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) 2000-2005 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 int sn_force_interrupt_flag = 1;
  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         u64 event_occurred, mask = 0;
  80
  81         irq = irq & 0xff;
  82         event_occurred =
  83             HUB_L((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED));
  84         mask = event_occurred & SH_ALL_INT_MASK;
  85         HUB_S((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS),
  86               mask);
  87         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
  88
  89         move_irq(irq);
  90 }
  91
  92 static void sn_end_irq(unsigned int irq)
  93 {
  94         int ivec;
  95         u64 event_occurred;
  96
  97         ivec = irq & 0xff;
  98         if (ivec == SGI_UART_VECTOR) {
  99                 event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR (SH_EVENT_OCCURRED));
 100                 /* If the UART bit is set here, we may have received an
 101                  * interrupt from the UART that the driver missed.  To
 102                  * make sure, we IPI ourselves to force us to look again.
 103                  */
 104                 if (event_occurred & SH_EVENT_OCCURRED_UART_INT_MASK) {
 105                         platform_send_ipi(smp_processor_id(), SGI_UART_VECTOR,
 106                                           IA64_IPI_DM_INT, 0);
 107                 }
 108         }
 109         __clear_bit(ivec, (volatile void *)pda->sn_in_service_ivecs);
 110         if (sn_force_interrupt_flag)
 111                 force_interrupt(irq);
 112 }
 113
 114 static void sn_irq_info_free(struct rcu_head *head);
 115
 116 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
 117 {
 118         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 119         int cpuid, cpuphys;
 120
 121         cpuid = first_cpu(mask);
 122         cpuphys = cpu_physical_id(cpuid);
 123
 124         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 125                                  sn_irq_lh[irq], list) {
 126                 uint64_t bridge;
 127                 int local_widget, status;
 128                 nasid_t local_nasid;
 129                 struct sn_irq_info *new_irq_info;
 130                 struct sn_pcibus_provider *pci_provider;
 131
 132                 new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 133                 if (new_irq_info == NULL)
 134                         break;
 135                 memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
 136
 137                 bridge = (uint64_t) new_irq_info->irq_bridge;
 138                 if (!bridge) {
 139                         kfree(new_irq_info);
 140                         break; /* irq is not a device interrupt */
 141                 }
 142
 143                 local_nasid = NASID_GET(bridge);
 144
 145                 if (local_nasid & 1)
 146                         local_widget = TIO_SWIN_WIDGETNUM(bridge);
 147                 else
 148                         local_widget = SWIN_WIDGETNUM(bridge);
 149
 150                 /* Free the old PROM new_irq_info structure */
 151                 sn_intr_free(local_nasid, local_widget, new_irq_info);
 152                 /* Update kernels new_irq_info with new target info */
 153                 unregister_intr_pda(new_irq_info);
 154
 155                 /* allocate a new PROM new_irq_info struct */
 156                 status = sn_intr_alloc(local_nasid, local_widget,
 157                                        __pa(new_irq_info), irq,
 158                                        cpuid_to_nasid(cpuid),
 159                                        cpuid_to_slice(cpuid));
 160
 161                 /* SAL call failed */
 162                 if (status) {
 163                         kfree(new_irq_info);
 164                         break;
 165                 }
 166
 167                 new_irq_info->irq_cpuid = cpuid;
 168                 register_intr_pda(new_irq_info);
 169
 170                 pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 171                 if (pci_provider && pci_provider->target_interrupt)
 172                         (pci_provider->target_interrupt)(new_irq_info);
 173
 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                 call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 178
 179 #ifdef CONFIG_SMP
 180                 set_irq_affinity_info((irq & 0xff), cpuphys, 0);
 181 #endif
 182         }
 183 }
 184
 185 struct hw_interrupt_type irq_type_sn = {
 186         .typename       = "SN hub",
 187         .startup        = sn_startup_irq,
 188         .shutdown       = sn_shutdown_irq,
 189         .enable         = sn_enable_irq,
 190         .disable        = sn_disable_irq,
 191         .ack            = sn_ack_irq,
 192         .end            = sn_end_irq,
 193         .set_affinity   = sn_set_affinity_irq
 194 };
 195
 196 unsigned int sn_local_vector_to_irq(u8 vector)
 197 {
 198         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 199 }
 200
 201 void sn_irq_init(void)
 202 {
 203         int i;
 204         irq_desc_t *base_desc = irq_desc;
 205
 206         for (i = 0; i < NR_IRQS; i++) {
 207                 if (base_desc[i].handler == &no_irq_type) {
 208                         base_desc[i].handler = &irq_type_sn;
 209                 }
 210         }
 211 }
 212
 213 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 214 {
 215         int irq = sn_irq_info->irq_irq;
 216         int cpu = sn_irq_info->irq_cpuid;
 217
 218         if (pdacpu(cpu)->sn_last_irq < irq) {
 219                 pdacpu(cpu)->sn_last_irq = irq;
 220         }
 221
 222         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq) {
 223                 pdacpu(cpu)->sn_first_irq = irq;
 224         }
 225 }
 226
 227 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 228 {
 229         int irq = sn_irq_info->irq_irq;
 230         int cpu = sn_irq_info->irq_cpuid;
 231         struct sn_irq_info *tmp_irq_info;
 232         int i, foundmatch;
 233
 234         rcu_read_lock();
 235         if (pdacpu(cpu)->sn_last_irq == irq) {
 236                 foundmatch = 0;
 237                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 238                      i && !foundmatch; i--) {
 239                         list_for_each_entry_rcu(tmp_irq_info,
 240                                                 sn_irq_lh[i],
 241                                                 list) {
 242                                 if (tmp_irq_info->irq_cpuid == cpu) {
 243                                         foundmatch = 1;
 244                                         break;
 245                                 }
 246                         }
 247                 }
 248                 pdacpu(cpu)->sn_last_irq = i;
 249         }
 250
 251         if (pdacpu(cpu)->sn_first_irq == irq) {
