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 writeable. */
 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 = pci_get_word(dev->config + msi_flags_off(dev));
 168     uint8_t cap_size = msi_cap_sizeof(flags);
 169     pci_del_capability(dev, PCI_CAP_ID_MSIX, cap_size);
 170     MSI_DEV_PRINTF(dev, "uninit\n");
 171 }
 172
 173 void msi_reset(PCIDevice *dev)
 174 {
 175     uint16_t flags;
 176     bool msi64bit;
 177
 178     flags = pci_get_word(dev->config + msi_flags_off(dev));
 179     flags &= ~(PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);
 180     msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 181
 182     pci_set_word(dev->config + msi_flags_off(dev), flags);
 183     pci_set_long(dev->config + msi_address_lo_off(dev), 0);
 184     if (msi64bit) {
 185         pci_set_long(dev->config + msi_address_hi_off(dev), 0);
 186     }
 187     pci_set_word(dev->config + msi_data_off(dev, msi64bit), 0);
 188     if (flags & PCI_MSI_FLAGS_MASKBIT) {
 189         pci_set_long(dev->config + msi_mask_off(dev, msi64bit), 0);
 190         pci_set_long(dev->config + msi_pending_off(dev, msi64bit), 0);
 191     }
 192     MSI_DEV_PRINTF(dev, "reset\n");
 193 }
 194
 195 static bool msi_is_masked(const PCIDevice *dev, unsigned int vector)
 196 {
 197     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 198     uint32_t mask;
 199     assert(vector < PCI_MSI_VECTORS_MAX);
 200
 201     if (!(flags & PCI_MSI_FLAGS_MASKBIT)) {
 202         return false;
 203     }
 204
 205     mask = pci_get_long(dev->config +
 206                         msi_mask_off(dev, flags & PCI_MSI_FLAGS_64BIT));
 207     return mask & (1U << vector);
 208 }
 209
 210 void msi_notify(PCIDevice *dev, unsigned int vector)
 211 {
 212     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 213     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 214     unsigned int nr_vectors = msi_nr_vectors(flags);
 215     uint64_t address;
 216     uint32_t data;
 217
 218     assert(vector < nr_vectors);
 219     if (msi_is_masked(dev, vector)) {
 220         assert(flags & PCI_MSI_FLAGS_MASKBIT);
 221         pci_long_test_and_set_mask(
 222             dev->config + msi_pending_off(dev, msi64bit), 1U << vector);
 223         MSI_DEV_PRINTF(dev, "pending vector 0x%x\n", vector);
 224         return;
 225     }
 226
 227     if (msi64bit) {
 228         address = pci_get_quad(dev->config + msi_address_lo_off(dev));
 229     } else {
 230         address = pci_get_long(dev->config + msi_address_lo_off(dev));
 231     }
 232
 233     /* upper bit 31:16 is zero */
 234     data = pci_get_word(dev->config + msi_data_off(dev, msi64bit));
 235     if (nr_vectors > 1) {
 236         data &= ~(nr_vectors - 1);
 237         data |= vector;
 238     }
 239
 240     MSI_DEV_PRINTF(dev,
 241                    "notify vector 0x%x"
 242                    " address: 0x%"PRIx64" data: 0x%"PRIx32"\n",
 243                    vector, address, data);
 244     stl_phys(address, data);
 245 }
 246
 247 /* call this function after updating configs by pci_default_write_config(). */
 248 void msi_write_config(PCIDevice *dev, uint32_t addr, uint32_t val, int len)
 249 {
 250     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 251     bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
 252     bool msi_per_vector_mask = flags & PCI_MSI_FLAGS_MASKBIT;
 253     unsigned int nr_vectors;
 254     uint8_t log_num_vecs;
 255     uint8_t log_max_vecs;
 256     unsigned int vector;
 257     uint32_t pending;
