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) 2000-2006 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 <asm/sn/addrs.h>
  15 #include <asm/sn/arch.h>
  16 #include <asm/sn/intr.h>
  17 #include <asm/sn/pcibr_provider.h>
  18 #include <asm/sn/pcibus_provider_defs.h>
  19 #include <asm/sn/pcidev.h>
  20 #include <asm/sn/shub_mmr.h>
  21 #include <asm/sn/sn_sal.h>
  22
  23 static void force_interrupt(int irq);
  24 static void register_intr_pda(struct sn_irq_info *sn_irq_info);
  25 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info);
  26
  27 int sn_force_interrupt_flag = 1;
  28 extern int sn_ioif_inited;
  29 static struct list_head **sn_irq_lh;
  30 static spinlock_t sn_irq_info_lock = SPIN_LOCK_UNLOCKED; /* non-IRQ lock */
  31
  32 static inline u64 sn_intr_alloc(nasid_t local_nasid, int local_widget,
  33                                      u64 sn_irq_info,
  34                                      int req_irq, nasid_t req_nasid,
  35                                      int req_slice)
  36 {
  37         struct ia64_sal_retval ret_stuff;
  38         ret_stuff.status = 0;
  39         ret_stuff.v0 = 0;
  40
  41         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  42                         (u64) SAL_INTR_ALLOC, (u64) local_nasid,
  43                         (u64) local_widget, (u64) sn_irq_info, (u64) req_irq,
  44                         (u64) req_nasid, (u64) req_slice);
  45         return ret_stuff.status;
  46 }
  47
  48 static inline void sn_intr_free(nasid_t local_nasid, int local_widget,
  49                                 struct sn_irq_info *sn_irq_info)
  50 {
  51         struct ia64_sal_retval ret_stuff;
  52         ret_stuff.status = 0;
  53         ret_stuff.v0 = 0;
  54
  55         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  56                         (u64) SAL_INTR_FREE, (u64) local_nasid,
  57                         (u64) local_widget, (u64) sn_irq_info->irq_irq,
  58                         (u64) sn_irq_info->irq_cookie, 0, 0);
  59 }
  60
  61 static unsigned int sn_startup_irq(unsigned int irq)
  62 {
  63         return 0;
  64 }
  65
  66 static void sn_shutdown_irq(unsigned int irq)
  67 {
  68 }
  69
  70 static void sn_disable_irq(unsigned int irq)
  71 {
  72 }
  73
  74 static void sn_enable_irq(unsigned int irq)
  75 {
  76 }
  77
  78 static void sn_ack_irq(unsigned int irq)
  79 {
  80         u64 event_occurred, mask;
  81
  82         irq = irq & 0xff;
  83         event_occurred = 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), mask);
  86         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
  87
  88         move_native_irq(irq);
  89 }
  90
  91 static void sn_end_irq(unsigned int irq)
  92 {
  93         int ivec;
  94         u64 event_occurred;
  95
  96         ivec = irq & 0xff;
  97         if (ivec == SGI_UART_VECTOR) {
  98                 event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR (SH_EVENT_OCCURRED));
  99                 /* If the UART bit is set here, we may have received an
 100                  * interrupt from the UART that the driver missed.  To
 101                  * make sure, we IPI ourselves to force us to look again.
 102                  */
 103                 if (event_occurred & SH_EVENT_OCCURRED_UART_INT_MASK) {
 104                         platform_send_ipi(smp_processor_id(), SGI_UART_VECTOR,
 105                                           IA64_IPI_DM_INT, 0);
 106                 }
 107         }
 108         __clear_bit(ivec, (volatile void *)pda->sn_in_service_ivecs);
 109         if (sn_force_interrupt_flag)
 110                 force_interrupt(irq);
 111 }
 112
 113 static void sn_irq_info_free(struct rcu_head *head);
 114
 115 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
 116 {
 117         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 118         int cpuid, cpuphys;
 119
 120         cpuid = first_cpu(mask);
 121         cpuphys = cpu_physical_id(cpuid);
 122
 123         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 124                                  sn_irq_lh[irq], list) {
 125                 u64 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                 new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 132                 if (new_irq_info == NULL)
 133                         break;
 134                 memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
 135
 136                 bridge = (u64) new_irq_info->irq_bridge;
 137                 if (!bridge) {
 138                         kfree(new_irq_info);
 139                         break; /* irq is not a device interrupt */
 140                 }
 141
 142                 local_nasid = NASID_GET(bridge);
 143
 144                 if (local_nasid & 1)
 145                         local_widget = TIO_SWIN_WIDGETNUM(bridge);
 146                 else
 147                         local_widget = SWIN_WIDGETNUM(bridge);
 148
 149                 /* Free the old PROM new_irq_info structure */
 150                 sn_intr_free(local_nasid, local_widget, new_irq_info);
 151                 /* Update kernels new_irq_info with new target info */
 152                 unregister_intr_pda(new_irq_info);
 153
 154                 /* allocate a new PROM new_irq_info struct */
 155                 status = sn_intr_alloc(local_nasid, local_widget,
 156                                        __pa(new_irq_info), irq,
 157                                        cpuid_to_nasid(cpuid),
 158                                        cpuid_to_slice(cpuid));
 159
 160                 /* SAL call failed */
