LXR linux-old/drivers/acpi/pci

   1/*
   2 *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 35 $)
   3 *
   4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6 *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>
   7 *
   8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9 *
  10 *  This program is free software; you can redistribute it and/or modify
  11 *  it under the terms of the GNU General Public License as published by
  12 *  the Free Software Foundation; either version 2 of the License, or (at
  13 *  your option) any later version.
  14 *
  15 *  This program is distributed in the hope that it will be useful, but
  16 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 *  General Public License for more details.
  19 *
  20 *  You should have received a copy of the GNU General Public License along
  21 *  with this program; if not, write to the Free Software Foundation, Inc.,
  22 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23 *
  24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25 *
  26 * TBD: 
  27 *      1. Support more than one IRQ resource entry per link device (index).
  28 *      2. Implement start/stop mechanism and use ACPI Bus Driver facilities
  29 *         for IRQ management (e.g. start()->_SRS).
  30 */
  31
  32#include <linux/kernel.h>
  33#include <linux/module.h>
  34#include <linux/init.h>
  35#include <linux/types.h>
  36#include <linux/proc_fs.h>
  37#include <linux/spinlock.h>
  38#include <linux/pm.h>
  39#include <linux/pci.h>
  40
  41#include <acpi/acpi_bus.h>
  42#include <acpi/acpi_drivers.h>
  43
  44
  45#define _COMPONENT              ACPI_PCI_COMPONENT
  46ACPI_MODULE_NAME                ("pci_link")
  47
  48#define PREFIX                  "ACPI: "
  49
  50
  51#define ACPI_PCI_LINK_MAX_POSSIBLE 16
  52
  53static int acpi_pci_link_add (struct acpi_device *device);
  54static int acpi_pci_link_remove (struct acpi_device *device, int type);
  55
  56static struct acpi_driver acpi_pci_link_driver = {
  57        .name =         ACPI_PCI_LINK_DRIVER_NAME,
  58        .class =        ACPI_PCI_LINK_CLASS,
  59        .ids =          ACPI_PCI_LINK_HID,
  60        .ops =          {
  61                                .add =    acpi_pci_link_add,
  62                                .remove = acpi_pci_link_remove,
  63                        },
  64};
  65
  66struct acpi_pci_link_irq {
  67        u8                      active;                 /* Current IRQ */
  68        u8                      edge_level;             /* All IRQs */
  69        u8                      active_high_low;        /* All IRQs */
  70        u8                      setonboot;
  71        u8                      possible_count;
  72        u8                      possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  73};
  74
  75struct acpi_pci_link {
  76        struct list_head        node;
  77        struct acpi_device      *device;
  78        acpi_handle             handle;
  79        struct acpi_pci_link_irq irq;
  80};
  81
  82static struct {
  83        int                     count;
  84        struct list_head        entries;
  85}                               acpi_link;
  86
  87
  88/* --------------------------------------------------------------------------
  89                            PCI Link Device Management
  90   -------------------------------------------------------------------------- */
  91
  92static acpi_status
  93acpi_pci_link_check_possible (
  94        struct acpi_resource    *resource,
  95        void                    *context)
  96{
  97        struct acpi_pci_link    *link = (struct acpi_pci_link *) context;
  98        u32                     i = 0;
  99
 100        ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");
 101
 102        switch (resource->id) {
 103        case ACPI_RSTYPE_START_DPF:
 104                return AE_OK;
 105        case ACPI_RSTYPE_IRQ:
 106        {
 107                struct acpi_resource_irq *p = &resource->data.irq;
 108                if (!p || !p->number_of_interrupts) {
 109                        ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Blank IRQ resource\n"));
 110                        return AE_OK;
 111                }
 112                for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 113                        if (!p->interrupts[i]) {
 114                                ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
 115                                continue;
 116                        }
 117                        link->irq.possible[i] = p->interrupts[i];
 118                        link->irq.possible_count++;
 119                }
 120                link->irq.edge_level = p->edge_level;
 121                link->irq.active_high_low = p->active_high_low;
 122                break;
 123        }
 124        case ACPI_RSTYPE_EXT_IRQ:
 125        {
 126                struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
 127                if (!p || !p->number_of_interrupts) {
 128                        ACPI_DEBUG_PRINT((ACPI_DB_WARN, 
 129                                "Blank IRQ resource\n"));
