sys/dev/virtio/mmio/virtio_mmio.c

   1 /*-
   2  * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
   3  * Copyright (c) 2014 The FreeBSD Foundation
   4  * All rights reserved.
   5  *
   6  * This software was developed by SRI International and the University of
   7  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
   8  * ("CTSRD"), as part of the DARPA CRASH research programme.
   9  *
  10  * Portions of this software were developed by Andrew Turner
  11  * under sponsorship from the FreeBSD Foundation.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 /*
  36  * VirtIO MMIO interface.
  37  * This driver is heavily based on VirtIO PCI interface driver.
  38  */
  39
  40 /*
  41  * FDT example:
  42  *              virtio_block@1000 {
  43  *                      compatible = "virtio,mmio";
  44  *                      reg = <0x1000 0x100>;
  45  *                      interrupts = <63>;
  46  *                      interrupt-parent = <&GIC>;
  47  *              };
  48  */
  49
  50 #include <sys/cdefs.h>
  51 __FBSDID("$FreeBSD$");
  52
  53 #include <sys/param.h>
  54 #include <sys/systm.h>
  55 #include <sys/bus.h>
  56 #include <sys/kernel.h>
  57 #include <sys/module.h>
  58 #include <sys/malloc.h>
  59 #include <sys/rman.h>
  60
  61 #include <machine/bus.h>
  62 #include <machine/resource.h>
  63
  64 #include <dev/fdt/fdt_common.h>
  65 #include <dev/ofw/openfirm.h>
  66 #include <dev/ofw/ofw_bus.h>
  67 #include <dev/ofw/ofw_bus_subr.h>
  68
  69 #include <dev/virtio/virtio.h>
  70 #include <dev/virtio/virtqueue.h>
  71 #include <dev/virtio/mmio/virtio_mmio.h>
  72
  73 #include "virtio_mmio_if.h"
  74 #include "virtio_bus_if.h"
  75 #include "virtio_if.h"
  76
  77 #define PAGE_SHIFT      12
  78
  79 struct vtmmio_virtqueue {
  80         struct virtqueue        *vtv_vq;
  81         int                      vtv_no_intr;
  82 };
  83
  84 struct vtmmio_softc {
  85         device_t                        dev;
  86         device_t                        platform;
  87         struct resource                 *res[2];
  88
  89         uint64_t                        vtmmio_features;
  90         uint32_t                        vtmmio_flags;
  91
  92         /* This "bus" will only ever have one child. */
  93         device_t                        vtmmio_child_dev;
  94         struct virtio_feature_desc      *vtmmio_child_feat_desc;
  95
  96         int                             vtmmio_nvqs;
  97         struct vtmmio_virtqueue         *vtmmio_vqs;
  98         void                            *ih;
  99 };
 100
 101 static int      vtmmio_probe(device_t);
 102 static int      vtmmio_attach(device_t);
 103 static int      vtmmio_detach(device_t);
 104 static int      vtmmio_suspend(device_t);
 105 static int      vtmmio_resume(device_t);
 106 static int      vtmmio_shutdown(device_t);
 107 static void     vtmmio_driver_added(device_t, driver_t *);
 108 static void     vtmmio_child_detached(device_t, device_t);
 109 static int      vtmmio_read_ivar(device_t, device_t, int, uintptr_t *);
 110 static int      vtmmio_write_ivar(device_t, device_t, int, uintptr_t);
 111 static uint64_t vtmmio_negotiate_features(device_t, uint64_t);
 112 static int      vtmmio_with_feature(device_t, uint64_t);
 113 static int      vtmmio_alloc_virtqueues(device_t, int, int,
 114                     struct vq_alloc_info *);
 115 static int      vtmmio_setup_intr(device_t, enum intr_type);
 116 static void     vtmmio_stop(device_t);
 117 static void     vtmmio_poll(device_t);
 118 static int      vtmmio_reinit(device_t, uint64_t);
 119 static void     vtmmio_reinit_complete(device_t);
 120 static void     vtmmio_notify_virtqueue(device_t, uint16_t);
 121 static uint8_t  vtmmio_get_status(device_t);
 122 static void     vtmmio_set_status(device_t, uint8_t);
 123 static void     vtmmio_read_dev_config(device_t, bus_size_t, void *, int);
 124 static void     vtmmio_write_dev_config(device_t, bus_size_t, void *, int);
 125 static void     vtmmio_describe_features(struct vtmmio_softc *, const char *,
 126                     uint64_t);
 127 static void     vtmmio_probe_and_attach_child(struct vtmmio_softc *);
 128 static int      vtmmio_reinit_virtqueue(struct vtmmio_softc *, int);
 129 static void     vtmmio_free_interrupts(struct vtmmio_softc *);
 130 static void     vtmmio_free_virtqueues(struct vtmmio_softc *);
 131 static void     vtmmio_release_child_resources(struct vtmmio_softc *);
 132 static void     vtmmio_reset(struct vtmmio_softc *);
 133 static void     vtmmio_select_virtqueue(struct vtmmio_softc *, int);
 134 static void     vtmmio_vq_intr(void *);
 135
 136 /*
 137  * I/O port read/write wrappers.
