drivers/pci/msi.c

   1 /*
   2  * File:        msi.c
   3  * Purpose:     PCI Message Signaled Interrupt (MSI)
   4  *
   5  * Copyright (C) 2003-2004 Intel
   6  * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
   7  */
   8
   9 #include <linux/mm.h>
  10 #include <linux/irq.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/init.h>
  13 #include <linux/config.h>
  14 #include <linux/ioport.h>
  15 #include <linux/smp_lock.h>
  16 #include <linux/pci.h>
  17 #include <linux/proc_fs.h>
  18
  19 #include <asm/errno.h>
  20 #include <asm/io.h>
  21 #include <asm/smp.h>
  22
  23 #include "pci.h"
  24 #include "msi.h"
  25
  26 #define MSI_TARGET_CPU          first_cpu(cpu_online_map)
  27
  28 static DEFINE_SPINLOCK(msi_lock);
  29 static struct msi_desc* msi_desc[NR_IRQS] = { [0 ... NR_IRQS-1] = NULL };
  30 static kmem_cache_t* msi_cachep;
  31
  32 static int pci_msi_enable = 1;
  33 static int last_alloc_vector;
  34 static int nr_released_vectors;
  35 static int nr_reserved_vectors = NR_HP_RESERVED_VECTORS;
  36 static int nr_msix_devices;
  37
  38 #ifndef CONFIG_X86_IO_APIC
  39 int vector_irq[NR_VECTORS] = { [0 ... NR_VECTORS - 1] = -1};
  40 u8 irq_vector[NR_IRQ_VECTORS] = { FIRST_DEVICE_VECTOR , 0 };
  41 #endif
  42
  43 static void msi_cache_ctor(void *p, kmem_cache_t *cache, unsigned long flags)
  44 {
  45         memset(p, 0, NR_IRQS * sizeof(struct msi_desc));
  46 }
  47
  48 static int msi_cache_init(void)
  49 {
  50         msi_cachep = kmem_cache_create("msi_cache",
  51                         NR_IRQS * sizeof(struct msi_desc),
  52                         0, SLAB_HWCACHE_ALIGN, msi_cache_ctor, NULL);
  53         if (!msi_cachep)
  54                 return -ENOMEM;
  55
  56         return 0;
  57 }
  58
  59 static void msi_set_mask_bit(unsigned int vector, int flag)
  60 {
  61         struct msi_desc *entry;
  62
  63         entry = (struct msi_desc *)msi_desc[vector];
  64         if (!entry || !entry->dev || !entry->mask_base)
  65                 return;
  66         switch (entry->msi_attrib.type) {
  67         case PCI_CAP_ID_MSI:
  68         {
  69                 int             pos;
  70                 u32             mask_bits;
  71
  72                 pos = (long)entry->mask_base;
  73                 pci_read_config_dword(entry->dev, pos, &mask_bits);
  74                 mask_bits &= ~(1);
  75                 mask_bits |= flag;
  76                 pci_write_config_dword(entry->dev, pos, mask_bits);
  77                 break;
  78         }
  79         case PCI_CAP_ID_MSIX:
  80         {
  81                 int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
  82                         PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
  83                 writel(flag, entry->mask_base + offset);
  84                 break;
  85         }
  86         default:
  87                 break;
  88         }
  89 }
  90
  91 #ifdef CONFIG_SMP
  92 static void set_msi_affinity(unsigned int vector, cpumask_t cpu_mask)
  93 {
  94         struct msi_desc *entry;
  95         struct msg_address address;
  96         unsigned int irq = vector;
  97         unsigned int dest_cpu = first_cpu(cpu_mask);
  98
  99         entry = (struct msi_desc *)msi_desc[vector];
 100         if (!entry || !entry->dev)
 101                 return;
 102
 103         switch (entry->msi_attrib.type) {
 104         case PCI_CAP_ID_MSI:
 105         {
 106                 int pos;
 107
 108                 if (!(pos = pci_find_capability(entry->dev, PCI_CAP_ID_MSI)))
 109                         return;
 110
 111                 pci_read_config_dword(entry->dev, msi_lower_address_reg(pos),
 112                         &address.lo_address.value);
 113                 address.lo_address.value &= MSI_ADDRESS_DEST_ID_MASK;
 114                 address.lo_address.value |= (cpu_physical_id(dest_cpu) <<
 115                                                                         MSI_TARGET_CPU_SHIFT);
 116                 entry->msi_attrib.current_cpu = cpu_physical_id(dest_cpu);
 117                 pci_write_config_dword(entry->dev, msi_lower_address_reg(pos),
 118                         address.lo_address.value);
 119                 set_native_irq_info(irq, cpu_mask);
 120                 break;
 121         }
 122         case PCI_CAP_ID_MSIX:
 123         {
 124                 int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
 125                         PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET;
 126
 127                 address.lo_address.value = readl(entry->mask_base + offset);
 128                 address.lo_address.value &= MSI_ADDRESS_DEST_ID_MASK;
 129                 address.lo_address.value |= (cpu_physical_id(dest_cpu) <<
 130                                                                         MSI_TARGET_CPU_SHIFT);
 131                 entry->msi_attrib.current_cpu = cpu_physical_id(dest_cpu);
 132                 writel(address.lo_address.value, entry->mask_base + offset);
 133                 set_native_irq_info(irq, cpu_mask);
 134                 break;
 135         }
 136         default:
 137                 break;
 138         }
 139 }
