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 static void
 209 sn_mask_irq(unsigned int irq)
 210 {
 211 }
 212
 213 static void
 214 sn_unmask_irq(unsigned int irq)
 215 {
 216 }
 217
 218 struct irq_chip irq_type_sn = {
 219         .name           = "SN hub",
 220         .startup        = sn_startup_irq,
 221         .shutdown       = sn_shutdown_irq,
 222         .enable         = sn_enable_irq,
 223         .disable        = sn_disable_irq,
 224         .ack            = sn_ack_irq,
 225         .end            = sn_end_irq,
 226         .mask           = sn_mask_irq,
 227         .unmask         = sn_unmask_irq,
 228         .set_affinity   = sn_set_affinity_irq
 229 };
 230
 231 unsigned int sn_local_vector_to_irq(u8 vector)
 232 {
 233         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 234 }
 235
 236 void sn_irq_init(void)
 237 {
 238         int i;
 239         irq_desc_t *base_desc = irq_desc;
 240
 241         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 242         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 243
 244         for (i = 0; i < NR_IRQS; i++) {
 245                 if (base_desc[i].chip == &no_irq_type) {
 246                         base_desc[i].chip = &irq_type_sn;
 247                 }
 248         }
 249 }
 250
 251 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 252 {
 253         int irq = sn_irq_info->irq_irq;
 254         int cpu = sn_irq_info->irq_cpuid;
 255
 256         if (pdacpu(cpu)->sn_last_irq < irq) {
 257                 pdacpu(cpu)->sn_last_irq = irq;
 258         }
 259
 260         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 261                 pdacpu(cpu)->sn_first_irq = irq;
 262 }
 263
 264 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 265 {
 266         int irq = sn_irq_info->irq_irq;
 267         int cpu = sn_irq_info->irq_cpuid;
 268         struct sn_irq_info *tmp_irq_info;
 269         int i, foundmatch;
 270
 271         rcu_read_lock();
 272         if (pdacpu(cpu)->sn_last_irq == irq) {
 273                 foundmatch = 0;
 274                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 275                      i && !foundmatch; i--) {
 276                         list_for_each_entry_rcu(tmp_irq_info,
 277                                                 sn_irq_lh[i],
 278                                                 list) {
 279                                 if (tmp_irq_info->irq_cpuid == cpu) {
 280                                         foundmatch = 1;
 281                                         break;
 282                                 }
 283                         }
 284                 }
 285                 pdacpu(cpu)->sn_last_irq = i;
 286         }
 287
 288         if (pdacpu(cpu)->sn_first_irq == irq) {
 289                 foundmatch = 0;
 290                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 291                      i < NR_IRQS && !foundmatch; i++) {
 292                         list_for_each_entry_rcu(tmp_irq_info,
 293                                                 sn_irq_lh[i],
 294                                                 list) {
 295                                 if (tmp_irq_info->irq_cpuid == cpu) {
 296                                         foundmatch = 1;
 297                                         break;
 298                                 }
 299                         }
 300                 }
 301                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 302         }
 303         rcu_read_unlock();
 304 }
 305
 306 static void sn_irq_info_free(struct rcu_head *head)
 307 {
 308         struct sn_irq_info *sn_irq_info;
 309
 310         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 311         kfree(sn_irq_info);
 312 }
 313
 314 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 315 {
 316         nasid_t nasid = sn_irq_info->irq_nasid;
 317         int slice = sn_irq_info->irq_slice;
 318         int cpu = nasid_slice_to_cpuid(nasid, slice);
 319 #ifdef CONFIG_SMP
 320         int cpuphys;
 321 #endif
 322
 323         pci_dev_get(pci_dev);
 324         sn_irq_info->irq_cpuid = cpu;
 325         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 326
 327         /* link it into the sn_irq[irq] list */
 328         spin_lock(&sn_irq_info_lock);
 329         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 330         reserve_irq_vector(sn_irq_info->irq_irq);
 331         spin_unlock(&sn_irq_info_lock);
 332
 333         register_intr_pda(sn_irq_info);
 334 #ifdef CONFIG_SMP
 335         cpuphys = cpu_physical_id(cpu);
 336         set_irq_affinity_info(sn_irq_info->irq_irq, cpuphys, 0);
 337 #endif
 338 }
 339
