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         irq_move_irq(data);
 113 }
 114
 115 struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info,
 116                                        nasid_t nasid, int slice)
 117 {
 118         int vector;
 119         int cpuid;
 120 #ifdef CONFIG_SMP
 121         int cpuphys;
 122 #endif
 123         int64_t bridge;
 124         int local_widget, status;
 125         nasid_t local_nasid;
 126         struct sn_irq_info *new_irq_info;
 127         struct sn_pcibus_provider *pci_provider;
 128
 129         bridge = (u64) sn_irq_info->irq_bridge;
 130         if (!bridge) {
 131                 return NULL; /* irq is not a device interrupt */
 132         }
 133
 134         local_nasid = NASID_GET(bridge);
 135
 136         if (local_nasid & 1)
 137                 local_widget = TIO_SWIN_WIDGETNUM(bridge);
 138         else
 139                 local_widget = SWIN_WIDGETNUM(bridge);
 140         vector = sn_irq_info->irq_irq;
 141
 142         /* Make use of SAL_INTR_REDIRECT if PROM supports it */
 143         status = sn_intr_redirect(local_nasid, local_widget, sn_irq_info, nasid, slice);
 144         if (!status) {
 145                 new_irq_info = sn_irq_info;
 146                 goto finish_up;
 147         }
 148
 149         /*
 150          * PROM does not support SAL_INTR_REDIRECT, or it failed.
 151          * Revert to old method.
 152          */
 153         new_irq_info = kmemdup(sn_irq_info, sizeof(struct sn_irq_info),
 154                                GFP_ATOMIC);
 155         if (new_irq_info == NULL)
 156                 return NULL;
 157
 158         /* Free the old PROM new_irq_info structure */
 159         sn_intr_free(local_nasid, local_widget, new_irq_info);
 160         unregister_intr_pda(new_irq_info);
 161
 162         /* allocate a new PROM new_irq_info struct */
 163         status = sn_intr_alloc(local_nasid, local_widget,
 164                                new_irq_info, vector,
 165                                nasid, slice);
 166
 167         /* SAL call failed */
 168         if (status) {
 169                 kfree(new_irq_info);
 170                 return NULL;
 171         }
 172
 173         register_intr_pda(new_irq_info);
 174         spin_lock(&sn_irq_info_lock);
 175         list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
 176         spin_unlock(&sn_irq_info_lock);
 177         kfree_rcu(sn_irq_info, rcu);
 178
 179
 180 finish_up:
 181         /* Update kernels new_irq_info with new target info */
 182         cpuid = nasid_slice_to_cpuid(new_irq_info->irq_nasid,
 183                                      new_irq_info->irq_slice);
 184         new_irq_info->irq_cpuid = cpuid;
 185
 186         pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 187
 188         /*
 189          * If this represents a line interrupt, target it.  If it's
 190          * an msi (irq_int_bit < 0), it's already targeted.
 191          */
 192         if (new_irq_info->irq_int_bit >= 0 &&
 193             pci_provider && pci_provider->target_interrupt)
 194                 (pci_provider->target_interrupt)(new_irq_info);
 195
 196 #ifdef CONFIG_SMP
 197         cpuphys = cpu_physical_id(cpuid);
 198         set_irq_affinity_info((vector & 0xff), cpuphys, 0);
 199 #endif
 200
 201         return new_irq_info;
 202 }
 203
 204 static int sn_set_affinity_irq(struct irq_data *data,
 205                                const struct cpumask *mask, bool force)
 206 {
 207         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 208         unsigned int irq = data->irq;
 209         nasid_t nasid;
 210         int slice;
 211
 212         nasid = cpuid_to_nasid(cpumask_first(mask));
 213         slice = cpuid_to_slice(cpumask_first(mask));
 214
 215         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 216                                  sn_irq_lh[irq], list)
 217                 (void)sn_retarget_vector(sn_irq_info, nasid, slice);
 218
 219         return 0;
 220 }
 221
 222 #ifdef CONFIG_SMP
 223 void sn_set_err_irq_affinity(unsigned int irq)
 224 {
 225         /*
 226          * On systems which support CPU disabling (SHub2), all error interrupts
 227          * are targeted at the boot CPU.