 252                 foundmatch = 0;
 253                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 254                      i < NR_IRQS && !foundmatch; i++) {
 255                         list_for_each_entry_rcu(tmp_irq_info,
 256                                                 sn_irq_lh[i],
 257                                                 list) {
 258                                 if (tmp_irq_info->irq_cpuid == cpu) {
 259                                         foundmatch = 1;
 260                                         break;
 261                                 }
 262                         }
 263                 }
 264                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 265         }
 266         rcu_read_unlock();
 267 }
 268
 269 static void sn_irq_info_free(struct rcu_head *head)
 270 {
 271         struct sn_irq_info *sn_irq_info;
 272
 273         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 274         kfree(sn_irq_info);
 275 }
 276
 277 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 278 {
 279         nasid_t nasid = sn_irq_info->irq_nasid;
 280         int slice = sn_irq_info->irq_slice;
 281         int cpu = nasid_slice_to_cpuid(nasid, slice);
 282
 283         pci_dev_get(pci_dev);
 284         sn_irq_info->irq_cpuid = cpu;
 285         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 286
 287         /* link it into the sn_irq[irq] list */
 288         spin_lock(&sn_irq_info_lock);
 289         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 290         spin_unlock(&sn_irq_info_lock);
 291
 292         (void)register_intr_pda(sn_irq_info);
 293 }
 294
 295 void sn_irq_unfixup(struct pci_dev *pci_dev)
 296 {
 297         struct sn_irq_info *sn_irq_info;
 298
 299         /* Only cleanup IRQ stuff if this device has a host bus context */
 300         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 301                 return;
 302
 303         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 304         if (!sn_irq_info || !sn_irq_info->irq_irq) {
 305                 kfree(sn_irq_info);
 306                 return;
 307         }
 308
 309         unregister_intr_pda(sn_irq_info);
 310         spin_lock(&sn_irq_info_lock);
 311         list_del_rcu(&sn_irq_info->list);
 312         spin_unlock(&sn_irq_info_lock);
 313         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 314         pci_dev_put(pci_dev);
 315 }
 316
 317 static inline void
 318 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 319 {
 320         struct sn_pcibus_provider *pci_provider;
 321
 322         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 323         if (pci_provider && pci_provider->force_interrupt)
 324                 (*pci_provider->force_interrupt)(sn_irq_info);
 325 }
 326
 327 static void force_interrupt(int irq)
 328 {
 329         struct sn_irq_info *sn_irq_info;
 330
 331         if (!sn_ioif_inited)
 332                 return;
 333
 334         rcu_read_lock();
 335         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 336                 sn_call_force_intr_provider(sn_irq_info);
 337
 338         rcu_read_unlock();
 339 }
 340
 341 /*
 342  * Check for lost interrupts.  If the PIC int_status reg. says that
 343  * an interrupt has been sent, but not handled, and the interrupt
 344  * is not pending in either the cpu irr regs or in the soft irr regs,
 345  * and the interrupt is not in service, then the interrupt may have
 346  * been lost.  Force an interrupt on that pin.  It is possible that
 347  * the interrupt is in flight, so we may generate a spurious interrupt,
 348  * but we should never miss a real lost interrupt.
 349  */
 350 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 351 {
 352         uint64_t regval;
 353         int irr_reg_num;
 354         int irr_bit;
 355         uint64_t irr_reg;
 356         struct pcidev_info *pcidev_info;
 357         struct pcibus_info *pcibus_info;
 358
 359         /*
 360          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 361          * since they do not target Shub II interrupt registers.  If that
 362          * ever changes, this check needs to accomodate.
 363          */
 364         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 365                 return;
 366
 367         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 368         if (!pcidev_info)
 369                 return;
 370
 371         pcibus_info =
 372             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 373             pdi_pcibus_info;
 374         regval = pcireg_intr_status_get(pcibus_info);
 375
 376         irr_reg_num = irq_to_vector(irq) / 64;
 377         irr_bit = irq_to_vector(irq) % 64;
 378         switch (irr_reg_num) {
 379         case 0:
 380                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR0);
 381                 break;
 382         case 1:
 383                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR1);
 384                 break;
 385         case 2:
 386                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR2);
 387                 break;
 388         case 3:
 389                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR3);
 390                 break;
 391         }
 392         if (!test_bit(irr_bit, &irr_reg)) {
 393                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 394                         regval &= 0xff;
 395                         if (sn_irq_info->irq_int_bit & regval &
 396                             sn_irq_info->irq_last_intr) {
 397                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 398                                 sn_call_force_intr_provider(sn_irq_info);
 399                         }
 400                 }
 401         }
 402         sn_irq_info->irq_last_intr = regval;
 403 }
 404
 405 void sn_lb_int_war_check(void)
 406 {
 407         struct sn_irq_info *sn_irq_info;
 408         int i;
 409
 410         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 411                 return;
 412
 413         rcu_read_lock();
 414         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 415                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 416                         sn_check_intr(i, sn_irq_info);
 417                 }
 418         }
 419         rcu_read_unlock();
 420 }
 421
 422 void sn_irq_lh_init(void)
 423 {
 424         int i;
 425
 426         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 427         if (!sn_irq_lh)
 428                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 429
 430         for (i = 0; i < NR_IRQS; i++) {
 431                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 432                 if (!sn_irq_lh[i])
 433                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 434
 435                 INIT_LIST_HEAD(sn_irq_lh[i]);
 436         }
 437
 438 }