 340 void sn_irq_unfixup(struct pci_dev *pci_dev)
 341 {
 342         struct sn_irq_info *sn_irq_info;
 343
 344         /* Only cleanup IRQ stuff if this device has a host bus context */
 345         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 346                 return;
 347
 348         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 349         if (!sn_irq_info)
 350                 return;
 351         if (!sn_irq_info->irq_irq) {
 352                 kfree(sn_irq_info);
 353                 return;
 354         }
 355
 356         unregister_intr_pda(sn_irq_info);
 357         spin_lock(&sn_irq_info_lock);
 358         list_del_rcu(&sn_irq_info->list);
 359         spin_unlock(&sn_irq_info_lock);
 360         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 361                 free_irq_vector(sn_irq_info->irq_irq);
 362         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 363         pci_dev_put(pci_dev);
 364
 365 }
 366
 367 static inline void
 368 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 369 {
 370         struct sn_pcibus_provider *pci_provider;
 371
 372         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 373         if (pci_provider && pci_provider->force_interrupt)
 374                 (*pci_provider->force_interrupt)(sn_irq_info);
 375 }
 376
 377 static void force_interrupt(int irq)
 378 {
 379         struct sn_irq_info *sn_irq_info;
 380
 381         if (!sn_ioif_inited)
 382                 return;
 383
 384         rcu_read_lock();
 385         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 386                 sn_call_force_intr_provider(sn_irq_info);
 387
 388         rcu_read_unlock();
 389 }
 390
 391 /*
 392  * Check for lost interrupts.  If the PIC int_status reg. says that
 393  * an interrupt has been sent, but not handled, and the interrupt
 394  * is not pending in either the cpu irr regs or in the soft irr regs,
 395  * and the interrupt is not in service, then the interrupt may have
 396  * been lost.  Force an interrupt on that pin.  It is possible that
 397  * the interrupt is in flight, so we may generate a spurious interrupt,
 398  * but we should never miss a real lost interrupt.
 399  */
 400 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 401 {
 402         u64 regval;
 403         struct pcidev_info *pcidev_info;
 404         struct pcibus_info *pcibus_info;
 405
 406         /*
 407          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 408          * since they do not target Shub II interrupt registers.  If that
 409          * ever changes, this check needs to accomodate.
 410          */
 411         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 412                 return;
 413
 414         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 415         if (!pcidev_info)
 416                 return;
 417
 418         pcibus_info =
 419             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 420             pdi_pcibus_info;
 421         regval = pcireg_intr_status_get(pcibus_info);
 422
 423         if (!ia64_get_irr(irq_to_vector(irq))) {
 424                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 425                         regval &= 0xff;
 426                         if (sn_irq_info->irq_int_bit & regval &
 427                             sn_irq_info->irq_last_intr) {
 428                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 429                                 sn_call_force_intr_provider(sn_irq_info);
 430                         }
 431                 }
 432         }
 433         sn_irq_info->irq_last_intr = regval;
 434 }
 435
 436 void sn_lb_int_war_check(void)
 437 {
 438         struct sn_irq_info *sn_irq_info;
 439         int i;
 440
 441         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 442                 return;
 443
 444         rcu_read_lock();
 445         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 446                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 447                         sn_check_intr(i, sn_irq_info);
 448                 }
 449         }
 450         rcu_read_unlock();
 451 }
 452
 453 void __init sn_irq_lh_init(void)
 454 {
 455         int i;
 456
 457         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 458         if (!sn_irq_lh)
 459                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 460
 461         for (i = 0; i < NR_IRQS; i++) {
 462                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 463                 if (!sn_irq_lh[i])
 464                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 465
 466                 INIT_LIST_HEAD(sn_irq_lh[i]);
 467         }
 468 }