 140 #endif /* CONFIG_SMP */
 141
 142 static void mask_MSI_irq(unsigned int vector)
 143 {
 144         msi_set_mask_bit(vector, 1);
 145 }
 146
 147 static void unmask_MSI_irq(unsigned int vector)
 148 {
 149         msi_set_mask_bit(vector, 0);
 150 }
 151
 152 static unsigned int startup_msi_irq_wo_maskbit(unsigned int vector)
 153 {
 154         struct msi_desc *entry;
 155         unsigned long flags;
 156
 157         spin_lock_irqsave(&msi_lock, flags);
 158         entry = msi_desc[vector];
 159         if (!entry || !entry->dev) {
 160                 spin_unlock_irqrestore(&msi_lock, flags);
 161                 return 0;
 162         }
 163         entry->msi_attrib.state = 1;    /* Mark it active */
 164         spin_unlock_irqrestore(&msi_lock, flags);
 165
 166         return 0;       /* never anything pending */
 167 }
 168
 169 static unsigned int startup_msi_irq_w_maskbit(unsigned int vector)
 170 {
 171         startup_msi_irq_wo_maskbit(vector);
 172         unmask_MSI_irq(vector);
 173         return 0;       /* never anything pending */
 174 }
 175
 176 static void shutdown_msi_irq(unsigned int vector)
 177 {
 178         struct msi_desc *entry;
 179         unsigned long flags;
 180
 181         spin_lock_irqsave(&msi_lock, flags);
 182         entry = msi_desc[vector];
 183         if (entry && entry->dev)
 184                 entry->msi_attrib.state = 0;    /* Mark it not active */
 185         spin_unlock_irqrestore(&msi_lock, flags);
 186 }
 187
 188 static void end_msi_irq_wo_maskbit(unsigned int vector)
 189 {
 190         move_native_irq(vector);
 191         ack_APIC_irq();
 192 }
 193
 194 static void end_msi_irq_w_maskbit(unsigned int vector)
 195 {
 196         move_native_irq(vector);
 197         unmask_MSI_irq(vector);
 198         ack_APIC_irq();
 199 }
 200
 201 static void do_nothing(unsigned int vector)
 202 {
 203 }
 204
 205 /*
 206  * Interrupt Type for MSI-X PCI/PCI-X/PCI-Express Devices,
 207  * which implement the MSI-X Capability Structure.
 208  */
 209 static struct hw_interrupt_type msix_irq_type = {
 210         .typename       = "PCI-MSI-X",
 211         .startup        = startup_msi_irq_w_maskbit,
 212         .shutdown       = shutdown_msi_irq,
 213         .enable         = unmask_MSI_irq,
 214         .disable        = mask_MSI_irq,
 215         .ack            = mask_MSI_irq,
 216         .end            = end_msi_irq_w_maskbit,
 217         .set_affinity   = set_msi_irq_affinity
 218 };
 219
 220 /*
 221  * Interrupt Type for MSI PCI/PCI-X/PCI-Express Devices,
 222  * which implement the MSI Capability Structure with
 223  * Mask-and-Pending Bits.
 224  */
 225 static struct hw_interrupt_type msi_irq_w_maskbit_type = {
 226         .typename       = "PCI-MSI",
 227         .startup        = startup_msi_irq_w_maskbit,
 228         .shutdown       = shutdown_msi_irq,
 229         .enable         = unmask_MSI_irq,
 230         .disable        = mask_MSI_irq,
 231         .ack            = mask_MSI_irq,
 232         .end            = end_msi_irq_w_maskbit,
 233         .set_affinity   = set_msi_irq_affinity
 234 };
 235
 236 /*
 237  * Interrupt Type for MSI PCI/PCI-X/PCI-Express Devices,
 238  * which implement the MSI Capability Structure without
 239  * Mask-and-Pending Bits.
 240  */
 241 static struct hw_interrupt_type msi_irq_wo_maskbit_type = {
 242         .typename       = "PCI-MSI",
 243         .startup        = startup_msi_irq_wo_maskbit,
 244         .shutdown       = shutdown_msi_irq,
 245         .enable         = do_nothing,
 246         .disable        = do_nothing,
 247         .ack            = do_nothing,
 248         .end            = end_msi_irq_wo_maskbit,
 249         .set_affinity   = set_msi_irq_affinity
 250 };
 251
 252 static void msi_data_init(struct msg_data *msi_data,
 253                           unsigned int vector)
 254 {
 255         memset(msi_data, 0, sizeof(struct msg_data));
 256         msi_data->vector = (u8)vector;
 257         msi_data->delivery_mode = MSI_DELIVERY_MODE;
 258         msi_data->level = MSI_LEVEL_MODE;
 259         msi_data->trigger = MSI_TRIGGER_MODE;
 260 }
 261
 262 static void msi_address_init(struct msg_address *msi_address)
 263 {
 264         unsigned int    dest_id;
 265         unsigned long   dest_phys_id = cpu_physical_id(MSI_TARGET_CPU);
 266
 267         memset(msi_address, 0, sizeof(struct msg_address));
 268         msi_address->hi_address = (u32)0;
 269         dest_id = (MSI_ADDRESS_HEADER << MSI_ADDRESS_HEADER_SHIFT);
 270         msi_address->lo_address.u.dest_mode = MSI_PHYSICAL_MODE;
 271         msi_address->lo_address.u.redirection_hint = MSI_REDIRECTION_HINT_MODE;
 272         msi_address->lo_address.u.dest_id = dest_id;
 273         msi_address->lo_address.value |= (dest_phys_id << MSI_TARGET_CPU_SHIFT);
 274 }
 275
 276 static int msi_free_vector(struct pci_dev* dev, int vector, int reassign);
 277 static int assign_msi_vector(void)
 278 {
 279         static int new_vector_avail = 1;
 280         int vector;
 281         unsigned long flags;
 282
 283         /*
 284          * msi_lock is provided to ensure that successful allocation of MSI
 285          * vector is assigned unique among drivers.
