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 /* PCI_MSI_ADDRESS_LO */
  25 #define PCI_MSI_ADDRESS_LO_MASK         (~0x3)
  26
  27 /* If we get rid of cap allocator, we won't need those. */
  28 #define PCI_MSI_32_SIZEOF       0x0a
  29 #define PCI_MSI_64_SIZEOF       0x0e
  30 #define PCI_MSI_32M_SIZEOF      0x14
  31 #define PCI_MSI_64M_SIZEOF      0x18
  32
  33 #define PCI_MSI_VECTORS_MAX     32
  34
  35 /* Flag for interrupt controller to declare MSI/MSI-X support */
  36 bool msi_supported;
  37
  38 /* If we get rid of cap allocator, we won't need this. */
  39 static inline uint8_t msi_cap_sizeof(uint16_t flags)
  40 {
  41     switch (flags & (PCI_MSI_FLAGS_MASKBIT | PCI_MSI_FLAGS_64BIT)) {
  42     case PCI_MSI_FLAGS_MASKBIT | PCI_MSI_FLAGS_64BIT:
  43         return PCI_MSI_64M_SIZEOF;
  44     case PCI_MSI_FLAGS_64BIT:
  45         return PCI_MSI_64_SIZEOF;
  46     case PCI_MSI_FLAGS_MASKBIT:
  47         return PCI_MSI_32M_SIZEOF;
  48     case 0:
  49         return PCI_MSI_32_SIZEOF;
  50     default:
  51         abort();
  52         break;
  53     }
  54     return 0;
  55 }
  56
  57 //#define MSI_DEBUG
  58
  59 #ifdef MSI_DEBUG
  60 # define MSI_DPRINTF(fmt, ...)                                          \
  61     fprintf(stderr, "%s:%d " fmt, __func__, __LINE__, ## __VA_ARGS__)
  62 #else
  63 # define MSI_DPRINTF(fmt, ...)  do { } while (0)
  64 #endif
  65 #define MSI_DEV_PRINTF(dev, fmt, ...)                                   \
  66     MSI_DPRINTF("%s:%x " fmt, (dev)->name, (dev)->devfn, ## __VA_ARGS__)
  67
  68 static inline unsigned int msi_nr_vectors(uint16_t flags)
  69 {
  70     return 1U <<
  71         ((flags & PCI_MSI_FLAGS_QSIZE) >> ctz32(PCI_MSI_FLAGS_QSIZE));
  72 }
  73
  74 static inline uint8_t msi_flags_off(const PCIDevice* dev)
  75 {
  76     return dev->msi_cap + PCI_MSI_FLAGS;
  77 }
  78
  79 static inline uint8_t msi_address_lo_off(const PCIDevice* dev)
  80 {
  81     return dev->msi_cap + PCI_MSI_ADDRESS_LO;
  82 }
  83
  84 static inline uint8_t msi_address_hi_off(const PCIDevice* dev)
  85 {
  86     return dev->msi_cap + PCI_MSI_ADDRESS_HI;
  87 }
  88
  89 static inline uint8_t msi_data_off(const PCIDevice* dev, bool msi64bit)
  90 {
  91     return dev->msi_cap + (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32);
  92 }
  93
  94 static inline uint8_t msi_mask_off(const PCIDevice* dev, bool msi64bit)
  95 {
  96     return dev->msi_cap + (msi64bit ? PCI_MSI_MASK_64 : PCI_MSI_MASK_32);
  97 }
  98
  99 static inline uint8_t msi_pending_off(const PCIDevice* dev, bool msi64bit)
 100 {
 101     return dev->msi_cap + (msi64bit ? PCI_MSI_PENDING_64 : PCI_MSI_PENDING_32);
 102 }
 103
 104 /*
 105  * Special API for POWER to configure the vectors through
 106  * a side channel. Should never be used by devices.
