git.oblomov.eu Git - linux-2.6/blob - arch/ia64/kernel/iosapic.c

   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 struct iosapic_rte_info {
 122         struct list_head rte_list;      /* node in list of RTEs sharing the
 123                                          * same vector */
 124         char __iomem    *addr;          /* base address of IOSAPIC */
 125         unsigned int    gsi_base;       /* first GSI assigned to this
 126                                          * IOSAPIC */
 127         char            rte_index;      /* IOSAPIC RTE index */
 128         int             refcnt;         /* reference counter */
 129         unsigned int    flags;          /* flags */
 130 } ____cacheline_aligned;
 131
 132 static struct iosapic_intr_info {
 133         struct list_head rtes;          /* RTEs using this vector (empty =>
 134                                          * not an IOSAPIC interrupt) */
 135         int             count;          /* # of RTEs that shares this vector */
 136         u32             low32;          /* current value of low word of
 137                                          * Redirection table entry */
 138         unsigned int    dest;           /* destination CPU physical ID */
 139         unsigned char   dmode   : 3;    /* delivery mode (see iosapic.h) */
 140         unsigned char   polarity: 1;    /* interrupt polarity
 141                                          * (see iosapic.h) */
 142         unsigned char   trigger : 1;    /* trigger mode (see iosapic.h) */
 143 } iosapic_intr_info[IA64_NUM_VECTORS];
 144
 145 static struct iosapic {
 146         char __iomem    *addr;          /* base address of IOSAPIC */
 147         unsigned int    gsi_base;       /* first GSI assigned to this
 148                                          * IOSAPIC */
 149         unsigned short  num_rte;        /* # of RTEs on this IOSAPIC */
 150         int             rtes_inuse;     /* # of RTEs in use on this IOSAPIC */
 151 #ifdef CONFIG_NUMA
 152         unsigned short  node;           /* numa node association via pxm */
 153 #endif
 154 } iosapic_lists[NR_IOSAPICS];
 155
 156 static unsigned char pcat_compat __devinitdata; /* 8259 compatibility flag */
 157
 158 static int iosapic_kmalloc_ok;
 159 static LIST_HEAD(free_rte_list);
 160
 161 /*
 162  * Find an IOSAPIC associated with a GSI
 163  */
 164 static inline int
 165 find_iosapic (unsigned int gsi)
 166 {
 167         int i;
 168
 169         for (i = 0; i < NR_IOSAPICS; i++) {
 170                 if ((unsigned) (gsi - iosapic_lists[i].gsi_base) <
 171                     iosapic_lists[i].num_rte)
 172                         return i;
 173         }
 174
 175         return -1;
 176 }
 177
 178 static inline int
 179 _gsi_to_vector (unsigned int gsi)
 180 {
 181         struct iosapic_intr_info *info;
 182         struct iosapic_rte_info *rte;
 183
 184         for (info = iosapic_intr_info; info <
 185                      iosapic_intr_info + IA64_NUM_VECTORS; ++info)
 186                 list_for_each_entry(rte, &info->rtes, rte_list)
 187                         if (rte->gsi_base + rte->rte_index == gsi)
 188                                 return info - iosapic_intr_info;
 189         return -1;
 190 }
 191
 192 /*
 193  * Translate GSI number to the corresponding IA-64 interrupt vector.  If no
 194  * entry exists, return -1.
 195  */
 196 inline int
 197 gsi_to_vector (unsigned int gsi)
 198 {
 199         return _gsi_to_vector(gsi);
 200 }
 201
 202 int
 203 gsi_to_irq (unsigned int gsi)
 204 {
 205         unsigned long flags;
 206         int irq;
 207         /*
 208          * XXX fix me: this assumes an identity mapping between IA-64 vector
 209          * and Linux irq numbers...