 286          */
 287         spin_lock_irqsave(&msi_lock, flags);
 288
 289         if (!new_vector_avail) {
 290                 int free_vector = 0;
 291
 292                 /*
 293                  * vector_irq[] = -1 indicates that this specific vector is:
 294                  * - assigned for MSI (since MSI have no associated IRQ) or
 295                  * - assigned for legacy if less than 16, or
 296                  * - having no corresponding 1:1 vector-to-IOxAPIC IRQ mapping
 297                  * vector_irq[] = 0 indicates that this vector, previously
 298                  * assigned for MSI, is freed by hotplug removed operations.
 299                  * This vector will be reused for any subsequent hotplug added
 300                  * operations.
 301                  * vector_irq[] > 0 indicates that this vector is assigned for
 302                  * IOxAPIC IRQs. This vector and its value provides a 1-to-1
 303                  * vector-to-IOxAPIC IRQ mapping.
 304                  */
 305                 for (vector = FIRST_DEVICE_VECTOR; vector < NR_IRQS; vector++) {
 306                         if (vector_irq[vector] != 0)
 307                                 continue;
 308                         free_vector = vector;
 309                         if (!msi_desc[vector])
 310                                 break;
 311                         else
 312                                 continue;
 313                 }
 314                 if (!free_vector) {
 315                         spin_unlock_irqrestore(&msi_lock, flags);
 316                         return -EBUSY;
 317                 }
 318                 vector_irq[free_vector] = -1;
 319                 nr_released_vectors--;
 320                 spin_unlock_irqrestore(&msi_lock, flags);
 321                 if (msi_desc[free_vector] != NULL) {
 322                         struct pci_dev *dev;
 323                         int tail;
 324
 325                         /* free all linked vectors before re-assign */
 326                         do {
 327                                 spin_lock_irqsave(&msi_lock, flags);
 328                                 dev = msi_desc[free_vector]->dev;
 329                                 tail = msi_desc[free_vector]->link.tail;
 330                                 spin_unlock_irqrestore(&msi_lock, flags);
 331                                 msi_free_vector(dev, tail, 1);
 332                         } while (free_vector != tail);
 333                 }
 334
 335                 return free_vector;
 336         }
 337         vector = assign_irq_vector(AUTO_ASSIGN);
 338         last_alloc_vector = vector;
 339         if (vector  == LAST_DEVICE_VECTOR)
 340                 new_vector_avail = 0;
 341
 342         spin_unlock_irqrestore(&msi_lock, flags);
 343         return vector;
 344 }
 345
 346 static int get_new_vector(void)
 347 {
 348         int vector;
 349
 350         if ((vector = assign_msi_vector()) > 0)
 351                 set_intr_gate(vector, interrupt[vector]);
 352
 353         return vector;
 354 }
 355
 356 static int msi_init(void)
 357 {
 358         static int status = -ENOMEM;
 359
 360         if (!status)
 361                 return status;
 362
 363         if (pci_msi_quirk) {
 364                 pci_msi_enable = 0;
 365                 printk(KERN_WARNING "PCI: MSI quirk detected. MSI disabled.\n");
 366                 status = -EINVAL;
 367                 return status;
 368         }
 369
 370         if ((status = msi_cache_init()) < 0) {
 371                 pci_msi_enable = 0;
 372                 printk(KERN_WARNING "PCI: MSI cache init failed\n");
 373                 return status;
 374         }
 375         last_alloc_vector = assign_irq_vector(AUTO_ASSIGN);
 376         if (last_alloc_vector < 0) {
 377                 pci_msi_enable = 0;
 378                 printk(KERN_WARNING "PCI: No interrupt vectors available for MSI\n");
 379                 status = -EBUSY;
 380                 return status;
 381         }
 382         vector_irq[last_alloc_vector] = 0;
 383         nr_released_vectors++;
 384
 385         return status;
 386 }
 387
 388 static int get_msi_vector(struct pci_dev *dev)
 389 {
 390         return get_new_vector();
 391 }
 392
 393 static struct msi_desc* alloc_msi_entry(void)
 394 {
 395         struct msi_desc *entry;
 396
 397         entry = kmem_cache_alloc(msi_cachep, SLAB_KERNEL);
 398         if (!entry)
 399                 return NULL;
 400
 401         memset(entry, 0, sizeof(struct msi_desc));
 402         entry->link.tail = entry->link.head = 0;        /* single message */
 403         entry->dev = NULL;
 404
 405         return entry;
 406 }
 407
 408 static void attach_msi_entry(struct msi_desc *entry, int vector)
 409 {
 410         unsigned long flags;
 411
 412         spin_lock_irqsave(&msi_lock, flags);
 413         msi_desc[vector] = entry;
 414         spin_unlock_irqrestore(&msi_lock, flags);
 415 }
 416
 417 static void irq_handler_init(int cap_id, int pos, int mask)
 418 {
 419         spin_lock(&irq_desc[pos].lock);
 420         if (cap_id == PCI_CAP_ID_MSIX)
 421                 irq_desc[pos].handler = &msix_irq_type;
 422         else {
 423                 if (!mask)
 424                         irq_desc[pos].handler = &msi_irq_wo_maskbit_type;
 425                 else
 426                         irq_desc[pos].handler = &msi_irq_w_maskbit_type;
 427         }
 428         spin_unlock(&irq_desc[pos].lock);
 429 }
 430
 431 static void enable_msi_mode(struct pci_dev *dev, int pos, int type)
 432 {
 433         u16 control;
 434
 435         pci_read_config_word(dev, msi_control_reg(pos), &control);
 436         if (type == PCI_CAP_ID_MSI) {
 437                 /* Set enabled bits to single MSI & enable MSI_enable bit */
 438                 msi_enable(control, 1);
 439                 pci_write_config_word(dev, msi_control_reg(pos), control);
 440         } else {
 441                 msix_enable(control);
 442                 pci_write_config_word(dev, msi_control_reg(pos), control);
 443         }
 444         if (pci_find_capability(dev, PCI_CAP_ID_EXP)) {
 445                 /* PCI Express Endpoint device detected */
 446                 pci_intx(dev, 0);  /* disable intx */
