hw/pci/msi.c

   1 /*
   2  * msi.c
   3  *
   4  * Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>
   5  *                    VA Linux Systems Japan K.K.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "hw/pci/msi.h"
  22 #include "qemu/range.h"
  23
  24 /* Eventually those constants should go to Linux pci_regs.h */
  25 #define PCI_MSI_PENDING_32      0x10
  26 #define PCI_MSI_PENDING_64      0x14
  27
  28 /* PCI_MSI_ADDRESS_LO */
  29 #define PCI_MSI_ADDRESS_LO_MASK         (~0x3)
  30
  31 /* If we get rid of cap allocator, we won't need those. */
  32 #define PCI_MSI_32_SIZEOF       0x0a
  33 #define PCI_MSI_64_SIZEOF       0x0e
  34 #define PCI_MSI_32M_SIZEOF      0x14
  35 #define PCI_MSI_64M_SIZEOF      0x18
  36
  37 #define PCI_MSI_VECTORS_MAX     32
  38
  39 /* Flag for interrupt controller to declare MSI/MSI-X support */
  40 bool msi_supported;
  41
  42 /* If we get rid of cap allocator, we won't need this. */
  43 static inline uint8_t msi_cap_sizeof(uint16_t flags)
  44 {
  45     switch (flags & (PCI_MSI_FLAGS_MASKBIT | PCI_MSI_FLAGS_64BIT)) {
  46     case PCI_MSI_FLAGS_MASKBIT | PCI_MSI_FLAGS_64BIT:
  47         return PCI_MSI_64M_SIZEOF;
  48     case PCI_MSI_FLAGS_64BIT:
  49         return PCI_MSI_64_SIZEOF;
  50     case PCI_MSI_FLAGS_MASKBIT:
  51         return PCI_MSI_32M_SIZEOF;
  52     case 0:
  53         return PCI_MSI_32_SIZEOF;
  54     default:
  55         abort();
  56         break;
  57     }
  58     return 0;
  59 }
  60
  61 //#define MSI_DEBUG
  62
  63 #ifdef MSI_DEBUG
  64 # define MSI_DPRINTF(fmt, ...)                                          \
  65     fprintf(stderr, "%s:%d " fmt, __func__, __LINE__, ## __VA_ARGS__)
  66 #else
  67 # define MSI_DPRINTF(fmt, ...)  do { } while (0)
  68 #endif
  69 #define MSI_DEV_PRINTF(dev, fmt, ...)                                   \
  70     MSI_DPRINTF("%s:%x " fmt, (dev)->name, (dev)->devfn, ## __VA_ARGS__)
  71
  72 static inline unsigned int msi_nr_vectors(uint16_t flags)
  73 {
  74     return 1U <<
  75         ((flags & PCI_MSI_FLAGS_QSIZE) >> (ffs(PCI_MSI_FLAGS_QSIZE) - 1));
  76 }
  77
  78 static inline uint8_t msi_flags_off(const PCIDevice* dev)
  79 {
  80     return dev->msi_cap + PCI_MSI_FLAGS;
  81 }
  82
  83 static inline uint8_t msi_address_lo_off(const PCIDevice* dev)
  84 {
  85     return dev->msi_cap + PCI_MSI_ADDRESS_LO;
  86 }
  87
  88 static inline uint8_t msi_address_hi_off(const PCIDevice* dev)
  89 {
  90     return dev->msi_cap + PCI_MSI_ADDRESS_HI;
  91 }
  92
  93 static inline uint8_t msi_data_off(const PCIDevice* dev, bool msi64bit)
  94 {
  95     return dev->msi_cap + (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32);
  96 }
  97
  98 static inline uint8_t msi_mask_off(const PCIDevice* dev, bool msi64bit)
  99 {
 100     return dev->msi_cap + (msi64bit ? PCI_MSI_MASK_64 : PCI_MSI_MASK_32);
 101 }
 102
 103 static inline uint8_t msi_pending_off(const PCIDevice* dev, bool msi64bit)
 104 {
 105     return dev->msi_cap + (msi64bit ? PCI_MSI_PENDING_64 : PCI_MSI_PENDING_32);
 106 }
 107
 108 /*
 109  * Special API for POWER to configure the vectors through
 110  * a side channel. Should never be used by devices.