 210          */
 211         spin_lock_irqsave(&iosapic_lock, flags);
 212         {
 213                 irq = _gsi_to_vector(gsi);
 214         }
 215         spin_unlock_irqrestore(&iosapic_lock, flags);
 216
 217         return irq;
 218 }
 219
 220 static struct iosapic_rte_info *gsi_vector_to_rte(unsigned int gsi,
 221                                                   unsigned int vec)
 222 {
 223         struct iosapic_rte_info *rte;
 224
 225         list_for_each_entry(rte, &iosapic_intr_info[vec].rtes, rte_list)
 226                 if (rte->gsi_base + rte->rte_index == gsi)
 227                         return rte;
 228         return NULL;
 229 }
 230
 231 static void
 232 set_rte (unsigned int gsi, unsigned int vector, unsigned int dest, int mask)
 233 {
 234         unsigned long pol, trigger, dmode;
 235         u32 low32, high32;
 236         char __iomem *addr;
 237         int rte_index;
 238         char redir;
 239         struct iosapic_rte_info *rte;
 240
 241         DBG(KERN_DEBUG"IOSAPIC: routing vector %d to 0x%x\n", vector, dest);
 242
 243         rte = gsi_vector_to_rte(gsi, vector);
 244         if (!rte)
 245                 return;         /* not an IOSAPIC interrupt */
 246
 247         rte_index = rte->rte_index;
 248         addr    = rte->addr;
 249         pol     = iosapic_intr_info[vector].polarity;
 250         trigger = iosapic_intr_info[vector].trigger;
 251         dmode   = iosapic_intr_info[vector].dmode;
 252
 253         redir = (dmode == IOSAPIC_LOWEST_PRIORITY) ? 1 : 0;
 254
 255 #ifdef CONFIG_SMP
 256         {
 257                 unsigned int irq;
 258
 259                 for (irq = 0; irq < NR_IRQS; ++irq)
 260                         if (irq_to_vector(irq) == vector) {
 261                                 set_irq_affinity_info(irq,
 262                                                       (int)(dest & 0xffff),
 263                                                       redir);
 264                                 break;
 265                         }
 266         }
 267 #endif
 268
 269         low32 = ((pol << IOSAPIC_POLARITY_SHIFT) |
 270                  (trigger << IOSAPIC_TRIGGER_SHIFT) |
 271                  (dmode << IOSAPIC_DELIVERY_SHIFT) |
 272                  ((mask ? 1 : 0) << IOSAPIC_MASK_SHIFT) |
 273                  vector);
 274
 275         /* dest contains both id and eid */
 276         high32 = (dest << IOSAPIC_DEST_SHIFT);
 277
 278         iosapic_write(addr, IOSAPIC_RTE_HIGH(rte_index), high32);
 279         iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
 280         iosapic_intr_info[vector].low32 = low32;
 281         iosapic_intr_info[vector].dest = dest;
 282 }
 283
 284 static void
 285 nop (unsigned int irq)
 286 {
 287         /* do nothing... */
 288 }
 289
 290
 291 #ifdef CONFIG_KEXEC
 292 void
 293 kexec_disable_iosapic(void)
 294 {
 295         struct iosapic_intr_info *info;
 296         struct iosapic_rte_info *rte;
 297         u8 vec = 0;
 298         for (info = iosapic_intr_info; info <
 299                         iosapic_intr_info + IA64_NUM_VECTORS; ++info, ++vec) {
 300                 list_for_each_entry(rte, &info->rtes,
 301                                 rte_list) {
 302                         iosapic_write(rte->addr,
 303                                         IOSAPIC_RTE_LOW(rte->rte_index),
 304                                         IOSAPIC_MASK|vec);
 305                         iosapic_eoi(rte->addr, vec);
 306                 }
 307         }
 308 }
 309 #endif
 310
 311 static void
 312 mask_irq (unsigned int irq)
 313 {
 314         unsigned long flags;
 315         char __iomem *addr;
 316         u32 low32;
 317         int rte_index;
 318         ia64_vector vec = irq_to_vector(irq);
 319         struct iosapic_rte_info *rte;
 320
 321         if (list_empty(&iosapic_intr_info[vec].rtes))
 322                 return;                 /* not an IOSAPIC interrupt! */
 323
 324         spin_lock_irqsave(&iosapic_lock, flags);
 325         {
 326                 /* set only the mask bit */
 327                 low32 = iosapic_intr_info[vec].low32 |= IOSAPIC_MASK;
 328                 list_for_each_entry(rte, &iosapic_intr_info[vec].rtes,
 329                                     rte_list) {
 330                         addr = rte->addr;
 331                         rte_index = rte->rte_index;
 332                         iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
 333                 }
 334         }
 335         spin_unlock_irqrestore(&iosapic_lock, flags);
 336 }
 337
 338 static void
 339 unmask_irq (unsigned int irq)
 340 {
 341         unsigned long flags;
 342         char __iomem *addr;
 343         u32 low32;
 344         int rte_index;
 345         ia64_vector vec = irq_to_vector(irq);
 346         struct iosapic_rte_info *rte;
 347
 348         if (list_empty(&iosapic_intr_info[vec].rtes))
 349                 return;                 /* not an IOSAPIC interrupt! */
 350
 351         spin_lock_irqsave(&iosapic_lock, flags);
 352         {
 353                 low32 = iosapic_intr_info[vec].low32 &= ~IOSAPIC_MASK;
 354                 list_for_each_entry(rte, &iosapic_intr_info[vec].rtes,
 355                                     rte_list) {
 356                         addr = rte->addr;
 357                         rte_index = rte->rte_index;
 358                         iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
 359                 }
 360         }
 361         spin_unlock_irqrestore(&iosapic_lock, flags);
 362 }
 363
 364
 365 static void
 366 iosapic_set_affinity (unsigned int irq, cpumask_t mask)
 367 {
 368 #ifdef CONFIG_SMP
 369         unsigned long flags;
 370         u32 high32, low32;
 371         int dest, rte_index;
 372         char __iomem *addr;
 373         int redir = (irq & IA64_IRQ_REDIRECTED) ? 1 : 0;
 374         ia64_vector vec;
 375         struct iosapic_rte_info *rte;
 376
 377         irq &= (~IA64_IRQ_REDIRECTED);
 378         vec = irq_to_vector(irq);
 379
 380         if (cpus_empty(mask))
 381                 return;
 382
 383         dest = cpu_physical_id(first_cpu(mask));
 384
 385         if (list_empty(&iosapic_intr_info[vec].rtes))
 386                 return;                 /* not an IOSAPIC interrupt */
 387
 388         set_irq_affinity_info(irq, dest, redir);
 389
 390         /* dest contains both id and eid */
 391         high32 = dest << IOSAPIC_DEST_SHIFT;
 392
 393         spin_lock_irqsave(&iosapic_lock, flags);
 394         {
 395                 low32 = iosapic_intr_info[vec].low32 &
 396                         ~(7 << IOSAPIC_DELIVERY_SHIFT);
 397
 398                 if (redir)
 399                         /* change delivery mode to lowest priority */
 400                         low32 |= (IOSAPIC_LOWEST_PRIORITY <<
 401                                   IOSAPIC_DELIVERY_SHIFT);
 402                 else
 403                         /* change delivery mode to fixed */
 404                         low32 |= (IOSAPIC_FIXED << IOSAPIC_DELIVERY_SHIFT);
 405
 406                 iosapic_intr_info[vec].low32 = low32;
 407                 iosapic_intr_info[vec].dest = dest;
 408                 list_for_each_entry(rte, &iosapic_intr_info[vec].rtes,
 409                                     rte_list) {
 410                         addr = rte->addr;
 411                         rte_index = rte->rte_index;
 412                         iosapic_write(addr, IOSAPIC_RTE_HIGH(rte_index),
 413                                       high32);
 414                         iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
 415                 }
 416         }
 417         spin_unlock_irqrestore(&iosapic_lock, flags);
 418 #endif
 419 }
 420
 421 /*
 422  * Handlers for level-triggered interrupts.
