arch/ia64/kernel/iosapic.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * I/O SAPIC support.
   4  *
   5  * Copyright (C) 1999 Intel Corp.
   6  * Copyright (C) 1999 Asit Mallick <[email protected]>
   7  * Copyright (C) 2000-2002 J.I. Lee <[email protected]>
   8  * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co.
   9  *      David Mosberger-Tang <[email protected]>
  10  * Copyright (C) 1999 VA Linux Systems
  11  * Copyright (C) 1999,2000 Walt Drummond <[email protected]>
  12  *
  13  * 00/04/19     D. Mosberger    Rewritten to mirror more closely the x86 I/O
  14  *                              APIC code.  In particular, we now have separate
  15  *                              handlers for edge and level triggered
  16  *                              interrupts.
  17  * 00/10/27     Asit Mallick, Goutham Rao <[email protected]> IRQ vector
  18  *                              allocation PCI to vector mapping, shared PCI
  19  *                              interrupts.
  20  * 00/10/27     D. Mosberger    Document things a bit more to make them more
  21  *                              understandable.  Clean up much of the old
  22  *                              IOSAPIC cruft.
  23  * 01/07/27     J.I. Lee        PCI irq routing, Platform/Legacy interrupts
  24  *                              and fixes for ACPI S5(SoftOff) support.
  25  * 02/01/23     J.I. Lee        iosapic pgm fixes for PCI irq routing from _PRT
  26  * 02/01/07     E. Focht        <[email protected]> Redirectable interrupt
  27  *                              vectors in iosapic_set_affinity(),
  28  *                              initializations for /proc/irq/#/smp_affinity
  29  * 02/04/02     P. Diefenbaugh  Cleaned up ACPI PCI IRQ routing.
  30  * 02/04/18     J.I. Lee        bug fix in iosapic_init_pci_irq
  31  * 02/04/30     J.I. Lee        bug fix in find_iosapic to fix ACPI PCI IRQ to
  32  *                              IOSAPIC mapping error
  33  * 02/07/29     T. Kochi        Allocate interrupt vectors dynamically
  34  * 02/08/04     T. Kochi        Cleaned up terminology (irq, global system
  35  *                              interrupt, vector, etc.)
  36  * 02/09/20     D. Mosberger    Simplified by taking advantage of ACPI's
  37  *                              pci_irq code.
  38  * 03/02/19     B. Helgaas      Make pcat_compat system-wide, not per-IOSAPIC.
  39  *                              Remove iosapic_address & gsi_base from
  40  *                              external interfaces.  Rationalize
  41  *                              __init/__devinit attributes.
  42  * 04/12/04 Ashok Raj   <[email protected]> Intel Corporation 2004
  43  *                              Updated to work with irq migration necessary
  44  *                              for CPU Hotplug
  45  */
  46 /*
  47  * Here is what the interrupt logic between a PCI device and the kernel looks
  48  * like:
  49  *
  50  * (1) A PCI device raises one of the four interrupt pins (INTA, INTB, INTC,
  51  *     INTD).  The device is uniquely identified by its bus-, and slot-number
  52  *     (the function number does not matter here because all functions share
  53  *     the same interrupt lines).
  54  *
  55  * (2) The motherboard routes the interrupt line to a pin on a IOSAPIC
  56  *     controller.  Multiple interrupt lines may have to share the same
  57  *     IOSAPIC pin (if they're level triggered and use the same polarity).
  58  *     Each interrupt line has a unique Global System Interrupt (GSI) number
  59  *     which can be calculated as the sum of the controller's base GSI number
  60  *     and the IOSAPIC pin number to which the line connects.
  61  *
  62  * (3) The IOSAPIC uses an internal routing table entries (RTEs) to map the
  63  * IOSAPIC pin into the IA-64 interrupt vector.  This interrupt vector is then
  64  * sent to the CPU.
  65  *
  66  * (4) The kernel recognizes an interrupt as an IRQ.  The IRQ interface is
  67  *     used as architecture-independent interrupt handling mechanism in Linux.
  68  *     As an IRQ is a number, we have to have
  69  *     IA-64 interrupt vector number <-> IRQ number mapping.  On smaller
  70  *     systems, we use one-to-one mapping between IA-64 vector and IRQ.
  71  *
  72  * To sum up, there are three levels of mappings involved:
  73  *
  74  *      PCI pin -> global system interrupt (GSI) -> IA-64 vector <-> IRQ
  75  *
  76  * Note: The term "IRQ" is loosely used everywhere in Linux kernel to
  77  * describe interrupts.  Now we use "IRQ" only for Linux IRQ's.  ISA IRQ
  78  * (isa_irq) is the only exception in this source code.
  79  */
  80
  81 #include <linux/acpi.h>
  82 #include <linux/init.h>
  83 #include <linux/irq.h>
  84 #include <linux/kernel.h>
  85 #include <linux/list.h>
  86 #include <linux/pci.h>
  87 #include <linux/slab.h>
  88 #include <linux/smp.h>
  89 #include <linux/string.h>
  90 #include <linux/memblock.h>
  91
  92 #include <asm/delay.h>
  93 #include <asm/hw_irq.h>
  94 #include <asm/io.h>
  95 #include <asm/iosapic.h>
  96 #include <asm/processor.h>
  97 #include <asm/ptrace.h>
  98
  99 #undef DEBUG_INTERRUPT_ROUTING
 100
 101 #ifdef DEBUG_INTERRUPT_ROUTING
 102 #define DBG(fmt...)     printk(fmt)
 103 #else
 104 #define DBG(fmt...)
