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   1 /*
   2  * I/O SAPIC support.
   3  *
   4  * Copyright (C) 1999 Intel Corp.
   5  * Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com>
   6  * Copyright (C) 2000-2002 J.I. Lee <jung-ik.lee@intel.com>
   7  * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co.
   8  *      David Mosberger-Tang <davidm@hpl.hp.com>
   9  * Copyright (C) 1999 VA Linux Systems
  10  * Copyright (C) 1999,2000 Walt Drummond <drummond@valinux.com>
  11  *
  12  * 00/04/19     D. Mosberger    Rewritten to mirror more closely the x86 I/O
  13  *                              APIC code.  In particular, we now have separate
  14  *                              handlers for edge and level triggered
  15  *                              interrupts.
  16  * 00/10/27     Asit Mallick, Goutham Rao <goutham.rao@intel.com> IRQ vector
  17  *                              allocation PCI to vector mapping, shared PCI
  18  *                              interrupts.
  19  * 00/10/27     D. Mosberger    Document things a bit more to make them more
  20  *                              understandable.  Clean up much of the old
  21  *                              IOSAPIC cruft.
  22  * 01/07/27     J.I. Lee        PCI irq routing, Platform/Legacy interrupts
  23  *                              and fixes for ACPI S5(SoftOff) support.
  24  * 02/01/23     J.I. Lee        iosapic pgm fixes for PCI irq routing from _PRT
  25  * 02/01/07     E. Focht        <efocht@ess.nec.de> Redirectable interrupt
  26  *                              vectors in iosapic_set_affinity(),
  27  *                              initializations for /proc/irq/#/smp_affinity
  28  * 02/04/02     P. Diefenbaugh  Cleaned up ACPI PCI IRQ routing.
  29  * 02/04/18     J.I. Lee        bug fix in iosapic_init_pci_irq
  30  * 02/04/30     J.I. Lee        bug fix in find_iosapic to fix ACPI PCI IRQ to
  31  *                              IOSAPIC mapping error
  32  * 02/07/29     T. Kochi        Allocate interrupt vectors dynamically
  33  * 02/08/04     T. Kochi        Cleaned up terminology (irq, global system
  34  *                              interrupt, vector, etc.)
  35  * 02/09/20     D. Mosberger    Simplified by taking advantage of ACPI's
  36  *                              pci_irq code.
  37  * 03/02/19     B. Helgaas      Make pcat_compat system-wide, not per-IOSAPIC.
  38  *                              Remove iosapic_address & gsi_base from
  39  *                              external interfaces.  Rationalize
  40  *                              __init/__devinit attributes.
  41  * 04/12/04 Ashok Raj   <ashok.raj@intel.com> Intel Corporation 2004
  42  *                              Updated to work with irq migration necessary
  43  *                              for CPU Hotplug
  44  */
  45 /*
  46  * Here is what the interrupt logic between a PCI device and the kernel looks
  47  * like:
  48  *
  49  * (1) A PCI device raises one of the four interrupt pins (INTA, INTB, INTC,
  50  *     INTD).  The device is uniquely identified by its bus-, and slot-number
  51  *     (the function number does not matter here because all functions share
  52  *     the same interrupt lines).
  53  *
  54  * (2) The motherboard routes the interrupt line to a pin on a IOSAPIC
  55  *     controller.  Multiple interrupt lines may have to share the same
  56  *     IOSAPIC pin (if they're level triggered and use the same polarity).
  57  *     Each interrupt line has a unique Global System Interrupt (GSI) number
  58  *     which can be calculated as the sum of the controller's base GSI number
  59  *     and the IOSAPIC pin number to which the line connects.
  60  *
  61  * (3) The IOSAPIC uses an internal routing table entries (RTEs) to map the
  62  * IOSAPIC pin into the IA-64 interrupt vector.  This interrupt vector is then
  63  * sent to the CPU.
  64  *
  65  * (4) The kernel recognizes an interrupt as an IRQ.  The IRQ interface is
  66  *     used as architecture-independent interrupt handling mechanism in Linux.
  67  *     As an IRQ is a number, we have to have
  68  *     IA-64 interrupt vector number <-> IRQ number mapping.  On smaller
  69  *     systems, we use one-to-one mapping between IA-64 vector and IRQ.  A
  70  *     platform can implement platform_irq_to_vector(irq) and
  71  *     platform_local_vector_to_irq(vector) APIs to differentiate the mapping.
  72  *     Please see also include/asm-ia64/hw_irq.h for those APIs.
  73  *
  74  * To sum up, there are three levels of mappings involved:
  75  *
  76  *      PCI pin -> global system interrupt (GSI) -> IA-64 vector <-> IRQ
  77  *
  78  * Note: The term "IRQ" is loosely used everywhere in Linux kernel to
  79  * describeinterrupts.  Now we use "IRQ" only for Linux IRQ's.  ISA IRQ
  80  * (isa_irq) is the only exception in this source code.
  81  */
  82
  83 #include <linux/acpi.h>
  84 #include <linux/init.h>
  85 #include <linux/irq.h>
  86 #include <linux/kernel.h>
  87 #include <linux/list.h>
  88 #include <linux/pci.h>
  89 #include <linux/smp.h>
  90 #include <linux/string.h>
  91 #include <linux/bootmem.h>
  92
  93 #include <asm/delay.h>
  94 #include <asm/hw_irq.h>
  95 #include <asm/io.h>
  96 #include <asm/iosapic.h>
  97 #include <asm/machvec.h>
  98 #include <asm/processor.h>
  99 #include <asm/ptrace.h>
 100 #include <asm/system.h>
 101
 102 #undef DEBUG_INTERRUPT_ROUTING
 103
 104 #ifdef DEBUG_INTERRUPT_ROUTING
 105 #define DBG(fmt...)     printk(fmt)
 106 #else
 107 #define DBG(fmt...)