 423  */
 424
 425 static unsigned int
 426 iosapic_startup_level_irq (unsigned int irq)
 427 {
 428         unmask_irq(irq);
 429         return 0;
 430 }
 431
 432 static void
 433 iosapic_end_level_irq (unsigned int irq)
 434 {
 435         ia64_vector vec = irq_to_vector(irq);
 436         struct iosapic_rte_info *rte;
 437
 438         move_native_irq(irq);
 439         list_for_each_entry(rte, &iosapic_intr_info[vec].rtes, rte_list)
 440                 iosapic_eoi(rte->addr, vec);
 441 }
 442
 443 #define iosapic_shutdown_level_irq      mask_irq
 444 #define iosapic_enable_level_irq        unmask_irq
 445 #define iosapic_disable_level_irq       mask_irq
 446 #define iosapic_ack_level_irq           nop
 447
 448 struct irq_chip irq_type_iosapic_level = {
 449         .name =         "IO-SAPIC-level",
 450         .startup =      iosapic_startup_level_irq,
 451         .shutdown =     iosapic_shutdown_level_irq,
 452         .enable =       iosapic_enable_level_irq,
 453         .disable =      iosapic_disable_level_irq,
 454         .ack =          iosapic_ack_level_irq,
 455         .end =          iosapic_end_level_irq,
 456         .mask =         mask_irq,
 457         .unmask =       unmask_irq,
 458         .set_affinity = iosapic_set_affinity
 459 };
 460
 461 /*
 462  * Handlers for edge-triggered interrupts.
 463  */
 464
 465 static unsigned int
 466 iosapic_startup_edge_irq (unsigned int irq)
 467 {
 468         unmask_irq(irq);
 469         /*
 470          * IOSAPIC simply drops interrupts pended while the
 471          * corresponding pin was masked, so we can't know if an
 472          * interrupt is pending already.  Let's hope not...
 473          */
 474         return 0;
 475 }
 476
 477 static void
 478 iosapic_ack_edge_irq (unsigned int irq)
 479 {
 480         irq_desc_t *idesc = irq_desc + irq;
 481
 482         move_native_irq(irq);
 483         /*
 484          * Once we have recorded IRQ_PENDING already, we can mask the
 485          * interrupt for real. This prevents IRQ storms from unhandled
 486          * devices.
 487          */
 488         if ((idesc->status & (IRQ_PENDING|IRQ_DISABLED)) ==
 489             (IRQ_PENDING|IRQ_DISABLED))
 490                 mask_irq(irq);
 491 }
 492
 493 #define iosapic_enable_edge_irq         unmask_irq
 494 #define iosapic_disable_edge_irq        nop
 495 #define iosapic_end_edge_irq            nop
 496
 497 struct irq_chip irq_type_iosapic_edge = {
 498         .name =         "IO-SAPIC-edge",
 499         .startup =      iosapic_startup_edge_irq,
 500         .shutdown =     iosapic_disable_edge_irq,
 501         .enable =       iosapic_enable_edge_irq,
 502         .disable =      iosapic_disable_edge_irq,
 503         .ack =          iosapic_ack_edge_irq,
 504         .end =          iosapic_end_edge_irq,
 505         .mask =         mask_irq,
 506         .unmask =       unmask_irq,
 507         .set_affinity = iosapic_set_affinity
 508 };
 509
 510 unsigned int
 511 iosapic_version (char __iomem *addr)
 512 {
 513         /*
 514          * IOSAPIC Version Register return 32 bit structure like:
 515          * {
 516          *      unsigned int version   : 8;
 517          *      unsigned int reserved1 : 8;
 518          *      unsigned int max_redir : 8;
 519          *      unsigned int reserved2 : 8;
 520          * }
 521          */
 522         return iosapic_read(addr, IOSAPIC_VERSION);
 523 }
 524
 525 static int iosapic_find_sharable_vector (unsigned long trigger,
 526                                          unsigned long pol)
 527 {
 528         int i, vector = -1, min_count = -1;
 529         struct iosapic_intr_info *info;
 530
 531         /*
 532          * shared vectors for edge-triggered interrupts are not
 533          * supported yet
 534          */
 535         if (trigger == IOSAPIC_EDGE)
 536                 return -1;
 537
 538         for (i = IA64_FIRST_DEVICE_VECTOR; i <= IA64_LAST_DEVICE_VECTOR; i++) {
 539                 info = &iosapic_intr_info[i];
 540                 if (info->trigger == trigger && info->polarity == pol &&
 541                     (info->dmode == IOSAPIC_FIXED || info->dmode ==
 542                      IOSAPIC_LOWEST_PRIORITY)) {
 543                         if (min_count == -1 || info->count < min_count) {
 544                                 vector = i;
 545                                 min_count = info->count;
 546                         }
 547                 }
 548         }
 549
 550         return vector;
 551 }
 552
 553 /*
 554  * if the given vector is already owned by other,
 555  *  assign a new vector for the other and make the vector available
 556  */
 557 static void __init