 447         }
 448 }
 449
 450 void disable_msi_mode(struct pci_dev *dev, int pos, int type)
 451 {
 452         u16 control;
 453
 454         pci_read_config_word(dev, msi_control_reg(pos), &control);
 455         if (type == PCI_CAP_ID_MSI) {
 456                 /* Set enabled bits to single MSI & enable MSI_enable bit */
 457                 msi_disable(control);
 458                 pci_write_config_word(dev, msi_control_reg(pos), control);
 459         } else {
 460                 msix_disable(control);
 461                 pci_write_config_word(dev, msi_control_reg(pos), control);
 462         }
 463         if (pci_find_capability(dev, PCI_CAP_ID_EXP)) {
 464                 /* PCI Express Endpoint device detected */
 465                 pci_intx(dev, 1);  /* enable intx */
 466         }
 467 }
 468
 469 static int msi_lookup_vector(struct pci_dev *dev, int type)
 470 {
 471         int vector;
 472         unsigned long flags;
 473
 474         spin_lock_irqsave(&msi_lock, flags);
 475         for (vector = FIRST_DEVICE_VECTOR; vector < NR_IRQS; vector++) {
 476                 if (!msi_desc[vector] || msi_desc[vector]->dev != dev ||
 477                         msi_desc[vector]->msi_attrib.type != type ||
 478                         msi_desc[vector]->msi_attrib.default_vector != dev->irq)
 479                         continue;
 480                 spin_unlock_irqrestore(&msi_lock, flags);
 481                 /* This pre-assigned MSI vector for this device
 482                    already exits. Override dev->irq with this vector */
 483                 dev->irq = vector;
 484                 return 0;
 485         }
 486         spin_unlock_irqrestore(&msi_lock, flags);
 487
 488         return -EACCES;
 489 }
 490
 491 void pci_scan_msi_device(struct pci_dev *dev)
 492 {
 493         if (!dev)
 494                 return;
 495
 496         if (pci_find_capability(dev, PCI_CAP_ID_MSIX) > 0)
 497                 nr_msix_devices++;
 498         else if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0)
 499                 nr_reserved_vectors++;
 500 }
 501
 502 /**
 503  * msi_capability_init - configure device's MSI capability structure
 504  * @dev: pointer to the pci_dev data structure of MSI device function
 505  *
 506  * Setup the MSI capability structure of device function with a single
 507  * MSI vector, regardless of device function is capable of handling
 508  * multiple messages. A return of zero indicates the successful setup
 509  * of an entry zero with the new MSI vector or non-zero for otherwise.
 510  **/
 511 static int msi_capability_init(struct pci_dev *dev)
 512 {
 513         struct msi_desc *entry;
 514         struct msg_address address;
 515         struct msg_data data;
 516         int pos, vector;
 517         u16 control;
 518
 519         pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
 520         pci_read_config_word(dev, msi_control_reg(pos), &control);
 521         /* MSI Entry Initialization */
 522         if (!(entry = alloc_msi_entry()))
 523                 return -ENOMEM;
 524
 525         if ((vector = get_msi_vector(dev)) < 0) {
 526                 kmem_cache_free(msi_cachep, entry);
 527                 return -EBUSY;
 528         }
 529         entry->link.head = vector;
 530         entry->link.tail = vector;
 531         entry->msi_attrib.type = PCI_CAP_ID_MSI;
 532         entry->msi_attrib.state = 0;                    /* Mark it not active */
 533         entry->msi_attrib.entry_nr = 0;
 534         entry->msi_attrib.maskbit = is_mask_bit_support(control);
 535         entry->msi_attrib.default_vector = dev->irq;    /* Save IOAPIC IRQ */
 536         dev->irq = vector;
 537         entry->dev = dev;
 538         if (is_mask_bit_support(control)) {
 539                 entry->mask_base = (void __iomem *)(long)msi_mask_bits_reg(pos,
 540                                 is_64bit_address(control));
 541         }
 542         /* Replace with MSI handler */
 543         irq_handler_init(PCI_CAP_ID_MSI, vector, entry->msi_attrib.maskbit);
 544         /* Configure MSI capability structure */
 545         msi_address_init(&address);
 546         msi_data_init(&data, vector);
 547         entry->msi_attrib.current_cpu = ((address.lo_address.u.dest_id >>
 548                                 MSI_TARGET_CPU_SHIFT) & MSI_TARGET_CPU_MASK);
 549         pci_write_config_dword(dev, msi_lower_address_reg(pos),
 550                         address.lo_address.value);
 551         if (is_64bit_address(control)) {
 552                 pci_write_config_dword(dev,
 553                         msi_upper_address_reg(pos), address.hi_address);
 554                 pci_write_config_word(dev,
 555                         msi_data_reg(pos, 1), *((u32*)&data));
 556         } else
 557                 pci_write_config_word(dev,
 558                         msi_data_reg(pos, 0), *((u32*)&data));
 559         if (entry->msi_attrib.maskbit) {
 560                 unsigned int maskbits, temp;
 561                 /* All MSIs are unmasked by default, Mask them all */
 562                 pci_read_config_dword(dev,
 563                         msi_mask_bits_reg(pos, is_64bit_address(control)),
 564                         &maskbits);
 565                 temp = (1 << multi_msi_capable(control));
 566                 temp = ((temp - 1) & ~temp);
 567                 maskbits |= temp;
 568                 pci_write_config_dword(dev,
 569                         msi_mask_bits_reg(pos, is_64bit_address(control)),
 570                         maskbits);
 571         }
 572         attach_msi_entry(entry, vector);
 573         /* Set MSI enabled bits  */
 574         enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
 575
 576         return 0;
 577 }
 578
 579 /**
 580  * msix_capability_init - configure device's MSI-X capability
 581  * @dev: pointer to the pci_dev data structure of MSI-X device function
 582  * @entries: pointer to an array of struct msix_entry entries
 583  * @nvec: number of @entries
 584  *
 585  * Setup the MSI-X capability structure of device function with a
 586  * single MSI-X vector. A return of zero indicates the successful setup of
 587  * requested MSI-X entries with allocated vectors or non-zero for otherwise.