 107  */
 108 void msi_set_message(PCIDevice *dev, MSIMessage msg)
 109 {
 110     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 111     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 112
 113     if (msi64bit) {
 114         pci_set_quad(dev->config + msi_address_lo_off(dev), msg.address);
 115     } else {
 116         pci_set_long(dev->config + msi_address_lo_off(dev), msg.address);
 117     }
 118     pci_set_word(dev->config + msi_data_off(dev, msi64bit), msg.data);
 119 }
 120
 121 MSIMessage msi_get_message(PCIDevice *dev, unsigned int vector)
 122 {
 123     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 124     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 125     unsigned int nr_vectors = msi_nr_vectors(flags);
 126     MSIMessage msg;
 127
 128     assert(vector < nr_vectors);
 129
 130     if (msi64bit) {
 131         msg.address = pci_get_quad(dev->config + msi_address_lo_off(dev));
 132     } else {
 133         msg.address = pci_get_long(dev->config + msi_address_lo_off(dev));
 134     }
 135
 136     /* upper bit 31:16 is zero */
 137     msg.data = pci_get_word(dev->config + msi_data_off(dev, msi64bit));
 138     if (nr_vectors > 1) {
 139         msg.data &= ~(nr_vectors - 1);
 140         msg.data |= vector;
 141     }
 142
 143     return msg;
 144 }
 145
 146 bool msi_enabled(const PCIDevice *dev)
 147 {
 148     return msi_present(dev) &&
 149         (pci_get_word(dev->config + msi_flags_off(dev)) &
 150          PCI_MSI_FLAGS_ENABLE);
 151 }
 152
 153 int msi_init(struct PCIDevice *dev, uint8_t offset,
 154              unsigned int nr_vectors, bool msi64bit, bool msi_per_vector_mask)
 155 {
 156     unsigned int vectors_order;
 157     uint16_t flags;
 158     uint8_t cap_size;
 159     int config_offset;
 160
 161     if (!msi_supported) {
 162         return -ENOTSUP;
 163     }
 164
 165     MSI_DEV_PRINTF(dev,
 166                    "init offset: 0x%"PRIx8" vector: %"PRId8
 167                    " 64bit %d mask %d\n",
 168                    offset, nr_vectors, msi64bit, msi_per_vector_mask);
 169
 170     assert(!(nr_vectors & (nr_vectors - 1)));   /* power of 2 */
 171     assert(nr_vectors > 0);
 172     assert(nr_vectors <= PCI_MSI_VECTORS_MAX);
 173     /* the nr of MSI vectors is up to 32 */
 174     vectors_order = ctz32(nr_vectors);
 175
 176     flags = vectors_order << ctz32(PCI_MSI_FLAGS_QMASK);
 177     if (msi64bit) {
 178         flags |= PCI_MSI_FLAGS_64BIT;
 179     }
 180     if (msi_per_vector_mask) {
 181         flags |= PCI_MSI_FLAGS_MASKBIT;
 182     }
 183
 184     cap_size = msi_cap_sizeof(flags);
 185     config_offset = pci_add_capability(dev, PCI_CAP_ID_MSI, offset, cap_size);
 186     if (config_offset < 0) {
 187         return config_offset;
 188     }
 189
 190     dev->msi_cap = config_offset;
 191     dev->cap_present |= QEMU_PCI_CAP_MSI;
 192
 193     pci_set_word(dev->config + msi_flags_off(dev), flags);
 194     pci_set_word(dev->wmask + msi_flags_off(dev),
 195                  PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);
 196     pci_set_long(dev->wmask + msi_address_lo_off(dev),
 197                  PCI_MSI_ADDRESS_LO_MASK);
 198     if (msi64bit) {
 199         pci_set_long(dev->wmask + msi_address_hi_off(dev), 0xffffffff);
 200     }
 201     pci_set_word(dev->wmask + msi_data_off(dev, msi64bit), 0xffff);
 202
 203     if (msi_per_vector_mask) {
 204         /* Make mask bits 0 to nr_vectors - 1 writable. */
 205         pci_set_long(dev->wmask + msi_mask_off(dev, msi64bit),
 206                      0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors));