 558 iosapic_reassign_vector (int vector)
 559 {
 560         int new_vector;
 561
 562         if (!list_empty(&iosapic_intr_info[vector].rtes)) {
 563                 new_vector = assign_irq_vector(AUTO_ASSIGN);
 564                 if (new_vector < 0)
 565                         panic("%s: out of interrupt vectors!\n", __FUNCTION__);
 566                 printk(KERN_INFO "Reassigning vector %d to %d\n",
 567                        vector, new_vector);
 568                 memcpy(&iosapic_intr_info[new_vector], &iosapic_intr_info[vector],
 569                        sizeof(struct iosapic_intr_info));
 570                 INIT_LIST_HEAD(&iosapic_intr_info[new_vector].rtes);
 571                 list_move(iosapic_intr_info[vector].rtes.next,
 572                           &iosapic_intr_info[new_vector].rtes);
 573                 memset(&iosapic_intr_info[vector], 0,
 574                        sizeof(struct iosapic_intr_info));
 575                 iosapic_intr_info[vector].low32 = IOSAPIC_MASK;
 576                 INIT_LIST_HEAD(&iosapic_intr_info[vector].rtes);
 577         }
 578 }
 579
 580 static struct iosapic_rte_info *iosapic_alloc_rte (void)
 581 {
 582         int i;
 583         struct iosapic_rte_info *rte;
 584         int preallocated = 0;
 585
 586         if (!iosapic_kmalloc_ok && list_empty(&free_rte_list)) {
 587                 rte = alloc_bootmem(sizeof(struct iosapic_rte_info) *
 588                                     NR_PREALLOCATE_RTE_ENTRIES);
 589                 if (!rte)
 590                         return NULL;
 591                 for (i = 0; i < NR_PREALLOCATE_RTE_ENTRIES; i++, rte++)
 592                         list_add(&rte->rte_list, &free_rte_list);
 593         }
 594
 595         if (!list_empty(&free_rte_list)) {
 596                 rte = list_entry(free_rte_list.next, struct iosapic_rte_info,
 597                                  rte_list);
 598                 list_del(&rte->rte_list);
 599                 preallocated++;
 600         } else {
 601                 rte = kmalloc(sizeof(struct iosapic_rte_info), GFP_ATOMIC);
 602                 if (!rte)
 603                         return NULL;
 604         }
 605
 606         memset(rte, 0, sizeof(struct iosapic_rte_info));
 607         if (preallocated)
 608                 rte->flags |= RTE_PREALLOCATED;
 609
 610         return rte;
 611 }
 612
 613 static void iosapic_free_rte (struct iosapic_rte_info *rte)
 614 {
 615         if (rte->flags & RTE_PREALLOCATED)
 616                 list_add_tail(&rte->rte_list, &free_rte_list);
 617         else
 618                 kfree(rte);
 619 }
 620
 621 static inline int vector_is_shared (int vector)
 622 {
 623         return (iosapic_intr_info[vector].count > 1);
 624 }
 625
 626 static int
 627 register_intr (unsigned int gsi, int vector, unsigned char delivery,
 628                unsigned long polarity, unsigned long trigger)
 629 {
 630         irq_desc_t *idesc;
 631         struct hw_interrupt_type *irq_type;
 632         int rte_index;
 633         int index;
 634         unsigned long gsi_base;
 635         void __iomem *iosapic_address;
 636         struct iosapic_rte_info *rte;
 637
 638         index = find_iosapic(gsi);
 639         if (index < 0) {
 640                 printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
 641                        __FUNCTION__, gsi);
 642                 return -ENODEV;
 643         }
 644
 645         iosapic_address = iosapic_lists[index].addr;
 646         gsi_base = iosapic_lists[index].gsi_base;
 647
 648         rte = gsi_vector_to_rte(gsi, vector);
 649         if (!rte) {
 650                 rte = iosapic_alloc_rte();
 651                 if (!rte) {
 652                         printk(KERN_WARNING "%s: cannot allocate memory\n",
 653                                __FUNCTION__);
 654                         return -ENOMEM;
 655                 }
 656
 657                 rte_index = gsi - gsi_base;
 658                 rte->rte_index  = rte_index;
 659                 rte->addr       = iosapic_address;
 660                 rte->gsi_base   = gsi_base;
 661                 rte->refcnt++;
 662                 list_add_tail(&rte->rte_list, &iosapic_intr_info[vector].rtes);
 663                 iosapic_intr_info[vector].count++;
 664                 iosapic_lists[index].rtes_inuse++;
 665         }
 666         else if (vector_is_shared(vector)) {
 667                 struct iosapic_intr_info *info = &iosapic_intr_info[vector];
 668                 if (info->trigger != trigger || info->polarity != polarity) {
 669                         printk (KERN_WARNING
 670                                 "%s: cannot override the interrupt\n",