 138  */
 139 #define vtmmio_write_config_1(sc, o, v)                         \
 140 do {                                                            \
 141         bus_write_1((sc)->res[0], (o), (v));                    \
 142         if (sc->platform != NULL)                               \
 143                 VIRTIO_MMIO_NOTE(sc->platform, (o), (v));       \
 144 } while (0)
 145 #define vtmmio_write_config_2(sc, o, v)                         \
 146 do {                                                            \
 147         bus_write_2((sc)->res[0], (o), (v));                    \
 148         if (sc->platform != NULL)                               \
 149                 VIRTIO_MMIO_NOTE(sc->platform, (o), (v));       \
 150 } while (0)
 151 #define vtmmio_write_config_4(sc, o, v)                         \
 152 do {                                                            \
 153         bus_write_4((sc)->res[0], (o), (v));                    \
 154         if (sc->platform != NULL)                               \
 155                 VIRTIO_MMIO_NOTE(sc->platform, (o), (v));       \
 156 } while (0)
 157
 158 #define vtmmio_read_config_1(sc, o) \
 159         bus_read_1((sc)->res[0], (o))
 160 #define vtmmio_read_config_2(sc, o) \
 161         bus_read_2((sc)->res[0], (o))
 162 #define vtmmio_read_config_4(sc, o) \
 163         bus_read_4((sc)->res[0], (o))
 164
 165 static device_method_t vtmmio_methods[] = {
 166         /* Device interface. */
 167         DEVMETHOD(device_probe,                   vtmmio_probe),
 168         DEVMETHOD(device_attach,                  vtmmio_attach),
 169         DEVMETHOD(device_detach,                  vtmmio_detach),
 170         DEVMETHOD(device_suspend,                 vtmmio_suspend),
 171         DEVMETHOD(device_resume,                  vtmmio_resume),
 172         DEVMETHOD(device_shutdown,                vtmmio_shutdown),
 173
 174         /* Bus interface. */
 175         DEVMETHOD(bus_driver_added,               vtmmio_driver_added),
 176         DEVMETHOD(bus_child_detached,             vtmmio_child_detached),
 177         DEVMETHOD(bus_read_ivar,                  vtmmio_read_ivar),
 178         DEVMETHOD(bus_write_ivar,                 vtmmio_write_ivar),
 179
 180         /* VirtIO bus interface. */
 181         DEVMETHOD(virtio_bus_negotiate_features,  vtmmio_negotiate_features),
 182         DEVMETHOD(virtio_bus_with_feature,        vtmmio_with_feature),
 183         DEVMETHOD(virtio_bus_alloc_virtqueues,    vtmmio_alloc_virtqueues),
 184         DEVMETHOD(virtio_bus_setup_intr,          vtmmio_setup_intr),
 185         DEVMETHOD(virtio_bus_stop,                vtmmio_stop),
 186         DEVMETHOD(virtio_bus_poll,                vtmmio_poll),
 187         DEVMETHOD(virtio_bus_reinit,              vtmmio_reinit),
 188         DEVMETHOD(virtio_bus_reinit_complete,     vtmmio_reinit_complete),
 189         DEVMETHOD(virtio_bus_notify_vq,           vtmmio_notify_virtqueue),
 190         DEVMETHOD(virtio_bus_read_device_config,  vtmmio_read_dev_config),
 191         DEVMETHOD(virtio_bus_write_device_config, vtmmio_write_dev_config),
 192
 193         DEVMETHOD_END
 194 };
 195
 196 static driver_t vtmmio_driver = {
 197         "virtio_mmio",
 198         vtmmio_methods,
 199         sizeof(struct vtmmio_softc)
 200 };
 201
 202 devclass_t vtmmio_devclass;
 203
 204 DRIVER_MODULE(virtio_mmio, simplebus, vtmmio_driver, vtmmio_devclass, 0, 0);
 205 DRIVER_MODULE(virtio_mmio, ofwbus, vtmmio_driver, vtmmio_devclass, 0, 0);
 206 MODULE_VERSION(virtio_mmio, 1);
 207 MODULE_DEPEND(virtio_mmio, simplebus, 1, 1, 1);