 105 #endif
 106
 107 static DEFINE_SPINLOCK(iosapic_lock);
 108
 109 /*
 110  * These tables map IA-64 vectors to the IOSAPIC pin that generates this
 111  * vector.
 112  */
 113
 114 #define NO_REF_RTE      0
 115
 116 static struct iosapic {
 117         char __iomem    *addr;          /* base address of IOSAPIC */
 118         unsigned int    gsi_base;       /* GSI base */
 119         unsigned short  num_rte;        /* # of RTEs on this IOSAPIC */
 120         int             rtes_inuse;     /* # of RTEs in use on this IOSAPIC */
 121 #ifdef CONFIG_NUMA
 122         unsigned short  node;           /* numa node association via pxm */
 123 #endif
 124         spinlock_t      lock;           /* lock for indirect reg access */
 125 } iosapic_lists[NR_IOSAPICS];
 126
 127 struct iosapic_rte_info {
 128         struct list_head rte_list;      /* RTEs sharing the same vector */
 129         char            rte_index;      /* IOSAPIC RTE index */
 130         int             refcnt;         /* reference counter */
 131         struct iosapic  *iosapic;
 132 } ____cacheline_aligned;
 133
 134 static struct iosapic_intr_info {
 135         struct list_head rtes;          /* RTEs using this vector (empty =>
 136                                          * not an IOSAPIC interrupt) */
 137         int             count;          /* # of registered RTEs */
 138         u32             low32;          /* current value of low word of
 139                                          * Redirection table entry */
 140         unsigned int    dest;           /* destination CPU physical ID */
 141         unsigned char   dmode   : 3;    /* delivery mode (see iosapic.h) */
 142         unsigned char   polarity: 1;    /* interrupt polarity
 143                                          * (see iosapic.h) */
 144         unsigned char   trigger : 1;    /* trigger mode (see iosapic.h) */
 145 } iosapic_intr_info[NR_IRQS];
 146
 147 static unsigned char pcat_compat;       /* 8259 compatibility flag */
 148
 149 static inline void
 150 iosapic_write(struct iosapic *iosapic, unsigned int reg, u32 val)
 151 {
 152         unsigned long flags;
 153
 154         spin_lock_irqsave(&iosapic->lock, flags);
 155         __iosapic_write(iosapic->addr, reg, val);
 156         spin_unlock_irqrestore(&iosapic->lock, flags);
 157 }
 158
 159 /*
 160  * Find an IOSAPIC associated with a GSI
 161  */
 162 static inline int
 163 find_iosapic (unsigned int gsi)
 164 {
 165         int i;
 166
 167         for (i = 0; i < NR_IOSAPICS; i++) {
 168                 if ((unsigned) (gsi - iosapic_lists[i].gsi_base) <
 169                     iosapic_lists[i].num_rte)
 170                         return i;
 171         }
 172
 173         return -1;
 174 }
 175
 176 static inline int __gsi_to_irq(unsigned int gsi)
 177 {
 178         int irq;
 179         struct iosapic_intr_info *info;
 180         struct iosapic_rte_info *rte;
 181
 182         for (irq = 0; irq < NR_IRQS; irq++) {
 183                 info = &iosapic_intr_info[irq];
 184                 list_for_each_entry(rte, &info->rtes, rte_list)
 185                         if (rte->iosapic->gsi_base + rte->rte_index == gsi)
 186                                 return irq;
 187         }
 188         return -1;
 189 }
 190
 191 int
 192 gsi_to_irq (unsigned int gsi)
 193 {
 194         unsigned long flags;
 195         int irq;
 196
 197         spin_lock_irqsave(&iosapic_lock, flags);
 198         irq = __gsi_to_irq(gsi);
 199         spin_unlock_irqrestore(&iosapic_lock, flags);
 200         return irq;
 201 }
 202
 203 static struct iosapic_rte_info *find_rte(unsigned int irq, unsigned int gsi)
 204 {
 205         struct iosapic_rte_info *rte;
 206
 207         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list)
 208                 if (rte->iosapic->gsi_base + rte->rte_index == gsi)
 209                         return rte;
 210         return NULL;
 211 }
 212
 213 static void
 214 set_rte (unsigned int gsi, unsigned int irq, unsigned int dest, int mask)
 215 {
 216         unsigned long pol, trigger, dmode;
 217         u32 low32, high32;
 218         int rte_index;
 219         char redir;
 220         struct iosapic_rte_info *rte;
 221         ia64_vector vector = irq_to_vector(irq);
 222
 223         DBG(KERN_DEBUG"IOSAPIC: routing vector %d to 0x%x\n", vector, dest);
 224
 225         rte = find_rte(irq, gsi);
 226         if (!rte)
 227                 return;         /* not an IOSAPIC interrupt */
 228
 229         rte_index = rte->rte_index;
 230         pol     = iosapic_intr_info[irq].polarity;
 231         trigger = iosapic_intr_info[irq].trigger;
 232         dmode   = iosapic_intr_info[irq].dmode;
 233
 234         redir = (dmode == IOSAPIC_LOWEST_PRIORITY) ? 1 : 0;
 235
 236 #ifdef CONFIG_SMP
 237         set_irq_affinity_info(irq, (int)(dest & 0xffff), redir);
 238 #endif
 239
 240         low32 = ((pol << IOSAPIC_POLARITY_SHIFT) |
 241                  (trigger << IOSAPIC_TRIGGER_SHIFT) |
 242                  (dmode << IOSAPIC_DELIVERY_SHIFT) |
 243                  ((mask ? 1 : 0) << IOSAPIC_MASK_SHIFT) |
 244                  vector);
 245
 246         /* dest contains both id and eid */
 247         high32 = (dest << IOSAPIC_DEST_SHIFT);
 248
 249         iosapic_write(rte->iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
 250         iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 251         iosapic_intr_info[irq].low32 = low32;
 252         iosapic_intr_info[irq].dest = dest;
 253 }
 254
 255 static void
 256 iosapic_nop (struct irq_data *data)
 257 {
 258         /* do nothing... */
 259 }
 260
 261
 262 #ifdef CONFIG_KEXEC
 263 void
 264 kexec_disable_iosapic(void)
 265 {
 266         struct iosapic_intr_info *info;
 267         struct iosapic_rte_info *rte;
 268         ia64_vector vec;
