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) 2000-2007 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 <linux/rculist.h>
  15 #include <asm/sn/addrs.h>
  16 #include <asm/sn/arch.h>
  17 #include <asm/sn/intr.h>
  18 #include <asm/sn/pcibr_provider.h>
  19 #include <asm/sn/pcibus_provider_defs.h>
  20 #include <asm/sn/pcidev.h>
  21 #include <asm/sn/shub_mmr.h>
  22 #include <asm/sn/sn_sal.h>
  23 #include <asm/sn/sn_feature_sets.h>
  24
  25 static void force_interrupt(int irq);
  26 static void register_intr_pda(struct sn_irq_info *sn_irq_info);
  27 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info);
  28
  29 int sn_force_interrupt_flag = 1;
  30 extern int sn_ioif_inited;
  31 struct list_head **sn_irq_lh;
  32 static DEFINE_SPINLOCK(sn_irq_info_lock); /* non-IRQ lock */
  33
  34 u64 sn_intr_alloc(nasid_t local_nasid, int local_widget,
  35                                      struct sn_irq_info *sn_irq_info,
  36                                      int req_irq, nasid_t req_nasid,
  37                                      int req_slice)
  38 {
  39         struct ia64_sal_retval ret_stuff;
  40         ret_stuff.status = 0;
  41         ret_stuff.v0 = 0;
  42
  43         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  44                         (u64) SAL_INTR_ALLOC, (u64) local_nasid,
  45                         (u64) local_widget, __pa(sn_irq_info), (u64) req_irq,
  46                         (u64) req_nasid, (u64) req_slice);
  47
  48         return ret_stuff.status;
  49 }
  50
  51 void sn_intr_free(nasid_t local_nasid, int local_widget,
  52                                 struct sn_irq_info *sn_irq_info)
  53 {
  54         struct ia64_sal_retval ret_stuff;
  55         ret_stuff.status = 0;
  56         ret_stuff.v0 = 0;
  57
  58         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  59                         (u64) SAL_INTR_FREE, (u64) local_nasid,
  60                         (u64) local_widget, (u64) sn_irq_info->irq_irq,
  61                         (u64) sn_irq_info->irq_cookie, 0, 0);
  62 }
  63
  64 u64 sn_intr_redirect(nasid_t local_nasid, int local_widget,
  65                       struct sn_irq_info *sn_irq_info,
  66                       nasid_t req_nasid, int req_slice)
  67 {
  68         struct ia64_sal_retval ret_stuff;
  69         ret_stuff.status = 0;
  70         ret_stuff.v0 = 0;
  71
  72         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  73                         (u64) SAL_INTR_REDIRECT, (u64) local_nasid,
  74                         (u64) local_widget, __pa(sn_irq_info),
  75                         (u64) req_nasid, (u64) req_slice, 0);
  76
  77         return ret_stuff.status;
  78 }
  79
  80 static unsigned int sn_startup_irq(unsigned int irq)
  81 {
  82         return 0;
  83 }
  84
  85 static void sn_shutdown_irq(unsigned int irq)
  86 {
  87 }
  88
  89 extern void ia64_mca_register_cpev(int);
  90
  91 static void sn_disable_irq(unsigned int irq)
  92 {
  93         if (irq == local_vector_to_irq(IA64_CPE_VECTOR))
  94                 ia64_mca_register_cpev(0);
  95 }
  96
  97 static void sn_enable_irq(unsigned int irq)
  98 {
  99         if (irq == local_vector_to_irq(IA64_CPE_VECTOR))
 100                 ia64_mca_register_cpev(irq);
 101 }
 102
 103 static void sn_ack_irq(unsigned int irq)
 104 {
 105         u64 event_occurred, mask;
 106
 107         irq = irq & 0xff;
 108         event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED));
 109         mask = event_occurred & SH_ALL_INT_MASK;
 110         HUB_S((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS), mask);
 111         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
 112
 113         move_native_irq(irq);
 114 }
 115
 116 static void sn_end_irq(unsigned int irq)
 117 {
 118         int ivec;
 119         u64 event_occurred;
 120
 121         ivec = irq & 0xff;
 122         if (ivec == SGI_UART_VECTOR) {
 123                 event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR (SH_EVENT_OCCURRED));
 124                 /* If the UART bit is set here, we may have received an
 125                  * interrupt from the UART that the driver missed.  To
 126                  * make sure, we IPI ourselves to force us to look again.