 671                                 __FUNCTION__);
 672                         return -EINVAL;
 673                 }
 674         }
 675
 676         iosapic_intr_info[vector].polarity = polarity;
 677         iosapic_intr_info[vector].dmode    = delivery;
 678         iosapic_intr_info[vector].trigger  = trigger;
 679
 680         if (trigger == IOSAPIC_EDGE)
 681                 irq_type = &irq_type_iosapic_edge;
 682         else
 683                 irq_type = &irq_type_iosapic_level;
 684
 685         idesc = irq_desc + vector;
 686         if (idesc->chip != irq_type) {
 687                 if (idesc->chip != &no_irq_type)
 688                         printk(KERN_WARNING
 689                                "%s: changing vector %d from %s to %s\n",
 690                                __FUNCTION__, vector,
 691                                idesc->chip->name, irq_type->name);
 692                 idesc->chip = irq_type;
 693         }
 694         return 0;
 695 }
 696
 697 static unsigned int
 698 get_target_cpu (unsigned int gsi, int vector)
 699 {
 700 #ifdef CONFIG_SMP
 701         static int cpu = -1;
 702         extern int cpe_vector;
 703
 704         /*
 705          * In case of vector shared by multiple RTEs, all RTEs that
 706          * share the vector need to use the same destination CPU.
 707          */
 708         if (!list_empty(&iosapic_intr_info[vector].rtes))
 709                 return iosapic_intr_info[vector].dest;
 710
 711         /*
 712          * If the platform supports redirection via XTP, let it
 713          * distribute interrupts.
 714          */
 715         if (smp_int_redirect & SMP_IRQ_REDIRECTION)
 716                 return cpu_physical_id(smp_processor_id());
 717
 718         /*
 719          * Some interrupts (ACPI SCI, for instance) are registered
 720          * before the BSP is marked as online.
 721          */
 722         if (!cpu_online(smp_processor_id()))
 723                 return cpu_physical_id(smp_processor_id());
 724
 725 #ifdef CONFIG_ACPI
 726         if (cpe_vector > 0 && vector == IA64_CPEP_VECTOR)
 727                 return get_cpei_target_cpu();
 728 #endif
 729
 730 #ifdef CONFIG_NUMA
 731         {
 732                 int num_cpus, cpu_index, iosapic_index, numa_cpu, i = 0;
 733                 cpumask_t cpu_mask;
 734
 735                 iosapic_index = find_iosapic(gsi);
 736                 if (iosapic_index < 0 ||
 737                     iosapic_lists[iosapic_index].node == MAX_NUMNODES)
 738                         goto skip_numa_setup;
 739
 740                 cpu_mask = node_to_cpumask(iosapic_lists[iosapic_index].node);
 741
 742                 for_each_cpu_mask(numa_cpu, cpu_mask) {
 743                         if (!cpu_online(numa_cpu))
 744                                 cpu_clear(numa_cpu, cpu_mask);
 745                 }
 746
 747                 num_cpus = cpus_weight(cpu_mask);
 748
 749                 if (!num_cpus)
 750                         goto skip_numa_setup;
 751
 752                 /* Use vector assignment to distribute across cpus in node */
 753                 cpu_index = vector % num_cpus;
 754
 755                 for (numa_cpu = first_cpu(cpu_mask) ; i < cpu_index ; i++)
 756                         numa_cpu = next_cpu(numa_cpu, cpu_mask);
 757
 758                 if (numa_cpu != NR_CPUS)
 759                         return cpu_physical_id(numa_cpu);
 760         }
 761 skip_numa_setup:
 762 #endif
 763         /*
 764          * Otherwise, round-robin interrupt vectors across all the
 765          * processors.  (It'd be nice if we could be smarter in the
 766          * case of NUMA.)
 767          */
 768         do {
 769                 if (++cpu >= NR_CPUS)
 770                         cpu = 0;
 771         } while (!cpu_online(cpu));
 772
 773         return cpu_physical_id(cpu);
 774 #else  /* CONFIG_SMP */
 775         return cpu_physical_id(smp_processor_id());
 776 #endif
 777 }
 778
 779 /*
 780  * ACPI can describe IOSAPIC interrupts via static tables and namespace
 781  * methods.  This provides an interface to register those interrupts and
 782  * program the IOSAPIC RTE.
 783  */
 784 int
 785 iosapic_register_intr (unsigned int gsi,
 786                        unsigned long polarity, unsigned long trigger)
 787 {
 788         int vector, mask = 1, err;
 789         unsigned int dest;
 790         unsigned long flags;
 791         struct iosapic_rte_info *rte;
 792         u32 low32;
 793 again:
 794         /*
 795          * If this GSI has already been registered (i.e., it's a
 796          * shared interrupt, or we lost a race to register it),
 797          * don't touch the RTE.
