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 struct list_head **sn_irq_lh;
  30 static DEFINE_SPINLOCK(sn_irq_info_lock); /* non-IRQ lock */
  31
  32 u64 sn_intr_alloc(nasid_t local_nasid, int local_widget,
  33                                      struct sn_irq_info *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, __pa(sn_irq_info), (u64) req_irq,
  44                         (u64) req_nasid, (u64) req_slice);
  45
  46         return ret_stuff.status;
  47 }
  48
  49 void sn_intr_free(nasid_t local_nasid, int local_widget,
  50                                 struct sn_irq_info *sn_irq_info)
  51 {
  52         struct ia64_sal_retval ret_stuff;
  53         ret_stuff.status = 0;
  54         ret_stuff.v0 = 0;
  55
  56         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
  57                         (u64) SAL_INTR_FREE, (u64) local_nasid,
  58                         (u64) local_widget, (u64) sn_irq_info->irq_irq,
  59                         (u64) sn_irq_info->irq_cookie, 0, 0);
  60 }
  61
  62 static unsigned int sn_startup_irq(unsigned int irq)
  63 {
  64         return 0;
  65 }
  66
  67 static void sn_shutdown_irq(unsigned int irq)
  68 {
  69 }
  70
  71 static void sn_disable_irq(unsigned int irq)
  72 {
  73 }
  74
  75 static void sn_enable_irq(unsigned int irq)
  76 {
  77 }
  78
  79 static void sn_ack_irq(unsigned int irq)
  80 {
  81         u64 event_occurred, mask;
  82
  83         irq = irq & 0xff;
  84         event_occurred = HUB_L((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED));
  85         mask = event_occurred & SH_ALL_INT_MASK;
  86         HUB_S((u64*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS), mask);
  87         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
  88
  89         move_native_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 struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info,
 117                                        nasid_t nasid, int slice)
 118 {
 119         int vector;
 120         int cpuid;
 121 #ifdef CONFIG_SMP
 122         int cpuphys;
 123 #endif
 124         int64_t bridge;
 125         int local_widget, status;
 126         nasid_t local_nasid;
 127         struct sn_irq_info *new_irq_info;
 128         struct sn_pcibus_provider *pci_provider;
 129
 130         new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 131         if (new_irq_info == NULL)
 132                 return NULL;
 133
 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                 return NULL; /* 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         vector = sn_irq_info->irq_irq;
 150         /* Free the old PROM new_irq_info structure */
 151         sn_intr_free(local_nasid, local_widget, new_irq_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                                new_irq_info, vector,
 157                                nasid, slice);
 158
 159         /* SAL call failed */
 160         if (status) {
 161                 kfree(new_irq_info);
 162                 return NULL;
 163         }
 164
 165         /* Update kernels new_irq_info with new target info */
 166         cpuid = nasid_slice_to_cpuid(new_irq_info->irq_nasid,
 167                                      new_irq_info->irq_slice);
 168         new_irq_info->irq_cpuid = cpuid;
 169         register_intr_pda(new_irq_info);
 170
 171         pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 172
 173         /*
 174          * If this represents a line interrupt, target it.  If it's
 175          * an msi (irq_int_bit < 0), it's already targeted.
