hw/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 "msi.h"
  22 #include "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 /* If we get rid of cap allocator, we won't need this. */
  40 static inline uint8_t msi_cap_sizeof(uint16_t flags)
  41 {
  42     switch (flags & (PCI_MSI_FLAGS_MASKBIT | PCI_MSI_FLAGS_64BIT)) {
  43     case PCI_MSI_FLAGS_MASKBIT | PCI_MSI_FLAGS_64BIT:
  44         return PCI_MSI_64M_SIZEOF;
  45     case PCI_MSI_FLAGS_64BIT:
  46         return PCI_MSI_64_SIZEOF;
  47     case PCI_MSI_FLAGS_MASKBIT:
  48         return PCI_MSI_32M_SIZEOF;
  49     case 0:
  50         return PCI_MSI_32_SIZEOF;
  51     default:
  52         abort();
  53         break;
  54     }
  55     return 0;
  56 }
  57
  58 //#define MSI_DEBUG
  59
  60 #ifdef MSI_DEBUG
  61 # define MSI_DPRINTF(fmt, ...)                                          \
  62     fprintf(stderr, "%s:%d " fmt, __func__, __LINE__, ## __VA_ARGS__)
  63 #else
  64 # define MSI_DPRINTF(fmt, ...)  do { } while (0)
  65 #endif
  66 #define MSI_DEV_PRINTF(dev, fmt, ...)                                   \
  67     MSI_DPRINTF("%s:%x " fmt, (dev)->name, (dev)->devfn, ## __VA_ARGS__)
  68
  69 static inline unsigned int msi_nr_vectors(uint16_t flags)
  70 {
  71     return 1U <<
  72         ((flags & PCI_MSI_FLAGS_QSIZE) >> (ffs(PCI_MSI_FLAGS_QSIZE) - 1));
  73 }
  74
  75 static inline uint8_t msi_flags_off(const PCIDevice* dev)
  76 {
  77     return dev->msi_cap + PCI_MSI_FLAGS;
  78 }
  79
  80 static inline uint8_t msi_address_lo_off(const PCIDevice* dev)
  81 {
  82     return dev->msi_cap + PCI_MSI_ADDRESS_LO;
  83 }
  84
  85 static inline uint8_t msi_address_hi_off(const PCIDevice* dev)
  86 {
  87     return dev->msi_cap + PCI_MSI_ADDRESS_HI;
  88 }
  89
  90 static inline uint8_t msi_data_off(const PCIDevice* dev, bool msi64bit)
  91 {
  92     return dev->msi_cap + (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32);
  93 }
  94
  95 static inline uint8_t msi_mask_off(const PCIDevice* dev, bool msi64bit)
  96 {
  97     return dev->msi_cap + (msi64bit ? PCI_MSI_MASK_64 : PCI_MSI_MASK_32);
  98 }
  99
 100 static inline uint8_t msi_pending_off(const PCIDevice* dev, bool msi64bit)
 101 {
 102     return dev->msi_cap + (msi64bit ? PCI_MSI_PENDING_64 : PCI_MSI_PENDING_32);
 103 }
 104
 105 bool msi_enabled(const PCIDevice *dev)
 106 {
 107     return msi_present(dev) &&
 108         (pci_get_word(dev->config + msi_flags_off(dev)) &
 109          PCI_MSI_FLAGS_ENABLE);
 110 }
 111
 112 int msi_init(struct PCIDevice *dev, uint8_t offset,
 113              unsigned int nr_vectors, bool msi64bit, bool msi_per_vector_mask)
 114 {
 115     unsigned int vectors_order;
 116     uint16_t flags;
 117     uint8_t cap_size;
 118     int config_offset;
 119     MSI_DEV_PRINTF(dev,
 120                    "init offset: 0x%"PRIx8" vector: %"PRId8
 121                    " 64bit %d mask %d\n",
 122                    offset, nr_vectors, msi64bit, msi_per_vector_mask);
 123
 124     assert(!(nr_vectors & (nr_vectors - 1)));   /* power of 2 */
 125     assert(nr_vectors > 0);
 126     assert(nr_vectors <= PCI_MSI_VECTORS_MAX);
 127     /* the nr of MSI vectors is up to 32 */
 128     vectors_order = ffs(nr_vectors) - 1;
 129
 130     flags = vectors_order << (ffs(PCI_MSI_FLAGS_QMASK) - 1);
 131     if (msi64bit) {
 132         flags |= PCI_MSI_FLAGS_64BIT;
 133     }
 134     if (msi_per_vector_mask) {
 135         flags |= PCI_MSI_FLAGS_MASKBIT;
 136     }
 137
 138     cap_size = msi_cap_sizeof(flags);
 139     config_offset = pci_add_capability(dev, PCI_CAP_ID_MSI, offset, cap_size);
 140     if (config_offset < 0) {
 141         return config_offset;
 142     }
 143
 144     dev->msi_cap = config_offset;
 145     dev->cap_present |= QEMU_PCI_CAP_MSI;
 146
 147     pci_set_word(dev->config + msi_flags_off(dev), flags);
 148     pci_set_word(dev->wmask + msi_flags_off(dev),