 269         int irq;
 270
 271         for (irq = 0; irq < NR_IRQS; irq++) {
 272                 info = &iosapic_intr_info[irq];
 273                 vec = irq_to_vector(irq);
 274                 list_for_each_entry(rte, &info->rtes,
 275                                 rte_list) {
 276                         iosapic_write(rte->iosapic,
 277                                         IOSAPIC_RTE_LOW(rte->rte_index),
 278                                         IOSAPIC_MASK|vec);
 279                         iosapic_eoi(rte->iosapic->addr, vec);
 280                 }
 281         }
 282 }
 283 #endif
 284
 285 static void
 286 mask_irq (struct irq_data *data)
 287 {
 288         unsigned int irq = data->irq;
 289         u32 low32;
 290         int rte_index;
 291         struct iosapic_rte_info *rte;
 292
 293         if (!iosapic_intr_info[irq].count)
 294                 return;                 /* not an IOSAPIC interrupt! */
 295
 296         /* set only the mask bit */
 297         low32 = iosapic_intr_info[irq].low32 |= IOSAPIC_MASK;
 298         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
 299                 rte_index = rte->rte_index;
 300                 iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 301         }
 302 }
 303
 304 static void
 305 unmask_irq (struct irq_data *data)
 306 {
 307         unsigned int irq = data->irq;
 308         u32 low32;
 309         int rte_index;
 310         struct iosapic_rte_info *rte;
 311
 312         if (!iosapic_intr_info[irq].count)
 313                 return;                 /* not an IOSAPIC interrupt! */
 314
 315         low32 = iosapic_intr_info[irq].low32 &= ~IOSAPIC_MASK;
 316         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
 317                 rte_index = rte->rte_index;
 318                 iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 319         }
 320 }
 321
 322
 323 static int
 324 iosapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
 325                      bool force)
 326 {
 327 #ifdef CONFIG_SMP
 328         unsigned int irq = data->irq;
 329         u32 high32, low32;
 330         int cpu, dest, rte_index;
 331         int redir = (irq & IA64_IRQ_REDIRECTED) ? 1 : 0;
 332         struct iosapic_rte_info *rte;
 333         struct iosapic *iosapic;
 334
 335         irq &= (~IA64_IRQ_REDIRECTED);
 336
 337         cpu = cpumask_first_and(cpu_online_mask, mask);
 338         if (cpu >= nr_cpu_ids)
 339                 return -1;
 340
 341         if (irq_prepare_move(irq, cpu))
 342                 return -1;
 343
 344         dest = cpu_physical_id(cpu);
 345
 346         if (!iosapic_intr_info[irq].count)
 347                 return -1;                      /* not an IOSAPIC interrupt */
 348
 349         set_irq_affinity_info(irq, dest, redir);
 350
 351         /* dest contains both id and eid */
 352         high32 = dest << IOSAPIC_DEST_SHIFT;
 353
 354         low32 = iosapic_intr_info[irq].low32 & ~(7 << IOSAPIC_DELIVERY_SHIFT);
 355         if (redir)
 356                 /* change delivery mode to lowest priority */
 357                 low32 |= (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
 358         else
 359                 /* change delivery mode to fixed */
 360                 low32 |= (IOSAPIC_FIXED << IOSAPIC_DELIVERY_SHIFT);
 361         low32 &= IOSAPIC_VECTOR_MASK;
 362         low32 |= irq_to_vector(irq);
 363
 364         iosapic_intr_info[irq].low32 = low32;
 365         iosapic_intr_info[irq].dest = dest;
 366         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
 367                 iosapic = rte->iosapic;
 368                 rte_index = rte->rte_index;
 369                 iosapic_write(iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
 370                 iosapic_write(iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 371         }
 372
 373 #endif
 374         return 0;
 375 }
 376
 377 /*
 378  * Handlers for level-triggered interrupts.
 379  */
 380
 381 static unsigned int
 382 iosapic_startup_level_irq (struct irq_data *data)
 383 {
 384         unmask_irq(data);
 385         return 0;
 386 }
 387
 388 static void
 389 iosapic_unmask_level_irq (struct irq_data *data)
 390 {
 391         unsigned int irq = data->irq;
 392         ia64_vector vec = irq_to_vector(irq);
 393         struct iosapic_rte_info *rte;
 394         int do_unmask_irq = 0;
 395
 396         irq_complete_move(irq);
 397         if (unlikely(irqd_is_setaffinity_pending(data))) {
 398                 do_unmask_irq = 1;
 399                 mask_irq(data);
 400         } else
 401                 unmask_irq(data);
 402
 403         list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list)
 404                 iosapic_eoi(rte->iosapic->addr, vec);
 405
 406         if (unlikely(do_unmask_irq)) {
 407                 irq_move_masked_irq(data);
 408                 unmask_irq(data);
 409         }
 410 }
 411
 412 #define iosapic_shutdown_level_irq      mask_irq
 413 #define iosapic_enable_level_irq        unmask_irq
 414 #define iosapic_disable_level_irq       mask_irq
 415 #define iosapic_ack_level_irq           iosapic_nop
 416
 417 static struct irq_chip irq_type_iosapic_level = {
 418         .name =                 "IO-SAPIC-level",
 419         .irq_startup =          iosapic_startup_level_irq,
 420         .irq_shutdown =         iosapic_shutdown_level_irq,
 421         .irq_enable =           iosapic_enable_level_irq,
 422         .irq_disable =          iosapic_disable_level_irq,
 423         .irq_ack =              iosapic_ack_level_irq,
 424         .irq_mask =             mask_irq,
 425         .irq_unmask =           iosapic_unmask_level_irq,
 426         .irq_set_affinity =     iosapic_set_affinity
 427 };
 428
 429 /*
 430  * Handlers for edge-triggered interrupts.
