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) 2000-2004 Silicon Graphics, Inc.  All Rights Reserved.
   9  */
  10
  11 #include <linux/irq.h>
  12 #include <linux/spinlock.h>
  13 #include <asm/sn/addrs.h>
  14 #include <asm/sn/arch.h>
  15 #include <asm/sn/intr.h>
  16 #include <asm/sn/pcibr_provider.h>
  17 #include <asm/sn/pcibus_provider_defs.h>
  18 #include <asm/sn/pcidev.h>
  19 #include <asm/sn/shub_mmr.h>
  20 #include <asm/sn/sn_sal.h>
  21
  22 static void force_interrupt(int irq);
  23 static void register_intr_pda(struct sn_irq_info *sn_irq_info);
  24 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info);
  25
  26 extern int sn_force_interrupt_flag;
  27 extern int sn_ioif_inited;
  28 static struct list_head **sn_irq_lh;
  29 static spinlock_t sn_irq_info_lock = SPIN_LOCK_UNLOCKED; /* non-IRQ lock */
  30
  31 static inline uint64_t sn_intr_alloc(nasid_t local_nasid, int local_widget,
  32                                      u64 sn_irq_info,
  33                                      int req_irq, nasid_t req_nasid,
  34                                      int req_slice)
  35 {
  36         struct ia64_sal_retval ret_stuff;
  37         ret_stuff.status = 0;
  38         ret_stuff.v0 = 0;
  39
  40         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  41                         (u64) SAL_INTR_ALLOC, (u64) local_nasid,
  42                         (u64) local_widget, (u64) sn_irq_info, (u64) req_irq,
  43                         (u64) req_nasid, (u64) req_slice);
  44         return ret_stuff.status;
  45 }
  46
  47 static inline void sn_intr_free(nasid_t local_nasid, int local_widget,
  48                                 struct sn_irq_info *sn_irq_info)
  49 {
  50         struct ia64_sal_retval ret_stuff;
  51         ret_stuff.status = 0;
  52         ret_stuff.v0 = 0;
  53
  54         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  55                         (u64) SAL_INTR_FREE, (u64) local_nasid,
  56                         (u64) local_widget, (u64) sn_irq_info->irq_irq,
  57                         (u64) sn_irq_info->irq_cookie, 0, 0);
  58 }
  59
  60 static unsigned int sn_startup_irq(unsigned int irq)
  61 {
  62         return 0;
  63 }
  64
  65 static void sn_shutdown_irq(unsigned int irq)
  66 {
  67 }
  68
  69 static void sn_disable_irq(unsigned int irq)
  70 {
  71 }
  72
  73 static void sn_enable_irq(unsigned int irq)
  74 {
  75 }
  76
  77 static void sn_ack_irq(unsigned int irq)
  78 {
  79         uint64_t event_occurred, mask = 0;
  80         int nasid;
  81
  82         irq = irq & 0xff;
  83         nasid = get_nasid();
  84         event_occurred =
  85             HUB_L((uint64_t *) GLOBAL_MMR_ADDR(nasid, SH_EVENT_OCCURRED));
  86         mask = event_occurred & SH_ALL_INT_MASK;
  87         HUB_S((uint64_t *) GLOBAL_MMR_ADDR(nasid, SH_EVENT_OCCURRED_ALIAS),
  88                  mask);
  89         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
  90
  91         move_irq(irq);
  92 }
  93
  94 static void sn_end_irq(unsigned int irq)
  95 {
  96         int nasid;
  97         int ivec;
  98         uint64_t event_occurred;
  99
 100         ivec = irq & 0xff;
 101         if (ivec == SGI_UART_VECTOR) {
 102                 nasid = get_nasid();
 103                 event_occurred = HUB_L((uint64_t *) GLOBAL_MMR_ADDR
 104                                        (nasid, SH_EVENT_OCCURRED));
 105                 /* If the UART bit is set here, we may have received an
 106                  * interrupt from the UART that the driver missed.  To
 107                  * make sure, we IPI ourselves to force us to look again.