 127                  */
 128                 if (event_occurred & SH_EVENT_OCCURRED_UART_INT_MASK) {
 129                         platform_send_ipi(smp_processor_id(), SGI_UART_VECTOR,
 130                                           IA64_IPI_DM_INT, 0);
 131                 }
 132         }
 133         __clear_bit(ivec, (volatile void *)pda->sn_in_service_ivecs);
 134         if (sn_force_interrupt_flag)
 135                 force_interrupt(irq);
 136 }
 137
 138 static void sn_irq_info_free(struct rcu_head *head);
 139
 140 struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info,
 141                                        nasid_t nasid, int slice)
 142 {
 143         int vector;
 144         int cpuid;
 145 #ifdef CONFIG_SMP
 146         int cpuphys;
 147 #endif
 148         int64_t bridge;
 149         int local_widget, status;
 150         nasid_t local_nasid;
 151         struct sn_irq_info *new_irq_info;
 152         struct sn_pcibus_provider *pci_provider;
 153
 154         bridge = (u64) sn_irq_info->irq_bridge;
 155         if (!bridge) {
 156                 return NULL; /* irq is not a device interrupt */
 157         }
 158
 159         local_nasid = NASID_GET(bridge);
 160
 161         if (local_nasid & 1)
 162                 local_widget = TIO_SWIN_WIDGETNUM(bridge);
 163         else
 164                 local_widget = SWIN_WIDGETNUM(bridge);
 165         vector = sn_irq_info->irq_irq;
 166
 167         /* Make use of SAL_INTR_REDIRECT if PROM supports it */
 168         status = sn_intr_redirect(local_nasid, local_widget, sn_irq_info, nasid, slice);
 169         if (!status) {
 170                 new_irq_info = sn_irq_info;
 171                 goto finish_up;
 172         }
 173
 174         /*
 175          * PROM does not support SAL_INTR_REDIRECT, or it failed.
 176          * Revert to old method.
 177          */
 178         new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 179         if (new_irq_info == NULL)
 180                 return NULL;
 181
 182         memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
 183
 184         /* Free the old PROM new_irq_info structure */
 185         sn_intr_free(local_nasid, local_widget, new_irq_info);
 186         unregister_intr_pda(new_irq_info);
 187
 188         /* allocate a new PROM new_irq_info struct */
 189         status = sn_intr_alloc(local_nasid, local_widget,
 190                                new_irq_info, vector,
 191                                nasid, slice);
 192
 193         /* SAL call failed */
 194         if (status) {
 195                 kfree(new_irq_info);
 196                 return NULL;
 197         }
 198
 199         register_intr_pda(new_irq_info);
 200         spin_lock(&sn_irq_info_lock);
 201         list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
 202         spin_unlock(&sn_irq_info_lock);
 203         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 204
 205
 206 finish_up:
 207         /* Update kernels new_irq_info with new target info */
 208         cpuid = nasid_slice_to_cpuid(new_irq_info->irq_nasid,
 209                                      new_irq_info->irq_slice);
 210         new_irq_info->irq_cpuid = cpuid;
 211
 212         pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 213
 214         /*
 215          * If this represents a line interrupt, target it.  If it's
 216          * an msi (irq_int_bit < 0), it's already targeted.
 217          */
 218         if (new_irq_info->irq_int_bit >= 0 &&
 219             pci_provider && pci_provider->target_interrupt)
 220                 (pci_provider->target_interrupt)(new_irq_info);
 221
 222 #ifdef CONFIG_SMP
 223         cpuphys = cpu_physical_id(cpuid);
 224         set_irq_affinity_info((vector & 0xff), cpuphys, 0);
 225 #endif
 226
 227         return new_irq_info;
 228 }
 229
 230 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
 231 {
 232         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 233         nasid_t nasid;
 234         int slice;
 235
 236         nasid = cpuid_to_nasid(first_cpu(mask));
 237         slice = cpuid_to_slice(first_cpu(mask));
 238
 239         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 240                                  sn_irq_lh[irq], list)
 241                 (void)sn_retarget_vector(sn_irq_info, nasid, slice);
 242 }
 243
 244 #ifdef CONFIG_SMP
 245 void sn_set_err_irq_affinity(unsigned int irq)
 246 {
 247         /*
 248          * On systems which support CPU disabling (SHub2), all error interrupts
 249          * are targetted at the boot CPU.