 130                        return AE_OK;
 131                }
 132                for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 133                        if (!p->interrupts[i]) {
 134                                ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
 135                                continue;
 136                        }
 137                        link->irq.possible[i] = p->interrupts[i];
 138                        link->irq.possible_count++;
 139                }
 140                link->irq.edge_level = p->edge_level;
 141                link->irq.active_high_low = p->active_high_low;
 142                break;
 143        }
 144        default:
 145                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
 146                        "Resource is not an IRQ entry\n"));
 147                return AE_OK;
 148        }
 149
 150        return AE_CTRL_TERMINATE;
 151}
 152
 153
 154static int
 155acpi_pci_link_get_possible (
 156        struct acpi_pci_link    *link)
 157{
 158        acpi_status             status;
 159
 160        ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");
 161
 162        if (!link)
 163                return_VALUE(-EINVAL);
 164
 165        status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
 166                        acpi_pci_link_check_possible, link);
 167        if (ACPI_FAILURE(status)) {
 168                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
 169                return_VALUE(-ENODEV);
 170        }
 171
 172        ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
 173                "Found %d possible IRQs\n", link->irq.possible_count));
 174
 175        return_VALUE(0);
 176}
 177
 178
 179static acpi_status
 180acpi_pci_link_check_current (
 181        struct acpi_resource    *resource,
 182        void                    *context)
 183{
 184        int                     *irq = (int *) context;
 185
 186        ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");
 187
 188        switch (resource->id) {
 189        case ACPI_RSTYPE_IRQ:
 190        {
 191                struct acpi_resource_irq *p = &resource->data.irq;
 192                if (!p || !p->number_of_interrupts) {
 193                        ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 194                                "Blank IRQ resource\n"));
 195                        return AE_OK;
 196                }
 197                *irq = p->interrupts[0];
 198                break;
 199        }
 200        case ACPI_RSTYPE_EXT_IRQ:
 201        {
 202                struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
 203                if (!p || !p->number_of_interrupts) {
 204                        ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 205                                "Blank IRQ resource\n"));
 206                        return AE_OK;
 207                }
 208                *irq = p->interrupts[0];
 209                break;
 210        }
 211        default:
 212                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 213                        "Resource isn't an IRQ\n"));
 214                return AE_OK;
 215        }
 216        return AE_CTRL_TERMINATE;
 217}
 218
 219static int
 220acpi_pci_link_get_current (
 221        struct acpi_pci_link    *link)
 222{
 223        int                     result = 0;
 224        acpi_status             status = AE_OK;
 225        int                     irq = 0;
 226
 227        ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");
 228
 229        if (!link || !link->handle)
 230                return_VALUE(-EINVAL);
 231
 232        link->irq.active = 0;
 233
 234        /* Make sure the link is enabled (no use querying if it isn't). */
 235        result = acpi_bus_get_status(link->device);
 236        if (result) {
 237                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 238                goto end;
 239        }
 240        if (!link->device->status.enabled) {
 241                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 242                return_VALUE(0);
 243        }
 244
 245        /* 
 246         * Query and parse _CRS to get the current IRQ assignment. 
 247         */
 248
 249        status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
 250                        acpi_pci_link_check_current, &irq);
 251        if (ACPI_FAILURE(status)) {
 252                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
 253                result = -ENODEV;
 254                goto end;
 255        }
 256
 257        if (!irq) {
 258                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "No IRQ resource found\n"));
 259                result = -ENODEV;
 260                goto end;
 261        }
 262
 263        /*
 264         * Note that we don't validate that the current IRQ (_CRS) exists
 265         * within the possible IRQs (_PRS): we blindly assume that whatever
 266         * IRQ a boot-enabled Link device is set to is the correct one.
 267         * (Required to support systems such as the Toshiba 5005-S504.)