 108 #endif
 109
 110 #define NR_PREALLOCATE_RTE_ENTRIES \
 111         (PAGE_SIZE / sizeof(struct iosapic_rte_info))
 112 #define RTE_PREALLOCATED        (1)
 113
 114 static DEFINE_SPINLOCK(iosapic_lock);
 115
 116 /*
 117  * These tables map IA-64 vectors to the IOSAPIC pin that generates this
 118  * vector.
 119  */
 120
 121 #define NO_REF_RTE      0
 122
 123 static struct iosapic {
 124         char __iomem    *addr;          /* base address of IOSAPIC */
 125         unsigned int    gsi_base;       /* GSI base */
 126         unsigned short  num_rte;        /* # of RTEs on this IOSAPIC */
 127         int             rtes_inuse;     /* # of RTEs in use on this IOSAPIC */
 128 #ifdef CONFIG_NUMA
 129         unsigned short  node;           /* numa node association via pxm */
 130 #endif
 131         spinlock_t      lock;           /* lock for indirect reg access */
 132 } iosapic_lists[NR_IOSAPICS];
 133
 134 struct iosapic_rte_info {
 135         struct list_head rte_list;      /* RTEs sharing the same vector */
 136         char            rte_index;      /* IOSAPIC RTE index */
 137         int             refcnt;         /* reference counter */
 138         unsigned int    flags;          /* flags */
 139         struct iosapic  *iosapic;
 140 } ____cacheline_aligned;
 141
 142 static struct iosapic_intr_info {
 143         struct list_head rtes;          /* RTEs using this vector (empty =>
 144                                          * not an IOSAPIC interrupt) */
 145         int             count;          /* # of registered RTEs */
 146         u32             low32;          /* current value of low word of
 147                                          * Redirection table entry */
 148         unsigned int    dest;           /* destination CPU physical ID */
 149         unsigned char   dmode   : 3;    /* delivery mode (see iosapic.h) */
 150         unsigned char   polarity: 1;    /* interrupt polarity
 151                                          * (see iosapic.h) */
 152         unsigned char   trigger : 1;    /* trigger mode (see iosapic.h) */
 153 } iosapic_intr_info[NR_IRQS];
 154
 155 static unsigned char pcat_compat __devinitdata; /* 8259 compatibility flag */
 156
 157 static int iosapic_kmalloc_ok;
 158 static LIST_HEAD(free_rte_list);
 159
 160 static inline void
 161 iosapic_write(struct iosapic *iosapic, unsigned int reg, u32 val)
 162 {
 163         unsigned long flags;
 164
 165         spin_lock_irqsave(&iosapic->lock, flags);
 166         __iosapic_write(iosapic->addr, reg, val);
 167         spin_unlock_irqrestore(&iosapic->lock, flags);
 168 }
 169
 170 /*
 171  * Find an IOSAPIC associated with a GSI
 172  */
 173 static inline int
 174 find_iosapic (unsigned int gsi)
 175 {
 176         int i;
 177
 178         for (i = 0; i < NR_IOSAPICS; i++) {
 179                 if ((unsigned) (gsi - iosapic_lists[i].gsi_base) <
 180                     iosapic_lists[i].num_rte)
 181                         return i;
 182         }
 183
 184         return -1;
 185 }
 186
 187 static inline int __gsi_to_irq(unsigned int gsi)
 188 {
 189         int irq;
 190         struct iosapic_intr_info *info;
 191         struct iosapic_rte_info *rte;
 192
 193         for (irq = 0; irq < NR_IRQS; irq++) {
 194                 info = &iosapic_intr_info[irq];
 195                 list_for_each_entry(rte, &info->rtes, rte_list)
 196                         if (rte->iosapic->gsi_base + rte->rte_index == gsi)
 197                                 return irq;
 198         }
 199         return -1;
 200 }
 201
 202 int
 203 gsi_to_irq (unsigned int gsi)
 204 {
 205         unsigned long flags;
 206         int irq;
 207
 208         spin_lock_irqsave(&iosapic_lock, flags);
 209         irq = __gsi_to_irq(gsi);
 210         spin_unlock_irqrestore(&iosapic_lock, flags);
 211         return irq;
 212 }
 213
 214 static struct iosapic_rte_info *find_rte(unsigned int irq, unsigned int gsi)
 215 {
 216         struct iosapic_rte_info *rte;
 217
 218         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list)
 219                 if (rte->iosapic->gsi_base + rte->rte_index == gsi)
 220                         return rte;
 221         return NULL;
 222 }
 223
 224 static void
 225 set_rte (unsigned int gsi, unsigned int irq, unsigned int dest, int mask)
 226 {
 227         unsigned long pol, trigger, dmode;
 228         u32 low32, high32;
 229         int rte_index;
 230         char redir;
 231         struct iosapic_rte_info *rte;
 232         ia64_vector vector = irq_to_vector(irq);
 233
 234         DBG(KERN_DEBUG"IOSAPIC: routing vector %d to 0x%x\n", vector, dest);
 235
 236         rte = find_rte(irq, gsi);
 237         if (!rte)
 238                 return;         /* not an IOSAPIC interrupt */
 239
 240         rte_index = rte->rte_index;
 241         pol     = iosapic_intr_info[irq].polarity;
 242         trigger = iosapic_intr_info[irq].trigger;
 243         dmode   = iosapic_intr_info[irq].dmode;
 244
 245         redir = (dmode == IOSAPIC_LOWEST_PRIORITY) ? 1 : 0;
 246
 247 #ifdef CONFIG_SMP
 248         set_irq_affinity_info(irq, (int)(dest & 0xffff), redir);
 249 #endif
 250
 251         low32 = ((pol << IOSAPIC_POLARITY_SHIFT) |
 252                  (trigger << IOSAPIC_TRIGGER_SHIFT) |
 253                  (dmode << IOSAPIC_DELIVERY_SHIFT) |
 254                  ((mask ? 1 : 0) << IOSAPIC_MASK_SHIFT) |
 255                  vector);
 256
 257         /* dest contains both id and eid */
 258         high32 = (dest << IOSAPIC_DEST_SHIFT);
 259
 260         iosapic_write(rte->iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
 261         iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 262         iosapic_intr_info[irq].low32 = low32;
 263         iosapic_intr_info[irq].dest = dest;