 149                  PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);
 150     pci_set_long(dev->wmask + msi_address_lo_off(dev),
 151                  PCI_MSI_ADDRESS_LO_MASK);
 152     if (msi64bit) {
 153         pci_set_long(dev->wmask + msi_address_hi_off(dev), 0xffffffff);
 154     }
 155     pci_set_word(dev->wmask + msi_data_off(dev, msi64bit), 0xffff);
 156
 157     if (msi_per_vector_mask) {
 158         /* Make mask bits 0 to nr_vectors - 1 writable. */
 159         pci_set_long(dev->wmask + msi_mask_off(dev, msi64bit),
 160                      0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors));
 161     }
 162     return config_offset;
 163 }
 164
 165 void msi_uninit(struct PCIDevice *dev)
 166 {
 167     uint16_t flags;
 168     uint8_t cap_size;
 169
 170     if (!(dev->cap_present & QEMU_PCI_CAP_MSI)) {
 171         return;
 172     }
 173     flags = pci_get_word(dev->config + msi_flags_off(dev));
 174     cap_size = msi_cap_sizeof(flags);
 175     pci_del_capability(dev, PCI_CAP_ID_MSI, cap_size);
 176     dev->cap_present &= ~QEMU_PCI_CAP_MSI;
 177
 178     MSI_DEV_PRINTF(dev, "uninit\n");
 179 }
 180
 181 void msi_reset(PCIDevice *dev)
 182 {
 183     uint16_t flags;
 184     bool msi64bit;
 185
 186     flags = pci_get_word(dev->config + msi_flags_off(dev));
 187     flags &= ~(PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);
 188     msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 189
 190     pci_set_word(dev->config + msi_flags_off(dev), flags);
 191     pci_set_long(dev->config + msi_address_lo_off(dev), 0);
 192     if (msi64bit) {
 193         pci_set_long(dev->config + msi_address_hi_off(dev), 0);
 194     }
 195     pci_set_word(dev->config + msi_data_off(dev, msi64bit), 0);
 196     if (flags & PCI_MSI_FLAGS_MASKBIT) {
 197         pci_set_long(dev->config + msi_mask_off(dev, msi64bit), 0);
 198         pci_set_long(dev->config + msi_pending_off(dev, msi64bit), 0);
 199     }
 200     MSI_DEV_PRINTF(dev, "reset\n");
 201 }
 202
 203 static bool msi_is_masked(const PCIDevice *dev, unsigned int vector)
 204 {
 205     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 206     uint32_t mask;
 207     assert(vector < PCI_MSI_VECTORS_MAX);
 208
 209     if (!(flags & PCI_MSI_FLAGS_MASKBIT)) {
 210         return false;
 211     }
 212
 213     mask = pci_get_long(dev->config +
 214                         msi_mask_off(dev, flags & PCI_MSI_FLAGS_64BIT));
 215     return mask & (1U << vector);
 216 }
 217
 218 void msi_notify(PCIDevice *dev, unsigned int vector)
 219 {
 220     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 221     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 222     unsigned int nr_vectors = msi_nr_vectors(flags);
 223     uint64_t address;
 224     uint32_t data;
 225
 226     assert(vector < nr_vectors);
 227     if (msi_is_masked(dev, vector)) {
 228         assert(flags & PCI_MSI_FLAGS_MASKBIT);
 229         pci_long_test_and_set_mask(
 230             dev->config + msi_pending_off(dev, msi64bit), 1U << vector);
 231         MSI_DEV_PRINTF(dev, "pending vector 0x%x\n", vector);
 232         return;
 233     }
 234
 235     if (msi64bit) {
 236         address = pci_get_quad(dev->config + msi_address_lo_off(dev));
 237     } else {
 238         address = pci_get_long(dev->config + msi_address_lo_off(dev));
 239     }
 240
 241     /* upper bit 31:16 is zero */
 242     data = pci_get_word(dev->config + msi_data_off(dev, msi64bit));
 243     if (nr_vectors > 1) {
 244         data &= ~(nr_vectors - 1);
 245         data |= vector;
 246     }
 247
 248     MSI_DEV_PRINTF(dev,
 249                    "notify vector 0x%x"
 250                    " address: 0x%"PRIx64" data: 0x%"PRIx32"\n",
 251                    vector, address, data);
 252     stl_le_phys(address, data);
 253 }
 254
 255 /* call this function after updating configs by pci_default_write_config(). */