 431  */
 432
 433 static unsigned int
 434 iosapic_startup_edge_irq (struct irq_data *data)
 435 {
 436         unmask_irq(data);
 437         /*
 438          * IOSAPIC simply drops interrupts pended while the
 439          * corresponding pin was masked, so we can't know if an
 440          * interrupt is pending already.  Let's hope not...
 441          */
 442         return 0;
 443 }
 444
 445 static void
 446 iosapic_ack_edge_irq (struct irq_data *data)
 447 {
 448         irq_complete_move(data->irq);
 449         irq_move_irq(data);
 450 }
 451
 452 #define iosapic_enable_edge_irq         unmask_irq
 453 #define iosapic_disable_edge_irq        iosapic_nop
 454
 455 static struct irq_chip irq_type_iosapic_edge = {
 456         .name =                 "IO-SAPIC-edge",
 457         .irq_startup =          iosapic_startup_edge_irq,
 458         .irq_shutdown =         iosapic_disable_edge_irq,
 459         .irq_enable =           iosapic_enable_edge_irq,
 460         .irq_disable =          iosapic_disable_edge_irq,
 461         .irq_ack =              iosapic_ack_edge_irq,
 462         .irq_mask =             mask_irq,
 463         .irq_unmask =           unmask_irq,
 464         .irq_set_affinity =     iosapic_set_affinity
 465 };
 466
 467 static unsigned int
 468 iosapic_version (char __iomem *addr)
 469 {
 470         /*
 471          * IOSAPIC Version Register return 32 bit structure like:
 472          * {
 473          *      unsigned int version   : 8;
 474          *      unsigned int reserved1 : 8;
 475          *      unsigned int max_redir : 8;
 476          *      unsigned int reserved2 : 8;
 477          * }
 478          */
 479         return __iosapic_read(addr, IOSAPIC_VERSION);
 480 }
 481
 482 static int iosapic_find_sharable_irq(unsigned long trigger, unsigned long pol)
 483 {
 484         int i, irq = -ENOSPC, min_count = -1;
 485         struct iosapic_intr_info *info;
 486
 487         /*
 488          * shared vectors for edge-triggered interrupts are not
 489          * supported yet
 490          */
 491         if (trigger == IOSAPIC_EDGE)
 492                 return -EINVAL;
 493
 494         for (i = 0; i < NR_IRQS; i++) {
 495                 info = &iosapic_intr_info[i];
 496                 if (info->trigger == trigger && info->polarity == pol &&
 497                     (info->dmode == IOSAPIC_FIXED ||
 498                      info->dmode == IOSAPIC_LOWEST_PRIORITY) &&
 499                     can_request_irq(i, IRQF_SHARED)) {
 500                         if (min_count == -1 || info->count < min_count) {
 501                                 irq = i;
 502                                 min_count = info->count;
 503                         }
 504                 }
 505         }
 506         return irq;
 507 }
 508
 509 /*
 510  * if the given vector is already owned by other,
 511  *  assign a new vector for the other and make the vector available
 512  */
 513 static void __init
 514 iosapic_reassign_vector (int irq)
 515 {
 516         int new_irq;
 517
 518         if (iosapic_intr_info[irq].count) {
 519                 new_irq = create_irq();
 520                 if (new_irq < 0)
 521                         panic("%s: out of interrupt vectors!\n", __func__);
 522                 printk(KERN_INFO "Reassigning vector %d to %d\n",
 523                        irq_to_vector(irq), irq_to_vector(new_irq));
 524                 memcpy(&iosapic_intr_info[new_irq], &iosapic_intr_info[irq],
 525                        sizeof(struct iosapic_intr_info));
 526                 INIT_LIST_HEAD(&iosapic_intr_info[new_irq].rtes);
 527                 list_move(iosapic_intr_info[irq].rtes.next,
 528                           &iosapic_intr_info[new_irq].rtes);
 529                 memset(&iosapic_intr_info[irq], 0,
 530                        sizeof(struct iosapic_intr_info));
 531                 iosapic_intr_info[irq].low32 = IOSAPIC_MASK;
 532                 INIT_LIST_HEAD(&iosapic_intr_info[irq].rtes);
 533         }
 534 }
 535
 536 static inline int irq_is_shared (int irq)
 537 {
 538         return (iosapic_intr_info[irq].count > 1);
 539 }
 540
 541 struct irq_chip*
 542 ia64_native_iosapic_get_irq_chip(unsigned long trigger)
 543 {
 544         if (trigger == IOSAPIC_EDGE)
 545                 return &irq_type_iosapic_edge;
 546         else
 547                 return &irq_type_iosapic_level;
 548 }
 549
 550 static int
 551 register_intr (unsigned int gsi, int irq, unsigned char delivery,
 552                unsigned long polarity, unsigned long trigger)
 553 {
 554         struct irq_chip *chip, *irq_type;
 555         int index;
 556         struct iosapic_rte_info *rte;
 557
 558         index = find_iosapic(gsi);
 559         if (index < 0) {
 560                 printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
 561                        __func__, gsi);
 562                 return -ENODEV;
 563         }
 564
 565         rte = find_rte(irq, gsi);
