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) 2000-2008 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 <linux/slab.h>
  16 #include <asm/sn/addrs.h>
  17 #include <asm/sn/arch.h>
  18 #include <asm/sn/intr.h>
  19 #include <asm/sn/pcibr_provider.h>
  20 #include <asm/sn/pcibus_provider_defs.h>
  21 #include <asm/sn/pcidev.h>
  22 #include <asm/sn/shub_mmr.h>
  23 #include <asm/sn/sn_sal.h>
  24 #include <asm/sn/sn_feature_sets.h>
  25
  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 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(struct irq_data *data)
  80 {
  81         return 0;
  82 }
  83
  84 static void sn_shutdown_irq(struct irq_data *data)
  85 {
  86 }
  87
  88 extern void ia64_mca_register_cpev(int);
  89
  90 static void sn_disable_irq(struct irq_data *data)
  91 {
  92         if (data->irq == local_vector_to_irq(IA64_CPE_VECTOR))
  93                 ia64_mca_register_cpev(0);
  94 }
  95
  96 static void sn_enable_irq(struct irq_data *data)
  97 {
  98         if (data->irq == local_vector_to_irq(IA64_CPE_VECTOR))
  99                 ia64_mca_register_cpev(data->irq);
 100 }
 101
 102 static void sn_ack_irq(struct irq_data *data)
 103 {
 104         u64 event_occurred, mask;
 105         unsigned int irq = data->irq & 0xff;
 106
 107         event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED));
 108         mask = event_occurred & SH_ALL_INT_MASK;
 109         HUB_S((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS), mask);
 110         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
 111
 112         move_native_irq(irq);
 113 }
 114
 115 static void sn_irq_info_free(struct rcu_head *head);
 116
 117 struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info,
 118                                        nasid_t nasid, int slice)
 119 {
 120         int vector;
 121         int cpuid;
 122 #ifdef CONFIG_SMP
 123         int cpuphys;
 124 #endif
 125         int64_t bridge;
 126         int local_widget, status;
 127         nasid_t local_nasid;
 128         struct sn_irq_info *new_irq_info;
 129         struct sn_pcibus_provider *pci_provider;
 130
 131         bridge = (u64) sn_irq_info->irq_bridge;
 132         if (!bridge) {
 133                 return NULL; /* irq is not a device interrupt */
 134         }
 135
 136         local_nasid = NASID_GET(bridge);
 137
 138         if (local_nasid & 1)
 139                 local_widget = TIO_SWIN_WIDGETNUM(bridge);
 140         else
 141                 local_widget = SWIN_WIDGETNUM(bridge);
 142         vector = sn_irq_info->irq_irq;
 143
 144         /* Make use of SAL_INTR_REDIRECT if PROM supports it */
 145         status = sn_intr_redirect(local_nasid, local_widget, sn_irq_info, nasid, slice);
 146         if (!status) {
 147                 new_irq_info = sn_irq_info;
 148                 goto finish_up;
 149         }
 150
 151         /*
 152          * PROM does not support SAL_INTR_REDIRECT, or it failed.
 153          * Revert to old method.
 154          */
 155         new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 156         if (new_irq_info == NULL)
 157                 return NULL;
 158
 159         memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
 160
 161         /* Free the old PROM new_irq_info structure */
 162         sn_intr_free(local_nasid, local_widget, new_irq_info);
 163         unregister_intr_pda(new_irq_info);
 164
 165         /* allocate a new PROM new_irq_info struct */
 166         status = sn_intr_alloc(local_nasid, local_widget,
 167                                new_irq_info, vector,
 168                                nasid, slice);
 169
 170         /* SAL call failed */
 171         if (status) {
 172                 kfree(new_irq_info);
 173                 return NULL;
 174         }
 175
 176         register_intr_pda(new_irq_info);
 177         spin_lock(&sn_irq_info_lock);
 178         list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
 179         spin_unlock(&sn_irq_info_lock);
 180         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 181
 182
 183 finish_up:
 184         /* Update kernels new_irq_info with new target info */
 185         cpuid = nasid_slice_to_cpuid(new_irq_info->irq_nasid,
 186                                      new_irq_info->irq_slice);
 187         new_irq_info->irq_cpuid = cpuid;
 188
 189         pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 190
 191         /*
 192          * If this represents a line interrupt, target it.  If it's
 193          * an msi (irq_int_bit < 0), it's already targeted.