 264 }
 265
 266 static void
 267 nop (unsigned int irq)
 268 {
 269         /* do nothing... */
 270 }
 271
 272
 273 #ifdef CONFIG_KEXEC
 274 void
 275 kexec_disable_iosapic(void)
 276 {
 277         struct iosapic_intr_info *info;
 278         struct iosapic_rte_info *rte;
 279         ia64_vector vec;
 280         int irq;
 281
 282         for (irq = 0; irq < NR_IRQS; irq++) {
 283                 info = &iosapic_intr_info[irq];
 284                 vec = irq_to_vector(irq);
 285                 list_for_each_entry(rte, &info->rtes,
 286                                 rte_list) {
 287                         iosapic_write(rte->iosapic,
 288                                         IOSAPIC_RTE_LOW(rte->rte_index),
 289                                         IOSAPIC_MASK|vec);
 290                         iosapic_eoi(rte->iosapic->addr, vec);
 291                 }
 292         }
 293 }
 294 #endif
 295
 296 static void
 297 mask_irq (unsigned int irq)
 298 {
 299         u32 low32;
 300         int rte_index;
 301         struct iosapic_rte_info *rte;
 302
 303         if (!iosapic_intr_info[irq].count)
 304                 return;                 /* not an IOSAPIC interrupt! */
 305
 306         /* set only the mask bit */
 307         low32 = iosapic_intr_info[irq].low32 |= IOSAPIC_MASK;
 308         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
 309                 rte_index = rte->rte_index;
 310                 iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 311         }
 312 }
 313
 314 static void
 315 unmask_irq (unsigned int irq)
 316 {
 317         u32 low32;
 318         int rte_index;
 319         struct iosapic_rte_info *rte;
 320
 321         if (!iosapic_intr_info[irq].count)
 322                 return;                 /* not an IOSAPIC interrupt! */
 323
 324         low32 = iosapic_intr_info[irq].low32 &= ~IOSAPIC_MASK;
 325         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
 326                 rte_index = rte->rte_index;
 327                 iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 328         }
 329 }
 330
 331
 332 static void
 333 iosapic_set_affinity (unsigned int irq, cpumask_t mask)
 334 {
 335 #ifdef CONFIG_SMP
 336         u32 high32, low32;
 337         int dest, rte_index;
 338         int redir = (irq & IA64_IRQ_REDIRECTED) ? 1 : 0;
 339         struct iosapic_rte_info *rte;
 340         struct iosapic *iosapic;
 341
 342         irq &= (~IA64_IRQ_REDIRECTED);
 343
 344         cpus_and(mask, mask, cpu_online_map);
 345         if (cpus_empty(mask))
 346                 return;
 347
 348         if (irq_prepare_move(irq, first_cpu(mask)))
 349                 return;
 350
 351         dest = cpu_physical_id(first_cpu(mask));
 352
 353         if (!iosapic_intr_info[irq].count)
 354                 return;                 /* not an IOSAPIC interrupt */
 355
 356         set_irq_affinity_info(irq, dest, redir);
 357
 358         /* dest contains both id and eid */
 359         high32 = dest << IOSAPIC_DEST_SHIFT;
 360
 361         low32 = iosapic_intr_info[irq].low32 & ~(7 << IOSAPIC_DELIVERY_SHIFT);
 362         if (redir)
 363                 /* change delivery mode to lowest priority */
 364                 low32 |= (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
 365         else
 366                 /* change delivery mode to fixed */
 367                 low32 |= (IOSAPIC_FIXED << IOSAPIC_DELIVERY_SHIFT);
 368         low32 &= IOSAPIC_VECTOR_MASK;
 369         low32 |= irq_to_vector(irq);
 370
 371         iosapic_intr_info[irq].low32 = low32;
 372         iosapic_intr_info[irq].dest = dest;
 373         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
 374                 iosapic = rte->iosapic;
 375                 rte_index = rte->rte_index;
 376                 iosapic_write(iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
 377                 iosapic_write(iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 378         }
 379 #endif
 380 }
 381
 382 /*
 383  * Handlers for level-triggered interrupts.
 384  */
 385
 386 static unsigned int
 387 iosapic_startup_level_irq (unsigned int irq)
 388 {
 389         unmask_irq(irq);
 390         return 0;
 391 }
 392
 393 static void
 394 iosapic_end_level_irq (unsigned int irq)
 395 {
 396         ia64_vector vec = irq_to_vector(irq);
 397         struct iosapic_rte_info *rte;
 398         int do_unmask_irq = 0;
 399
 400         irq_complete_move(irq);
 401         if (unlikely(irq_desc[irq].status & IRQ_MOVE_PENDING)) {
 402                 do_unmask_irq = 1;
 403                 mask_irq(irq);
 404         }
 405
 406         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list)
 407                 iosapic_eoi(rte->iosapic->addr, vec);
 408
 409         if (unlikely(do_unmask_irq)) {
 410                 move_masked_irq(irq);
 411                 unmask_irq(irq);
 412         }
 413 }
 414
 415 #define iosapic_shutdown_level_irq      mask_irq
 416 #define iosapic_enable_level_irq        unmask_irq
 417 #define iosapic_disable_level_irq       mask_irq
 418 #define iosapic_ack_level_irq           nop
 419
 420 static struct irq_chip irq_type_iosapic_level = {
 421         .name =         "IO-SAPIC-level",
 422         .startup =      iosapic_startup_level_irq,
 423         .shutdown =     iosapic_shutdown_level_irq,
 424         .enable =       iosapic_enable_level_irq,
 425         .disable =      iosapic_disable_level_irq,
 426         .ack =          iosapic_ack_level_irq,
 427         .end =          iosapic_end_level_irq,
 428         .mask =         mask_irq,
 429         .unmask =       unmask_irq,
 430         .set_affinity = iosapic_set_affinity
 431 };
 432
 433 /*
 434  * Handlers for edge-triggered interrupts.