 566         if (!rte) {
 567                 rte = kzalloc(sizeof (*rte), GFP_ATOMIC);
 568                 if (!rte) {
 569                         printk(KERN_WARNING "%s: cannot allocate memory\n",
 570                                __func__);
 571                         return -ENOMEM;
 572                 }
 573
 574                 rte->iosapic    = &iosapic_lists[index];
 575                 rte->rte_index  = gsi - rte->iosapic->gsi_base;
 576                 rte->refcnt++;
 577                 list_add_tail(&rte->rte_list, &iosapic_intr_info[irq].rtes);
 578                 iosapic_intr_info[irq].count++;
 579                 iosapic_lists[index].rtes_inuse++;
 580         }
 581         else if (rte->refcnt == NO_REF_RTE) {
 582                 struct iosapic_intr_info *info = &iosapic_intr_info[irq];
 583                 if (info->count > 0 &&
 584                     (info->trigger != trigger || info->polarity != polarity)){
 585                         printk (KERN_WARNING
 586                                 "%s: cannot override the interrupt\n",
 587                                 __func__);
 588                         return -EINVAL;
 589                 }
 590                 rte->refcnt++;
 591                 iosapic_intr_info[irq].count++;
 592                 iosapic_lists[index].rtes_inuse++;
 593         }
 594
 595         iosapic_intr_info[irq].polarity = polarity;
 596         iosapic_intr_info[irq].dmode    = delivery;
 597         iosapic_intr_info[irq].trigger  = trigger;
 598
 599         irq_type = iosapic_get_irq_chip(trigger);
 600
 601         chip = irq_get_chip(irq);
 602         if (irq_type != NULL && chip != irq_type) {
 603                 if (chip != &no_irq_chip)
 604                         printk(KERN_WARNING
 605                                "%s: changing vector %d from %s to %s\n",
 606                                __func__, irq_to_vector(irq),
 607                                chip->name, irq_type->name);
 608                 chip = irq_type;
 609         }
 610         irq_set_chip_handler_name_locked(irq_get_irq_data(irq), chip,
 611                 trigger == IOSAPIC_EDGE ? handle_edge_irq : handle_level_irq,
 612                 NULL);
 613         return 0;
 614 }
 615
 616 static unsigned int
 617 get_target_cpu (unsigned int gsi, int irq)
 618 {
 619 #ifdef CONFIG_SMP
 620         static int cpu = -1;
 621         extern int cpe_vector;
 622         cpumask_t domain = irq_to_domain(irq);
 623
 624         /*
 625          * In case of vector shared by multiple RTEs, all RTEs that
 626          * share the vector need to use the same destination CPU.
 627          */
 628         if (iosapic_intr_info[irq].count)
 629                 return iosapic_intr_info[irq].dest;
 630
 631         /*
 632          * If the platform supports redirection via XTP, let it
 633          * distribute interrupts.
 634          */
 635         if (smp_int_redirect & SMP_IRQ_REDIRECTION)
 636                 return cpu_physical_id(smp_processor_id());
 637
 638         /*
 639          * Some interrupts (ACPI SCI, for instance) are registered
 640          * before the BSP is marked as online.
 641          */
 642         if (!cpu_online(smp_processor_id()))
 643                 return cpu_physical_id(smp_processor_id());
 644
 645         if (cpe_vector > 0 && irq_to_vector(irq) == IA64_CPEP_VECTOR)
 646                 return get_cpei_target_cpu();
 647
 648 #ifdef CONFIG_NUMA
 649         {
 650                 int num_cpus, cpu_index, iosapic_index, numa_cpu, i = 0;
 651                 const struct cpumask *cpu_mask;
 652
 653                 iosapic_index = find_iosapic(gsi);
 654                 if (iosapic_index < 0 ||
 655                     iosapic_lists[iosapic_index].node == MAX_NUMNODES)
 656                         goto skip_numa_setup;
 657
 658                 cpu_mask = cpumask_of_node(iosapic_lists[iosapic_index].node);
 659                 num_cpus = 0;
 660                 for_each_cpu_and(numa_cpu, cpu_mask, &domain) {
 661                         if (cpu_online(numa_cpu))
 662                                 num_cpus++;
 663                 }
 664
 665                 if (!num_cpus)
 666                         goto skip_numa_setup;
 667
 668                 /* Use irq assignment to distribute across cpus in node */
 669                 cpu_index = irq % num_cpus;
 670
 671                 for_each_cpu_and(numa_cpu, cpu_mask, &domain)
 672                         if (cpu_online(numa_cpu) && i++ >= cpu_index)
 673                                 break;
 674
 675                 if (numa_cpu < nr_cpu_ids)
 676                         return cpu_physical_id(numa_cpu);
 677         }
 678 skip_numa_setup:
 679 #endif
 680         /*
 681          * Otherwise, round-robin interrupt vectors across all the
 682          * processors.  (It'd be nice if we could be smarter in the
 683          * case of NUMA.)