 161                 if (status) {
 162                         kfree(new_irq_info);
 163                         break;
 164                 }
 165
 166                 new_irq_info->irq_cpuid = cpuid;
 167                 register_intr_pda(new_irq_info);
 168
 169                 pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 170                 if (pci_provider && pci_provider->target_interrupt)
 171                         (pci_provider->target_interrupt)(new_irq_info);
 172
 173                 spin_lock(&sn_irq_info_lock);
 174                 list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
 175                 spin_unlock(&sn_irq_info_lock);
 176                 call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 177
 178 #ifdef CONFIG_SMP
 179                 set_irq_affinity_info((irq & 0xff), cpuphys, 0);
 180 #endif
 181         }
 182 }
 183
 184 struct hw_interrupt_type irq_type_sn = {
 185         .typename       = "SN hub",
 186         .startup        = sn_startup_irq,
 187         .shutdown       = sn_shutdown_irq,
 188         .enable         = sn_enable_irq,
 189         .disable        = sn_disable_irq,
 190         .ack            = sn_ack_irq,
 191         .end            = sn_end_irq,
 192         .set_affinity   = sn_set_affinity_irq
 193 };
 194
 195 unsigned int sn_local_vector_to_irq(u8 vector)
 196 {
 197         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 198 }
 199
 200 void sn_irq_init(void)
 201 {
 202         int i;
 203         irq_desc_t *base_desc = irq_desc;
 204
 205         for (i = 0; i < NR_IRQS; i++) {
 206                 if (base_desc[i].handler == &no_irq_type) {
 207                         base_desc[i].handler = &irq_type_sn;
 208                 }
 209         }
 210 }
 211
 212 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 213 {
 214         int irq = sn_irq_info->irq_irq;
 215         int cpu = sn_irq_info->irq_cpuid;
 216
 217         if (pdacpu(cpu)->sn_last_irq < irq) {
 218                 pdacpu(cpu)->sn_last_irq = irq;
 219         }
 220
 221         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 222                 pdacpu(cpu)->sn_first_irq = irq;
 223 }
 224
 225 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 226 {
 227         int irq = sn_irq_info->irq_irq;
 228         int cpu = sn_irq_info->irq_cpuid;
 229         struct sn_irq_info *tmp_irq_info;
 230         int i, foundmatch;
 231
 232         rcu_read_lock();
 233         if (pdacpu(cpu)->sn_last_irq == irq) {
 234                 foundmatch = 0;
 235                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 236                      i && !foundmatch; i--) {
 237                         list_for_each_entry_rcu(tmp_irq_info,
 238                                                 sn_irq_lh[i],
 239                                                 list) {
 240                                 if (tmp_irq_info->irq_cpuid == cpu) {
 241                                         foundmatch = 1;
 242                                         break;
 243                                 }
 244                         }
 245                 }
 246                 pdacpu(cpu)->sn_last_irq = i;
 247         }
 248
 249         if (pdacpu(cpu)->sn_first_irq == irq) {
 250                 foundmatch = 0;
 251                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 252                      i < NR_IRQS && !foundmatch; i++) {
 253                         list_for_each_entry_rcu(tmp_irq_info,
 254                                                 sn_irq_lh[i],
 255                                                 list) {
 256                                 if (tmp_irq_info->irq_cpuid == cpu) {
 257                                         foundmatch = 1;
 258                                         break;
 259                                 }
 260                         }
 261                 }
 262                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 263         }
 264         rcu_read_unlock();
 265 }
 266
 267 static void sn_irq_info_free(struct rcu_head *head)
 268 {
 269         struct sn_irq_info *sn_irq_info;
 270
 271         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 272         kfree(sn_irq_info);
 273 }
 274
 275 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 276 {
 277         nasid_t nasid = sn_irq_info->irq_nasid;
 278         int slice = sn_irq_info->irq_slice;
 279         int cpu = nasid_slice_to_cpuid(nasid, slice);
 280
 281         pci_dev_get(pci_dev);
 282         sn_irq_info->irq_cpuid = cpu;
 283         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 284
 285         /* link it into the sn_irq[irq] list */
 286         spin_lock(&sn_irq_info_lock);
 287         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 288         spin_unlock(&sn_irq_info_lock);
 289
 290         register_intr_pda(sn_irq_info);
 291 }
 292
 293 void sn_irq_unfixup(struct pci_dev *pci_dev)
 294 {
 295         struct sn_irq_info *sn_irq_info;
 296
 297         /* Only cleanup IRQ stuff if this device has a host bus context */
 298         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 299                 return;
 300
 301         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 302         if (!sn_irq_info)
 303                 return;
 304         if (!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         u64 regval;
 353         int irr_reg_num;
 354         int irr_bit;
 355         u64 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 __init 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 }