 435  */
 436
 437 static unsigned int
 438 iosapic_startup_edge_irq (unsigned int irq)
 439 {
 440         unmask_irq(irq);
 441         /*
 442          * IOSAPIC simply drops interrupts pended while the
 443          * corresponding pin was masked, so we can't know if an
 444          * interrupt is pending already.  Let's hope not...
 445          */
 446         return 0;
 447 }
 448
 449 static void
 450 iosapic_ack_edge_irq (unsigned int irq)
 451 {
 452         irq_desc_t *idesc = irq_desc + irq;
 453
 454         irq_complete_move(irq);
 455         move_native_irq(irq);
 456         /*
 457          * Once we have recorded IRQ_PENDING already, we can mask the
 458          * interrupt for real. This prevents IRQ storms from unhandled
 459          * devices.
 460          */
 461         if ((idesc->status & (IRQ_PENDING|IRQ_DISABLED)) ==
 462             (IRQ_PENDING|IRQ_DISABLED))
 463                 mask_irq(irq);
 464 }
 465
 466 #define iosapic_enable_edge_irq         unmask_irq
 467 #define iosapic_disable_edge_irq        nop
 468 #define iosapic_end_edge_irq            nop
 469
 470 static struct irq_chip irq_type_iosapic_edge = {
 471         .name =         "IO-SAPIC-edge",
 472         .startup =      iosapic_startup_edge_irq,
 473         .shutdown =     iosapic_disable_edge_irq,
 474         .enable =       iosapic_enable_edge_irq,
 475         .disable =      iosapic_disable_edge_irq,
 476         .ack =          iosapic_ack_edge_irq,
 477         .end =          iosapic_end_edge_irq,
 478         .mask =         mask_irq,
 479         .unmask =       unmask_irq,
 480         .set_affinity = iosapic_set_affinity
 481 };
 482
 483 static unsigned int
 484 iosapic_version (char __iomem *addr)
 485 {
 486         /*
 487          * IOSAPIC Version Register return 32 bit structure like:
 488          * {
 489          *      unsigned int version   : 8;
 490          *      unsigned int reserved1 : 8;
 491          *      unsigned int max_redir : 8;
 492          *      unsigned int reserved2 : 8;
 493          * }
 494          */
 495         return __iosapic_read(addr, IOSAPIC_VERSION);
 496 }
 497
 498 static int iosapic_find_sharable_irq(unsigned long trigger, unsigned long pol)
 499 {
 500         int i, irq = -ENOSPC, min_count = -1;
 501         struct iosapic_intr_info *info;
 502
 503         /*
 504          * shared vectors for edge-triggered interrupts are not
 505          * supported yet
 506          */
 507         if (trigger == IOSAPIC_EDGE)
 508                 return -EINVAL;
 509
 510         for (i = 0; i <= NR_IRQS; i++) {
 511                 info = &iosapic_intr_info[i];
 512                 if (info->trigger == trigger && info->polarity == pol &&
 513                     (info->dmode == IOSAPIC_FIXED ||
 514                      info->dmode == IOSAPIC_LOWEST_PRIORITY) &&
 515                     can_request_irq(i, IRQF_SHARED)) {
 516                         if (min_count == -1 || info->count < min_count) {
 517                                 irq = i;
 518                                 min_count = info->count;
 519                         }
 520                 }
 521         }
 522         return irq;
 523 }
 524
 525 /*
 526  * if the given vector is already owned by other,
 527  *  assign a new vector for the other and make the vector available
 528  */
 529 static void __init
 530 iosapic_reassign_vector (int irq)
 531 {
 532         int new_irq;
 533
 534         if (iosapic_intr_info[irq].count) {
 535                 new_irq = create_irq();
 536                 if (new_irq < 0)
 537                         panic("%s: out of interrupt vectors!\n", __func__);
 538                 printk(KERN_INFO "Reassigning vector %d to %d\n",
 539                        irq_to_vector(irq), irq_to_vector(new_irq));
 540                 memcpy(&iosapic_intr_info[new_irq], &iosapic_intr_info[irq],
 541                        sizeof(struct iosapic_intr_info));
 542                 INIT_LIST_HEAD(&iosapic_intr_info[new_irq].rtes);
 543                 list_move(iosapic_intr_info[irq].rtes.next,
 544                           &iosapic_intr_info[new_irq].rtes);
 545                 memset(&iosapic_intr_info[irq], 0,
 546                        sizeof(struct iosapic_intr_info));
 547                 iosapic_intr_info[irq].low32 = IOSAPIC_MASK;
 548                 INIT_LIST_HEAD(&iosapic_intr_info[irq].rtes);
 549         }
 550 }
 551
 552 static struct iosapic_rte_info * __init_refok iosapic_alloc_rte (void)
 553 {
 554         int i;
 555         struct iosapic_rte_info *rte;
 556         int preallocated = 0;
 557
 558         if (!iosapic_kmalloc_ok && list_empty(&free_rte_list)) {
 559                 rte = alloc_bootmem(sizeof(struct iosapic_rte_info) *