 108                  */
 109                 if (event_occurred & SH_EVENT_OCCURRED_UART_INT_MASK) {
 110                         platform_send_ipi(smp_processor_id(), SGI_UART_VECTOR,
 111                                           IA64_IPI_DM_INT, 0);
 112                 }
 113         }
 114         __clear_bit(ivec, (volatile void *)pda->sn_in_service_ivecs);
 115         if (sn_force_interrupt_flag)
 116                 force_interrupt(irq);
 117 }
 118
 119 static void sn_irq_info_free(struct rcu_head *head);
 120
 121 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
 122 {
 123         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 124         int cpuid, cpuphys;
 125
 126         cpuid = first_cpu(mask);
 127         cpuphys = cpu_physical_id(cpuid);
 128
 129         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 130                                  sn_irq_lh[irq], list) {
 131                 uint64_t bridge;
 132                 int local_widget, status;
 133                 nasid_t local_nasid;
 134                 struct sn_irq_info *new_irq_info;
 135
 136                 new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 137                 if (new_irq_info == NULL)
 138                         break;
 139                 memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
 140
 141                 bridge = (uint64_t) new_irq_info->irq_bridge;
 142                 if (!bridge) {
 143                         kfree(new_irq_info);
 144                         break; /* irq is not a device interrupt */
 145                 }
 146
 147                 local_nasid = NASID_GET(bridge);
 148
 149                 if (local_nasid & 1)
 150                         local_widget = TIO_SWIN_WIDGETNUM(bridge);
 151                 else
 152                         local_widget = SWIN_WIDGETNUM(bridge);
 153
 154                 /* Free the old PROM new_irq_info structure */
 155                 sn_intr_free(local_nasid, local_widget, new_irq_info);
 156                 /* Update kernels new_irq_info with new target info */
 157                 unregister_intr_pda(new_irq_info);
 158
 159                 /* allocate a new PROM new_irq_info struct */
 160                 status = sn_intr_alloc(local_nasid, local_widget,
 161                                        __pa(new_irq_info), irq,
 162                                        cpuid_to_nasid(cpuid),
 163                                        cpuid_to_slice(cpuid));
 164
 165                 /* SAL call failed */
 166                 if (status) {
 167                         kfree(new_irq_info);
 168                         break;
 169                 }
 170
 171                 new_irq_info->irq_cpuid = cpuid;
 172                 register_intr_pda(new_irq_info);
 173
 174                 if (IS_PCI_BRIDGE_ASIC(new_irq_info->irq_bridge_type))
 175                         pcibr_change_devices_irq(new_irq_info);
 176
 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 #ifdef CONFIG_SMP
 183                 set_irq_affinity_info((irq & 0xff), cpuphys, 0);
 184 #endif
 185         }
 186 }
 187
 188 struct hw_interrupt_type irq_type_sn = {
 189         .typename       = "SN hub",
 190         .startup        = sn_startup_irq,
 191         .shutdown       = sn_shutdown_irq,
 192         .enable         = sn_enable_irq,
 193         .disable        = sn_disable_irq,
 194         .ack            = sn_ack_irq,
 195         .end            = sn_end_irq,
 196         .set_affinity   = sn_set_affinity_irq
 197 };
 198
 199 unsigned int sn_local_vector_to_irq(u8 vector)
 200 {
 201         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 202 }
 203
 204 void sn_irq_init(void)
 205 {
 206         int i;
 207         irq_desc_t *base_desc = irq_desc;
 208
 209         for (i = 0; i < NR_IRQS; i++) {
 210                 if (base_desc[i].handler == &no_irq_type) {
 211                         base_desc[i].handler = &irq_type_sn;
 212                 }
 213         }
 214 }
 215
 216 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 217 {
 218         int irq = sn_irq_info->irq_irq;
 219         int cpu = sn_irq_info->irq_cpuid;
 220
 221         if (pdacpu(cpu)->sn_last_irq < irq) {
 222                 pdacpu(cpu)->sn_last_irq = irq;
 223         }
 224
 225         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq) {
 226                 pdacpu(cpu)->sn_first_irq = irq;
 227         }
 228 }
 229
 230 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 231 {
 232         int irq = sn_irq_info->irq_irq;
 233         int cpu = sn_irq_info->irq_cpuid;
 234         struct sn_irq_info *tmp_irq_info;
 235         int i, foundmatch;
 236
 237         rcu_read_lock();
 238         if (pdacpu(cpu)->sn_last_irq == irq) {
 239                 foundmatch = 0;
 240                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 241                      i && !foundmatch; i--) {
 242                         list_for_each_entry_rcu(tmp_irq_info,
 243                                                 sn_irq_lh[i],
 244                                                 list) {
 245                                 if (tmp_irq_info->irq_cpuid == cpu) {
 246                                         foundmatch = 1;
 247                                         break;
 248                                 }
 249                         }
 250                 }
 251                 pdacpu(cpu)->sn_last_irq = i;
 252         }
 253
 254         if (pdacpu(cpu)->sn_first_irq == irq) {
 255                 foundmatch = 0;
 256                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 257                      i < NR_IRQS && !foundmatch; i++) {
 258                         list_for_each_entry_rcu(tmp_irq_info,
 259                                                 sn_irq_lh[i],
 260                                                 list) {
 261                                 if (tmp_irq_info->irq_cpuid == cpu) {
 262                                         foundmatch = 1;
 263                                         break;
 264                                 }
 265                         }
 266                 }
 267                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 268         }