 684          */
 685         do {
 686                 if (++cpu >= nr_cpu_ids)
 687                         cpu = 0;
 688         } while (!cpu_online(cpu) || !cpumask_test_cpu(cpu, &domain));
 689
 690         return cpu_physical_id(cpu);
 691 #else  /* CONFIG_SMP */
 692         return cpu_physical_id(smp_processor_id());
 693 #endif
 694 }
 695
 696 static inline unsigned char choose_dmode(void)
 697 {
 698 #ifdef CONFIG_SMP
 699         if (smp_int_redirect & SMP_IRQ_REDIRECTION)
 700                 return IOSAPIC_LOWEST_PRIORITY;
 701 #endif
 702         return IOSAPIC_FIXED;
 703 }
 704
 705 /*
 706  * ACPI can describe IOSAPIC interrupts via static tables and namespace
 707  * methods.  This provides an interface to register those interrupts and
 708  * program the IOSAPIC RTE.
 709  */
 710 int
 711 iosapic_register_intr (unsigned int gsi,
 712                        unsigned long polarity, unsigned long trigger)
 713 {
 714         int irq, mask = 1, err;
 715         unsigned int dest;
 716         unsigned long flags;
 717         struct iosapic_rte_info *rte;
 718         u32 low32;
 719         unsigned char dmode;
 720         struct irq_desc *desc;
 721
 722         /*
 723          * If this GSI has already been registered (i.e., it's a
 724          * shared interrupt, or we lost a race to register it),
 725          * don't touch the RTE.
 726          */
 727         spin_lock_irqsave(&iosapic_lock, flags);
 728         irq = __gsi_to_irq(gsi);
 729         if (irq > 0) {
 730                 rte = find_rte(irq, gsi);
 731                 if(iosapic_intr_info[irq].count == 0) {
 732                         assign_irq_vector(irq);
 733                         irq_init_desc(irq);
 734                 } else if (rte->refcnt != NO_REF_RTE) {
 735                         rte->refcnt++;
 736                         goto unlock_iosapic_lock;
 737                 }
 738         } else
 739                 irq = create_irq();
 740
 741         /* If vector is running out, we try to find a sharable vector */
 742         if (irq < 0) {
 743                 irq = iosapic_find_sharable_irq(trigger, polarity);
 744                 if (irq < 0)
 745                         goto unlock_iosapic_lock;
 746         }
 747
 748         desc = irq_to_desc(irq);
 749         raw_spin_lock(&desc->lock);
 750         dest = get_target_cpu(gsi, irq);
 751         dmode = choose_dmode();
 752         err = register_intr(gsi, irq, dmode, polarity, trigger);
 753         if (err < 0) {
 754                 raw_spin_unlock(&desc->lock);
 755                 irq = err;
 756                 goto unlock_iosapic_lock;
 757         }
 758
 759         /*
 760          * If the vector is shared and already unmasked for other
 761          * interrupt sources, don't mask it.
 762          */
 763         low32 = iosapic_intr_info[irq].low32;
 764         if (irq_is_shared(irq) && !(low32 & IOSAPIC_MASK))
 765                 mask = 0;
 766         set_rte(gsi, irq, dest, mask);
 767
 768         printk(KERN_INFO "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d\n",
 769                gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
 770                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 771                cpu_logical_id(dest), dest, irq_to_vector(irq));
 772
 773         raw_spin_unlock(&desc->lock);
 774  unlock_iosapic_lock:
 775         spin_unlock_irqrestore(&iosapic_lock, flags);
 776         return irq;
 777 }
 778
 779 void
 780 iosapic_unregister_intr (unsigned int gsi)
 781 {
 782         unsigned long flags;
 783         int irq, index;
 784         u32 low32;
 785         unsigned long trigger, polarity;
 786         unsigned int dest;
 787         struct iosapic_rte_info *rte;
 788
 789         /*
 790          * If the irq associated with the gsi is not found,
 791          * iosapic_unregister_intr() is unbalanced. We need to check
 792          * this again after getting locks.
 793          */
 794         irq = gsi_to_irq(gsi);
 795         if (irq < 0) {
 796                 printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
 797                        gsi);
 798                 WARN_ON(1);
 799                 return;
 800         }
 801
 802         spin_lock_irqsave(&iosapic_lock, flags);
 803         if ((rte = find_rte(irq, gsi)) == NULL) {
 804                 printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
 805                        gsi);
 806                 WARN_ON(1);
 807                 goto out;
 808         }
 809
 810         if (--rte->refcnt > 0)
 811                 goto out;
 812
 813         rte->refcnt = NO_REF_RTE;
 814
 815         /* Mask the interrupt */
 816         low32 = iosapic_intr_info[irq].low32 | IOSAPIC_MASK;
 817         iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte->rte_index), low32);
 818
 819         iosapic_intr_info[irq].count--;
 820         index = find_iosapic(gsi);
 821         iosapic_lists[index].rtes_inuse--;
 822         WARN_ON(iosapic_lists[index].rtes_inuse < 0);
 823
 824         trigger  = iosapic_intr_info[irq].trigger;
 825         polarity = iosapic_intr_info[irq].polarity;
 826         dest     = iosapic_intr_info[irq].dest;
 827         printk(KERN_INFO
 828                "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d unregistered\n",
 829                gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
 830                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 831                cpu_logical_id(dest), dest, irq_to_vector(irq));
 832
 833         if (iosapic_intr_info[irq].count == 0) {
 834 #ifdef CONFIG_SMP
 835                 /* Clear affinity */
 836                 cpumask_setall(irq_get_affinity_mask(irq));
 837 #endif
 838                 /* Clear the interrupt information */
 839                 iosapic_intr_info[irq].dest = 0;
 840                 iosapic_intr_info[irq].dmode = 0;
 841                 iosapic_intr_info[irq].polarity = 0;
 842                 iosapic_intr_info[irq].trigger = 0;
 843                 iosapic_intr_info[irq].low32 |= IOSAPIC_MASK;
 844
 845                 /* Destroy and reserve IRQ */
 846                 destroy_and_reserve_irq(irq);
 847         }
 848  out:
 849         spin_unlock_irqrestore(&iosapic_lock, flags);
 850 }
 851
 852 /*
 853  * ACPI calls this when it finds an entry for a platform interrupt.