 268         */
 269        link->irq.active = irq;
 270
 271        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 272
 273end:
 274        return_VALUE(result);
 275}
 276
 277static int
 278acpi_pci_link_try_get_current (
 279        struct acpi_pci_link *link,
 280        int irq)
 281{
 282        int result;
 283
 284        ACPI_FUNCTION_TRACE("acpi_pci_link_try_get_current");
 285
 286        result = acpi_pci_link_get_current(link);
 287        if (result && link->irq.active) {
 288                return_VALUE(result);
 289        }
 290
 291        if (!link->irq.active) {
 292                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "No active IRQ resource found\n"));
 293                printk(KERN_WARNING "_CRS returns NULL! Using IRQ %d for"
 294                        "device (%s [%s]).\n", irq,
 295                        acpi_device_name(link->device),
 296                        acpi_device_bid(link->device));
 297                link->irq.active = irq;
 298        }
 299        
 300        return 0;
 301}
 302
 303static int
 304acpi_pci_link_set (
 305        struct acpi_pci_link    *link,
 306        int                     irq)
 307{
 308        int                     result = 0;
 309        acpi_status             status = AE_OK;
 310        struct {
 311                struct acpi_resource    res;
 312                struct acpi_resource    end;
 313        }                       resource;
 314        struct acpi_buffer      buffer = {sizeof(resource)+1, &resource};
 315        int                     i = 0;
 316        int                     valid = 0;
 317        int                     resource_type = 0;
 318   
 319        ACPI_FUNCTION_TRACE("acpi_pci_link_set");
 320
 321        if (!link || !irq)
 322                return_VALUE(-EINVAL);
 323
 324        /* We don't check irqs the first time around */
 325        if (link->irq.setonboot) {
 326                /* See if we're already at the target IRQ. */
 327                if (irq == link->irq.active)
 328                        return_VALUE(0);
 329
 330                /* Make sure the target IRQ in the list of possible IRQs. */
 331                for (i=0; i<link->irq.possible_count; i++) {
 332                        if (irq == link->irq.possible[i])
 333                                valid = 1;
 334                }
 335                if (!valid) {
 336                        ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Target IRQ %d invalid\n", irq));
 337                        return_VALUE(-EINVAL);
 338                }
 339        }
 340
 341        /* If IRQ<=15, first try with a "normal" IRQ descriptor. If that fails, try with
 342         * an extended one */
 343        if (irq <= 15) {
 344                resource_type = ACPI_RSTYPE_IRQ;
 345        } else {
 346                resource_type = ACPI_RSTYPE_EXT_IRQ;
 347        }
 348
 349retry_programming:
 350   
 351        memset(&resource, 0, sizeof(resource));
 352
 353        /* NOTE: PCI interrupts are always level / active_low / shared. But not all
 354           interrupts > 15 are PCI interrupts. Rely on the ACPI IRQ definition for 
 355           parameters */
 356        switch(resource_type) {
 357        case ACPI_RSTYPE_IRQ:
 358                resource.res.id = ACPI_RSTYPE_IRQ;
 359                resource.res.length = sizeof(struct acpi_resource);
 360                resource.res.data.irq.edge_level = link->irq.edge_level;
 361                resource.res.data.irq.active_high_low = link->irq.active_high_low;
 362                resource.res.data.irq.shared_exclusive = ACPI_SHARED;
 363                resource.res.data.irq.number_of_interrupts = 1;
 364                resource.res.data.irq.interrupts[0] = irq;
 365                break;
 366           
 367        case ACPI_RSTYPE_EXT_IRQ:
 368                resource.res.id = ACPI_RSTYPE_EXT_IRQ;
 369                resource.res.length = sizeof(struct acpi_resource);
 370                resource.res.data.extended_irq.producer_consumer = ACPI_CONSUMER;
 371                resource.res.data.extended_irq.edge_level = link->irq.edge_level;
 372                resource.res.data.extended_irq.active_high_low = link->irq.active_high_low;
 373                resource.res.data.extended_irq.shared_exclusive = ACPI_SHARED;
 374                resource.res.data.extended_irq.number_of_interrupts = 1;
 375                resource.res.data.extended_irq.interrupts[0] = irq;
 376                /* ignore resource_source, it's optional */
 377                break;
 378        }
 379        resource.end.id = ACPI_RSTYPE_END_TAG;
 380
 381        /* Attempt to set the resource */
 382        status = acpi_set_current_resources(link->handle, &buffer);
 383   
 384
 385        /* if we failed and IRQ <= 15, try again with an extended descriptor */
 386        if (ACPI_FAILURE(status) && (resource_type == ACPI_RSTYPE_IRQ)) {
 387                resource_type = ACPI_RSTYPE_EXT_IRQ;
 388                printk(PREFIX "Retrying with extended IRQ descriptor\n");
 389                goto retry_programming;
 390        }
 391  
 392        /* check for total failure */
 393        if (ACPI_FAILURE(status)) {
 394                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
