drivers/remoteproc/remoteproc_virtio.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Remote processor messaging transport (OMAP platform-specific bits)
   4  *
   5  * Copyright (C) 2011 Texas Instruments, Inc.
   6  * Copyright (C) 2011 Google, Inc.
   7  *
   8  * Ohad Ben-Cohen <ohad@wizery.com>
   9  * Brian Swetland <swetland@google.com>
  10  */
  11
  12 #include <linux/dma-direct.h>
  13 #include <linux/dma-map-ops.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/export.h>
  16 #include <linux/of_reserved_mem.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/remoteproc.h>
  19 #include <linux/virtio.h>
  20 #include <linux/virtio_config.h>
  21 #include <linux/virtio_ids.h>
  22 #include <linux/virtio_ring.h>
  23 #include <linux/err.h>
  24 #include <linux/kref.h>
  25 #include <linux/slab.h>
  26
  27 #include "remoteproc_internal.h"
  28
  29 static int copy_dma_range_map(struct device *to, struct device *from)
  30 {
  31         const struct bus_dma_region *map = from->dma_range_map, *new_map, *r;
  32         int num_ranges = 0;
  33
  34         if (!map)
  35                 return 0;
  36
  37         for (r = map; r->size; r++)
  38                 num_ranges++;
  39
  40         new_map = kmemdup(map, array_size(num_ranges + 1, sizeof(*map)),
  41                           GFP_KERNEL);
  42         if (!new_map)
  43                 return -ENOMEM;
  44         to->dma_range_map = new_map;
  45         return 0;
  46 }
  47
  48 static struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
  49 {
  50         struct platform_device *pdev;
  51
  52         pdev = container_of(vdev->dev.parent, struct platform_device, dev);
  53
  54         return platform_get_drvdata(pdev);
  55 }
  56
  57 static  struct rproc *vdev_to_rproc(struct virtio_device *vdev)
  58 {
  59         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
  60
  61         return rvdev->rproc;
  62 }
  63
  64 /* kick the remote processor, and let it know which virtqueue to poke at */
  65 static bool rproc_virtio_notify(struct virtqueue *vq)
  66 {
  67         struct rproc_vring *rvring = vq->priv;
  68         struct rproc *rproc = rvring->rvdev->rproc;
  69         int notifyid = rvring->notifyid;
  70
  71         dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);
  72
  73         rproc->ops->kick(rproc, notifyid);
  74         return true;
  75 }
  76
  77 /**
  78  * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
  79  * @rproc: handle to the remote processor
  80  * @notifyid: index of the signalled virtqueue (unique per this @rproc)
  81  *
  82  * This function should be called by the platform-specific rproc driver,
  83  * when the remote processor signals that a specific virtqueue has pending
  84  * messages available.
  85  *
  86  * Return: IRQ_NONE if no message was found in the @notifyid virtqueue,
  87  * and otherwise returns IRQ_HANDLED.
  88  */
  89 irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
  90 {
  91         struct rproc_vring *rvring;
  92
  93         dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid);
  94
  95         rvring = idr_find(&rproc->notifyids, notifyid);
  96         if (!rvring || !rvring->vq)
  97                 return IRQ_NONE;
  98
  99         return vring_interrupt(0, rvring->vq);
 100 }
 101 EXPORT_SYMBOL(rproc_vq_interrupt);
 102
 103 static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
 104                                     unsigned int id,
 105                                     void (*callback)(struct virtqueue *vq),
 106                                     const char *name, bool ctx)
 107 {
 108         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 109         struct rproc *rproc = vdev_to_rproc(vdev);
 110         struct device *dev = &rproc->dev;
 111         struct rproc_mem_entry *mem;
 112         struct rproc_vring *rvring;
 113         struct fw_rsc_vdev *rsc;
 114         struct virtqueue *vq;
 115         void *addr;
 116         int num, size;
 117
 118         /* we're temporarily limited to two virtqueues per rvdev */
 119         if (id >= ARRAY_SIZE(rvdev->vring))
 120                 return ERR_PTR(-EINVAL);
 121
 122         if (!name)
 123                 return NULL;
 124
 125         /* Search allocated memory region by name */
 126         mem = rproc_find_carveout_by_name(rproc, "vdev%dvring%d", rvdev->index,
 127                                           id);
 128         if (!mem || !mem->va)
 129                 return ERR_PTR(-ENOMEM);
 130
 131         rvring = &rvdev->vring[id];
 132         addr = mem->va;
 133         num = rvring->num;
 134
 135         /* zero vring */
 136         size = vring_size(num, rvring->align);
 137         memset(addr, 0, size);
 138
 139         dev_dbg(dev, "vring%d: va %pK qsz %d notifyid %d\n",
 140                 id, addr, num, rvring->notifyid);
 141
 142         /*
 143          * Create the new vq, and tell virtio we're not interested in
 144          * the 'weak' smp barriers, since we're talking with a real device.