 208 MODULE_DEPEND(virtio_mmio, virtio, 1, 1, 1);
 209
 210 static int
 211 vtmmio_setup_intr(device_t dev, enum intr_type type)
 212 {
 213         struct vtmmio_softc *sc;
 214         int rid;
 215         int err;
 216
 217         sc = device_get_softc(dev);
 218
 219         if (sc->platform != NULL) {
 220                 err = VIRTIO_MMIO_SETUP_INTR(sc->platform, sc->dev,
 221                                         vtmmio_vq_intr, sc);
 222                 if (err == 0) {
 223                         /* Okay we have backend-specific interrupts */
 224                         return (0);
 225                 }
 226         }
 227
 228         rid = 0;
 229         sc->res[1] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
 230                 RF_ACTIVE);
 231         if (!sc->res[1]) {
 232                 device_printf(dev, "Can't allocate interrupt\n");
 233                 return (ENXIO);
 234         }
 235
 236         if (bus_setup_intr(dev, sc->res[1], INTR_TYPE_MISC | INTR_MPSAFE,
 237                 NULL, vtmmio_vq_intr, sc, &sc->ih)) {
 238                 device_printf(dev, "Can't setup the interrupt\n");
 239                 return (ENXIO);
 240         }
 241
 242         return (0);
 243 }
 244
 245 static int
 246 vtmmio_probe(device_t dev)
 247 {
 248
 249         if (!ofw_bus_status_okay(dev))
 250                 return (ENXIO);
 251
 252         if (!ofw_bus_is_compatible(dev, "virtio,mmio"))
 253                 return (ENXIO);
 254
 255         device_set_desc(dev, "VirtIO MMIO adapter");
 256         return (BUS_PROBE_DEFAULT);
 257 }
 258
 259 static int
 260 vtmmio_setup_platform(struct vtmmio_softc *sc)
 261 {
 262         phandle_t platform_node;
 263         struct fdt_ic *ic;
 264         phandle_t xref;
 265         phandle_t node;
 266
 267         sc->platform = NULL;
 268
 269         if ((node = ofw_bus_get_node(sc->dev)) == -1)
 270                 return (ENXIO);
 271
 272         if (OF_searchencprop(node, "platform", &xref,
 273                 sizeof(xref)) == -1) {
 274                 return (ENXIO);
 275         }
 276
 277         platform_node = OF_node_from_xref(xref);
 278
 279         SLIST_FOREACH(ic, &fdt_ic_list_head, fdt_ics) {
 280                 if (ic->iph == platform_node) {
 281                         sc->platform = ic->dev;
 282                         break;
 283                 }
 284         }
 285
 286         if (sc->platform == NULL) {
 287                 /* No platform-specific device. Ignore it. */
 288         }
 289
 290         return (0);
 291 }
 292
 293 static int
 294 vtmmio_attach(device_t dev)
 295 {
 296         struct vtmmio_softc *sc;
 297         device_t child;
 298         int rid;
 299
 300         sc = device_get_softc(dev);
 301         sc->dev = dev;
 302
 303         vtmmio_setup_platform(sc);
 304
 305         rid = 0;
 306         sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
 307                         RF_ACTIVE);
 308         if (!sc->res[0]) {
 309                 device_printf(dev, "Cannot allocate memory window.\n");
 310                 return (ENXIO);
 311         }
 312
 313         vtmmio_reset(sc);
 314
 315         /* Tell the host we've noticed this device. */
 316         vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
 317
 318         if ((child = device_add_child(dev, NULL, -1)) == NULL) {
 319                 device_printf(dev, "Cannot create child device.\n");
 320                 vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_FAILED);
 321                 vtmmio_detach(dev);
 322                 return (ENOMEM);
 323         }
 324
 325         sc->vtmmio_child_dev = child;