 207     }
 208     return config_offset;
 209 }
 210
 211 void msi_uninit(struct PCIDevice *dev)
 212 {
 213     uint16_t flags;
 214     uint8_t cap_size;
 215
 216     if (!msi_present(dev)) {
 217         return;
 218     }
 219     flags = pci_get_word(dev->config + msi_flags_off(dev));
 220     cap_size = msi_cap_sizeof(flags);
 221     pci_del_capability(dev, PCI_CAP_ID_MSI, cap_size);
 222     dev->cap_present &= ~QEMU_PCI_CAP_MSI;
 223
 224     MSI_DEV_PRINTF(dev, "uninit\n");
 225 }
 226
 227 void msi_reset(PCIDevice *dev)
 228 {
 229     uint16_t flags;
 230     bool msi64bit;
 231
 232     if (!msi_present(dev)) {
 233         return;
 234     }
 235
 236     flags = pci_get_word(dev->config + msi_flags_off(dev));
 237     flags &= ~(PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);
 238     msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 239
 240     pci_set_word(dev->config + msi_flags_off(dev), flags);
 241     pci_set_long(dev->config + msi_address_lo_off(dev), 0);
 242     if (msi64bit) {
 243         pci_set_long(dev->config + msi_address_hi_off(dev), 0);
 244     }
 245     pci_set_word(dev->config + msi_data_off(dev, msi64bit), 0);
 246     if (flags & PCI_MSI_FLAGS_MASKBIT) {
 247         pci_set_long(dev->config + msi_mask_off(dev, msi64bit), 0);
 248         pci_set_long(dev->config + msi_pending_off(dev, msi64bit), 0);
 249     }
 250     MSI_DEV_PRINTF(dev, "reset\n");
 251 }
 252
 253 static bool msi_is_masked(const PCIDevice *dev, unsigned int vector)
 254 {
 255     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 256     uint32_t mask;
 257     assert(vector < PCI_MSI_VECTORS_MAX);
 258
 259     if (!(flags & PCI_MSI_FLAGS_MASKBIT)) {
 260         return false;
 261     }
 262
 263     mask = pci_get_long(dev->config +
 264                         msi_mask_off(dev, flags & PCI_MSI_FLAGS_64BIT));
 265     return mask & (1U << vector);
 266 }
 267
 268 void msi_notify(PCIDevice *dev, unsigned int vector)
 269 {
 270     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 271     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 272     unsigned int nr_vectors = msi_nr_vectors(flags);
 273     MSIMessage msg;
 274
 275     assert(vector < nr_vectors);
 276     if (msi_is_masked(dev, vector)) {
 277         assert(flags & PCI_MSI_FLAGS_MASKBIT);
 278         pci_long_test_and_set_mask(
 279             dev->config + msi_pending_off(dev, msi64bit), 1U << vector);
 280         MSI_DEV_PRINTF(dev, "pending vector 0x%x\n", vector);
 281         return;
 282     }
 283
 284     msg = msi_get_message(dev, vector);
 285
 286     MSI_DEV_PRINTF(dev,
 287                    "notify vector 0x%x"
 288                    " address: 0x%"PRIx64" data: 0x%"PRIx32"\n",
 289                    vector, msg.address, msg.data);
 290     msi_send_message(dev, msg);
 291 }
 292
 293 void msi_send_message(PCIDevice *dev, MSIMessage msg)
 294 {
 295     MemTxAttrs attrs = {};
 296
 297     attrs.requester_id = pci_requester_id(dev);
 298     address_space_stl_le(&dev->bus_master_as, msg.address, msg.data,
 299                          attrs, NULL);
 300 }
 301
 302 /* Normally called by pci_default_write_config(). */
 303 void msi_write_config(PCIDevice *dev, uint32_t addr, uint32_t val, int len)
 304 {
 305     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 306     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 307     bool msi_per_vector_mask = flags & PCI_MSI_FLAGS_MASKBIT;
 308     unsigned int nr_vectors;
 309     uint8_t log_num_vecs;
 310     uint8_t log_max_vecs;
