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 cpuphys;
 121         int64_t bridge;
 122         int local_widget, status;
 123         nasid_t local_nasid;
 124         struct sn_irq_info *new_irq_info;
 125         struct sn_pcibus_provider *pci_provider;
 126
 127         new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
 128         if (new_irq_info == NULL)
 129                 return NULL;
 130
 131         memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
 132
 133         bridge = (u64) new_irq_info->irq_bridge;
 134         if (!bridge) {
 135                 kfree(new_irq_info);
 136                 return NULL; /* irq is not a device interrupt */
 137         }
 138
 139         local_nasid = NASID_GET(bridge);
 140
 141         if (local_nasid & 1)
 142                 local_widget = TIO_SWIN_WIDGETNUM(bridge);
 143         else
 144                 local_widget = SWIN_WIDGETNUM(bridge);
 145
 146         vector = sn_irq_info->irq_irq;
 147         /* Free the old PROM new_irq_info structure */
 148         sn_intr_free(local_nasid, local_widget, new_irq_info);
 149         /* Update kernels new_irq_info with new target info */
 150         unregister_intr_pda(new_irq_info);
 151
 152         /* allocate a new PROM new_irq_info struct */
 153         status = sn_intr_alloc(local_nasid, local_widget,
 154                                new_irq_info, vector,
 155                                nasid, slice);
 156
 157         /* SAL call failed */
 158         if (status) {
 159                 kfree(new_irq_info);
 160                 return NULL;
 161         }
 162
 163         cpuphys = nasid_slice_to_cpuid(nasid, slice);
 164         new_irq_info->irq_cpuid = cpuphys;
 165         register_intr_pda(new_irq_info);
 166
 167         pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
 168
 169         /*
 170          * If this represents a line interrupt, target it.  If it's
 171          * an msi (irq_int_bit < 0), it's already targeted.
 172          */
 173         if (new_irq_info->irq_int_bit >= 0 &&
 174             pci_provider && pci_provider->target_interrupt)
 175                 (pci_provider->target_interrupt)(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((vector & 0xff), cpuphys, 0);
 184 #endif
 185
 186         return new_irq_info;
 187 }
 188
 189 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
 190 {
 191         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 192         nasid_t nasid;
 193         int slice;
 194
 195         nasid = cpuid_to_nasid(first_cpu(mask));
 196         slice = cpuid_to_slice(first_cpu(mask));
 197
 198         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 199                                  sn_irq_lh[irq], list)
 200                 (void)sn_retarget_vector(sn_irq_info, nasid, slice);
 201 }
 202
 203 struct hw_interrupt_type irq_type_sn = {
 204         .typename       = "SN hub",
 205         .startup        = sn_startup_irq,
 206         .shutdown       = sn_shutdown_irq,
 207         .enable         = sn_enable_irq,
 208         .disable        = sn_disable_irq,
 209         .ack            = sn_ack_irq,
 210         .end            = sn_end_irq,
 211         .set_affinity   = sn_set_affinity_irq
 212 };
 213
 214 unsigned int sn_local_vector_to_irq(u8 vector)
 215 {
 216         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
 217 }
 218
 219 void sn_irq_init(void)
 220 {
 221         int i;
 222         irq_desc_t *base_desc = irq_desc;
 223
 224         ia64_first_device_vector = IA64_SN2_FIRST_DEVICE_VECTOR;
 225         ia64_last_device_vector = IA64_SN2_LAST_DEVICE_VECTOR;
 226
 227         for (i = 0; i < NR_IRQS; i++) {
 228                 if (base_desc[i].chip == &no_irq_type) {
 229                         base_desc[i].chip = &irq_type_sn;
 230                 }
 231         }
 232 }
 233
 234 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
 235 {
 236         int irq = sn_irq_info->irq_irq;
 237         int cpu = sn_irq_info->irq_cpuid;
 238
 239         if (pdacpu(cpu)->sn_last_irq < irq) {
 240                 pdacpu(cpu)->sn_last_irq = irq;
 241         }
 242
 243         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq)
 244                 pdacpu(cpu)->sn_first_irq = irq;
 245 }
 246
 247 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
 248 {
 249         int irq = sn_irq_info->irq_irq;
 250         int cpu = sn_irq_info->irq_cpuid;
 251         struct sn_irq_info *tmp_irq_info;
 252         int i, foundmatch;
 253
 254         rcu_read_lock();
 255         if (pdacpu(cpu)->sn_last_irq == irq) {
 256                 foundmatch = 0;
 257                 for (i = pdacpu(cpu)->sn_last_irq - 1;
 258                      i && !foundmatch; i--) {
 259                         list_for_each_entry_rcu(tmp_irq_info,
 260                                                 sn_irq_lh[i],
 261                                                 list) {
 262                                 if (tmp_irq_info->irq_cpuid == cpu) {
 263                                         foundmatch = 1;
 264                                         break;
 265                                 }
 266                         }
 267                 }
 268                 pdacpu(cpu)->sn_last_irq = i;
 269         }
 270
 271         if (pdacpu(cpu)->sn_first_irq == irq) {
 272                 foundmatch = 0;
 273                 for (i = pdacpu(cpu)->sn_first_irq + 1;
 274                      i < NR_IRQS && !foundmatch; i++) {
 275                         list_for_each_entry_rcu(tmp_irq_info,
 276                                                 sn_irq_lh[i],
 277                                                 list) {
 278                                 if (tmp_irq_info->irq_cpuid == cpu) {
 279                                         foundmatch = 1;
 280                                         break;