 326         vtmmio_probe_and_attach_child(sc);
 327
 328         return (0);
 329 }
 330
 331 static int
 332 vtmmio_detach(device_t dev)
 333 {
 334         struct vtmmio_softc *sc;
 335         device_t child;
 336         int error;
 337
 338         sc = device_get_softc(dev);
 339
 340         if ((child = sc->vtmmio_child_dev) != NULL) {
 341                 error = device_delete_child(dev, child);
 342                 if (error)
 343                         return (error);
 344                 sc->vtmmio_child_dev = NULL;
 345         }
 346
 347         vtmmio_reset(sc);
 348
 349         if (sc->res[0] != NULL) {
 350                 bus_release_resource(dev, SYS_RES_MEMORY, 0,
 351                     sc->res[0]);
 352                 sc->res[0] = NULL;
 353         }
 354
 355         return (0);
 356 }
 357
 358 static int
 359 vtmmio_suspend(device_t dev)
 360 {
 361
 362         return (bus_generic_suspend(dev));
 363 }
 364
 365 static int
 366 vtmmio_resume(device_t dev)
 367 {
 368
 369         return (bus_generic_resume(dev));
 370 }
 371
 372 static int
 373 vtmmio_shutdown(device_t dev)
 374 {
 375
 376         (void) bus_generic_shutdown(dev);
 377
 378         /* Forcibly stop the host device. */
 379         vtmmio_stop(dev);
 380
 381         return (0);
 382 }
 383
 384 static void
 385 vtmmio_driver_added(device_t dev, driver_t *driver)
 386 {
 387         struct vtmmio_softc *sc;
 388
 389         sc = device_get_softc(dev);
 390
 391         vtmmio_probe_and_attach_child(sc);
 392 }
 393
 394 static void
 395 vtmmio_child_detached(device_t dev, device_t child)
 396 {
 397         struct vtmmio_softc *sc;
 398
 399         sc = device_get_softc(dev);
 400
 401         vtmmio_reset(sc);
 402         vtmmio_release_child_resources(sc);
 403 }
 404
 405 static int
 406 vtmmio_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
 407 {
 408         struct vtmmio_softc *sc;
 409
 410         sc = device_get_softc(dev);
 411
 412         if (sc->vtmmio_child_dev != child)
 413                 return (ENOENT);
 414
 415         switch (index) {
 416         case VIRTIO_IVAR_DEVTYPE:
 417         case VIRTIO_IVAR_SUBDEVICE:
 418                 *result = vtmmio_read_config_4(sc, VIRTIO_MMIO_DEVICE_ID);
 419                 break;
 420         case VIRTIO_IVAR_VENDOR:
 421                 *result = vtmmio_read_config_4(sc, VIRTIO_MMIO_VENDOR_ID);
 422                 break;
 423         default:
 424                 return (ENOENT);
 425         }
 426
 427         return (0);
 428 }
 429
 430 static int
 431 vtmmio_write_ivar(device_t dev, device_t child, int index, uintptr_t value)
 432 {
 433         struct vtmmio_softc *sc;
 434
 435         sc = device_get_softc(dev);
 436
 437         if (sc->vtmmio_child_dev != child)
 438                 return (ENOENT);
 439
 440         switch (index) {
 441         case VIRTIO_IVAR_FEATURE_DESC:
 442                 sc->vtmmio_child_feat_desc = (void *) value;
 443                 break;
 444         default:
 445                 return (ENOENT);
 446         }
 447
 448         return (0);
 449 }
 450
 451 static uint64_t
 452 vtmmio_negotiate_features(device_t dev, uint64_t child_features)
 453 {
 454         struct vtmmio_softc *sc;
 455         uint64_t host_features, features;
 456
 457         sc = device_get_softc(dev);
 458
 459         host_features = vtmmio_read_config_4(sc, VIRTIO_MMIO_HOST_FEATURES);
 460         vtmmio_describe_features(sc, "host", host_features);
 461
 462         /*
 463          * Limit negotiated features to what the driver, virtqueue, and
 464          * host all support.