 194          */
 195         if (new_irq_info->irq_int_bit >= 0 &&
 196             pci_provider && pci_provider->target_interrupt)
 197                 (pci_provider->target_interrupt)(new_irq_info);
 198
 199 #ifdef CONFIG_SMP
 200         cpuphys = cpu_physical_id(cpuid);
 201         set_irq_affinity_info((vector & 0xff), cpuphys, 0);
 202 #endif
 203
 204         return new_irq_info;
 205 }
 206
 207 static int sn_set_affinity_irq(struct irq_data *data,
 208                                const struct cpumask *mask, bool force)
 209 {
 210         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 211         unsigned int irq = data->irq;
 212         nasid_t nasid;
 213         int slice;
 214
 215         nasid = cpuid_to_nasid(cpumask_first(mask));
 216         slice = cpuid_to_slice(cpumask_first(mask));
 217
 218         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 219                                  sn_irq_lh[irq], list)
 220                 (void)sn_retarget_vector(sn_irq_info, nasid, slice);
 221
 222         return 0;
 223 }
 224
 225 #ifdef CONFIG_SMP
 226 void sn_set_err_irq_affinity(unsigned int irq)
 227 {
 228         /*
 229          * On systems which support CPU disabling (SHub2), all error interrupts
 230          * are targetted at the boot CPU.
 231          */
 232         if (is_shub2() && sn_prom_feature_available(PRF_CPU_DISABLE_SUPPORT))
 233                 set_irq_affinity_info(irq, cpu_physical_id(0), 0);
 234 }
 235 #else
 236 void sn_set_err_irq_affinity(unsigned int irq) { }
 237 #endif
 238
 239 static void
 240 sn_mask_irq(struct irq_data *data)
 241 {
 242 }
 243
 244 static void
 245 sn_unmask_irq(struct irq_data *data)
 246 {
 247 }
 248
 249 struct irq_chip irq_type_sn = {
 250         .name                   = "SN hub",
 251         .irq_startup            = sn_startup_irq,
 252         .irq_shutdown           = sn_shutdown_irq,
 253         .irq_enable             = sn_enable_irq,
 254         .irq_disable            = sn_disable_irq,
 255         .irq_ack                = sn_ack_irq,
 256         .irq_mask               = sn_mask_irq,
 257         .irq_unmask             = sn_unmask_irq,
 258         .irq_set_affinity       = sn_set_affinity_irq
 259 };
 260
 261 ia64_vector sn_irq_to_vector(int irq)
 262 {
 263         if (irq >= IA64_NUM_VECTORS)
 264                 return 0;
 265         return (ia64_vector)irq;
 266 }
 267
 268 unsigned int sn_local_vector_to_irq(u8 vector)
 269 {
 270         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 271 }
 272
 273 void sn_irq_init(void)
 274 {
 275         int i;
 276         struct irq_desc *base_desc = irq_desc;
 277
 278         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 279         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 280
 281         for (i = 0; i < NR_IRQS; i++) {
 282                 if (base_desc[i].chip == &no_irq_chip) {
 283                         base_desc[i].chip = &irq_type_sn;
 284                 }
 285         }
 286 }
 287
 288 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 289 {
 290         int irq = sn_irq_info->irq_irq;
 291         int cpu = sn_irq_info->irq_cpuid;
 292
 293         if (pdacpu(cpu)->sn_last_irq < irq) {
 294                 pdacpu(cpu)->sn_last_irq = irq;
 295         }
 296
 297         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 298                 pdacpu(cpu)->sn_first_irq = irq;
 299 }
 300
 301 static void unregister_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         struct sn_irq_info *tmp_irq_info;
 306         int i, foundmatch;
 307
 308         rcu_read_lock();
 309         if (pdacpu(cpu)->sn_last_irq == irq) {
 310                 foundmatch = 0;
 311                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 312                      i && !foundmatch; i--) {
 313                         list_for_each_entry_rcu(tmp_irq_info,
 314                                                 sn_irq_lh[i],
 315                                                 list) {
 316                                 if (tmp_irq_info->irq_cpuid == cpu) {
 317                                         foundmatch = 1;
 318                                         break;
 319                                 }
 320                         }
 321                 }
 322                 pdacpu(cpu)->sn_last_irq = i;
 323         }
 324
 325         if (pdacpu(cpu)->sn_first_irq == irq) {
 326                 foundmatch = 0;
 327                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 328                      i < NR_IRQS && !foundmatch; i++) {
 329                         list_for_each_entry_rcu(tmp_irq_info,
 330                                                 sn_irq_lh[i],
 331                                                 list) {
 332                                 if (tmp_irq_info->irq_cpuid == cpu) {
 333                                         foundmatch = 1;
 334                                         break;
 335                                 }
 336                         }
 337                 }
 338                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 339         }
 340         rcu_read_unlock();
 341 }
 342
 343 static void sn_irq_info_free(struct rcu_head *head)
 344 {
 345         struct sn_irq_info *sn_irq_info;
 346
 347         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 348         kfree(sn_irq_info);
 349 }
 350
 351 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 352 {
 353         nasid_t nasid = sn_irq_info->irq_nasid;
 354         int slice = sn_irq_info->irq_slice;
 355         int cpu = nasid_slice_to_cpuid(nasid, slice);
 356 #ifdef CONFIG_SMP
 357         int cpuphys;
 358         struct irq_desc *desc;
 359 #endif
 360
 361         pci_dev_get(pci_dev);
 362         sn_irq_info->irq_cpuid = cpu;
 363         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 364
 365         /* link it into the sn_irq[irq] list */
 366         spin_lock(&sn_irq_info_lock);
 367         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 368         reserve_irq_vector(sn_irq_info->irq_irq);
 369         spin_unlock(&sn_irq_info_lock);
 370
 371         register_intr_pda(sn_irq_info);
 372 #ifdef CONFIG_SMP
 373         cpuphys = cpu_physical_id(cpu);
 374         set_irq_affinity_info(sn_irq_info->irq_irq, cpuphys, 0);
 375         desc = irq_to_desc(sn_irq_info->irq_irq);
 376         /*
 377          * Affinity was set by the PROM, prevent it from
 378          * being reset by the request_irq() path.