 798          */
 799         spin_lock_irqsave(&iosapic_lock, flags);
 800         {
 801                 vector = gsi_to_vector(gsi);
 802                 if (vector > 0) {
 803                         rte = gsi_vector_to_rte(gsi, vector);
 804                         rte->refcnt++;
 805                         spin_unlock_irqrestore(&iosapic_lock, flags);
 806                         return vector;
 807                 }
 808         }
 809         spin_unlock_irqrestore(&iosapic_lock, flags);
 810
 811         /* If vector is running out, we try to find a sharable vector */
 812         vector = assign_irq_vector(AUTO_ASSIGN);
 813         if (vector < 0) {
 814                 vector = iosapic_find_sharable_vector(trigger, polarity);
 815                 if (vector < 0)
 816                         return -ENOSPC;
 817         }
 818
 819         spin_lock_irqsave(&irq_desc[vector].lock, flags);
 820         spin_lock(&iosapic_lock);
 821         {
 822                 if (gsi_to_vector(gsi) > 0) {
 823                         if (list_empty(&iosapic_intr_info[vector].rtes))
 824                                 free_irq_vector(vector);
 825                         spin_unlock(&iosapic_lock);
 826                         spin_unlock_irqrestore(&irq_desc[vector].lock,
 827                                                flags);
 828                         goto again;
 829                 }
 830
 831                 dest = get_target_cpu(gsi, vector);
 832                 err = register_intr(gsi, vector, IOSAPIC_LOWEST_PRIORITY,
 833                               polarity, trigger);
 834                 if (err < 0) {
 835                         spin_unlock(&iosapic_lock);
 836                         spin_unlock_irqrestore(&irq_desc[vector].lock,
 837                                                flags);
 838                         return err;
 839                 }
 840
 841                 /*
 842                  * If the vector is shared and already unmasked for
 843                  * other interrupt sources, don't mask it.
 844                  */
 845                 low32 = iosapic_intr_info[vector].low32;
 846                 if (vector_is_shared(vector) && !(low32 & IOSAPIC_MASK))
 847                         mask = 0;
 848                 set_rte(gsi, vector, dest, mask);
 849         }
 850         spin_unlock(&iosapic_lock);
 851         spin_unlock_irqrestore(&irq_desc[vector].lock, flags);
 852
 853         printk(KERN_INFO "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d\n",
 854                gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
 855                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 856                cpu_logical_id(dest), dest, vector);
 857
 858         return vector;
 859 }
 860
 861 void
 862 iosapic_unregister_intr (unsigned int gsi)
 863 {
 864         unsigned long flags;
 865         int irq, vector, index;
 866         irq_desc_t *idesc;
 867         u32 low32;
 868         unsigned long trigger, polarity;
 869         unsigned int dest;
 870         struct iosapic_rte_info *rte;
 871
 872         /*
 873          * If the irq associated with the gsi is not found,
 874          * iosapic_unregister_intr() is unbalanced. We need to check
 875          * this again after getting locks.
 876          */
 877         irq = gsi_to_irq(gsi);
 878         if (irq < 0) {
 879                 printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
 880                        gsi);
 881                 WARN_ON(1);
 882                 return;
 883         }
 884         vector = irq_to_vector(irq);
 885
 886         idesc = irq_desc + irq;
 887         spin_lock_irqsave(&idesc->lock, flags);
 888         spin_lock(&iosapic_lock);
 889         {
 890                 if ((rte = gsi_vector_to_rte(gsi, vector)) == NULL) {
 891                         printk(KERN_ERR
 892                                "iosapic_unregister_intr(%u) unbalanced\n",
 893                                gsi);
 894                         WARN_ON(1);
 895                         goto out;
 896                 }
 897
 898                 if (--rte->refcnt > 0)
 899                         goto out;
 900
 901                 /* Mask the interrupt */
 902                 low32 = iosapic_intr_info[vector].low32 | IOSAPIC_MASK;
 903                 iosapic_write(rte->addr, IOSAPIC_RTE_LOW(rte->rte_index),
 904                               low32);
 905
 906                 /* Remove the rte entry from the list */
 907                 list_del(&rte->rte_list);
 908                 iosapic_intr_info[vector].count--;
 909                 iosapic_free_rte(rte);
 910                 index = find_iosapic(gsi);
 911                 iosapic_lists[index].rtes_inuse--;
 912                 WARN_ON(iosapic_lists[index].rtes_inuse < 0);
 913
 914                 trigger  = iosapic_intr_info[vector].trigger;
 915                 polarity = iosapic_intr_info[vector].polarity;
 916                 dest     = iosapic_intr_info[vector].dest;
 917                 printk(KERN_INFO
 918                        "GSI %u (%s, %s) -> CPU %d (0x%04x)"
 919                        " vector %d unregistered\n",
 920                        gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
 921                        (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 922                        cpu_logical_id(dest), dest, vector);
 923
 924                 if (list_empty(&iosapic_intr_info[vector].rtes)) {
 925                         /* Sanity check */
 926                         BUG_ON(iosapic_intr_info[vector].count);
 927
 928                         /* Clear the interrupt controller descriptor */
 929                         idesc->chip = &no_irq_type;
 930
 931 #ifdef CONFIG_SMP
 932                         /* Clear affinity */
 933                         cpus_setall(idesc->affinity);
 934 #endif
 935
 936                         /* Clear the interrupt information */
 937                         memset(&iosapic_intr_info[vector], 0,
 938                                sizeof(struct iosapic_intr_info));
 939                         iosapic_intr_info[vector].low32 |= IOSAPIC_MASK;
 940                         INIT_LIST_HEAD(&iosapic_intr_info[vector].rtes);
 941
 942                         if (idesc->action) {
 943                                 printk(KERN_ERR
 944                                        "interrupt handlers still exist on"
 945                                        "IRQ %u\n", irq);
 946                                 WARN_ON(1);
 947                         }
 948
 949                         /* Free the interrupt vector */
 950                         free_irq_vector(vector);
 951                 }
 952         }
 953  out:
 954         spin_unlock(&iosapic_lock);
 955         spin_unlock_irqrestore(&idesc->lock, flags);
 956 }
 957
 958 /*
 959  * ACPI calls this when it finds an entry for a platform interrupt.