 465          */
 466         features = host_features & child_features;
 467         features = virtqueue_filter_features(features);
 468         sc->vtmmio_features = features;
 469
 470         vtmmio_describe_features(sc, "negotiated", features);
 471         vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES, features);
 472
 473         return (features);
 474 }
 475
 476 static int
 477 vtmmio_with_feature(device_t dev, uint64_t feature)
 478 {
 479         struct vtmmio_softc *sc;
 480
 481         sc = device_get_softc(dev);
 482
 483         return ((sc->vtmmio_features & feature) != 0);
 484 }
 485
 486 static int
 487 vtmmio_alloc_virtqueues(device_t dev, int flags, int nvqs,
 488     struct vq_alloc_info *vq_info)
 489 {
 490         struct vtmmio_virtqueue *vqx;
 491         struct vq_alloc_info *info;
 492         struct vtmmio_softc *sc;
 493         struct virtqueue *vq;
 494         uint32_t size;
 495         int idx, error;
 496
 497         sc = device_get_softc(dev);
 498
 499         if (sc->vtmmio_nvqs != 0)
 500                 return (EALREADY);
 501         if (nvqs <= 0)
 502                 return (EINVAL);
 503
 504         sc->vtmmio_vqs = malloc(nvqs * sizeof(struct vtmmio_virtqueue),
 505             M_DEVBUF, M_NOWAIT | M_ZERO);
 506         if (sc->vtmmio_vqs == NULL)
 507                 return (ENOMEM);
 508
 509         for (idx = 0; idx < nvqs; idx++) {
 510                 vqx = &sc->vtmmio_vqs[idx];
 511                 info = &vq_info[idx];
 512
 513                 vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_SEL, idx);
 514
 515                 vtmmio_select_virtqueue(sc, idx);
 516                 size = vtmmio_read_config_4(sc, VIRTIO_MMIO_QUEUE_NUM_MAX);
 517
 518                 error = virtqueue_alloc(dev, idx, size,
 519                     VIRTIO_MMIO_VRING_ALIGN, 0xFFFFFFFFUL, info, &vq);
 520                 if (error) {
 521                         device_printf(dev,
 522                             "cannot allocate virtqueue %d: %d\n",
 523                             idx, error);
 524                         break;
 525                 }
 526
 527                 vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_NUM, size);
 528                 vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_ALIGN,
 529                     VIRTIO_MMIO_VRING_ALIGN);
 530 #if 0
 531                 device_printf(dev, "virtqueue paddr 0x%08lx\n",
 532                                 (uint64_t)virtqueue_paddr(vq));
 533 #endif
 534                 vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_PFN,
 535                         virtqueue_paddr(vq) >> PAGE_SHIFT);
 536
 537                 vqx->vtv_vq = *info->vqai_vq = vq;
 538                 vqx->vtv_no_intr = info->vqai_intr == NULL;
 539
 540                 sc->vtmmio_nvqs++;
 541         }
 542
 543         if (error)
 544                 vtmmio_free_virtqueues(sc);
 545
 546         return (error);
 547 }
 548
 549 static void
 550 vtmmio_stop(device_t dev)
 551 {
 552
 553         vtmmio_reset(device_get_softc(dev));
 554 }
 555
 556 static void
 557 vtmmio_poll(device_t dev)
 558 {
 559         struct vtmmio_softc *sc;
 560
 561         sc = device_get_softc(dev);
 562
 563         if (sc->platform != NULL)
 564                 VIRTIO_MMIO_POLL(sc->platform);
 565 }
 566
 567 static int
 568 vtmmio_reinit(device_t dev, uint64_t features)
 569 {
 570         struct vtmmio_softc *sc;
 571         int idx, error;
 572
 573         sc = device_get_softc(dev);
 574
 575         if (vtmmio_get_status(dev) != VIRTIO_CONFIG_STATUS_RESET)
 576                 vtmmio_stop(dev);
 577
 578         /*
 579          * Quickly drive the status through ACK and DRIVER. The device
 580          * does not become usable again until vtmmio_reinit_complete().