 258
 259     if (!ranges_overlap(addr, len, dev->msi_cap, msi_cap_sizeof(flags))) {
 260         return;
 261     }
 262
 263 #ifdef MSI_DEBUG
 264     MSI_DEV_PRINTF(dev, "addr 0x%"PRIx32" val 0x%"PRIx32" len %d\n",
 265                    addr, val, len);
 266     MSI_DEV_PRINTF(dev, "ctrl: 0x%"PRIx16" address: 0x%"PRIx32,
 267                    flags,
 268                    pci_get_long(dev->config + msi_address_lo_off(dev)));
 269     if (msi64bit) {
 270         fprintf(stderr, " address-hi: 0x%"PRIx32,
 271                 pci_get_long(dev->config + msi_address_hi_off(dev)));
 272     }
 273     fprintf(stderr, " data: 0x%"PRIx16,
 274             pci_get_word(dev->config + msi_data_off(dev, msi64bit)));
 275     if (flags & PCI_MSI_FLAGS_MASKBIT) {
 276         fprintf(stderr, " mask 0x%"PRIx32" pending 0x%"PRIx32,
 277                 pci_get_long(dev->config + msi_mask_off(dev, msi64bit)),
 278                 pci_get_long(dev->config + msi_pending_off(dev, msi64bit)));
 279     }
 280     fprintf(stderr, "\n");
 281 #endif
 282
 283     if (!(flags & PCI_MSI_FLAGS_ENABLE)) {
 284         return;
 285     }
 286
 287     /*
 288      * Now MSI is enabled, clear INTx# interrupts.
 289      * the driver is prohibited from writing enable bit to mask
 290      * a service request. But the guest OS could do this.
 291      * So we just discard the interrupts as moderate fallback.
 292      *
 293      * 6.8.3.3. Enabling Operation
 294      *   While enabled for MSI or MSI-X operation, a function is prohibited
 295      *   from using its INTx# pin (if implemented) to request
 296      *   service (MSI, MSI-X, and INTx# are mutually exclusive).
 297      */
 298     pci_device_deassert_intx(dev);
 299
 300     /*
 301      * nr_vectors might be set bigger than capable. So clamp it.
 302      * This is not legal by spec, so we can do anything we like,
 303      * just don't crash the host
 304      */
 305     log_num_vecs =
 306         (flags & PCI_MSI_FLAGS_QSIZE) >> (ffs(PCI_MSI_FLAGS_QSIZE) - 1);
 307     log_max_vecs =
 308         (flags & PCI_MSI_FLAGS_QMASK) >> (ffs(PCI_MSI_FLAGS_QMASK) - 1);
 309     if (log_num_vecs > log_max_vecs) {
 310         flags &= ~PCI_MSI_FLAGS_QSIZE;
 311         flags |= log_max_vecs << (ffs(PCI_MSI_FLAGS_QSIZE) - 1);
 312         pci_set_word(dev->config + msi_flags_off(dev), flags);
 313     }
 314
 315     if (!msi_per_vector_mask) {
 316         /* if per vector masking isn't supported,
 317            there is no pending interrupt. */
 318         return;
 319     }
 320
 321     nr_vectors = msi_nr_vectors(flags);
 322
 323     /* This will discard pending interrupts, if any. */
 324     pending = pci_get_long(dev->config + msi_pending_off(dev, msi64bit));
 325     pending &= 0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors);
 326     pci_set_long(dev->config + msi_pending_off(dev, msi64bit), pending);
 327
 328     /* deliver pending interrupts which are unmasked */
 329     for (vector = 0; vector < nr_vectors; ++vector) {
 330         if (msi_is_masked(dev, vector) || !(pending & (1U << vector))) {
 331             continue;
 332         }
 333
 334         pci_long_test_and_clear_mask(
 335             dev->config + msi_pending_off(dev, msi64bit), 1U << vector);
 336         msi_notify(dev, vector);
 337     }
 338 }
 339
 340 unsigned int msi_nr_vectors_allocated(const PCIDevice *dev)
 341 {
 342     uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));
 343     return msi_nr_vectors(flags);
 344 }