 111  */
 112 void msi_set_message(PCIDevice *dev, MSIMessage msg)
 113 {
 114     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 115     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 116
 117     if (msi64bit) {
 118         pci_set_quad(dev->config + msi_address_lo_off(dev), msg.address);
 119     } else {
 120         pci_set_long(dev->config + msi_address_lo_off(dev), msg.address);
 121     }
 122     pci_set_word(dev->config + msi_data_off(dev, msi64bit), msg.data);
 123 }
 124
 125 MSIMessage msi_get_message(PCIDevice *dev, unsigned int vector)
 126 {
 127     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 128     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 129     unsigned int nr_vectors = msi_nr_vectors(flags);
 130     MSIMessage msg;
 131
 132     assert(vector < nr_vectors);
 133
 134     if (msi64bit) {
 135         msg.address = pci_get_quad(dev->config + msi_address_lo_off(dev));
 136     } else {
 137         msg.address = pci_get_long(dev->config + msi_address_lo_off(dev));
 138     }
 139
 140     /* upper bit 31:16 is zero */
 141     msg.data = pci_get_word(dev->config + msi_data_off(dev, msi64bit));
 142     if (nr_vectors > 1) {
 143         msg.data &= ~(nr_vectors - 1);
 144         msg.data |= vector;
 145     }
 146
 147     return msg;
 148 }
 149
 150 bool msi_enabled(const PCIDevice *dev)
 151 {
 152     return msi_present(dev) &&
 153         (pci_get_word(dev->config + msi_flags_off(dev)) &
 154          PCI_MSI_FLAGS_ENABLE);
 155 }
 156
 157 int msi_init(struct PCIDevice *dev, uint8_t offset,
 158              unsigned int nr_vectors, bool msi64bit, bool msi_per_vector_mask)
 159 {
 160     unsigned int vectors_order;
 161     uint16_t flags;
 162     uint8_t cap_size;
 163     int config_offset;
 164
 165     if (!msi_supported) {
 166         return -ENOTSUP;
 167     }
 168
 169     MSI_DEV_PRINTF(dev,
 170                    "init offset: 0x%"PRIx8" vector: %"PRId8
 171                    " 64bit %d mask %d\n",
 172                    offset, nr_vectors, msi64bit, msi_per_vector_mask);
 173
 174     assert(!(nr_vectors & (nr_vectors - 1)));   /* power of 2 */
 175     assert(nr_vectors > 0);
 176     assert(nr_vectors <= PCI_MSI_VECTORS_MAX);
 177     /* the nr of MSI vectors is up to 32 */
 178     vectors_order = ffs(nr_vectors) - 1;
 179
 180     flags = vectors_order << (ffs(PCI_MSI_FLAGS_QMASK) - 1);
 181     if (msi64bit) {
 182         flags |= PCI_MSI_FLAGS_64BIT;
 183     }
 184     if (msi_per_vector_mask) {
 185         flags |= PCI_MSI_FLAGS_MASKBIT;
 186     }
 187
 188     cap_size = msi_cap_sizeof(flags);
 189     config_offset = pci_add_capability(dev, PCI_CAP_ID_MSI, offset, cap_size);
 190     if (config_offset < 0) {
 191         return config_offset;
 192     }
 193
 194     dev->msi_cap = config_offset;
 195     dev->cap_present |= QEMU_PCI_CAP_MSI;
 196
 197     pci_set_word(dev->config + msi_flags_off(dev), flags);
 198     pci_set_word(dev->wmask + msi_flags_off(dev),
 199                  PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);
 200     pci_set_long(dev->wmask + msi_address_lo_off(dev),
 201                  PCI_MSI_ADDRESS_LO_MASK);
 202     if (msi64bit) {
 203         pci_set_long(dev->wmask + msi_address_hi_off(dev), 0xffffffff);
 204     }
 205     pci_set_word(dev->wmask + msi_data_off(dev, msi64bit), 0xffff);
 206
 207     if (msi_per_vector_mask) {
 208         /* Make mask bits 0 to nr_vectors - 1 writable. */
 209         pci_set_long(dev->wmask + msi_mask_off(dev, msi64bit),