 581          */
 582         vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
 583         vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER);
 584
 585         vtmmio_negotiate_features(dev, features);
 586
 587         for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
 588                 error = vtmmio_reinit_virtqueue(sc, idx);
 589                 if (error)
 590                         return (error);
 591         }
 592
 593         return (0);
 594 }
 595
 596 static void
 597 vtmmio_reinit_complete(device_t dev)
 598 {
 599
 600         vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
 601 }
 602
 603 static void
 604 vtmmio_notify_virtqueue(device_t dev, uint16_t queue)
 605 {
 606         struct vtmmio_softc *sc;
 607
 608         sc = device_get_softc(dev);
 609
 610         vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_NOTIFY, queue);
 611 }
 612
 613 static uint8_t
 614 vtmmio_get_status(device_t dev)
 615 {
 616         struct vtmmio_softc *sc;
 617
 618         sc = device_get_softc(dev);
 619
 620         return (vtmmio_read_config_4(sc, VIRTIO_MMIO_STATUS));
 621 }
 622
 623 static void
 624 vtmmio_set_status(device_t dev, uint8_t status)
 625 {
 626         struct vtmmio_softc *sc;
 627
 628         sc = device_get_softc(dev);
 629
 630         if (status != VIRTIO_CONFIG_STATUS_RESET)
 631                 status |= vtmmio_get_status(dev);
 632
 633         vtmmio_write_config_4(sc, VIRTIO_MMIO_STATUS, status);
 634 }
 635
 636 static void
 637 vtmmio_read_dev_config(device_t dev, bus_size_t offset,
 638     void *dst, int length)
 639 {
 640         struct vtmmio_softc *sc;
 641         bus_size_t off;
 642         uint8_t *d;
 643         int size;
 644
 645         sc = device_get_softc(dev);
 646         off = VIRTIO_MMIO_CONFIG + offset;
 647
 648         for (d = dst; length > 0; d += size, off += size, length -= size) {
 649 #ifdef ALLOW_WORD_ALIGNED_ACCESS
 650                 if (length >= 4) {
 651                         size = 4;
 652                         *(uint32_t *)d = vtmmio_read_config_4(sc, off);
 653                 } else if (length >= 2) {
 654                         size = 2;
 655                         *(uint16_t *)d = vtmmio_read_config_2(sc, off);
 656                 } else
 657 #endif
 658                 {
 659                         size = 1;
 660                         *d = vtmmio_read_config_1(sc, off);
 661                 }
 662         }
 663 }
 664
 665 static void
 666 vtmmio_write_dev_config(device_t dev, bus_size_t offset,
 667     void *src, int length)
 668 {
 669         struct vtmmio_softc *sc;
 670         bus_size_t off;
 671         uint8_t *s;
 672         int size;
 673
 674         sc = device_get_softc(dev);
 675         off = VIRTIO_MMIO_CONFIG + offset;
 676
 677         for (s = src; length > 0; s += size, off += size, length -= size) {
 678 #ifdef ALLOW_WORD_ALIGNED_ACCESS
 679                 if (length >= 4) {
 680                         size = 4;
 681                         vtmmio_write_config_4(sc, off, *(uint32_t *)s);
 682                 } else if (length >= 2) {
 683                         size = 2;
 684                         vtmmio_write_config_2(sc, off, *(uint16_t *)s);
 685                 } else
 686 #endif
 687                 {
 688                         size = 1;
 689                         vtmmio_write_config_1(sc, off, *s);
 690                 }
 691         }
 692 }
 693
 694 static void
 695 vtmmio_describe_features(struct vtmmio_softc *sc, const char *msg,
 696     uint64_t features)
 697 {
 698         device_t dev, child;
 699
 700         dev = sc->dev;
 701         child = sc->vtmmio_child_dev;
 702
 703         if (device_is_attached(child) && bootverbose == 0)
 704                 return;
 705
 706         virtio_describe(dev, msg, features, sc->vtmmio_child_feat_desc);
 707 }
 708
 709 static void
 710 vtmmio_probe_and_attach_child(struct vtmmio_softc *sc)
 711 {
 712         device_t dev, child;
 713
 714         dev = sc->dev;
 715         child = sc->vtmmio_child_dev;
 716
 717         if (child == NULL)
 718                 return;
 719
 720         if (device_get_state(child) != DS_NOTPRESENT) {
 721                 return;