 311     unsigned int vector;
 312     uint32_t pending;
 313
 314     if (!msi_present(dev) ||
 315         !ranges_overlap(addr, len, dev->msi_cap, msi_cap_sizeof(flags))) {
 316         return;
 317     }
 318
 319 #ifdef MSI_DEBUG
 320     MSI_DEV_PRINTF(dev, "addr 0x%"PRIx32" val 0x%"PRIx32" len %d\n",
 321                    addr, val, len);
 322     MSI_DEV_PRINTF(dev, "ctrl: 0x%"PRIx16" address: 0x%"PRIx32,
 323                    flags,
 324                    pci_get_long(dev->config + msi_address_lo_off(dev)));
 325     if (msi64bit) {
 326         fprintf(stderr, " address-hi: 0x%"PRIx32,
 327                 pci_get_long(dev->config + msi_address_hi_off(dev)));
 328     }
 329     fprintf(stderr, " data: 0x%"PRIx16,
 330             pci_get_word(dev->config + msi_data_off(dev, msi64bit)));
 331     if (flags & PCI_MSI_FLAGS_MASKBIT) {
 332         fprintf(stderr, " mask 0x%"PRIx32" pending 0x%"PRIx32,
 333                 pci_get_long(dev->config + msi_mask_off(dev, msi64bit)),
 334                 pci_get_long(dev->config + msi_pending_off(dev, msi64bit)));
 335     }
 336     fprintf(stderr, "\n");
 337 #endif
 338
 339     if (!(flags & PCI_MSI_FLAGS_ENABLE)) {
 340         return;
 341     }
 342
 343     /*
 344      * Now MSI is enabled, clear INTx# interrupts.
 345      * the driver is prohibited from writing enable bit to mask
 346      * a service request. But the guest OS could do this.
 347      * So we just discard the interrupts as moderate fallback.
 348      *
 349      * 6.8.3.3. Enabling Operation
 350      *   While enabled for MSI or MSI-X operation, a function is prohibited
 351      *   from using its INTx# pin (if implemented) to request
 352      *   service (MSI, MSI-X, and INTx# are mutually exclusive).
 353      */
 354     pci_device_deassert_intx(dev);
 355
 356     /*
 357      * nr_vectors might be set bigger than capable. So clamp it.
 358      * This is not legal by spec, so we can do anything we like,
 359      * just don't crash the host
 360      */
 361     log_num_vecs =
 362         (flags & PCI_MSI_FLAGS_QSIZE) >> ctz32(PCI_MSI_FLAGS_QSIZE);
 363     log_max_vecs =
 364         (flags & PCI_MSI_FLAGS_QMASK) >> ctz32(PCI_MSI_FLAGS_QMASK);
 365     if (log_num_vecs > log_max_vecs) {
 366         flags &= ~PCI_MSI_FLAGS_QSIZE;
 367         flags |= log_max_vecs << ctz32(PCI_MSI_FLAGS_QSIZE);
 368         pci_set_word(dev->config + msi_flags_off(dev), flags);
 369     }
 370
 371     if (!msi_per_vector_mask) {
 372         /* if per vector masking isn't supported,
 373            there is no pending interrupt. */
 374         return;
 375     }
 376
 377     nr_vectors = msi_nr_vectors(flags);
 378
 379     /* This will discard pending interrupts, if any. */
 380     pending = pci_get_long(dev->config + msi_pending_off(dev, msi64bit));
 381     pending &= 0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors);
 382     pci_set_long(dev->config + msi_pending_off(dev, msi64bit), pending);
 383
 384     /* deliver pending interrupts which are unmasked */
 385     for (vector = 0; vector < nr_vectors; ++vector) {
 386         if (msi_is_masked(dev, vector) || !(pending & (1U << vector))) {
 387             continue;
 388         }
 389
 390         pci_long_test_and_clear_mask(
 391             dev->config + msi_pending_off(dev, msi64bit), 1U << vector);
 392         msi_notify(dev, vector);
 393     }
 394 }
 395
 396 unsigned int msi_nr_vectors_allocated(const PCIDevice *dev)
 397 {
 398     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 399     return msi_nr_vectors(flags);
 400 }