448             pdi_pcibus_info;
 449         regval = pcireg_intr_status_get(pcibus_info);
 450
 451         if (!ia64_get_irr(irq_to_vector(irq))) {
 452                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 453                         regval &= 0xff;
 454                         if (sn_irq_info->irq_int_bit & regval &
 455                             sn_irq_info->irq_last_intr) {
 456                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 457                                 sn_call_force_intr_provider(sn_irq_info);
 458                         }
 459                 }
 460         }
 461         sn_irq_info->irq_last_intr = regval;
 462 }
 463
 464 void sn_lb_int_war_check(void)
 465 {
 466         struct sn_irq_info *sn_irq_info;
 467         int i;
 468
 469         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 470                 return;
 471
 472         rcu_read_lock();
 473         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 474                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 475                         sn_check_intr(i, sn_irq_info);
 476                 }
 477         }
 478         rcu_read_unlock();
 479 }
 480
 481 void __init sn_irq_lh_init(void)
 482 {
 483         int i;
 484
 485         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 486         if (!sn_irq_lh)
 487                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 488
 489         for (i = 0; i < NR_IRQS; i++) {
 490                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 491                 if (!sn_irq_lh[i])
 492                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 493
 494                 INIT_LIST_HEAD(sn_irq_lh[i]);
 495         }
 496 }