 145          */
 146         vq = vring_new_virtqueue(id, num, rvring->align, vdev, false, ctx,
 147                                  addr, rproc_virtio_notify, callback, name);
 148         if (!vq) {
 149                 dev_err(dev, "vring_new_virtqueue %s failed\n", name);
 150                 rproc_free_vring(rvring);
 151                 return ERR_PTR(-ENOMEM);
 152         }
 153
 154         vq->num_max = num;
 155
 156         rvring->vq = vq;
 157         vq->priv = rvring;
 158
 159         /* Update vring in resource table */
 160         rsc = (void *)rproc->table_ptr + rvdev->rsc_offset;
 161         rsc->vring[id].da = mem->da;
 162
 163         return vq;
 164 }
 165
 166 static void __rproc_virtio_del_vqs(struct virtio_device *vdev)
 167 {
 168         struct virtqueue *vq, *n;
 169         struct rproc_vring *rvring;
 170
 171         list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 172                 rvring = vq->priv;
 173                 rvring->vq = NULL;
 174                 vring_del_virtqueue(vq);
 175         }
 176 }
 177
 178 static void rproc_virtio_del_vqs(struct virtio_device *vdev)
 179 {
 180         __rproc_virtio_del_vqs(vdev);
 181 }
 182
 183 static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
 184                                  struct virtqueue *vqs[],
 185                                  struct virtqueue_info vqs_info[],
 186                                  struct irq_affinity *desc)
 187 {
 188         int i, ret, queue_idx = 0;
 189
 190         for (i = 0; i < nvqs; ++i) {
 191                 struct virtqueue_info *vqi = &vqs_info[i];
 192
 193                 if (!vqi->name) {
 194                         vqs[i] = NULL;
 195                         continue;
 196                 }
 197
 198                 vqs[i] = rp_find_vq(vdev, queue_idx++, vqi->callback,
 199                                     vqi->name, vqi->ctx);
 200                 if (IS_ERR(vqs[i])) {
 201                         ret = PTR_ERR(vqs[i]);
 202                         goto error;
 203                 }
 204         }
 205
 206         return 0;
 207
 208 error:
 209         __rproc_virtio_del_vqs(vdev);
 210         return ret;
 211 }
 212
 213 static u8 rproc_virtio_get_status(struct virtio_device *vdev)
 214 {
 215         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 216         struct fw_rsc_vdev *rsc;
 217
 218         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 219
 220         return rsc->status;
 221 }
 222
 223 static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
 224 {
 225         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 226         struct fw_rsc_vdev *rsc;
 227
 228         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 229
 230         rsc->status = status;
 231         dev_dbg(&vdev->dev, "status: %d\n", status);
 232 }
 233
 234 static void rproc_virtio_reset(struct virtio_device *vdev)
 235 {
 236         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 237         struct fw_rsc_vdev *rsc;
 238
 239         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 240
 241         rsc->status = 0;
 242         dev_dbg(&vdev->dev, "reset !\n");
 243 }
 244
 245 /* provide the vdev features as retrieved from the firmware */
 246 static u64 rproc_virtio_get_features(struct virtio_device *vdev)
 247 {
 248         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 249         struct fw_rsc_vdev *rsc;
 250
 251         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 252
 253         return rsc->dfeatures;
 254 }
 255
 256 static void rproc_transport_features(struct virtio_device *vdev)
 257 {
 258         /*
 259          * Packed ring isn't enabled on remoteproc for now,
 260          * because remoteproc uses vring_new_virtqueue() which
 261          * creates virtio rings on preallocated memory.