 588  **/
 589 static int msix_capability_init(struct pci_dev *dev,
 590                                 struct msix_entry *entries, int nvec)
 591 {
 592         struct msi_desc *head = NULL, *tail = NULL, *entry = NULL;
 593         struct msg_address address;
 594         struct msg_data data;
 595         int vector, pos, i, j, nr_entries, temp = 0;
 596         u32 phys_addr, table_offset;
 597         u16 control;
 598         u8 bir;
 599         void __iomem *base;
 600
 601         pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
 602         /* Request & Map MSI-X table region */
 603         pci_read_config_word(dev, msi_control_reg(pos), &control);
 604         nr_entries = multi_msix_capable(control);
 605         pci_read_config_dword(dev, msix_table_offset_reg(pos),
 606                 &table_offset);
 607         bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
 608         phys_addr = pci_resource_start (dev, bir);
 609         phys_addr += (u32)(table_offset & ~PCI_MSIX_FLAGS_BIRMASK);
 610         base = ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
 611         if (base == NULL)
 612                 return -ENOMEM;
 613
 614         /* MSI-X Table Initialization */
 615         for (i = 0; i < nvec; i++) {
 616                 entry = alloc_msi_entry();
 617                 if (!entry)
 618                         break;
 619                 if ((vector = get_msi_vector(dev)) < 0)
 620                         break;
 621
 622                 j = entries[i].entry;
 623                 entries[i].vector = vector;
 624                 entry->msi_attrib.type = PCI_CAP_ID_MSIX;
 625                 entry->msi_attrib.state = 0;            /* Mark it not active */
 626                 entry->msi_attrib.entry_nr = j;
 627                 entry->msi_attrib.maskbit = 1;
 628                 entry->msi_attrib.default_vector = dev->irq;
 629                 entry->dev = dev;
 630                 entry->mask_base = base;
 631                 if (!head) {
 632                         entry->link.head = vector;
 633                         entry->link.tail = vector;
 634                         head = entry;
 635                 } else {
 636                         entry->link.head = temp;
 637                         entry->link.tail = tail->link.tail;
 638                         tail->link.tail = vector;
 639                         head->link.head = vector;
 640                 }
 641                 temp = vector;
 642                 tail = entry;
 643                 /* Replace with MSI-X handler */
 644                 irq_handler_init(PCI_CAP_ID_MSIX, vector, 1);
 645                 /* Configure MSI-X capability structure */
 646                 msi_address_init(&address);
 647                 msi_data_init(&data, vector);
 648                 entry->msi_attrib.current_cpu =
 649                         ((address.lo_address.u.dest_id >>
 650                         MSI_TARGET_CPU_SHIFT) & MSI_TARGET_CPU_MASK);
 651                 writel(address.lo_address.value,
 652                         base + j * PCI_MSIX_ENTRY_SIZE +
 653                         PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
 654                 writel(address.hi_address,
 655                         base + j * PCI_MSIX_ENTRY_SIZE +
 656                         PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
 657                 writel(*(u32*)&data,
 658                         base + j * PCI_MSIX_ENTRY_SIZE +
 659                         PCI_MSIX_ENTRY_DATA_OFFSET);
 660                 attach_msi_entry(entry, vector);
 661         }
 662         if (i != nvec) {
 663                 i--;
 664                 for (; i >= 0; i--) {
 665                         vector = (entries + i)->vector;
 666                         msi_free_vector(dev, vector, 0);
 667                         (entries + i)->vector = 0;
 668                 }
 669                 return -EBUSY;
 670         }
 671         /* Set MSI-X enabled bits */
 672         enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
 673
 674         return 0;
 675 }
 676
 677 /**
 678  * pci_enable_msi - configure device's MSI capability structure
 679  * @dev: pointer to the pci_dev data structure of MSI device function
 680  *
 681  * Setup the MSI capability structure of device function with
 682  * a single MSI vector upon its software driver call to request for
 683  * MSI mode enabled on its hardware device function. A return of zero
 684  * indicates the successful setup of an entry zero with the new MSI
 685  * vector or non-zero for otherwise.