 395                return_VALUE(-ENODEV);
 396        }
 397
 398        /* Make sure the device is enabled. */
 399        result = acpi_bus_get_status(link->device);
 400        if (result) {
 401                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 402                return_VALUE(result);
 403        }
 404        if (!link->device->status.enabled) {
 405                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link disabled\n"));
 406                return_VALUE(-ENODEV);
 407        }
 408
 409        /* Make sure the active IRQ is the one we requested. */
 410        result = acpi_pci_link_try_get_current(link, irq);
 411        if (result) {
 412                return_VALUE(result);
 413        }
 414   
 415        if (link->irq.active != irq) {
 416                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
 417                        "Attempt to enable at IRQ %d resulted in IRQ %d\n", 
 418                        irq, link->irq.active));
 419                link->irq.active = 0;
 420                acpi_ut_evaluate_object (link->handle, "_DIS", 0, NULL);           
 421                return_VALUE(-ENODEV);
 422        }
 423
 424        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 425        
 426        return_VALUE(0);
 427}
 428
 429
 430/* --------------------------------------------------------------------------
 431                            PCI Link IRQ Management
 432   -------------------------------------------------------------------------- */
 433
 434/*
 435 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 436 * Link Devices to move the PIRQs around to minimize sharing.
 437 * 
 438 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 439 * that the BIOS has already set to active.  This is necessary because
 440 * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 441 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 442 * even if acpi_irq_nobalance is set.
 443 *
 444 * A tables of penalties avoids directing PCI interrupts to well known
 445 * ISA IRQs. Boot params are available to over-ride the default table:
 446 *
 447 * List interrupts that are free for PCI use.
 448 * acpi_irq_pci=n[,m]
 449 *
 450 * List interrupts that should not be used for PCI:
 451 * acpi_irq_isa=n[,m]
 452 *
 453 * Note that PCI IRQ routers have a list of possible IRQs,
 454 * which may not include the IRQs this table says are available.
 455 * 
 456 * Since this heuristic can't tell the difference between a link
 457 * that no device will attach to, vs. a link which may be shared
 458 * by multiple active devices -- it is not optimal.
 459 *
 460 * If interrupt performance is that important, get an IO-APIC system
 461 * with a pin dedicated to each device.  Or for that matter, an MSI
 462 * enabled system.
 463 */
 464
 465#define ACPI_MAX_IRQS           256
 466#define ACPI_MAX_ISA_IRQ        16
 467
 468#define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 469#define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 470#define PIRQ_PENALTY_PCI_USING          (16*16*16)
 471#define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 472#define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 473#define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 474
 475static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 476        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 477        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 478        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 479        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 480        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 481        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 482        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 483        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 484        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 485        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 486        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 487        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 488        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ12 mouse */
 489        PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 490        PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 491        PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 492                        /* >IRQ15 */
 493};
 494
 495int
 496acpi_pci_link_check (void)
 497{
 498        struct list_head        *node = NULL;
 499        struct acpi_pci_link    *link = NULL;
 500        int                     i = 0;
 501
 502        ACPI_FUNCTION_TRACE("acpi_pci_link_check");
 503
 504        /*
 505         * Update penalties to facilitate IRQ balancing.
 506         */
 507        list_for_each(node, &acpi_link.entries) {
 508
 509                link = list_entry(node, struct acpi_pci_link, node);
 510                if (!link) {
 511                        ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 512                        continue;
 513                }
 514
 515                /*
 516                 * reflect the possible and active irqs in the penalty table --
 517                 * useful for breaking ties.