 262          */
 263         __virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED);
 264 }
 265
 266 static int rproc_virtio_finalize_features(struct virtio_device *vdev)
 267 {
 268         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 269         struct fw_rsc_vdev *rsc;
 270
 271         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 272
 273         /* Give virtio_ring a chance to accept features */
 274         vring_transport_features(vdev);
 275
 276         /* Give virtio_rproc a chance to accept features. */
 277         rproc_transport_features(vdev);
 278
 279         /* Make sure we don't have any features > 32 bits! */
 280         BUG_ON((u32)vdev->features != vdev->features);
 281
 282         /*
 283          * Remember the finalized features of our vdev, and provide it
 284          * to the remote processor once it is powered on.
 285          */
 286         rsc->gfeatures = vdev->features;
 287
 288         return 0;
 289 }
 290
 291 static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset,
 292                              void *buf, unsigned int len)
 293 {
 294         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 295         struct fw_rsc_vdev *rsc;
 296         void *cfg;
 297
 298         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 299         cfg = &rsc->vring[rsc->num_of_vrings];
 300
 301         if (offset + len > rsc->config_len || offset + len < len) {
 302                 dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n");
 303                 return;
 304         }
 305
 306         memcpy(buf, cfg + offset, len);
 307 }
 308
 309 static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset,
 310                              const void *buf, unsigned int len)
 311 {
 312         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 313         struct fw_rsc_vdev *rsc;
 314         void *cfg;
 315
 316         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 317         cfg = &rsc->vring[rsc->num_of_vrings];
 318
 319         if (offset + len > rsc->config_len || offset + len < len) {
 320                 dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n");
 321                 return;
 322         }
 323
 324         memcpy(cfg + offset, buf, len);
 325 }
 326
 327 static const struct virtio_config_ops rproc_virtio_config_ops = {
 328         .get_features   = rproc_virtio_get_features,
 329         .finalize_features = rproc_virtio_finalize_features,
 330         .find_vqs       = rproc_virtio_find_vqs,
 331         .del_vqs        = rproc_virtio_del_vqs,
 332         .reset          = rproc_virtio_reset,
 333         .set_status     = rproc_virtio_set_status,
 334         .get_status     = rproc_virtio_get_status,
 335         .get            = rproc_virtio_get,
 336         .set            = rproc_virtio_set,
 337 };
 338
 339 /*
 340  * This function is called whenever vdev is released, and is responsible
 341  * to decrement the remote processor's refcount which was taken when vdev was
 342  * added.
 343  *
 344  * Never call this function directly; it will be called by the driver
 345  * core when needed.
 346  */
 347 static void rproc_virtio_dev_release(struct device *dev)
 348 {
 349         struct virtio_device *vdev = dev_to_virtio(dev);
 350         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 351
 352         kfree(vdev);
 353
 354         of_reserved_mem_device_release(&rvdev->pdev->dev);
 355         dma_release_coherent_memory(&rvdev->pdev->dev);
 356
 357         put_device(&rvdev->pdev->dev);
 358 }
 359
 360 /**
 361  * rproc_add_virtio_dev() - register an rproc-induced virtio device
 362  * @rvdev: the remote vdev
 363  * @id: the device type identification (used to match it with a driver).
 364  *
 365  * This function registers a virtio device. This vdev's partent is
 366  * the rproc device.