 379          */
 380         desc->status |= IRQ_AFFINITY_SET;
 381 #endif
 382 }
 383
 384 void sn_irq_unfixup(struct pci_dev *pci_dev)
 385 {
 386         struct sn_irq_info *sn_irq_info;
 387
 388         /* Only cleanup IRQ stuff if this device has a host bus context */
 389         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 390                 return;
 391
 392         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 393         if (!sn_irq_info)
 394                 return;
 395         if (!sn_irq_info->irq_irq) {
 396                 kfree(sn_irq_info);
 397                 return;
 398         }
 399
 400         unregister_intr_pda(sn_irq_info);
 401         spin_lock(&sn_irq_info_lock);
 402         list_del_rcu(&sn_irq_info->list);
 403         spin_unlock(&sn_irq_info_lock);
 404         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 405                 free_irq_vector(sn_irq_info->irq_irq);
 406         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 407         pci_dev_put(pci_dev);
 408
 409 }
 410
 411 static inline void
 412 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 413 {
 414         struct sn_pcibus_provider *pci_provider;
 415
 416         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 417
 418         /* Don't force an interrupt if the irq has been disabled */
 419         if (!(irq_desc[sn_irq_info->irq_irq].status & IRQ_DISABLED) &&
 420             pci_provider && pci_provider->force_interrupt)
 421                 (*pci_provider->force_interrupt)(sn_irq_info);
 422 }
 423
 424 /*
 425  * Check for lost interrupts.  If the PIC int_status reg. says that
 426  * an interrupt has been sent, but not handled, and the interrupt
 427  * is not pending in either the cpu irr regs or in the soft irr regs,
 428  * and the interrupt is not in service, then the interrupt may have
 429  * been lost.  Force an interrupt on that pin.  It is possible that
 430  * the interrupt is in flight, so we may generate a spurious interrupt,
 431  * but we should never miss a real lost interrupt.
 432  */
 433 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 434 {
 435         u64 regval;
 436         struct pcidev_info *pcidev_info;
 437         struct pcibus_info *pcibus_info;
 438
 439         /*
 440          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 441          * since they do not target Shub II interrupt registers.  If that
 442          * ever changes, this check needs to accomodate.
 443          */
 444         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 445                 return;
 446
 447         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 448         if (!pcidev_info)
 449                 return;
 450
 451         pcibus_info =
 452             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 453             pdi_pcibus_info;
 454         regval = pcireg_intr_status_get(pcibus_info);
 455
 456         if (!ia64_get_irr(irq_to_vector(irq))) {
 457                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 458                         regval &= 0xff;
 459                         if (sn_irq_info->irq_int_bit & regval &
 460                             sn_irq_info->irq_last_intr) {
 461                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 462                                 sn_call_force_intr_provider(sn_irq_info);
 463                         }
 464                 }
 465         }
 466         sn_irq_info->irq_last_intr = regval;
 467 }
 468
 469 void sn_lb_int_war_check(void)
 470 {
 471         struct sn_irq_info *sn_irq_info;
 472         int i;
 473
 474         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 475                 return;
 476
 477         rcu_read_lock();
 478         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 479                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 480                         sn_check_intr(i, sn_irq_info);
 481                 }
 482         }
 483         rcu_read_unlock();
 484 }
 485
 486 void __init sn_irq_lh_init(void)
 487 {
 488         int i;
 489
 490         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 491         if (!sn_irq_lh)
 492                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 493
 494         for (i = 0; i < NR_IRQS; i++) {
 495                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 496                 if (!sn_irq_lh[i])
 497                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 498
 499                 INIT_LIST_HEAD(sn_irq_lh[i]);
 500         }
 501 }