 686  **/
 687 int pci_enable_msi(struct pci_dev* dev)
 688 {
 689         int pos, temp, status = -EINVAL;
 690         u16 control;
 691
 692         if (!pci_msi_enable || !dev)
 693                 return status;
 694
 695         if (dev->no_msi)
 696                 return status;
 697
 698         temp = dev->irq;
 699
 700         if ((status = msi_init()) < 0)
 701                 return status;
 702
 703         if (!(pos = pci_find_capability(dev, PCI_CAP_ID_MSI)))
 704                 return -EINVAL;
 705
 706         pci_read_config_word(dev, msi_control_reg(pos), &control);
 707         if (control & PCI_MSI_FLAGS_ENABLE)
 708                 return 0;                       /* Already in MSI mode */
 709
 710         if (!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
 711                 /* Lookup Sucess */
 712                 unsigned long flags;
 713
 714                 spin_lock_irqsave(&msi_lock, flags);
 715                 if (!vector_irq[dev->irq]) {
 716                         msi_desc[dev->irq]->msi_attrib.state = 0;
 717                         vector_irq[dev->irq] = -1;
 718                         nr_released_vectors--;
 719                         spin_unlock_irqrestore(&msi_lock, flags);
 720                         enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
 721                         return 0;
 722                 }
 723                 spin_unlock_irqrestore(&msi_lock, flags);
 724                 dev->irq = temp;
 725         }
 726         /* Check whether driver already requested for MSI-X vectors */
 727         if ((pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)) > 0 &&
 728                 !msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
 729                         printk(KERN_INFO "PCI: %s: Can't enable MSI.  "
 730                                "Device already has MSI-X vectors assigned\n",
 731                                pci_name(dev));
 732                         dev->irq = temp;
 733                         return -EINVAL;
 734         }
 735         status = msi_capability_init(dev);
 736         if (!status) {
 737                 if (!pos)
 738                         nr_reserved_vectors--;  /* Only MSI capable */
 739                 else if (nr_msix_devices > 0)
 740                         nr_msix_devices--;      /* Both MSI and MSI-X capable,
 741                                                    but choose enabling MSI */
 742         }
 743
 744         return status;
 745 }
 746
 747 void pci_disable_msi(struct pci_dev* dev)
 748 {
 749         struct msi_desc *entry;
 750         int pos, default_vector;
 751         u16 control;
 752         unsigned long flags;
 753
 754         if (!dev || !(pos = pci_find_capability(dev, PCI_CAP_ID_MSI)))
 755                 return;
 756
 757         pci_read_config_word(dev, msi_control_reg(pos), &control);
 758         if (!(control & PCI_MSI_FLAGS_ENABLE))
 759                 return;
 760
 761         spin_lock_irqsave(&msi_lock, flags);
 762         entry = msi_desc[dev->irq];
 763         if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {
 764                 spin_unlock_irqrestore(&msi_lock, flags);
 765                 return;
 766         }
 767         if (entry->msi_attrib.state) {
 768                 spin_unlock_irqrestore(&msi_lock, flags);
 769                 printk(KERN_WARNING "PCI: %s: pci_disable_msi() called without "
 770                        "free_irq() on MSI vector %d\n",
 771                        pci_name(dev), dev->irq);
 772                 BUG_ON(entry->msi_attrib.state > 0);
 773         } else {
 774                 vector_irq[dev->irq] = 0; /* free it */
 775                 nr_released_vectors++;
 776                 default_vector = entry->msi_attrib.default_vector;
 777                 spin_unlock_irqrestore(&msi_lock, flags);
 778                 /* Restore dev->irq to its default pin-assertion vector */
 779                 dev->irq = default_vector;
 780                 disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
 781                                         PCI_CAP_ID_MSI);
 782         }
 783 }
 784
 785 static int msi_free_vector(struct pci_dev* dev, int vector, int reassign)
 786 {
 787         struct msi_desc *entry;
 788         int head, entry_nr, type;
 789         void __iomem *base;
 790         unsigned long flags;
 791
 792         spin_lock_irqsave(&msi_lock, flags);
 793         entry = msi_desc[vector];
 794         if (!entry || entry->dev != dev) {
 795                 spin_unlock_irqrestore(&msi_lock, flags);
 796                 return -EINVAL;
 797         }
 798         type = entry->msi_attrib.type;
 799         entry_nr = entry->msi_attrib.entry_nr;
 800         head = entry->link.head;
 801         base = entry->mask_base;
 802         msi_desc[entry->link.head]->link.tail = entry->link.tail;
 803         msi_desc[entry->link.tail]->link.head = entry->link.head;
 804         entry->dev = NULL;
 805         if (!reassign) {
 806                 vector_irq[vector] = 0;
 807                 nr_released_vectors++;
 808         }
 809         msi_desc[vector] = NULL;
 810         spin_unlock_irqrestore(&msi_lock, flags);
 811
 812         kmem_cache_free(msi_cachep, entry);
 813
 814         if (type == PCI_CAP_ID_MSIX) {
 815                 if (!reassign)
 816                         writel(1, base +
 817                                 entry_nr * PCI_MSIX_ENTRY_SIZE +
 818                                 PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
 819
 820                 if (head == vector) {
 821                         /*
 822                          * Detect last MSI-X vector to be released.
 823                          * Release the MSI-X memory-mapped table.