 228          */
 229         if (is_shub2() && sn_prom_feature_available(PRF_CPU_DISABLE_SUPPORT))
 230                 set_irq_affinity_info(irq, cpu_physical_id(0), 0);
 231 }
 232 #else
 233 void sn_set_err_irq_affinity(unsigned int irq) { }
 234 #endif
 235
 236 static void
 237 sn_mask_irq(struct irq_data *data)
 238 {
 239 }
 240
 241 static void
 242 sn_unmask_irq(struct irq_data *data)
 243 {
 244 }
 245
 246 struct irq_chip irq_type_sn = {
 247         .name                   = "SN hub",
 248         .irq_startup            = sn_startup_irq,
 249         .irq_shutdown           = sn_shutdown_irq,
 250         .irq_enable             = sn_enable_irq,
 251         .irq_disable            = sn_disable_irq,
 252         .irq_ack                = sn_ack_irq,
 253         .irq_mask               = sn_mask_irq,
 254         .irq_unmask             = sn_unmask_irq,
 255         .irq_set_affinity       = sn_set_affinity_irq
 256 };
 257
 258 ia64_vector sn_irq_to_vector(int irq)
 259 {
 260         if (irq >= IA64_NUM_VECTORS)
 261                 return 0;
 262         return (ia64_vector)irq;
 263 }
 264
 265 unsigned int sn_local_vector_to_irq(u8 vector)
 266 {
 267         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 268 }
 269
 270 void sn_irq_init(void)
 271 {
 272         int i;
 273
 274         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 275         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 276
 277         for (i = 0; i < NR_IRQS; i++) {
 278                 if (irq_get_chip(i) == &no_irq_chip)
 279                         irq_set_chip(i, &irq_type_sn);
 280         }
 281 }
 282
 283 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 284 {
 285         int irq = sn_irq_info->irq_irq;
 286         int cpu = sn_irq_info->irq_cpuid;
 287
 288         if (pdacpu(cpu)->sn_last_irq < irq) {
 289                 pdacpu(cpu)->sn_last_irq = irq;
 290         }
 291
 292         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 293                 pdacpu(cpu)->sn_first_irq = irq;
 294 }
 295
 296 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 297 {
 298         int irq = sn_irq_info->irq_irq;
 299         int cpu = sn_irq_info->irq_cpuid;
 300         struct sn_irq_info *tmp_irq_info;
 301         int i, foundmatch;
 302
 303         rcu_read_lock();
 304         if (pdacpu(cpu)->sn_last_irq == irq) {
 305                 foundmatch = 0;
 306                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 307                      i && !foundmatch; i--) {
 308                         list_for_each_entry_rcu(tmp_irq_info,
 309                                                 sn_irq_lh[i],
 310                                                 list) {
 311                                 if (tmp_irq_info->irq_cpuid == cpu) {
 312                                         foundmatch = 1;
 313                                         break;
 314                                 }
 315                         }
 316                 }
 317                 pdacpu(cpu)->sn_last_irq = i;
 318         }
 319
 320         if (pdacpu(cpu)->sn_first_irq == irq) {
 321                 foundmatch = 0;
 322                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 323                      i < NR_IRQS && !foundmatch; i++) {
 324                         list_for_each_entry_rcu(tmp_irq_info,
 325                                                 sn_irq_lh[i],
 326                                                 list) {
 327                                 if (tmp_irq_info->irq_cpuid == cpu) {
 328                                         foundmatch = 1;
 329                                         break;
 330                                 }
 331                         }
 332                 }
 333                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 334         }
 335         rcu_read_unlock();
 336 }
 337
 338 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 339 {
 340         nasid_t nasid = sn_irq_info->irq_nasid;
 341         int slice = sn_irq_info->irq_slice;
 342         int cpu = nasid_slice_to_cpuid(nasid, slice);
 343 #ifdef CONFIG_SMP
 344         int cpuphys;
 345 #endif
 346
 347         pci_dev_get(pci_dev);
 348         sn_irq_info->irq_cpuid = cpu;
 349         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 350
 351         /* link it into the sn_irq[irq] list */
 352         spin_lock(&sn_irq_info_lock);
 353         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 354         reserve_irq_vector(sn_irq_info->irq_irq);
 355         spin_unlock(&sn_irq_info_lock);
 356
 357         register_intr_pda(sn_irq_info);
 358 #ifdef CONFIG_SMP
 359         cpuphys = cpu_physical_id(cpu);
 360         set_irq_affinity_info(sn_irq_info->irq_irq, cpuphys, 0);
 361         /*
 362          * Affinity was set by the PROM, prevent it from
 363          * being reset by the request_irq() path.