 518                 */
 519                if (link->irq.possible_count) {
 520                        int penalty = PIRQ_PENALTY_PCI_POSSIBLE / link->irq.possible_count;
 521
 522                        for (i = 0; i < link->irq.possible_count; i++) {
 523                                if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 524                                        acpi_irq_penalty[link->irq.possible[i]] += penalty;
 525                        }
 526
 527                } else if (link->irq.active) {
 528                        acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_POSSIBLE;
 529                }
 530        }
 531        /* Add a penalty for the SCI */
 532        acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
 533
 534        return_VALUE(0);
 535}
 536
 537static int acpi_irq_balance;    /* 0: static, 1: balance */
 538
 539static int acpi_pci_link_allocate(struct acpi_pci_link* link) {
 540        int irq;
 541        int i;
 542
 543        ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
 544
 545        if (link->irq.setonboot)
 546                return_VALUE(0);
 547
 548        if (link->irq.active) {
 549                irq = link->irq.active;
 550        } else {
 551                irq = link->irq.possible[0];
 552        }
 553
 554        if (acpi_irq_balance || !link->irq.active) {
 555                /*
 556                 * Select the best IRQ.  This is done in reverse to promote
 557                 * the use of IRQs 9, 10, 11, and >15.
 558                 */
 559                for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 560                        if (acpi_irq_penalty[irq] > acpi_irq_penalty[link->irq.possible[i]])
 561                                irq = link->irq.possible[i];
 562                }
 563        }
 564
 565        /* Attempt to enable the link device at this IRQ. */
 566        if (acpi_pci_link_set(link, irq)) {
 567                printk(PREFIX "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS). Aborting ACPI-based IRQ routing. Try pci=noacpi or acpi=off\n",
 568                        acpi_device_name(link->device),
 569                        acpi_device_bid(link->device));
 570                return_VALUE(-ENODEV);
 571        } else {
 572                acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 573                printk(PREFIX "%s [%s] enabled at IRQ %d\n", 
 574                        acpi_device_name(link->device),
 575                        acpi_device_bid(link->device), link->irq.active);
 576        }
 577
 578        link->irq.setonboot = 1;
 579
 580        return_VALUE(0);
 581}
 582
 583
 584int
 585acpi_pci_link_get_irq (
 586        acpi_handle             handle,
 587        int                     index,
 588        int*                    edge_level,
 589        int*                    active_high_low)
 590{
 591        int                     result = 0;
 592        struct acpi_device      *device = NULL;
 593        struct acpi_pci_link    *link = NULL;
 594
 595        ACPI_FUNCTION_TRACE("acpi_pci_link_get_irq");
 596
 597        result = acpi_bus_get_device(handle, &device);
 598        if (result) {
 599                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 600                return_VALUE(0);
 601        }
 602
 603        link = (struct acpi_pci_link *) acpi_driver_data(device);
 604        if (!link) {
 605                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 606                return_VALUE(0);
 607        }
 608
 609        /* TBD: Support multiple index (IRQ) entries per Link Device */
 610        if (index) {
 611                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
 612                return_VALUE(0);
 613        }
 614
 615        if (acpi_pci_link_allocate(link))
 616                return_VALUE(0);
 617
 618        if (!link->irq.active) {
 619                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link disabled\n"));
 620                return_VALUE(0);
 621        }
 622
 623        if (edge_level) *edge_level = link->irq.edge_level;
 624        if (active_high_low) *active_high_low = link->irq.active_high_low;
 625        return_VALUE(link->irq.active);
 626}
 627
 628
 629/* --------------------------------------------------------------------------
 630                                 Driver Interface
 631   -------------------------------------------------------------------------- */
 632
 633static int
 634acpi_pci_link_add (
 635        struct acpi_device *device)
 636{
 637        int                     result = 0;
 638        struct acpi_pci_link    *link = NULL;
 639        int                     i = 0;