 854  */
 855 int __init
 856 iosapic_register_platform_intr (u32 int_type, unsigned int gsi,
 857                                 int iosapic_vector, u16 eid, u16 id,
 858                                 unsigned long polarity, unsigned long trigger)
 859 {
 860         static const char * const name[] = {"unknown", "PMI", "INIT", "CPEI"};
 861         unsigned char delivery;
 862         int irq, vector, mask = 0;
 863         unsigned int dest = ((id << 8) | eid) & 0xffff;
 864
 865         switch (int_type) {
 866               case ACPI_INTERRUPT_PMI:
 867                 irq = vector = iosapic_vector;
 868                 bind_irq_vector(irq, vector, CPU_MASK_ALL);
 869                 /*
 870                  * since PMI vector is alloc'd by FW(ACPI) not by kernel,
 871                  * we need to make sure the vector is available
 872                  */
 873                 iosapic_reassign_vector(irq);
 874                 delivery = IOSAPIC_PMI;
 875                 break;
 876               case ACPI_INTERRUPT_INIT:
 877                 irq = create_irq();
 878                 if (irq < 0)
 879                         panic("%s: out of interrupt vectors!\n", __func__);
 880                 vector = irq_to_vector(irq);
 881                 delivery = IOSAPIC_INIT;
 882                 break;
 883               case ACPI_INTERRUPT_CPEI:
 884                 irq = vector = IA64_CPE_VECTOR;
 885                 BUG_ON(bind_irq_vector(irq, vector, CPU_MASK_ALL));
 886                 delivery = IOSAPIC_FIXED;
 887                 mask = 1;
 888                 break;
 889               default:
 890                 printk(KERN_ERR "%s: invalid int type 0x%x\n", __func__,
 891                        int_type);
 892                 return -1;
 893         }
 894
 895         register_intr(gsi, irq, delivery, polarity, trigger);
 896
 897         printk(KERN_INFO
 898                "PLATFORM int %s (0x%x): GSI %u (%s, %s) -> CPU %d (0x%04x)"
 899                " vector %d\n",
 900                int_type < ARRAY_SIZE(name) ? name[int_type] : "unknown",
 901                int_type, gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
 902                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 903                cpu_logical_id(dest), dest, vector);
 904
 905         set_rte(gsi, irq, dest, mask);
 906         return vector;
 907 }
 908
 909 /*
 910  * ACPI calls this when it finds an entry for a legacy ISA IRQ override.
 911  */
 912 void iosapic_override_isa_irq(unsigned int isa_irq, unsigned int gsi,
 913                               unsigned long polarity, unsigned long trigger)
 914 {
 915         int vector, irq;
 916         unsigned int dest = cpu_physical_id(smp_processor_id());
 917         unsigned char dmode;
 918
 919         irq = vector = isa_irq_to_vector(isa_irq);
 920         BUG_ON(bind_irq_vector(irq, vector, CPU_MASK_ALL));
 921         dmode = choose_dmode();
 922         register_intr(gsi, irq, dmode, polarity, trigger);
 923
 924         DBG("ISA: IRQ %u -> GSI %u (%s,%s) -> CPU %d (0x%04x) vector %d\n",
 925             isa_irq, gsi, trigger == IOSAPIC_EDGE ? "edge" : "level",
 926             polarity == IOSAPIC_POL_HIGH ? "high" : "low",
 927             cpu_logical_id(dest), dest, vector);
 928
 929         set_rte(gsi, irq, dest, 1);
 930 }
 931
 932 void __init
 933 ia64_native_iosapic_pcat_compat_init(void)
 934 {
 935         if (pcat_compat) {
 936                 /*
 937                  * Disable the compatibility mode interrupts (8259 style),
 938                  * needs IN/OUT support enabled.