 560                                     NR_PREALLOCATE_RTE_ENTRIES);
 561                 for (i = 0; i < NR_PREALLOCATE_RTE_ENTRIES; i++, rte++)
 562                         list_add(&rte->rte_list, &free_rte_list);
 563         }
 564
 565         if (!list_empty(&free_rte_list)) {
 566                 rte = list_entry(free_rte_list.next, struct iosapic_rte_info,
 567                                  rte_list);
 568                 list_del(&rte->rte_list);
 569                 preallocated++;
 570         } else {
 571                 rte = kmalloc(sizeof(struct iosapic_rte_info), GFP_ATOMIC);
 572                 if (!rte)
 573                         return NULL;
 574         }
 575
 576         memset(rte, 0, sizeof(struct iosapic_rte_info));
 577         if (preallocated)
 578                 rte->flags |= RTE_PREALLOCATED;
 579
 580         return rte;
 581 }
 582
 583 static inline int irq_is_shared (int irq)
 584 {
 585         return (iosapic_intr_info[irq].count > 1);
 586 }
 587
 588 static int
 589 register_intr (unsigned int gsi, int irq, unsigned char delivery,
 590                unsigned long polarity, unsigned long trigger)
 591 {
 592         irq_desc_t *idesc;
 593         struct hw_interrupt_type *irq_type;
 594         int index;
 595         struct iosapic_rte_info *rte;
 596
 597         index = find_iosapic(gsi);
 598         if (index < 0) {
 599                 printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
 600                        __func__, gsi);
 601                 return -ENODEV;
 602         }
 603
 604         rte = find_rte(irq, gsi);
 605         if (!rte) {
 606                 rte = iosapic_alloc_rte();
 607                 if (!rte) {
 608                         printk(KERN_WARNING "%s: cannot allocate memory\n",
 609                                __func__);
 610                         return -ENOMEM;
 611                 }
 612
 613                 rte->iosapic    = &iosapic_lists[index];
 614                 rte->rte_index  = gsi - rte->iosapic->gsi_base;
 615                 rte->refcnt++;
 616                 list_add_tail(&rte->rte_list, &iosapic_intr_info[irq].rtes);
 617                 iosapic_intr_info[irq].count++;
 618                 iosapic_lists[index].rtes_inuse++;
 619         }
 620         else if (rte->refcnt == NO_REF_RTE) {
 621                 struct iosapic_intr_info *info = &iosapic_intr_info[irq];
 622                 if (info->count > 0 &&
 623                     (info->trigger != trigger || info->polarity != polarity)){
 624                         printk (KERN_WARNING
 625                                 "%s: cannot override the interrupt\n",
 626                                 __func__);
 627                         return -EINVAL;
 628                 }
 629                 rte->refcnt++;
 630                 iosapic_intr_info[irq].count++;
 631                 iosapic_lists[index].rtes_inuse++;
 632         }
 633
 634         iosapic_intr_info[irq].polarity = polarity;
 635         iosapic_intr_info[irq].dmode    = delivery;
 636         iosapic_intr_info[irq].trigger  = trigger;
 637
 638         if (trigger == IOSAPIC_EDGE)
 639                 irq_type = &irq_type_iosapic_edge;
 640         else
 641                 irq_type = &irq_type_iosapic_level;
 642
 643         idesc = irq_desc + irq;
 644         if (idesc->chip != irq_type) {
 645                 if (idesc->chip != &no_irq_type)
 646                         printk(KERN_WARNING
 647                                "%s: changing vector %d from %s to %s\n",
 648                                __func__, irq_to_vector(irq),
 649                                idesc->chip->name, irq_type->name);
 650                 idesc->chip = irq_type;
 651         }
 652         return 0;
 653 }
 654
 655 static unsigned int
 656 get_target_cpu (unsigned int gsi, int irq)
 657 {
 658 #ifdef CONFIG_SMP
 659         static int cpu = -1;
 660         extern int cpe_vector;
 661         cpumask_t domain = irq_to_domain(irq);
 662
 663         /*
 664          * In case of vector shared by multiple RTEs, all RTEs that
 665          * share the vector need to use the same destination CPU.
 666          */
 667         if (iosapic_intr_info[irq].count)
 668                 return iosapic_intr_info[irq].dest;
 669
 670         /*
 671          * If the platform supports redirection via XTP, let it
 672          * distribute interrupts.
 673          */
 674         if (smp_int_redirect & SMP_IRQ_REDIRECTION)
 675                 return cpu_physical_id(smp_processor_id());
 676
 677         /*
 678          * Some interrupts (ACPI SCI, for instance) are registered
 679          * before the BSP is marked as online.