 176          */
 177         if (new_irq_info->irq_int_bit >= 0 &&
 178             pci_provider && pci_provider->target_interrupt)
 179                 (pci_provider->target_interrupt)(new_irq_info);
 180
 181         spin_lock(&sn_irq_info_lock);
 182         list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
 183         spin_unlock(&sn_irq_info_lock);
 184         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 185
 186 #ifdef CONFIG_SMP
 187         cpuphys = cpu_physical_id(cpuid);
 188         set_irq_affinity_info((vector & 0xff), cpuphys, 0);
 189 #endif
 190
 191         return new_irq_info;
 192 }
 193
 194 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
 195 {
 196         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 197         nasid_t nasid;
 198         int slice;
 199
 200         nasid = cpuid_to_nasid(first_cpu(mask));
 201         slice = cpuid_to_slice(first_cpu(mask));
 202
 203         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 204                                  sn_irq_lh[irq], list)
 205                 (void)sn_retarget_vector(sn_irq_info, nasid, slice);
 206 }
 207
 208 struct hw_interrupt_type irq_type_sn = {
 209         .name           = "SN hub",
 210         .startup        = sn_startup_irq,
 211         .shutdown       = sn_shutdown_irq,
 212         .enable         = sn_enable_irq,
 213         .disable        = sn_disable_irq,
 214         .ack            = sn_ack_irq,
 215         .end            = sn_end_irq,
 216         .set_affinity   = sn_set_affinity_irq
 217 };
 218
 219 unsigned int sn_local_vector_to_irq(u8 vector)
 220 {
 221         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 222 }
 223
 224 void sn_irq_init(void)
 225 {
 226         int i;
 227         irq_desc_t *base_desc = irq_desc;
 228
 229         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 230         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 231
 232         for (i = 0; i < NR_IRQS; i++) {
 233                 if (base_desc[i].chip == &no_irq_type) {
 234                         base_desc[i].chip = &irq_type_sn;
 235                 }
 236         }
 237 }
 238
 239 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 240 {
 241         int irq = sn_irq_info->irq_irq;
 242         int cpu = sn_irq_info->irq_cpuid;
 243
 244         if (pdacpu(cpu)->sn_last_irq < irq) {
 245                 pdacpu(cpu)->sn_last_irq = irq;
 246         }
 247
 248         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 249                 pdacpu(cpu)->sn_first_irq = irq;
 250 }
 251
 252 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 253 {
 254         int irq = sn_irq_info->irq_irq;
 255         int cpu = sn_irq_info->irq_cpuid;
 256         struct sn_irq_info *tmp_irq_info;
 257         int i, foundmatch;
 258
 259         rcu_read_lock();
 260         if (pdacpu(cpu)->sn_last_irq == irq) {
 261                 foundmatch = 0;
 262                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 263                      i && !foundmatch; i--) {
 264                         list_for_each_entry_rcu(tmp_irq_info,
 265                                                 sn_irq_lh[i],
 266                                                 list) {
 267                                 if (tmp_irq_info->irq_cpuid == cpu) {
 268                                         foundmatch = 1;
 269                                         break;
 270                                 }
 271                         }
 272                 }
 273                 pdacpu(cpu)->sn_last_irq = i;
 274         }
 275
 276         if (pdacpu(cpu)->sn_first_irq == irq) {
 277                 foundmatch = 0;
 278                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 279                      i < NR_IRQS && !foundmatch; i++) {
 280                         list_for_each_entry_rcu(tmp_irq_info,
 281                                                 sn_irq_lh[i],
 282                                                 list) {
 283                                 if (tmp_irq_info->irq_cpuid == cpu) {
 284                                         foundmatch = 1;
 285                                         break;
 286                                 }
 287                         }
 288                 }
 289                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 290         }
 291         rcu_read_unlock();
 292 }
 293
 294 static void sn_irq_info_free(struct rcu_head *head)
 295 {
 296         struct sn_irq_info *sn_irq_info;
 297
 298         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 299         kfree(sn_irq_info);
 300 }
 301
 302 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 303 {
 304         nasid_t nasid = sn_irq_info->irq_nasid;
 305         int slice = sn_irq_info->irq_slice;
 306         int cpu = nasid_slice_to_cpuid(nasid, slice);
 307 #ifdef CONFIG_SMP
 308         int cpuphys;
 309 #endif
 310
 311         pci_dev_get(pci_dev);
 312         sn_irq_info->irq_cpuid = cpu;
 313         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 314
 315         /* link it into the sn_irq[irq] list */