 250          */
 251         if (is_shub2() && sn_prom_feature_available(PRF_CPU_DISABLE_SUPPORT))
 252                 set_irq_affinity_info(irq, cpu_physical_id(0), 0);
 253 }
 254 #else
 255 void sn_set_err_irq_affinity(unsigned int irq) { }
 256 #endif
 257
 258 static void
 259 sn_mask_irq(unsigned int irq)
 260 {
 261 }
 262
 263 static void
 264 sn_unmask_irq(unsigned int irq)
 265 {
 266 }
 267
 268 struct irq_chip irq_type_sn = {
 269         .name           = "SN hub",
 270         .startup        = sn_startup_irq,
 271         .shutdown       = sn_shutdown_irq,
 272         .enable         = sn_enable_irq,
 273         .disable        = sn_disable_irq,
 274         .ack            = sn_ack_irq,
 275         .end            = sn_end_irq,
 276         .mask           = sn_mask_irq,
 277         .unmask         = sn_unmask_irq,
 278         .set_affinity   = sn_set_affinity_irq
 279 };
 280
 281 ia64_vector sn_irq_to_vector(int irq)
 282 {
 283         if (irq >= IA64_NUM_VECTORS)
 284                 return 0;
 285         return (ia64_vector)irq;
 286 }
 287
 288 unsigned int sn_local_vector_to_irq(u8 vector)
 289 {
 290         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 291 }
 292
 293 void sn_irq_init(void)
 294 {
 295         int i;
 296         irq_desc_t *base_desc = irq_desc;
 297
 298         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 299         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 300
 301         for (i = 0; i < NR_IRQS; i++) {
 302                 if (base_desc[i].chip == &no_irq_type) {
 303                         base_desc[i].chip = &irq_type_sn;
 304                 }
 305         }
 306 }
 307
 308 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 309 {
 310         int irq = sn_irq_info->irq_irq;
 311         int cpu = sn_irq_info->irq_cpuid;
 312
 313         if (pdacpu(cpu)->sn_last_irq < irq) {
 314                 pdacpu(cpu)->sn_last_irq = irq;
 315         }
 316
 317         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 318                 pdacpu(cpu)->sn_first_irq = irq;
 319 }
 320
 321 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 322 {
 323         int irq = sn_irq_info->irq_irq;
 324         int cpu = sn_irq_info->irq_cpuid;
 325         struct sn_irq_info *tmp_irq_info;
 326         int i, foundmatch;
 327
 328         rcu_read_lock();
 329         if (pdacpu(cpu)->sn_last_irq == irq) {
 330                 foundmatch = 0;
 331                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 332                      i && !foundmatch; i--) {
 333                         list_for_each_entry_rcu(tmp_irq_info,
 334                                                 sn_irq_lh[i],
 335                                                 list) {
 336                                 if (tmp_irq_info->irq_cpuid == cpu) {
 337                                         foundmatch = 1;
 338                                         break;
 339                                 }
 340                         }
 341                 }
 342                 pdacpu(cpu)->sn_last_irq = i;
 343         }
 344
 345         if (pdacpu(cpu)->sn_first_irq == irq) {
 346                 foundmatch = 0;
 347                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 348                      i < NR_IRQS && !foundmatch; i++) {
 349                         list_for_each_entry_rcu(tmp_irq_info,
 350                                                 sn_irq_lh[i],
 351                                                 list) {
 352                                 if (tmp_irq_info->irq_cpuid == cpu) {
 353                                         foundmatch = 1;
 354                                         break;
 355                                 }
 356                         }
 357                 }
 358                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 359         }
 360         rcu_read_unlock();
 361 }
 362
 363 static void sn_irq_info_free(struct rcu_head *head)
 364 {
 365         struct sn_irq_info *sn_irq_info;
 366
 367         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 368         kfree(sn_irq_info);
 369 }
 370
 371 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 372 {
 373         nasid_t nasid = sn_irq_info->irq_nasid;
 374         int slice = sn_irq_info->irq_slice;
 375         int cpu = nasid_slice_to_cpuid(nasid, slice);
 376 #ifdef CONFIG_SMP
 377         int cpuphys;
 378 #endif
 379
 380         pci_dev_get(pci_dev);
 381         sn_irq_info->irq_cpuid = cpu;
 382         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 383
 384         /* link it into the sn_irq[irq] list */
 385         spin_lock(&sn_irq_info_lock);
 386         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 387         reserve_irq_vector(sn_irq_info->irq_irq);
 388         spin_unlock(&sn_irq_info_lock);
 389
 390         register_intr_pda(sn_irq_info);
 391 #ifdef CONFIG_SMP
 392         cpuphys = cpu_physical_id(cpu);