 960  */
 961 int __init
 962 iosapic_register_platform_intr (u32 int_type, unsigned int gsi,
 963                                 int iosapic_vector, u16 eid, u16 id,
 964                                 unsigned long polarity, unsigned long trigger)
 965 {
 966         static const char * const name[] = {"unknown", "PMI", "INIT", "CPEI"};
 967         unsigned char delivery;
 968         int vector, mask = 0;
 969         unsigned int dest = ((id << 8) | eid) & 0xffff;
 970
 971         switch (int_type) {
 972               case ACPI_INTERRUPT_PMI:
 973                 vector = iosapic_vector;
 974                 /*
 975                  * since PMI vector is alloc'd by FW(ACPI) not by kernel,
 976                  * we need to make sure the vector is available
 977                  */
 978                 iosapic_reassign_vector(vector);
 979                 delivery = IOSAPIC_PMI;
 980                 break;
 981               case ACPI_INTERRUPT_INIT:
 982                 vector = assign_irq_vector(AUTO_ASSIGN);
 983                 if (vector < 0)
 984                         panic("%s: out of interrupt vectors!\n", __FUNCTION__);
 985                 delivery = IOSAPIC_INIT;
 986                 break;
 987               case ACPI_INTERRUPT_CPEI:
 988                 vector = IA64_CPE_VECTOR;
 989                 delivery = IOSAPIC_LOWEST_PRIORITY;
 990                 mask = 1;
 991                 break;
 992               default:
 993                 printk(KERN_ERR "%s: invalid int type 0x%x\n", __FUNCTION__,
 994                        int_type);
 995                 return -1;
 996         }
 997
 998         register_intr(gsi, vector, delivery, polarity, trigger);
 999
1000         printk(KERN_INFO
1001                "PLATFORM int %s (0x%x): GSI %u (%s, %s) -> CPU %d (0x%04x)"
1002                " vector %d\n",
1003                int_type < ARRAY_SIZE(name) ? name[int_type] : "unknown",
1004                int_type, gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
1005                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
1006                cpu_logical_id(dest), dest, vector);
1007
1008         set_rte(gsi, vector, dest, mask);
1009         return vector;
1010 }
1011
1012 /*
1013  * ACPI calls this when it finds an entry for a legacy ISA IRQ override.
1014  */
1015 void __devinit
1016 iosapic_override_isa_irq (unsigned int isa_irq, unsigned int gsi,
1017                           unsigned long polarity,
1018                           unsigned long trigger)
1019 {
1020         int vector;
1021         unsigned int dest = cpu_physical_id(smp_processor_id());
1022
1023         vector = isa_irq_to_vector(isa_irq);
1024
1025         register_intr(gsi, vector, IOSAPIC_LOWEST_PRIORITY, polarity, trigger);
1026
1027         DBG("ISA: IRQ %u -> GSI %u (%s,%s) -> CPU %d (0x%04x) vector %d\n",
1028             isa_irq, gsi, trigger == IOSAPIC_EDGE ? "edge" : "level",
1029             polarity == IOSAPIC_POL_HIGH ? "high" : "low",
1030             cpu_logical_id(dest), dest, vector);
1031
1032         set_rte(gsi, vector, dest, 1);
1033 }
1034
1035 void __init
1036 iosapic_system_init (int system_pcat_compat)
1037 {
1038         int vector;
1039
1040         for (vector = 0; vector < IA64_NUM_VECTORS; ++vector) {
1041                 iosapic_intr_info[vector].low32 = IOSAPIC_MASK;
1042                 /* mark as unused */
1043                 INIT_LIST_HEAD(&iosapic_intr_info[vector].rtes);
1044         }
1045
1046         pcat_compat = system_pcat_compat;
1047         if (pcat_compat) {
1048                 /*
1049                  * Disable the compatibility mode interrupts (8259 style),
1050                  * needs IN/OUT support enabled.