 939                  */
 940                 printk(KERN_INFO
 941                        "%s: Disabling PC-AT compatible 8259 interrupts\n",
 942                        __func__);
 943                 outb(0xff, 0xA1);
 944                 outb(0xff, 0x21);
 945         }
 946 }
 947
 948 void __init
 949 iosapic_system_init (int system_pcat_compat)
 950 {
 951         int irq;
 952
 953         for (irq = 0; irq < NR_IRQS; ++irq) {
 954                 iosapic_intr_info[irq].low32 = IOSAPIC_MASK;
 955                 /* mark as unused */
 956                 INIT_LIST_HEAD(&iosapic_intr_info[irq].rtes);
 957
 958                 iosapic_intr_info[irq].count = 0;
 959         }
 960
 961         pcat_compat = system_pcat_compat;
 962         if (pcat_compat)
 963                 iosapic_pcat_compat_init();
 964 }
 965
 966 static inline int
 967 iosapic_alloc (void)
 968 {
 969         int index;
 970
 971         for (index = 0; index < NR_IOSAPICS; index++)
 972                 if (!iosapic_lists[index].addr)
 973                         return index;
 974
 975         printk(KERN_WARNING "%s: failed to allocate iosapic\n", __func__);
 976         return -1;
 977 }
 978
 979 static inline void
 980 iosapic_free (int index)
 981 {
 982         memset(&iosapic_lists[index], 0, sizeof(iosapic_lists[0]));
 983 }
 984
 985 static inline int
 986 iosapic_check_gsi_range (unsigned int gsi_base, unsigned int ver)
 987 {
 988         int index;
 989         unsigned int gsi_end, base, end;
 990
 991         /* check gsi range */
 992         gsi_end = gsi_base + ((ver >> 16) & 0xff);
 993         for (index = 0; index < NR_IOSAPICS; index++) {
 994                 if (!iosapic_lists[index].addr)
 995                         continue;
 996
 997                 base = iosapic_lists[index].gsi_base;
 998                 end  = base + iosapic_lists[index].num_rte - 1;
 999
1000                 if (gsi_end < base || end < gsi_base)
1001                         continue; /* OK */
1002
1003                 return -EBUSY;
1004         }
1005         return 0;
1006 }
1007
1008 static int
1009 iosapic_delete_rte(unsigned int irq, unsigned int gsi)
1010 {
1011         struct iosapic_rte_info *rte, *temp;
1012
1013         list_for_each_entry_safe(rte, temp, &iosapic_intr_info[irq].rtes,
1014                                                                 rte_list) {
1015                 if (rte->iosapic->gsi_base + rte->rte_index == gsi) {
1016                         if (rte->refcnt)
1017                                 return -EBUSY;
1018
1019                         list_del(&rte->rte_list);
1020                         kfree(rte);
1021                         return 0;
1022                 }
1023         }
1024
1025         return -EINVAL;
1026 }
1027
1028 int iosapic_init(unsigned long phys_addr, unsigned int gsi_base)
1029 {
1030         int num_rte, err, index;
1031         unsigned int isa_irq, ver;
1032         char __iomem *addr;
1033         unsigned long flags;
1034
1035         spin_lock_irqsave(&iosapic_lock, flags);
1036         index = find_iosapic(gsi_base);
1037         if (index >= 0) {
1038                 spin_unlock_irqrestore(&iosapic_lock, flags);
1039                 return -EBUSY;
1040         }
1041
1042         addr = ioremap(phys_addr, 0);
1043         if (addr == NULL) {
1044                 spin_unlock_irqrestore(&iosapic_lock, flags);
1045                 return -ENOMEM;
1046         }
1047         ver = iosapic_version(addr);
1048         if ((err = iosapic_check_gsi_range(gsi_base, ver))) {
1049                 iounmap(addr);
1050                 spin_unlock_irqrestore(&iosapic_lock, flags);
1051                 return err;
1052         }
1053
1054         /*
1055          * The MAX_REDIR register holds the highest input pin number
1056          * (starting from 0).  We add 1 so that we can use it for
1057          * number of pins (= RTEs)
1058          */
1059         num_rte = ((ver >> 16) & 0xff) + 1;
1060
1061         index = iosapic_alloc();
1062         iosapic_lists[index].addr = addr;
1063         iosapic_lists[index].gsi_base = gsi_base;
1064         iosapic_lists[index].num_rte = num_rte;
1065 #ifdef CONFIG_NUMA
1066         iosapic_lists[index].node = MAX_NUMNODES;
1067 #endif
1068         spin_lock_init(&iosapic_lists[index].lock);
1069         spin_unlock_irqrestore(&iosapic_lock, flags);
1070
1071         if ((gsi_base == 0) && pcat_compat) {
1072                 /*
1073                  * Map the legacy ISA devices into the IOSAPIC data.  Some of
1074                  * these may get reprogrammed later on with data from the ACPI
1075                  * Interrupt Source Override table.
1076                  */
1077                 for (isa_irq = 0; isa_irq < 16; ++isa_irq)
1078                         iosapic_override_isa_irq(isa_irq, isa_irq,
1079                                                  IOSAPIC_POL_HIGH,
1080                                                  IOSAPIC_EDGE);
1081         }
1082         return 0;
1083 }
1084
1085 int iosapic_remove(unsigned int gsi_base)
1086 {
1087         int i, irq, index, err = 0;
1088         unsigned long flags;
1089
1090         spin_lock_irqsave(&iosapic_lock, flags);
1091         index = find_iosapic(gsi_base);
1092         if (index < 0) {
1093                 printk(KERN_WARNING "%s: No IOSAPIC for GSI base %u\n",
1094                        __func__, gsi_base);
1095                 goto out;
1096         }
1097
1098         if (iosapic_lists[index].rtes_inuse) {
1099                 err = -EBUSY;
1100                 printk(KERN_WARNING "%s: IOSAPIC for GSI base %u is busy\n",
1101                        __func__, gsi_base);
1102                 goto out;
1103         }
1104
1105         for (i = gsi_base; i < gsi_base + iosapic_lists[index].num_rte; i++) {
1106                 irq = __gsi_to_irq(i);
1107                 if (irq < 0)
1108                         continue;
1109
1110                 err = iosapic_delete_rte(irq, i);
1111                 if (err)
1112                         goto out;
1113         }
1114
1115         iounmap(iosapic_lists[index].addr);
1116         iosapic_free(index);
1117  out:
1118         spin_unlock_irqrestore(&iosapic_lock, flags);
1119         return err;
1120 }
1121
1122 #ifdef CONFIG_NUMA
1123 void map_iosapic_to_node(unsigned int gsi_base, int node)
1124 {
1125         int index;
1126
1127         index = find_iosapic(gsi_base);
1128         if (index < 0) {
1129                 printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
1130                        __func__, gsi_base);
1131                 return;
1132         }
1133         iosapic_lists[index].node = node;
1134         return;
1135 }
1136 #endif