 281                                 }
 282                         }
 283                 }
 284                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
 285         }
 286         rcu_read_unlock();
 287 }
 288
 289 static void sn_irq_info_free(struct rcu_head *head)
 290 {
 291         struct sn_irq_info *sn_irq_info;
 292
 293         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
 294         kfree(sn_irq_info);
 295 }
 296
 297 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
 298 {
 299         nasid_t nasid = sn_irq_info->irq_nasid;
 300         int slice = sn_irq_info->irq_slice;
 301         int cpu = nasid_slice_to_cpuid(nasid, slice);
 302
 303         pci_dev_get(pci_dev);
 304         sn_irq_info->irq_cpuid = cpu;
 305         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 306
 307         /* link it into the sn_irq[irq] list */
 308         spin_lock(&sn_irq_info_lock);
 309         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
 310         reserve_irq_vector(sn_irq_info->irq_irq);
 311         spin_unlock(&sn_irq_info_lock);
 312
 313         register_intr_pda(sn_irq_info);
 314 }
 315
 316 void sn_irq_unfixup(struct pci_dev *pci_dev)
 317 {
 318         struct sn_irq_info *sn_irq_info;
 319
 320         /* Only cleanup IRQ stuff if this device has a host bus context */
 321         if (!SN_PCIDEV_BUSSOFT(pci_dev))
 322                 return;
 323
 324         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
 325         if (!sn_irq_info)
 326                 return;
 327         if (!sn_irq_info->irq_irq) {
 328                 kfree(sn_irq_info);
 329                 return;
 330         }
 331
 332         unregister_intr_pda(sn_irq_info);
 333         spin_lock(&sn_irq_info_lock);
 334         list_del_rcu(&sn_irq_info->list);
 335         spin_unlock(&sn_irq_info_lock);
 336         if (list_empty(sn_irq_lh[sn_irq_info->irq_irq]))
 337                 free_irq_vector(sn_irq_info->irq_irq);
 338         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
 339         pci_dev_put(pci_dev);
 340
 341 }
 342
 343 static inline void
 344 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
 345 {
 346         struct sn_pcibus_provider *pci_provider;
 347
 348         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
 349         if (pci_provider && pci_provider->force_interrupt)
 350                 (*pci_provider->force_interrupt)(sn_irq_info);
 351 }
 352
 353 static void force_interrupt(int irq)
 354 {
 355         struct sn_irq_info *sn_irq_info;
 356
 357         if (!sn_ioif_inited)
 358                 return;
 359
 360         rcu_read_lock();
 361         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
 362                 sn_call_force_intr_provider(sn_irq_info);
 363
 364         rcu_read_unlock();
 365 }
 366
 367 /*
 368  * Check for lost interrupts.  If the PIC int_status reg. says that
 369  * an interrupt has been sent, but not handled, and the interrupt
 370  * is not pending in either the cpu irr regs or in the soft irr regs,
 371  * and the interrupt is not in service, then the interrupt may have
 372  * been lost.  Force an interrupt on that pin.  It is possible that
 373  * the interrupt is in flight, so we may generate a spurious interrupt,
 374  * but we should never miss a real lost interrupt.
 375  */
 376 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
 377 {
 378         u64 regval;
 379         struct pcidev_info *pcidev_info;
 380         struct pcibus_info *pcibus_info;
 381
 382         /*
 383          * Bridge types attached to TIO (anything but PIC) do not need this WAR
 384          * since they do not target Shub II interrupt registers.  If that
 385          * ever changes, this check needs to accomodate.
 386          */
 387         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
 388                 return;
 389
 390         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 391         if (!pcidev_info)
 392                 return;
 393
 394         pcibus_info =
 395             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
 396             pdi_pcibus_info;
 397         regval = pcireg_intr_status_get(pcibus_info);
 398
 399         if (!ia64_get_irr(irq_to_vector(irq))) {
 400                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
 401                         regval &= 0xff;
 402                         if (sn_irq_info->irq_int_bit & regval &
 403                             sn_irq_info->irq_last_intr) {
 404                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
 405                                 sn_call_force_intr_provider(sn_irq_info);
 406                         }
 407                 }
 408         }
 409         sn_irq_info->irq_last_intr = regval;
 410 }
 411
 412 void sn_lb_int_war_check(void)
 413 {
 414         struct sn_irq_info *sn_irq_info;
 415         int i;
 416
 417         if (!sn_ioif_inited || pda->sn_first_irq == 0)
 418                 return;
 419
 420         rcu_read_lock();
 421         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
 422                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
 423                         sn_check_intr(i, sn_irq_info);
 424                 }
 425         }
 426         rcu_read_unlock();
 427 }
 428
 429 void __init sn_irq_lh_init(void)
 430 {
 431         int i;
 432
 433         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
 434         if (!sn_irq_lh)
 435                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
 436
 437         for (i = 0; i < NR_IRQS; i++) {
 438                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
 439                 if (!sn_irq_lh[i])
 440                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
 441
 442                 INIT_LIST_HEAD(sn_irq_lh[i]);
 443         }
 444 }