 680          */
 681         if (!cpu_online(smp_processor_id()))
 682                 return cpu_physical_id(smp_processor_id());
 683
 684 #ifdef CONFIG_ACPI
 685         if (cpe_vector > 0 && irq_to_vector(irq) == IA64_CPEP_VECTOR)
 686                 return get_cpei_target_cpu();
 687 #endif
 688
 689 #ifdef CONFIG_NUMA
 690         {
 691                 int num_cpus, cpu_index, iosapic_index, numa_cpu, i = 0;
 692                 cpumask_t cpu_mask;
 693
 694                 iosapic_index = find_iosapic(gsi);
 695                 if (iosapic_index < 0 ||
 696                     iosapic_lists[iosapic_index].node == MAX_NUMNODES)
 697                         goto skip_numa_setup;
 698
 699                 cpu_mask = node_to_cpumask(iosapic_lists[iosapic_index].node);
 700                 cpus_and(cpu_mask, cpu_mask, domain);
 701                 for_each_cpu_mask(numa_cpu, cpu_mask) {
 702                         if (!cpu_online(numa_cpu))
 703                                 cpu_clear(numa_cpu, cpu_mask);
 704                 }
 705
 706                 num_cpus = cpus_weight(cpu_mask);
 707
 708                 if (!num_cpus)
 709                         goto skip_numa_setup;
 710
 711                 /* Use irq assignment to distribute across cpus in node */
 712                 cpu_index = irq % num_cpus;
 713
 714                 for (numa_cpu = first_cpu(cpu_mask) ; i < cpu_index ; i++)
 715                         numa_cpu = next_cpu(numa_cpu, cpu_mask);
 716
 717                 if (numa_cpu != NR_CPUS)
 718                         return cpu_physical_id(numa_cpu);
 719         }
 720 skip_numa_setup:
 721 #endif
 722         /*
 723          * Otherwise, round-robin interrupt vectors across all the
 724          * processors.  (It'd be nice if we could be smarter in the
 725          * case of NUMA.)
 726          */
 727         do {
 728                 if (++cpu >= NR_CPUS)
 729                         cpu = 0;
 730         } while (!cpu_online(cpu) || !cpu_isset(cpu, domain));
 731
 732         return cpu_physical_id(cpu);
 733 #else  /* CONFIG_SMP */
 734         return cpu_physical_id(smp_processor_id());
 735 #endif
 736 }
 737
 738 static inline unsigned char choose_dmode(void)
 739 {
 740 #ifdef CONFIG_SMP
 741         if (smp_int_redirect & SMP_IRQ_REDIRECTION)
 742                 return IOSAPIC_LOWEST_PRIORITY;
 743 #endif
 744         return IOSAPIC_FIXED;
 745 }
 746
 747 /*
 748  * ACPI can describe IOSAPIC interrupts via static tables and namespace
 749  * methods.  This provides an interface to register those interrupts and
 750  * program the IOSAPIC RTE.
 751  */
 752 int
 753 iosapic_register_intr (unsigned int gsi,
 754                        unsigned long polarity, unsigned long trigger)
 755 {
 756         int irq, mask = 1, err;
 757         unsigned int dest;
 758         unsigned long flags;
 759         struct iosapic_rte_info *rte;
 760         u32 low32;
 761         unsigned char dmode;
 762
 763         /*
 764          * If this GSI has already been registered (i.e., it's a
 765          * shared interrupt, or we lost a race to register it),
 766          * don't touch the RTE.
 767          */
 768         spin_lock_irqsave(&iosapic_lock, flags);
 769         irq = __gsi_to_irq(gsi);
 770         if (irq > 0) {
 771                 rte = find_rte(irq, gsi);
 772                 if(iosapic_intr_info[irq].count == 0) {
 773                         assign_irq_vector(irq);
 774                         dynamic_irq_init(irq);
 775                 } else if (rte->refcnt != NO_REF_RTE) {
 776                         rte->refcnt++;
 777                         goto unlock_iosapic_lock;
 778                 }
 779         } else
 780                 irq = create_irq();
 781
 782         /* If vector is running out, we try to find a sharable vector */
 783         if (irq < 0) {
 784                 irq = iosapic_find_sharable_irq(trigger, polarity);
 785                 if (irq < 0)
 786                         goto unlock_iosapic_lock;
 787         }
 788
 789         spin_lock(&irq_desc[irq].lock);
 790         dest = get_target_cpu(gsi, irq);
 791         dmode = choose_dmode();
 792         err = register_intr(gsi, irq, dmode, polarity, trigger);
 793         if (err < 0) {
 794                 spin_unlock(&irq_desc[irq].lock);
 795                 irq = err;
 796                 goto unlock_iosapic_lock;
 797         }
 798
 799         /*
 800          * If the vector is shared and already unmasked for other
 801          * interrupt sources, don't mask it.
 802          */
 803         low32 = iosapic_intr_info[irq].low32;
 804         if (irq_is_shared(irq) && !(low32 & IOSAPIC_MASK))
 805                 mask = 0;
 806         set_rte(gsi, irq, dest, mask);
 807
 808         printk(KERN_INFO "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d\n",
 809                gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
 810                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 811                cpu_logical_id(dest), dest, irq_to_vector(irq));
 812
 813         spin_unlock(&irq_desc[irq].lock);
 814  unlock_iosapic_lock:
 815         spin_unlock_irqrestore(&iosapic_lock, flags);
 816         return irq;
 817 }
 818
 819 void
 820 iosapic_unregister_intr (unsigned int gsi)
 821 {
 822         unsigned long flags;
 823         int irq, index;
 824         irq_desc_t *idesc;
 825         u32 low32;
 826         unsigned long trigger, polarity;
 827         unsigned int dest;
 828         struct iosapic_rte_info *rte;
 829
 830         /*
 831          * If the irq associated with the gsi is not found,
 832          * iosapic_unregister_intr() is unbalanced. We need to check
 833          * this again after getting locks.