 316         spin_lock(&sn_irq_info_lock);
 317         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 318         reserve_irq_vector(sn_irq_info->irq_irq);
 319         spin_unlock(&sn_irq_info_lock);
 320
 321         register_intr_pda(sn_irq_info);
 322 #ifdef CONFIG_SMP
 323         cpuphys = cpu_physical_id(cpu);
 324         set_irq_affinity_info(sn_irq_info->irq_irq, cpuphys, 0);
 325 #endif
 326 }
 327
 328 void sn_irq_unfixup(struct pci_dev *pci_dev)
 329 {
 330         struct sn_irq_info *sn_irq_info;
 331
 332         /* Only cleanup IRQ stuff if this device has a host bus context */
 333         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 334                 return;
 335
 336         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 337         if (!sn_irq_info)
 338                 return;
 339         if (!sn_irq_info->irq_irq) {
 340                 kfree(sn_irq_info);
 341                 return;
 342         }
 343
 344         unregister_intr_pda(sn_irq_info);
 345         spin_lock(&sn_irq_info_lock);
 346         list_del_rcu(&sn_irq_info->list);
 347         spin_unlock(&sn_irq_info_lock);
 348         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 349                 free_irq_vector(sn_irq_info->irq_irq);
 350         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 351         pci_dev_put(pci_dev);
 352
 353 }
 354
 355 static inline void
 356 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 357 {
 358         struct sn_pcibus_provider *pci_provider;
 359
 360         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 361         if (pci_provider && pci_provider->force_interrupt)
 362                 (*pci_provider->force_interrupt)(sn_irq_info);
 363 }
 364
 365 static void force_interrupt(int irq)
 366 {
 367         struct sn_irq_info *sn_irq_info;
 368
 369         if (!sn_ioif_inited)
 370                 return;
 371
 372         rcu_read_lock();
 373         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 374                 sn_call_force_intr_provider(sn_irq_info);
 375
 376         rcu_read_unlock();
 377 }
 378
 379 /*
 380  * Check for lost interrupts.  If the PIC int_status reg. says that
 381  * an interrupt has been sent, but not handled, and the interrupt
 382  * is not pending in either the cpu irr regs or in the soft irr regs,
 383  * and the interrupt is not in service, then the interrupt may have
 384  * been lost.  Force an interrupt on that pin.  It is possible that
 385  * the interrupt is in flight, so we may generate a spurious interrupt,
 386  * but we should never miss a real lost interrupt.
 387  */
 388 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 389 {
 390         u64 regval;
 391         struct pcidev_info *pcidev_info;
 392         struct pcibus_info *pcibus_info;
 393
 394         /*
 395          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 396          * since they do not target Shub II interrupt registers.  If that
 397          * ever changes, this check needs to accomodate.
 398          */
 399         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 400                 return;
 401
 402         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 403         if (!pcidev_info)
 404                 return;
 405
 406         pcibus_info =
 407             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 408             pdi_pcibus_info;
 409         regval = pcireg_intr_status_get(pcibus_info);
 410
 411         if (!ia64_get_irr(irq_to_vector(irq))) {
 412                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 413                         regval &= 0xff;
 414                         if (sn_irq_info->irq_int_bit & regval &
 415                             sn_irq_info->irq_last_intr) {
 416                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 417                                 sn_call_force_intr_provider(sn_irq_info);
 418                         }
 419                 }
 420         }
 421         sn_irq_info->irq_last_intr = regval;
 422 }
 423
 424 void sn_lb_int_war_check(void)
 425 {
 426         struct sn_irq_info *sn_irq_info;
 427         int i;
 428
 429         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 430                 return;
 431
 432         rcu_read_lock();
 433         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 434                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 435                         sn_check_intr(i, sn_irq_info);
 436                 }
 437         }
 438         rcu_read_unlock();
 439 }
 440
 441 void __init sn_irq_lh_init(void)
 442 {
 443         int i;
 444
 445         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 446         if (!sn_irq_lh)
 447                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 448
 449         for (i = 0; i < NR_IRQS; i++) {
 450                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 451                 if (!sn_irq_lh[i])
 452                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 453
 454                 INIT_LIST_HEAD(sn_irq_lh[i]);
 455         }
 456 }