 367  *
 368  * Return: 0 on success or an appropriate error value otherwise
 369  */
 370 static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
 371 {
 372         struct rproc *rproc = rvdev->rproc;
 373         struct device *dev = &rvdev->pdev->dev;
 374         struct virtio_device *vdev;
 375         struct rproc_mem_entry *mem;
 376         int ret;
 377
 378         if (rproc->ops->kick == NULL) {
 379                 ret = -EINVAL;
 380                 dev_err(dev, ".kick method not defined for %s\n", rproc->name);
 381                 goto out;
 382         }
 383
 384         /* Try to find dedicated vdev buffer carveout */
 385         mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
 386         if (mem) {
 387                 phys_addr_t pa;
 388
 389                 if (mem->of_resm_idx != -1) {
 390                         struct device_node *np = rproc->dev.parent->of_node;
 391
 392                         /* Associate reserved memory to vdev device */
 393                         ret = of_reserved_mem_device_init_by_idx(dev, np,
 394                                                                  mem->of_resm_idx);
 395                         if (ret) {
 396                                 dev_err(dev, "Can't associate reserved memory\n");
 397                                 goto out;
 398                         }
 399                 } else {
 400                         if (mem->va) {
 401                                 dev_warn(dev, "vdev %d buffer already mapped\n",
 402                                          rvdev->index);
 403                                 pa = rproc_va_to_pa(mem->va);
 404                         } else {
 405                                 /* Use dma address as carveout no memmapped yet */
 406                                 pa = (phys_addr_t)mem->dma;
 407                         }
 408
 409                         /* Associate vdev buffer memory pool to vdev subdev */
 410                         ret = dma_declare_coherent_memory(dev, pa,
 411                                                            mem->da,
 412                                                            mem->len);
 413                         if (ret < 0) {
 414                                 dev_err(dev, "Failed to associate buffer\n");
 415                                 goto out;
 416                         }
 417                 }
 418         } else {
 419                 struct device_node *np = rproc->dev.parent->of_node;
 420
 421                 /*
 422                  * If we don't have dedicated buffer, just attempt to re-assign
 423                  * the reserved memory from our parent. A default memory-region
 424                  * at index 0 from the parent's memory-regions is assigned for
 425                  * the rvdev dev to allocate from. Failure is non-critical and
 426                  * the allocations will fall back to global pools, so don't
 427                  * check return value either.
 428                  */
 429                 of_reserved_mem_device_init_by_idx(dev, np, 0);
 430         }
 431
 432         /* Allocate virtio device */
 433         vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
 434         if (!vdev) {
 435                 ret = -ENOMEM;
 436                 goto out;
 437         }
 438         vdev->id.device = id,
 439         vdev->config = &rproc_virtio_config_ops,
 440         vdev->dev.parent = dev;
 441         vdev->dev.release = rproc_virtio_dev_release;
 442
 443         /* Reference the vdev and vring allocations */
 444         get_device(dev);
 445
 446         ret = register_virtio_device(vdev);
 447         if (ret) {
 448                 put_device(&vdev->dev);
 449                 dev_err(dev, "failed to register vdev: %d\n", ret);
 450                 goto out;
 451         }
 452
 453         dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);
 454
 455 out:
 456         return ret;
 457 }
 458
 459 /**
 460  * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
 461  * @dev: the virtio device
 462  * @data: must be null
 463  *
 464  * This function unregisters an existing virtio device.