 834          */
 835         irq = gsi_to_irq(gsi);
 836         if (irq < 0) {
 837                 printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
 838                        gsi);
 839                 WARN_ON(1);
 840                 return;
 841         }
 842
 843         spin_lock_irqsave(&iosapic_lock, flags);
 844         if ((rte = find_rte(irq, gsi)) == NULL) {
 845                 printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
 846                        gsi);
 847                 WARN_ON(1);
 848                 goto out;
 849         }
 850
 851         if (--rte->refcnt > 0)
 852                 goto out;
 853
 854         idesc = irq_desc + irq;
 855         rte->refcnt = NO_REF_RTE;
 856
 857         /* Mask the interrupt */
 858         low32 = iosapic_intr_info[irq].low32 | IOSAPIC_MASK;
 859         iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte->rte_index), low32);
 860
 861         iosapic_intr_info[irq].count--;
 862         index = find_iosapic(gsi);
 863         iosapic_lists[index].rtes_inuse--;
 864         WARN_ON(iosapic_lists[index].rtes_inuse < 0);
 865
 866         trigger  = iosapic_intr_info[irq].trigger;
 867         polarity = iosapic_intr_info[irq].polarity;
 868         dest     = iosapic_intr_info[irq].dest;
 869         printk(KERN_INFO
 870                "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d unregistered\n",
 871                gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
 872                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 873                cpu_logical_id(dest), dest, irq_to_vector(irq));
 874
 875         if (iosapic_intr_info[irq].count == 0) {
 876 #ifdef CONFIG_SMP
 877                 /* Clear affinity */
 878                 cpus_setall(idesc->affinity);
 879 #endif
 880                 /* Clear the interrupt information */
 881                 iosapic_intr_info[irq].dest = 0;
 882                 iosapic_intr_info[irq].dmode = 0;
 883                 iosapic_intr_info[irq].polarity = 0;
 884                 iosapic_intr_info[irq].trigger = 0;
 885                 iosapic_intr_info[irq].low32 |= IOSAPIC_MASK;
 886
 887                 /* Destroy and reserve IRQ */
 888                 destroy_and_reserve_irq(irq);
 889         }
 890  out:
 891         spin_unlock_irqrestore(&iosapic_lock, flags);
 892 }
 893
 894 /*
 895  * ACPI calls this when it finds an entry for a platform interrupt.
 896  */
 897 int __init
 898 iosapic_register_platform_intr (u32 int_type, unsigned int gsi,
 899                                 int iosapic_vector, u16 eid, u16 id,
 900                                 unsigned long polarity, unsigned long trigger)
 901 {
 902         static const char * const name[] = {"unknown", "PMI", "INIT", "CPEI"};
 903         unsigned char delivery;
 904         int irq, vector, mask = 0;
 905         unsigned int dest = ((id << 8) | eid) & 0xffff;
 906
 907         switch (int_type) {
 908               case ACPI_INTERRUPT_PMI:
 909                 irq = vector = iosapic_vector;
 910                 bind_irq_vector(irq, vector, CPU_MASK_ALL);
 911                 /*
 912                  * since PMI vector is alloc'd by FW(ACPI) not by kernel,
 913                  * we need to make sure the vector is available
 914                  */
 915                 iosapic_reassign_vector(irq);
 916                 delivery = IOSAPIC_PMI;
 917                 break;
 918               case ACPI_INTERRUPT_INIT:
 919                 irq = create_irq();
 920                 if (irq < 0)
 921                         panic("%s: out of interrupt vectors!\n", __func__);
 922                 vector = irq_to_vector(irq);
 923                 delivery = IOSAPIC_INIT;
 924                 break;
 925               case ACPI_INTERRUPT_CPEI:
 926                 irq = vector = IA64_CPE_VECTOR;
 927                 BUG_ON(bind_irq_vector(irq, vector, CPU_MASK_ALL));
 928                 delivery = IOSAPIC_FIXED;
 929                 mask = 1;
 930                 break;
 931               default:
 932                 printk(KERN_ERR "%s: invalid int type 0x%x\n", __func__,
 933                        int_type);
 934                 return -1;
 935         }
 936
 937         register_intr(gsi, irq, delivery, polarity, trigger);
 938
 939         printk(KERN_INFO
 940                "PLATFORM int %s (0x%x): GSI %u (%s, %s) -> CPU %d (0x%04x)"
 941                " vector %d\n",
 942                int_type < ARRAY_SIZE(name) ? name[int_type] : "unknown",
 943                int_type, gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
 944                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 945                cpu_logical_id(dest), dest, vector);
 946
 947         set_rte(gsi, irq, dest, mask);
 948         return vector;
 949 }
 950
 951 /*
 952  * ACPI calls this when it finds an entry for a legacy ISA IRQ override.
 953  */
 954 void __devinit
 955 iosapic_override_isa_irq (unsigned int isa_irq, unsigned int gsi,
 956                           unsigned long polarity,
 957                           unsigned long trigger)
 958 {
 959         int vector, irq;
 960         unsigned int dest = cpu_physical_id(smp_processor_id());
 961         unsigned char dmode;
 962
 963         irq = vector = isa_irq_to_vector(isa_irq);
 964         BUG_ON(bind_irq_vector(irq, vector, CPU_MASK_ALL));
 965         dmode = choose_dmode();
 966         register_intr(gsi, irq, dmode, polarity, trigger);
 967
 968         DBG("ISA: IRQ %u -> GSI %u (%s,%s) -> CPU %d (0x%04x) vector %d\n",
 969             isa_irq, gsi, trigger == IOSAPIC_EDGE ? "edge" : "level",
 970             polarity == IOSAPIC_POL_HIGH ? "high" : "low",
 971             cpu_logical_id(dest), dest, vector);
 972
 973         set_rte(gsi, irq, dest, 1);
 974 }
 975
 976 void __init
 977 iosapic_system_init (int system_pcat_compat)
 978 {
 979         int irq;
 980
 981         for (irq = 0; irq < NR_IRQS; ++irq) {
 982                 iosapic_intr_info[irq].low32 = IOSAPIC_MASK;
 983                 /* mark as unused */
 984                 INIT_LIST_HEAD(&iosapic_intr_info[irq].rtes);
 985
 986                 iosapic_intr_info[irq].count = 0;
 987         }
 988
 989         pcat_compat = system_pcat_compat;
 990         if (pcat_compat) {
 991                 /*
 992                  * Disable the compatibility mode interrupts (8259 style),
 993                  * needs IN/OUT support enabled.