 824                          */
 825                         int pos, nr_entries;
 826                         u32 phys_addr, table_offset;
 827                         u16 control;
 828                         u8 bir;
 829
 830                         pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
 831                         pci_read_config_word(dev, msi_control_reg(pos),
 832                                 &control);
 833                         nr_entries = multi_msix_capable(control);
 834                         pci_read_config_dword(dev, msix_table_offset_reg(pos),
 835                                 &table_offset);
 836                         bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
 837                         phys_addr = pci_resource_start (dev, bir);
 838                         phys_addr += (u32)(table_offset &
 839                                 ~PCI_MSIX_FLAGS_BIRMASK);
 840                         iounmap(base);
 841                 }
 842         }
 843
 844         return 0;
 845 }
 846
 847 static int reroute_msix_table(int head, struct msix_entry *entries, int *nvec)
 848 {
 849         int vector = head, tail = 0;
 850         int i, j = 0, nr_entries = 0;
 851         void __iomem *base;
 852         unsigned long flags;
 853
 854         spin_lock_irqsave(&msi_lock, flags);
 855         while (head != tail) {
 856                 nr_entries++;
 857                 tail = msi_desc[vector]->link.tail;
 858                 if (entries[0].entry == msi_desc[vector]->msi_attrib.entry_nr)
 859                         j = vector;
 860                 vector = tail;
 861         }
 862         if (*nvec > nr_entries) {
 863                 spin_unlock_irqrestore(&msi_lock, flags);
 864                 *nvec = nr_entries;
 865                 return -EINVAL;
 866         }
 867         vector = ((j > 0) ? j : head);
 868         for (i = 0; i < *nvec; i++) {
 869                 j = msi_desc[vector]->msi_attrib.entry_nr;
 870                 msi_desc[vector]->msi_attrib.state = 0; /* Mark it not active */
 871                 vector_irq[vector] = -1;                /* Mark it busy */
 872                 nr_released_vectors--;
 873                 entries[i].vector = vector;
 874                 if (j != (entries + i)->entry) {
 875                         base = msi_desc[vector]->mask_base;
 876                         msi_desc[vector]->msi_attrib.entry_nr =
 877                                 (entries + i)->entry;
 878                         writel( readl(base + j * PCI_MSIX_ENTRY_SIZE +
 879                                 PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET), base +
 880                                 (entries + i)->entry * PCI_MSIX_ENTRY_SIZE +
 881                                 PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
 882                         writel( readl(base + j * PCI_MSIX_ENTRY_SIZE +
 883                                 PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET), base +
 884                                 (entries + i)->entry * PCI_MSIX_ENTRY_SIZE +
 885                                 PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
 886                         writel( (readl(base + j * PCI_MSIX_ENTRY_SIZE +
 887                                 PCI_MSIX_ENTRY_DATA_OFFSET) & 0xff00) | vector,
 888                                 base + (entries+i)->entry*PCI_MSIX_ENTRY_SIZE +
 889                                 PCI_MSIX_ENTRY_DATA_OFFSET);
 890                 }
 891                 vector = msi_desc[vector]->link.tail;
 892         }
 893         spin_unlock_irqrestore(&msi_lock, flags);
 894
 895         return 0;
 896 }
 897
 898 /**
 899  * pci_enable_msix - configure device's MSI-X capability structure
 900  * @dev: pointer to the pci_dev data structure of MSI-X device function
 901  * @entries: pointer to an array of MSI-X entries
 902  * @nvec: number of MSI-X vectors requested for allocation by device driver
 903  *
 904  * Setup the MSI-X capability structure of device function with the number
 905  * of requested vectors upon its software driver call to request for
 906  * MSI-X mode enabled on its hardware device function. A return of zero
 907  * indicates the successful configuration of MSI-X capability structure
 908  * with new allocated MSI-X vectors. A return of < 0 indicates a failure.
 909  * Or a return of > 0 indicates that driver request is exceeding the number
 910  * of vectors available. Driver should use the returned value to re-send
 911  * its request.
 912  **/
 913 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
 914 {
 915         int status, pos, nr_entries, free_vectors;
 916         int i, j, temp;
 917         u16 control;
 918         unsigned long flags;
 919
 920         if (!pci_msi_enable || !dev || !entries)
 921                 return -EINVAL;
 922
 923         if ((status = msi_init()) < 0)
 924                 return status;
 925
 926         if (!(pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)))
 927                 return -EINVAL;
 928
 929         pci_read_config_word(dev, msi_control_reg(pos), &control);
 930         if (control & PCI_MSIX_FLAGS_ENABLE)
 931                 return -EINVAL;                 /* Already in MSI-X mode */
 932
 933         nr_entries = multi_msix_capable(control);
 934         if (nvec > nr_entries)
 935                 return -EINVAL;
 936
 937         /* Check for any invalid entries */
 938         for (i = 0; i < nvec; i++) {
 939                 if (entries[i].entry >= nr_entries)
 940                         return -EINVAL;         /* invalid entry */
 941                 for (j = i + 1; j < nvec; j++) {
 942                         if (entries[i].entry == entries[j].entry)
 943                                 return -EINVAL; /* duplicate entry */
 944                 }
 945         }
 946         temp = dev->irq;
 947         if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
 948                 /* Lookup Sucess */
 949                 nr_entries = nvec;
 950                 /* Reroute MSI-X table */
 951                 if (reroute_msix_table(dev->irq, entries, &nr_entries)) {
 952                         /* #requested > #previous-assigned */
 953                         dev->irq = temp;
 954                         return nr_entries;
 955                 }
 956                 dev->irq = temp;
 957                 enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
 958                 return 0;
 959         }
 960         /* Check whether driver already requested for MSI vector */
 961         if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0 &&
 962                 !msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
 963                 printk(KERN_INFO "PCI: %s: Can't enable MSI-X.  "
 964                        "Device already has an MSI vector assigned\n",
 965                        pci_name(dev));
 966                 dev->irq = temp;
 967                 return -EINVAL;
 968         }
 969
 970         spin_lock_irqsave(&msi_lock, flags);
 971         /*
 972          * msi_lock is provided to ensure that enough vectors resources are
 973          * available before granting.