 256 void msi_write_config(PCIDevice *dev, uint32_t addr, uint32_t val, int len)
 257 {
 258     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 259     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 260     bool msi_per_vector_mask = flags & PCI_MSI_FLAGS_MASKBIT;
 261     unsigned int nr_vectors;
 262     uint8_t log_num_vecs;
 263     uint8_t log_max_vecs;
 264     unsigned int vector;
 265     uint32_t pending;
 266
 267     if (!ranges_overlap(addr, len, dev->msi_cap, msi_cap_sizeof(flags))) {
 268         return;
 269     }
 270
 271 #ifdef MSI_DEBUG
 272     MSI_DEV_PRINTF(dev, "addr 0x%"PRIx32" val 0x%"PRIx32" len %d\n",
 273                    addr, val, len);
 274     MSI_DEV_PRINTF(dev, "ctrl: 0x%"PRIx16" address: 0x%"PRIx32,
 275                    flags,
 276                    pci_get_long(dev->config + msi_address_lo_off(dev)));
 277     if (msi64bit) {
 278         fprintf(stderr, " address-hi: 0x%"PRIx32,
 279                 pci_get_long(dev->config + msi_address_hi_off(dev)));
 280     }
 281     fprintf(stderr, " data: 0x%"PRIx16,
 282             pci_get_word(dev->config + msi_data_off(dev, msi64bit)));
 283     if (flags & PCI_MSI_FLAGS_MASKBIT) {
 284         fprintf(stderr, " mask 0x%"PRIx32" pending 0x%"PRIx32,
 285                 pci_get_long(dev->config + msi_mask_off(dev, msi64bit)),
 286                 pci_get_long(dev->config + msi_pending_off(dev, msi64bit)));
 287     }
 288     fprintf(stderr, "\n");
 289 #endif
 290
 291     if (!(flags & PCI_MSI_FLAGS_ENABLE)) {
 292         return;
 293     }
 294
 295     /*
 296      * Now MSI is enabled, clear INTx# interrupts.
 297      * the driver is prohibited from writing enable bit to mask
 298      * a service request. But the guest OS could do this.
 299      * So we just discard the interrupts as moderate fallback.
 300      *
 301      * 6.8.3.3. Enabling Operation
 302      *   While enabled for MSI or MSI-X operation, a function is prohibited
 303      *   from using its INTx# pin (if implemented) to request
 304      *   service (MSI, MSI-X, and INTx# are mutually exclusive).
 305      */
 306     pci_device_deassert_intx(dev);
 307
 308     /*
 309      * nr_vectors might be set bigger than capable. So clamp it.
 310      * This is not legal by spec, so we can do anything we like,
 311      * just don't crash the host
 312      */
 313     log_num_vecs =
 314         (flags & PCI_MSI_FLAGS_QSIZE) >> (ffs(PCI_MSI_FLAGS_QSIZE) - 1);
 315     log_max_vecs =
 316         (flags & PCI_MSI_FLAGS_QMASK) >> (ffs(PCI_MSI_FLAGS_QMASK) - 1);
 317     if (log_num_vecs > log_max_vecs) {
 318         flags &= ~PCI_MSI_FLAGS_QSIZE;
 319         flags |= log_max_vecs << (ffs(PCI_MSI_FLAGS_QSIZE) - 1);
 320         pci_set_word(dev->config + msi_flags_off(dev), flags);
 321     }
 322
 323     if (!msi_per_vector_mask) {
 324         /* if per vector masking isn't supported,
 325            there is no pending interrupt. */
 326         return;
 327     }
 328
 329     nr_vectors = msi_nr_vectors(flags);
 330
 331     /* This will discard pending interrupts, if any. */
 332     pending = pci_get_long(dev->config + msi_pending_off(dev, msi64bit));
 333     pending &= 0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors);
 334     pci_set_long(dev->config + msi_pending_off(dev, msi64bit), pending);
 335
 336     /* deliver pending interrupts which are unmasked */
 337     for (vector = 0; vector < nr_vectors; ++vector) {
 338         if (msi_is_masked(dev, vector) || !(pending & (1U << vector))) {
 339             continue;
 340         }
 341
 342         pci_long_test_and_clear_mask(
 343             dev->config + msi_pending_off(dev, msi64bit), 1U << vector);
 344         msi_notify(dev, vector);
 345     }
 346 }
 347
 348 unsigned int msi_nr_vectors_allocated(const PCIDevice *dev)
 349 {
 350     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 351     return msi_nr_vectors(flags);
 352 }