 364          */
 365         irqd_mark_affinity_was_set(irq_get_irq_data(sn_irq_info->irq_irq));
 366 #endif
 367 }
 368
 369 void sn_irq_unfixup(struct pci_dev *pci_dev)
 370 {
 371         struct sn_irq_info *sn_irq_info;
 372
 373         /* Only cleanup IRQ stuff if this device has a host bus context */
 374         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 375                 return;
 376
 377         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 378         if (!sn_irq_info)
 379                 return;
 380         if (!sn_irq_info->irq_irq) {
 381                 kfree(sn_irq_info);
 382                 return;
 383         }
 384
 385         unregister_intr_pda(sn_irq_info);
 386         spin_lock(&sn_irq_info_lock);
 387         list_del_rcu(&sn_irq_info->list);
 388         spin_unlock(&sn_irq_info_lock);
 389         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 390                 free_irq_vector(sn_irq_info->irq_irq);
 391         kfree_rcu(sn_irq_info, rcu);
 392         pci_dev_put(pci_dev);
 393
 394 }
 395
 396 static inline void
 397 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 398 {
 399         struct sn_pcibus_provider *pci_provider;
 400
 401         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 402
 403         /* Don't force an interrupt if the irq has been disabled */
 404         if (!irqd_irq_disabled(irq_get_irq_data(sn_irq_info->irq_irq)) &&
 405             pci_provider && pci_provider->force_interrupt)
 406                 (*pci_provider->force_interrupt)(sn_irq_info);
 407 }
 408
 409 /*
 410  * Check for lost interrupts.  If the PIC int_status reg. says that
 411  * an interrupt has been sent, but not handled, and the interrupt
 412  * is not pending in either the cpu irr regs or in the soft irr regs,
 413  * and the interrupt is not in service, then the interrupt may have
 414  * been lost.  Force an interrupt on that pin.  It is possible that
 415  * the interrupt is in flight, so we may generate a spurious interrupt,
 416  * but we should never miss a real lost interrupt.
 417  */
 418 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 419 {
 420         u64 regval;
 421         struct pcidev_info *pcidev_info;
 422         struct pcibus_info *pcibus_info;
 423
 424         /*
 425          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 426          * since they do not target Shub II interrupt registers.  If that
 427          * ever changes, this check needs to accommodate.
 428          */
 429         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 430                 return;
 431
 432         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 433         if (!pcidev_info)
 434                 return;
 435
 436         pcibus_info =
 437             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 438             pdi_pcibus_info;
 439         regval = pcireg_intr_status_get(pcibus_info);
 440
 441         if (!ia64_get_irr(irq_to_vector(irq))) {
 442                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 443                         regval &= 0xff;
 444                         if (sn_irq_info->irq_int_bit & regval &
 445                             sn_irq_info->irq_last_intr) {
 446                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 447                                 sn_call_force_intr_provider(sn_irq_info);
 448                         }
 449                 }
 450         }
 451         sn_irq_info->irq_last_intr = regval;
 452 }
 453
 454 void sn_lb_int_war_check(void)
 455 {
 456         struct sn_irq_info *sn_irq_info;
 457         int i;
 458
 459         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 460                 return;
 461
 462         rcu_read_lock();
 463         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 464                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 465                         sn_check_intr(i, sn_irq_info);
 466                 }
 467         }
 468         rcu_read_unlock();
 469 }
 470
 471 void __init sn_irq_lh_init(void)
 472 {
 473         int i;
 474
 475         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 476         if (!sn_irq_lh)
 477                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 478
 479         for (i = 0; i < NR_IRQS; i++) {
 480                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 481                 if (!sn_irq_lh[i])
 482                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 483
 484                 INIT_LIST_HEAD(sn_irq_lh[i]);
 485         }
 486 }