 269         rcu_read_unlock();
 270 }
 271
 272 static void sn_irq_info_free(struct rcu_head *head)
 273 {
 274         struct sn_irq_info *sn_irq_info;
 275
 276         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 277         kfree(sn_irq_info);
 278 }
 279
 280 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 281 {
 282         nasid_t nasid = sn_irq_info->irq_nasid;
 283         int slice = sn_irq_info->irq_slice;
 284         int cpu = nasid_slice_to_cpuid(nasid, slice);
 285
 286         pci_dev_get(pci_dev);
 287         sn_irq_info->irq_cpuid = cpu;
 288         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 289
 290         /* link it into the sn_irq[irq] list */
 291         spin_lock(&sn_irq_info_lock);
 292         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 293         spin_unlock(&sn_irq_info_lock);
 294
 295         (void)register_intr_pda(sn_irq_info);
 296 }
 297
 298 void sn_irq_unfixup(struct pci_dev *pci_dev)
 299 {
 300         struct sn_irq_info *sn_irq_info;
 301
 302         /* Only cleanup IRQ stuff if this device has a host bus context */
 303         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 304                 return;
 305
 306         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 307         if (!sn_irq_info || !sn_irq_info->irq_irq) {
 308                 kfree(sn_irq_info);
 309                 return;
 310         }
 311
 312         unregister_intr_pda(sn_irq_info);
 313         spin_lock(&sn_irq_info_lock);
 314         list_del_rcu(&sn_irq_info->list);
 315         spin_unlock(&sn_irq_info_lock);
 316         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 317         pci_dev_put(pci_dev);
 318 }
 319
 320 static inline void
 321 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 322 {
 323         struct sn_pcibus_provider *pci_provider;
 324
 325         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 326         if (pci_provider && pci_provider->force_interrupt)
 327                 (*pci_provider->force_interrupt)(sn_irq_info);
 328 }
 329
 330 static void force_interrupt(int irq)
 331 {
 332         struct sn_irq_info *sn_irq_info;
 333
 334         if (!sn_ioif_inited)
 335                 return;
 336
 337         rcu_read_lock();
 338         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 339                 sn_call_force_intr_provider(sn_irq_info);
 340
 341         rcu_read_unlock();
 342 }
 343
 344 /*
 345  * Check for lost interrupts.  If the PIC int_status reg. says that
 346  * an interrupt has been sent, but not handled, and the interrupt
 347  * is not pending in either the cpu irr regs or in the soft irr regs,
 348  * and the interrupt is not in service, then the interrupt may have
 349  * been lost.  Force an interrupt on that pin.  It is possible that
 350  * the interrupt is in flight, so we may generate a spurious interrupt,
 351  * but we should never miss a real lost interrupt.
 352  */
 353 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 354 {
 355         uint64_t regval;
 356         int irr_reg_num;
 357         int irr_bit;
 358         uint64_t irr_reg;
 359         struct pcidev_info *pcidev_info;
 360         struct pcibus_info *pcibus_info;
 361
 362         /*
 363          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 364          * since they do not target Shub II interrupt registers.  If that
 365          * ever changes, this check needs to accomodate.
 366          */
 367         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 368                 return;
 369
 370         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 371         if (!pcidev_info)
 372                 return;
 373
 374         pcibus_info =
 375             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 376             pdi_pcibus_info;
 377         regval = pcireg_intr_status_get(pcibus_info);
 378
 379         irr_reg_num = irq_to_vector(irq) / 64;
 380         irr_bit = irq_to_vector(irq) % 64;
 381         switch (irr_reg_num) {
 382         case 0:
 383                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR0);
 384                 break;
 385         case 1:
 386                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR1);
 387                 break;
 388         case 2:
 389                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR2);
 390                 break;
 391         case 3:
 392                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR3);
 393                 break;
 394         }
 395         if (!test_bit(irr_bit, &irr_reg)) {
 396                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 397                         regval &= 0xff;
 398                         if (sn_irq_info->irq_int_bit & regval &
 399                             sn_irq_info->irq_last_intr) {
 400                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 401                                 sn_call_force_intr_provider(sn_irq_info);
 402                         }
 403                 }
 404         }
 405         sn_irq_info->irq_last_intr = regval;
 406 }
 407
 408 void sn_lb_int_war_check(void)
 409 {
 410         struct sn_irq_info *sn_irq_info;
 411         int i;
 412
 413         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 414                 return;
 415
 416         rcu_read_lock();
 417         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 418                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 419                         sn_check_intr(i, sn_irq_info);
 420                 }
 421         }
 422         rcu_read_unlock();
 423 }
 424
 425 void sn_irq_lh_init(void)
 426 {
 427         int i;
 428
 429         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 430         if (!sn_irq_lh)
 431                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 432
 433         for (i = 0; i < NR_IRQS; i++) {
 434                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 435                 if (!sn_irq_lh[i])
 436                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 437
 438                 INIT_LIST_HEAD(sn_irq_lh[i]);
 439         }
 440
 441 }