 210                      0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors));
 211     }
 212     return config_offset;
 213 }
 214
 215 void msi_uninit(struct PCIDevice *dev)
 216 {
 217     uint16_t flags;
 218     uint8_t cap_size;
 219
 220     if (!msi_present(dev)) {
 221         return;
 222     }
 223     flags = pci_get_word(dev->config + msi_flags_off(dev));
 224     cap_size = msi_cap_sizeof(flags);
 225     pci_del_capability(dev, PCI_CAP_ID_MSI, cap_size);
 226     dev->cap_present &= ~QEMU_PCI_CAP_MSI;
 227
 228     MSI_DEV_PRINTF(dev, "uninit\n");
 229 }
 230
 231 void msi_reset(PCIDevice *dev)
 232 {
 233     uint16_t flags;
 234     bool msi64bit;
 235
 236     if (!msi_present(dev)) {
 237         return;
 238     }
 239
 240     flags = pci_get_word(dev->config + msi_flags_off(dev));
 241     flags &= ~(PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);
 242     msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 243
 244     pci_set_word(dev->config + msi_flags_off(dev), flags);
 245     pci_set_long(dev->config + msi_address_lo_off(dev), 0);
 246     if (msi64bit) {
 247         pci_set_long(dev->config + msi_address_hi_off(dev), 0);
 248     }
 249     pci_set_word(dev->config + msi_data_off(dev, msi64bit), 0);
 250     if (flags & PCI_MSI_FLAGS_MASKBIT) {
 251         pci_set_long(dev->config + msi_mask_off(dev, msi64bit), 0);
 252         pci_set_long(dev->config + msi_pending_off(dev, msi64bit), 0);
 253     }
 254     MSI_DEV_PRINTF(dev, "reset\n");
 255 }
 256
 257 static bool msi_is_masked(const PCIDevice *dev, unsigned int vector)
 258 {
 259     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 260     uint32_t mask;
 261     assert(vector < PCI_MSI_VECTORS_MAX);
 262
 263     if (!(flags & PCI_MSI_FLAGS_MASKBIT)) {
 264         return false;
 265     }
 266
 267     mask = pci_get_long(dev->config +
 268                         msi_mask_off(dev, flags & PCI_MSI_FLAGS_64BIT));
 269     return mask & (1U << vector);
 270 }
 271
 272 void msi_notify(PCIDevice *dev, unsigned int vector)
 273 {
 274     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 275     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 276     unsigned int nr_vectors = msi_nr_vectors(flags);
 277     MSIMessage msg;
 278
 279     assert(vector < nr_vectors);
 280     if (msi_is_masked(dev, vector)) {
 281         assert(flags & PCI_MSI_FLAGS_MASKBIT);
 282         pci_long_test_and_set_mask(
 283             dev->config + msi_pending_off(dev, msi64bit), 1U << vector);
 284         MSI_DEV_PRINTF(dev, "pending vector 0x%x\n", vector);
 285         return;
 286     }
 287
 288     msg = msi_get_message(dev, vector);
 289
 290     MSI_DEV_PRINTF(dev,
 291                    "notify vector 0x%x"
 292                    " address: 0x%"PRIx64" data: 0x%"PRIx32"\n",
 293                    vector, msg.address, msg.data);
 294     stl_le_phys(&address_space_memory, msg.address, msg.data);
 295 }
 296
 297 /* Normally called by pci_default_write_config(). */
 298 void msi_write_config(PCIDevice *dev, uint32_t addr, uint32_t val, int len)
 299 {
 300     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 301     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 302     bool msi_per_vector_mask = flags & PCI_MSI_FLAGS_MASKBIT;
 303     unsigned int nr_vectors;
 304     uint8_t log_num_vecs;
 305     uint8_t log_max_vecs;
 306     unsigned int vector;
 307     uint32_t pending;
 308
 309     if (!msi_present(dev) ||