 994                  */
 995                 printk(KERN_INFO
 996                        "%s: Disabling PC-AT compatible 8259 interrupts\n",
 997                        __func__);
 998                 outb(0xff, 0xA1);
 999                 outb(0xff, 0x21);
1000         }
1001 }
1002
1003 static inline int
1004 iosapic_alloc (void)
1005 {
1006         int index;
1007
1008         for (index = 0; index < NR_IOSAPICS; index++)
1009                 if (!iosapic_lists[index].addr)
1010                         return index;
1011
1012         printk(KERN_WARNING "%s: failed to allocate iosapic\n", __func__);
1013         return -1;
1014 }
1015
1016 static inline void
1017 iosapic_free (int index)
1018 {
1019         memset(&iosapic_lists[index], 0, sizeof(iosapic_lists[0]));
1020 }
1021
1022 static inline int
1023 iosapic_check_gsi_range (unsigned int gsi_base, unsigned int ver)
1024 {
1025         int index;
1026         unsigned int gsi_end, base, end;
1027
1028         /* check gsi range */
1029         gsi_end = gsi_base + ((ver >> 16) & 0xff);
1030         for (index = 0; index < NR_IOSAPICS; index++) {
1031                 if (!iosapic_lists[index].addr)
1032                         continue;
1033
1034                 base = iosapic_lists[index].gsi_base;
1035                 end  = base + iosapic_lists[index].num_rte - 1;
1036
1037                 if (gsi_end < base || end < gsi_base)
1038                         continue; /* OK */
1039
1040                 return -EBUSY;
1041         }
1042         return 0;
1043 }
1044
1045 int __devinit
1046 iosapic_init (unsigned long phys_addr, unsigned int gsi_base)
1047 {
1048         int num_rte, err, index;
1049         unsigned int isa_irq, ver;
1050         char __iomem *addr;
1051         unsigned long flags;
1052
1053         spin_lock_irqsave(&iosapic_lock, flags);
1054         index = find_iosapic(gsi_base);
1055         if (index >= 0) {
1056                 spin_unlock_irqrestore(&iosapic_lock, flags);
1057                 return -EBUSY;
1058         }
1059
1060         addr = ioremap(phys_addr, 0);
1061         ver = iosapic_version(addr);
1062         if ((err = iosapic_check_gsi_range(gsi_base, ver))) {
1063                 iounmap(addr);
1064                 spin_unlock_irqrestore(&iosapic_lock, flags);
1065                 return err;
1066         }
1067
1068         /*
1069          * The MAX_REDIR register holds the highest input pin number
1070          * (starting from 0).  We add 1 so that we can use it for
1071          * number of pins (= RTEs)
1072          */
1073         num_rte = ((ver >> 16) & 0xff) + 1;
1074
1075         index = iosapic_alloc();
1076         iosapic_lists[index].addr = addr;
1077         iosapic_lists[index].gsi_base = gsi_base;
1078         iosapic_lists[index].num_rte = num_rte;
1079 #ifdef CONFIG_NUMA
1080         iosapic_lists[index].node = MAX_NUMNODES;
1081 #endif
1082         spin_lock_init(&iosapic_lists[index].lock);
1083         spin_unlock_irqrestore(&iosapic_lock, flags);
1084
1085         if ((gsi_base == 0) && pcat_compat) {
1086                 /*
1087                  * Map the legacy ISA devices into the IOSAPIC data.  Some of
1088                  * these may get reprogrammed later on with data from the ACPI
1089                  * Interrupt Source Override table.
1090                  */
1091                 for (isa_irq = 0; isa_irq < 16; ++isa_irq)
1092                         iosapic_override_isa_irq(isa_irq, isa_irq,
1093                                                  IOSAPIC_POL_HIGH,
1094                                                  IOSAPIC_EDGE);
1095         }
1096         return 0;
1097 }
1098
1099 #ifdef CONFIG_HOTPLUG
1100 int
1101 iosapic_remove (unsigned int gsi_base)
1102 {
1103         int index, err = 0;
1104         unsigned long flags;
1105
1106         spin_lock_irqsave(&iosapic_lock, flags);
1107         index = find_iosapic(gsi_base);
1108         if (index < 0) {
1109                 printk(KERN_WARNING "%s: No IOSAPIC for GSI base %u\n",
1110                        __func__, gsi_base);
1111                 goto out;
1112         }
1113
1114         if (iosapic_lists[index].rtes_inuse) {
1115                 err = -EBUSY;
1116                 printk(KERN_WARNING "%s: IOSAPIC for GSI base %u is busy\n",
1117                        __func__, gsi_base);
1118                 goto out;
1119         }
1120
1121         iounmap(iosapic_lists[index].addr);
1122         iosapic_free(index);
1123  out:
1124         spin_unlock_irqrestore(&iosapic_lock, flags);
1125         return err;
1126 }
1127 #endif /* CONFIG_HOTPLUG */
1128
1129 #ifdef CONFIG_NUMA
1130 void __devinit
1131 map_iosapic_to_node(unsigned int gsi_base, int node)
1132 {
1133         int index;
1134
1135         index = find_iosapic(gsi_base);
1136         if (index < 0) {
1137                 printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
1138                        __func__, gsi_base);
1139                 return;
1140         }
1141         iosapic_lists[index].node = node;
1142         return;
1143 }
1144 #endif
1145
1146 static int __init iosapic_enable_kmalloc (void)
1147 {
1148         iosapic_kmalloc_ok = 1;
1149         return 0;
1150 }
1151 core_initcall (iosapic_enable_kmalloc);