 974          */
 975         free_vectors = pci_vector_resources(last_alloc_vector,
 976                                 nr_released_vectors);
 977         /* Ensure that each MSI/MSI-X device has one vector reserved by
 978            default to avoid any MSI-X driver to take all available
 979            resources */
 980         free_vectors -= nr_reserved_vectors;
 981         /* Find the average of free vectors among MSI-X devices */
 982         if (nr_msix_devices > 0)
 983                 free_vectors /= nr_msix_devices;
 984         spin_unlock_irqrestore(&msi_lock, flags);
 985
 986         if (nvec > free_vectors) {
 987                 if (free_vectors > 0)
 988                         return free_vectors;
 989                 else
 990                         return -EBUSY;
 991         }
 992
 993         status = msix_capability_init(dev, entries, nvec);
 994         if (!status && nr_msix_devices > 0)
 995                 nr_msix_devices--;
 996
 997         return status;
 998 }
 999
1000 void pci_disable_msix(struct pci_dev* dev)
1001 {
1002         int pos, temp;
1003         u16 control;
1004
1005         if (!dev || !(pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)))
1006                 return;
1007
1008         pci_read_config_word(dev, msi_control_reg(pos), &control);
1009         if (!(control & PCI_MSIX_FLAGS_ENABLE))
1010                 return;
1011
1012         temp = dev->irq;
1013         if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
1014                 int state, vector, head, tail = 0, warning = 0;
1015                 unsigned long flags;
1016
1017                 vector = head = dev->irq;
1018                 spin_lock_irqsave(&msi_lock, flags);
1019                 while (head != tail) {
1020                         state = msi_desc[vector]->msi_attrib.state;
1021                         if (state)
1022                                 warning = 1;
1023                         else {
1024                                 vector_irq[vector] = 0; /* free it */
1025                                 nr_released_vectors++;
1026                         }
1027                         tail = msi_desc[vector]->link.tail;
1028                         vector = tail;
1029                 }
1030                 spin_unlock_irqrestore(&msi_lock, flags);
1031                 if (warning) {
1032                         dev->irq = temp;
1033                         printk(KERN_WARNING "PCI: %s: pci_disable_msix() called without "
1034                                "free_irq() on all MSI-X vectors\n",
1035                                pci_name(dev));
1036                         BUG_ON(warning > 0);
1037                 } else {
1038                         dev->irq = temp;
1039                         disable_msi_mode(dev,
1040                                 pci_find_capability(dev, PCI_CAP_ID_MSIX),
1041                                 PCI_CAP_ID_MSIX);
1042
1043                 }
1044         }
1045 }
1046
1047 /**
1048  * msi_remove_pci_irq_vectors - reclaim MSI(X) vectors to unused state
1049  * @dev: pointer to the pci_dev data structure of MSI(X) device function
1050  *
1051  * Being called during hotplug remove, from which the device function
1052  * is hot-removed. All previous assigned MSI/MSI-X vectors, if
1053  * allocated for this device function, are reclaimed to unused state,
1054  * which may be used later on.
1055  **/
1056 void msi_remove_pci_irq_vectors(struct pci_dev* dev)
1057 {
1058         int state, pos, temp;
1059         unsigned long flags;
1060
1061         if (!pci_msi_enable || !dev)
1062                 return;
1063
1064         temp = dev->irq;                /* Save IOAPIC IRQ */
1065         if ((pos = pci_find_capability(dev, PCI_CAP_ID_MSI)) > 0 &&
1066                 !msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
1067                 spin_lock_irqsave(&msi_lock, flags);
1068                 state = msi_desc[dev->irq]->msi_attrib.state;
1069                 spin_unlock_irqrestore(&msi_lock, flags);
1070                 if (state) {
1071                         printk(KERN_WARNING "PCI: %s: msi_remove_pci_irq_vectors() "
1072                                "called without free_irq() on MSI vector %d\n",
1073                                pci_name(dev), dev->irq);
1074                         BUG_ON(state > 0);
1075                 } else /* Release MSI vector assigned to this device */
1076                         msi_free_vector(dev, dev->irq, 0);
1077                 dev->irq = temp;                /* Restore IOAPIC IRQ */
1078         }
1079         if ((pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)) > 0 &&
1080                 !msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
1081                 int vector, head, tail = 0, warning = 0;
1082                 void __iomem *base = NULL;
1083
1084                 vector = head = dev->irq;
1085                 while (head != tail) {
1086                         spin_lock_irqsave(&msi_lock, flags);
1087                         state = msi_desc[vector]->msi_attrib.state;
1088                         tail = msi_desc[vector]->link.tail;
1089                         base = msi_desc[vector]->mask_base;
1090                         spin_unlock_irqrestore(&msi_lock, flags);
1091                         if (state)
1092                                 warning = 1;
1093                         else if (vector != head) /* Release MSI-X vector */
1094                                 msi_free_vector(dev, vector, 0);
1095                         vector = tail;
1096                 }
1097                 msi_free_vector(dev, vector, 0);
1098                 if (warning) {
1099                         /* Force to release the MSI-X memory-mapped table */
1100                         u32 phys_addr, table_offset;
1101                         u16 control;
1102                         u8 bir;
1103
1104                         pci_read_config_word(dev, msi_control_reg(pos),
1105                                 &control);
1106                         pci_read_config_dword(dev, msix_table_offset_reg(pos),
1107                                 &table_offset);
1108                         bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
1109                         phys_addr = pci_resource_start (dev, bir);
1110                         phys_addr += (u32)(table_offset &
1111                                 ~PCI_MSIX_FLAGS_BIRMASK);
1112                         iounmap(base);
1113                         printk(KERN_WARNING "PCI: %s: msi_remove_pci_irq_vectors() "
1114                                "called without free_irq() on all MSI-X vectors\n",
1115                                pci_name(dev));
1116                         BUG_ON(warning > 0);
1117                 }
1118                 dev->irq = temp;                /* Restore IOAPIC IRQ */
1119         }
1120 }
1121
1122 EXPORT_SYMBOL(pci_enable_msi);
1123 EXPORT_SYMBOL(pci_disable_msi);
1124 EXPORT_SYMBOL(pci_enable_msix);
1125 EXPORT_SYMBOL(pci_disable_msix);