 310         !ranges_overlap(addr, len, dev->msi_cap, msi_cap_sizeof(flags))) {
 311         return;
 312     }
 313
 314 #ifdef MSI_DEBUG
 315     MSI_DEV_PRINTF(dev, "addr 0x%"PRIx32" val 0x%"PRIx32" len %d\n",
 316                    addr, val, len);
 317     MSI_DEV_PRINTF(dev, "ctrl: 0x%"PRIx16" address: 0x%"PRIx32,
 318                    flags,
 319                    pci_get_long(dev->config + msi_address_lo_off(dev)));
 320     if (msi64bit) {
 321         fprintf(stderr, " address-hi: 0x%"PRIx32,
 322                 pci_get_long(dev->config + msi_address_hi_off(dev)));
 323     }
 324     fprintf(stderr, " data: 0x%"PRIx16,
 325             pci_get_word(dev->config + msi_data_off(dev, msi64bit)));
 326     if (flags & PCI_MSI_FLAGS_MASKBIT) {
 327         fprintf(stderr, " mask 0x%"PRIx32" pending 0x%"PRIx32,
 328                 pci_get_long(dev->config + msi_mask_off(dev, msi64bit)),
 329                 pci_get_long(dev->config + msi_pending_off(dev, msi64bit)));
 330     }
 331     fprintf(stderr, "\n");
 332 #endif
 333
 334     if (!(flags & PCI_MSI_FLAGS_ENABLE)) {
 335         return;
 336     }
 337
 338     /*
 339      * Now MSI is enabled, clear INTx# interrupts.
 340      * the driver is prohibited from writing enable bit to mask
 341      * a service request. But the guest OS could do this.
 342      * So we just discard the interrupts as moderate fallback.
 343      *
 344      * 6.8.3.3. Enabling Operation
 345      *   While enabled for MSI or MSI-X operation, a function is prohibited
 346      *   from using its INTx# pin (if implemented) to request
 347      *   service (MSI, MSI-X, and INTx# are mutually exclusive).
 348      */
 349     pci_device_deassert_intx(dev);
 350
 351     /*
 352      * nr_vectors might be set bigger than capable. So clamp it.
 353      * This is not legal by spec, so we can do anything we like,
 354      * just don't crash the host
 355      */
 356     log_num_vecs =
 357         (flags & PCI_MSI_FLAGS_QSIZE) >> (ffs(PCI_MSI_FLAGS_QSIZE) - 1);
 358     log_max_vecs =
 359         (flags & PCI_MSI_FLAGS_QMASK) >> (ffs(PCI_MSI_FLAGS_QMASK) - 1);
 360     if (log_num_vecs > log_max_vecs) {
 361         flags &= ~PCI_MSI_FLAGS_QSIZE;
 362         flags |= log_max_vecs << (ffs(PCI_MSI_FLAGS_QSIZE) - 1);
 363         pci_set_word(dev->config + msi_flags_off(dev), flags);
 364     }
 365
 366     if (!msi_per_vector_mask) {
 367         /* if per vector masking isn't supported,
 368            there is no pending interrupt. */
 369         return;
 370     }
 371
 372     nr_vectors = msi_nr_vectors(flags);
 373
 374     /* This will discard pending interrupts, if any. */
 375     pending = pci_get_long(dev->config + msi_pending_off(dev, msi64bit));
 376     pending &= 0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors);
 377     pci_set_long(dev->config + msi_pending_off(dev, msi64bit), pending);
 378
 379     /* deliver pending interrupts which are unmasked */
 380     for (vector = 0; vector < nr_vectors; ++vector) {
 381         if (msi_is_masked(dev, vector) || !(pending & (1U << vector))) {
 382             continue;
 383         }
 384
 385         pci_long_test_and_clear_mask(
 386             dev->config + msi_pending_off(dev, msi64bit), 1U << vector);
 387         msi_notify(dev, vector);
 388     }
 389 }
 390
 391 unsigned int msi_nr_vectors_allocated(const PCIDevice *dev)
 392 {
 393     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 394     return msi_nr_vectors(flags);
 395 }