 393         set_irq_affinity_info(sn_irq_info->irq_irq, cpuphys, 0);
 394 #endif
 395 }
 396
 397 void sn_irq_unfixup(struct pci_dev *pci_dev)
 398 {
 399         struct sn_irq_info *sn_irq_info;
 400
 401         /* Only cleanup IRQ stuff if this device has a host bus context */
 402         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 403                 return;
 404
 405         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 406         if (!sn_irq_info)
 407                 return;
 408         if (!sn_irq_info->irq_irq) {
 409                 kfree(sn_irq_info);
 410                 return;
 411         }
 412
 413         unregister_intr_pda(sn_irq_info);
 414         spin_lock(&sn_irq_info_lock);
 415         list_del_rcu(&sn_irq_info->list);
 416         spin_unlock(&sn_irq_info_lock);
 417         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 418                 free_irq_vector(sn_irq_info->irq_irq);
 419         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 420         pci_dev_put(pci_dev);
 421
 422 }
 423
 424 static inline void
 425 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 426 {
 427         struct sn_pcibus_provider *pci_provider;
 428
 429         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 430
 431         /* Don't force an interrupt if the irq has been disabled */
 432         if (!(irq_desc[sn_irq_info->irq_irq].status & IRQ_DISABLED) &&
 433             pci_provider && pci_provider->force_interrupt)
 434                 (*pci_provider->force_interrupt)(sn_irq_info);
 435 }
 436
 437 static void force_interrupt(int irq)
 438 {
 439         struct sn_irq_info *sn_irq_info;
 440
 441         if (!sn_ioif_inited)
 442                 return;
 443
 444         rcu_read_lock();
 445         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 446                 sn_call_force_intr_provider(sn_irq_info);
 447
 448         rcu_read_unlock();
 449 }
 450
 451 /*
 452  * Check for lost interrupts.  If the PIC int_status reg. says that
 453  * an interrupt has been sent, but not handled, and the interrupt
 454  * is not pending in either the cpu irr regs or in the soft irr regs,
 455  * and the interrupt is not in service, then the interrupt may have
 456  * been lost.  Force an interrupt on that pin.  It is possible that
 457  * the interrupt is in flight, so we may generate a spurious interrupt,
 458  * but we should never miss a real lost interrupt.
 459  */
 460 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 461 {
 462         u64 regval;
 463         struct pcidev_info *pcidev_info;
 464         struct pcibus_info *pcibus_info;
 465
 466         /*
 467          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 468          * since they do not target Shub II interrupt registers.  If that
 469          * ever changes, this check needs to accomodate.
 470          */
 471         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 472                 return;
 473
 474         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 475         if (!pcidev_info)
 476                 return;
 477
 478         pcibus_info =
 479             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 480             pdi_pcibus_info;
 481         regval = pcireg_intr_status_get(pcibus_info);
 482
 483         if (!ia64_get_irr(irq_to_vector(irq))) {
 484                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 485                         regval &= 0xff;
 486                         if (sn_irq_info->irq_int_bit & regval &
 487                             sn_irq_info->irq_last_intr) {
 488                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 489                                 sn_call_force_intr_provider(sn_irq_info);
 490                         }
 491                 }
 492         }
 493         sn_irq_info->irq_last_intr = regval;
 494 }
 495
 496 void sn_lb_int_war_check(void)
 497 {
 498         struct sn_irq_info *sn_irq_info;
 499         int i;
 500
 501         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 502                 return;
 503
 504         rcu_read_lock();
 505         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 506                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 507                         sn_check_intr(i, sn_irq_info);
 508                 }
 509         }
 510         rcu_read_unlock();
 511 }
 512
 513 void __init sn_irq_lh_init(void)
 514 {
 515         int i;
 516
 517         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 518         if (!sn_irq_lh)
 519                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 520
 521         for (i = 0; i < NR_IRQS; i++) {
 522                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 523                 if (!sn_irq_lh[i])
 524                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 525
 526                 INIT_LIST_HEAD(sn_irq_lh[i]);
 527         }
 528 }