 722         }
 723
 724         if (device_probe(child) != 0) {
 725                 return;
 726         }
 727
 728         vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER);
 729         if (device_attach(child) != 0) {
 730                 vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_FAILED);
 731                 vtmmio_reset(sc);
 732                 vtmmio_release_child_resources(sc);
 733                 /* Reset status for future attempt. */
 734                 vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
 735         } else {
 736                 vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
 737                 VIRTIO_ATTACH_COMPLETED(child);
 738         }
 739 }
 740
 741 static int
 742 vtmmio_reinit_virtqueue(struct vtmmio_softc *sc, int idx)
 743 {
 744         struct vtmmio_virtqueue *vqx;
 745         struct virtqueue *vq;
 746         int error;
 747         uint16_t size;
 748
 749         vqx = &sc->vtmmio_vqs[idx];
 750         vq = vqx->vtv_vq;
 751
 752         KASSERT(vq != NULL, ("%s: vq %d not allocated", __func__, idx));
 753
 754         vtmmio_select_virtqueue(sc, idx);
 755         size = vtmmio_read_config_4(sc, VIRTIO_MMIO_QUEUE_NUM_MAX);
 756
 757         error = virtqueue_reinit(vq, size);
 758         if (error)
 759                 return (error);
 760
 761         vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_PFN,
 762             virtqueue_paddr(vq) >> PAGE_SHIFT);
 763
 764         return (0);
 765 }
 766
 767 static void
 768 vtmmio_free_interrupts(struct vtmmio_softc *sc)
 769 {
 770
 771         if (sc->ih != NULL)
 772                 bus_teardown_intr(sc->dev, sc->res[1], sc->ih);
 773
 774         if (sc->res[1] != NULL)
 775                 bus_release_resource(sc->dev, SYS_RES_IRQ, 0, sc->res[1]);
 776 }
 777
 778 static void
 779 vtmmio_free_virtqueues(struct vtmmio_softc *sc)
 780 {
 781         struct vtmmio_virtqueue *vqx;
 782         int idx;
 783
 784         for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
 785                 vqx = &sc->vtmmio_vqs[idx];
 786
 787                 vtmmio_select_virtqueue(sc, idx);
 788                 vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_PFN, 0);
 789
 790                 virtqueue_free(vqx->vtv_vq);
 791                 vqx->vtv_vq = NULL;
 792         }
 793
 794         free(sc->vtmmio_vqs, M_DEVBUF);
 795         sc->vtmmio_vqs = NULL;
 796         sc->vtmmio_nvqs = 0;
 797 }
 798
 799 static void
 800 vtmmio_release_child_resources(struct vtmmio_softc *sc)
 801 {
 802
 803         vtmmio_free_interrupts(sc);
 804         vtmmio_free_virtqueues(sc);
 805 }
 806
 807 static void
 808 vtmmio_reset(struct vtmmio_softc *sc)
 809 {
 810
 811         /*
 812          * Setting the status to RESET sets the host device to
 813          * the original, uninitialized state.
 814          */
 815         vtmmio_set_status(sc->dev, VIRTIO_CONFIG_STATUS_RESET);
 816 }
 817
 818 static void
 819 vtmmio_select_virtqueue(struct vtmmio_softc *sc, int idx)
 820 {
 821
 822         vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_SEL, idx);
 823 }
 824
 825 static void
 826 vtmmio_vq_intr(void *arg)
 827 {
 828         struct vtmmio_virtqueue *vqx;
 829         struct vtmmio_softc *sc;
 830         struct virtqueue *vq;
 831         uint32_t status;
 832         int idx;
 833
 834         sc = arg;
 835
 836         status = vtmmio_read_config_4(sc, VIRTIO_MMIO_INTERRUPT_STATUS);
 837         vtmmio_write_config_4(sc, VIRTIO_MMIO_INTERRUPT_ACK, status);
 838
 839         /* The config changed */
 840         if (status & VIRTIO_MMIO_INT_CONFIG)
 841                 if (sc->vtmmio_child_dev != NULL)
 842                         VIRTIO_CONFIG_CHANGE(sc->vtmmio_child_dev);
 843
 844         /* Notify all virtqueues. */
 845         if (status & VIRTIO_MMIO_INT_VRING) {
 846                 for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
 847                         vqx = &sc->vtmmio_vqs[idx];
 848                         if (vqx->vtv_no_intr == 0) {
 849                                 vq = vqx->vtv_vq;
 850                                 virtqueue_intr(vq);
 851                         }
 852                 }
 853         }
 854 }