1051                  */
1052                 printk(KERN_INFO
1053                        "%s: Disabling PC-AT compatible 8259 interrupts\n",
1054                        __FUNCTION__);
1055                 outb(0xff, 0xA1);
1056                 outb(0xff, 0x21);
1057         }
1058 }
1059
1060 static inline int
1061 iosapic_alloc (void)
1062 {
1063         int index;
1064
1065         for (index = 0; index < NR_IOSAPICS; index++)
1066                 if (!iosapic_lists[index].addr)
1067                         return index;
1068
1069         printk(KERN_WARNING "%s: failed to allocate iosapic\n", __FUNCTION__);
1070         return -1;
1071 }
1072
1073 static inline void
1074 iosapic_free (int index)
1075 {
1076         memset(&iosapic_lists[index], 0, sizeof(iosapic_lists[0]));
1077 }
1078
1079 static inline int
1080 iosapic_check_gsi_range (unsigned int gsi_base, unsigned int ver)
1081 {
1082         int index;
1083         unsigned int gsi_end, base, end;
1084
1085         /* check gsi range */
1086         gsi_end = gsi_base + ((ver >> 16) & 0xff);
1087         for (index = 0; index < NR_IOSAPICS; index++) {
1088                 if (!iosapic_lists[index].addr)
1089                         continue;
1090
1091                 base = iosapic_lists[index].gsi_base;
1092                 end  = base + iosapic_lists[index].num_rte - 1;
1093
1094                 if (gsi_end < base || end < gsi_base)
1095                         continue; /* OK */
1096
1097                 return -EBUSY;
1098         }
1099         return 0;
1100 }
1101
1102 int __devinit
1103 iosapic_init (unsigned long phys_addr, unsigned int gsi_base)
1104 {
1105         int num_rte, err, index;
1106         unsigned int isa_irq, ver;
1107         char __iomem *addr;
1108         unsigned long flags;
1109
1110         spin_lock_irqsave(&iosapic_lock, flags);
1111         {
1112                 addr = ioremap(phys_addr, 0);
1113                 ver = iosapic_version(addr);
1114
1115                 if ((err = iosapic_check_gsi_range(gsi_base, ver))) {
1116                         iounmap(addr);
1117                         spin_unlock_irqrestore(&iosapic_lock, flags);
1118                         return err;
1119                 }
1120
1121                 /*
1122                  * The MAX_REDIR register holds the highest input pin
1123                  * number (starting from 0).
1124                  * We add 1 so that we can use it for number of pins (= RTEs)
1125                  */
1126                 num_rte = ((ver >> 16) & 0xff) + 1;
1127
1128                 index = iosapic_alloc();
1129                 iosapic_lists[index].addr = addr;
1130                 iosapic_lists[index].gsi_base = gsi_base;
1131                 iosapic_lists[index].num_rte = num_rte;
1132 #ifdef CONFIG_NUMA
1133                 iosapic_lists[index].node = MAX_NUMNODES;
1134 #endif
1135         }
1136         spin_unlock_irqrestore(&iosapic_lock, flags);
1137
1138         if ((gsi_base == 0) && pcat_compat) {
1139                 /*
1140                  * Map the legacy ISA devices into the IOSAPIC data.  Some of
1141                  * these may get reprogrammed later on with data from the ACPI
1142                  * Interrupt Source Override table.
1143                  */
1144                 for (isa_irq = 0; isa_irq < 16; ++isa_irq)
1145                         iosapic_override_isa_irq(isa_irq, isa_irq,
1146                                                  IOSAPIC_POL_HIGH,
1147                                                  IOSAPIC_EDGE);
1148         }
1149         return 0;
1150 }
1151
1152 #ifdef CONFIG_HOTPLUG
1153 int
1154 iosapic_remove (unsigned int gsi_base)
1155 {
1156         int index, err = 0;
1157         unsigned long flags;
1158
1159         spin_lock_irqsave(&iosapic_lock, flags);
1160         {
1161                 index = find_iosapic(gsi_base);
1162                 if (index < 0) {
1163                         printk(KERN_WARNING "%s: No IOSAPIC for GSI base %u\n",
1164                                __FUNCTION__, gsi_base);
1165                         goto out;
1166                 }
1167
1168                 if (iosapic_lists[index].rtes_inuse) {
1169                         err = -EBUSY;
1170                         printk(KERN_WARNING
1171                                "%s: IOSAPIC for GSI base %u is busy\n",
1172                                __FUNCTION__, gsi_base);
1173                         goto out;
1174                 }
1175
1176                 iounmap(iosapic_lists[index].addr);
1177                 iosapic_free(index);
1178         }
1179  out:
1180         spin_unlock_irqrestore(&iosapic_lock, flags);
1181         return err;
1182 }
1183 #endif /* CONFIG_HOTPLUG */
1184
1185 #ifdef CONFIG_NUMA
1186 void __devinit
1187 map_iosapic_to_node(unsigned int gsi_base, int node)
1188 {
1189         int index;
1190
1191         index = find_iosapic(gsi_base);
1192         if (index < 0) {
1193                 printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
1194                        __FUNCTION__, gsi_base);
1195                 return;
1196         }
1197         iosapic_lists[index].node = node;
1198         return;
1199 }
1200 #endif
1201
1202 static int __init iosapic_enable_kmalloc (void)
1203 {
1204         iosapic_kmalloc_ok = 1;
1205         return 0;
1206 }
1207 core_initcall (iosapic_enable_kmalloc);