 640        int                     found = 0;
 641
 642        ACPI_FUNCTION_TRACE("acpi_pci_link_add");
 643
 644        if (!device)
 645                return_VALUE(-EINVAL);
 646
 647        link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 648        if (!link)
 649                return_VALUE(-ENOMEM);
 650        memset(link, 0, sizeof(struct acpi_pci_link));
 651
 652        link->device = device;
 653        link->handle = device->handle;
 654        sprintf(acpi_device_name(device), "%s", ACPI_PCI_LINK_DEVICE_NAME);
 655        sprintf(acpi_device_class(device), "%s", ACPI_PCI_LINK_CLASS);
 656        acpi_driver_data(device) = link;
 657
 658        result = acpi_pci_link_get_possible(link);
 659        if (result)
 660                goto end;
 661
 662        /* query and set link->irq.active */
 663        acpi_pci_link_get_current(link);
 664
 665//#ifdef CONFIG_ACPI_DEBUG
 666        printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 667                acpi_device_bid(device));
 668        for (i = 0; i < link->irq.possible_count; i++) {
 669                if (link->irq.active == link->irq.possible[i]) {
 670                        printk(" *%d", link->irq.possible[i]);
 671                        found = 1;
 672                }
 673                else
 674                        printk(" %d", link->irq.possible[i]);
 675        }
 676        printk(")\n");
 677//#endif /* CONFIG_ACPI_DEBUG */
 678
 679        /* TBD: Acquire/release lock */
 680        list_add_tail(&link->node, &acpi_link.entries);
 681        acpi_link.count++;
 682
 683end:
 684        if (result)
 685                kfree(link);
 686
 687        return_VALUE(result);
 688}
 689
 690
 691static int
 692acpi_pci_link_remove (
 693        struct acpi_device      *device,
 694        int                     type)
 695{
 696        struct acpi_pci_link *link = NULL;
 697
 698        ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
 699
 700        if (!device || !acpi_driver_data(device))
 701                return_VALUE(-EINVAL);
 702
 703        link = (struct acpi_pci_link *) acpi_driver_data(device);
 704
 705        /* TBD: Acquire/release lock */
 706        list_del(&link->node);
 707
 708        kfree(link);
 709
 710        return_VALUE(0);
 711}
 712
 713/*
 714 * modify acpi_irq_penalty[] from cmdline
 715 */
 716static int __init acpi_irq_penalty_update(char *str, int used)
 717{
 718        int i;
 719
 720        for (i = 0; i < 16; i++) {
 721                int retval;
 722                int irq;
 723
 724                retval = get_option(&str,&irq);
 725
 726                if (!retval)
 727                        break;  /* no number found */
 728
 729                if (irq < 0)
 730                        continue;
 731                
 732                if (irq >= ACPI_MAX_IRQS)
 733                        continue;
 734
 735                if (used)
 736                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 737                else
 738                        acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 739
 740                if (retval != 2)        /* no next number */
 741                        break;
 742        }
 743        return 1;
 744}
 745
 746/*
 747 * Over-ride default table to reserve additional IRQs for use by ISA
 748 * e.g. acpi_irq_isa=5
 749 * Useful for telling ACPI how not to interfere with your ISA sound card.
 750 */
 751static int __init acpi_irq_isa(char *str)
 752{
 753        return(acpi_irq_penalty_update(str, 1));
 754}
 755__setup("acpi_irq_isa=", acpi_irq_isa);
 756
 757/*
 758 * Over-ride default table to free additional IRQs for use by PCI
 759 * e.g. acpi_irq_pci=7,15
 760 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 761 */
 762static int __init acpi_irq_pci(char *str)
 763{
 764        return(acpi_irq_penalty_update(str, 0));
 765}
 766__setup("acpi_irq_pci=", acpi_irq_pci);
 767
 768static int __init acpi_irq_nobalance_set(char *str)
 769{
 770printk("ACPI STATIC SET\n");
 771        acpi_irq_balance = 0;
 772        return(1);
 773}
 774__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 775
 776int __init acpi_irq_balance_set(char *str)
 777{
 778printk("ACPI BALANCE SET\n");
 779        acpi_irq_balance = 1;
 780        return(1);
 781}
 782__setup("acpi_irq_balance", acpi_irq_balance_set);
 783
 784
 785int __init
 786acpi_pci_link_init (void)
 787{
 788        ACPI_FUNCTION_TRACE("acpi_pci_link_init");
 789
 790        acpi_link.count = 0;
 791        INIT_LIST_HEAD(&acpi_link.entries);
 792
 793        if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 794                return_VALUE(-ENODEV);
 795
 796        return_VALUE(0);
 797}
 798