 465  *
 466  * Return: 0
 467  */
 468 static int rproc_remove_virtio_dev(struct device *dev, void *data)
 469 {
 470         struct virtio_device *vdev = dev_to_virtio(dev);
 471
 472         unregister_virtio_device(vdev);
 473         return 0;
 474 }
 475
 476 static int rproc_vdev_do_start(struct rproc_subdev *subdev)
 477 {
 478         struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
 479
 480         return rproc_add_virtio_dev(rvdev, rvdev->id);
 481 }
 482
 483 static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
 484 {
 485         struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
 486         struct device *dev = &rvdev->pdev->dev;
 487         int ret;
 488
 489         ret = device_for_each_child(dev, NULL, rproc_remove_virtio_dev);
 490         if (ret)
 491                 dev_warn(dev, "can't remove vdev child device: %d\n", ret);
 492 }
 493
 494 static int rproc_virtio_probe(struct platform_device *pdev)
 495 {
 496         struct device *dev = &pdev->dev;
 497         struct rproc_vdev_data *rvdev_data = dev->platform_data;
 498         struct rproc_vdev *rvdev;
 499         struct rproc *rproc = container_of(dev->parent, struct rproc, dev);
 500         struct fw_rsc_vdev *rsc;
 501         int i, ret;
 502
 503         if (!rvdev_data)
 504                 return -EINVAL;
 505
 506         rvdev = devm_kzalloc(dev, sizeof(*rvdev), GFP_KERNEL);
 507         if (!rvdev)
 508                 return -ENOMEM;
 509
 510         rvdev->id = rvdev_data->id;
 511         rvdev->rproc = rproc;
 512         rvdev->index = rvdev_data->index;
 513
 514         ret = copy_dma_range_map(dev, rproc->dev.parent);
 515         if (ret)
 516                 return ret;
 517
 518         /* Make device dma capable by inheriting from parent's capabilities */
 519         set_dma_ops(dev, get_dma_ops(rproc->dev.parent));
 520
 521         ret = dma_coerce_mask_and_coherent(dev, dma_get_mask(rproc->dev.parent));
 522         if (ret) {
 523                 dev_warn(dev, "Failed to set DMA mask %llx. Trying to continue... (%pe)\n",
 524                          dma_get_mask(rproc->dev.parent), ERR_PTR(ret));
 525         }
 526
 527         platform_set_drvdata(pdev, rvdev);
 528         rvdev->pdev = pdev;
 529
 530         rsc = rvdev_data->rsc;
 531
 532         /* parse the vrings */
 533         for (i = 0; i < rsc->num_of_vrings; i++) {
 534                 ret = rproc_parse_vring(rvdev, rsc, i);
 535                 if (ret)
 536                         return ret;
 537         }
 538
 539         /* remember the resource offset*/
 540         rvdev->rsc_offset = rvdev_data->rsc_offset;
 541
 542         /* allocate the vring resources */
 543         for (i = 0; i < rsc->num_of_vrings; i++) {
 544                 ret = rproc_alloc_vring(rvdev, i);
 545                 if (ret)
 546                         goto unwind_vring_allocations;
 547         }
 548
 549         rproc_add_rvdev(rproc, rvdev);
 550
 551         rvdev->subdev.start = rproc_vdev_do_start;
 552         rvdev->subdev.stop = rproc_vdev_do_stop;
 553
 554         rproc_add_subdev(rproc, &rvdev->subdev);
 555
 556         /*
 557          * We're indirectly making a non-temporary copy of the rproc pointer
 558          * here, because the platform device or the vdev device will indirectly
 559          * access the wrapping rproc.
 560          *
 561          * Therefore we must increment the rproc refcount here, and decrement
 562          * it _only_ on platform remove.
 563          */
 564         get_device(&rproc->dev);
 565
 566         return 0;
 567
 568 unwind_vring_allocations:
 569         for (i--; i >= 0; i--)
 570                 rproc_free_vring(&rvdev->vring[i]);
 571
 572         return ret;
 573 }
 574
 575 static void rproc_virtio_remove(struct platform_device *pdev)
 576 {
 577         struct rproc_vdev *rvdev = dev_get_drvdata(&pdev->dev);
 578         struct rproc *rproc = rvdev->rproc;
 579         struct rproc_vring *rvring;
 580         int id;
 581
 582         for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
 583                 rvring = &rvdev->vring[id];
 584                 rproc_free_vring(rvring);
 585         }
 586
 587         rproc_remove_subdev(rproc, &rvdev->subdev);
 588         rproc_remove_rvdev(rvdev);
 589
 590         put_device(&rproc->dev);
 591 }
 592
 593 /* Platform driver */
 594 static struct platform_driver rproc_virtio_driver = {
 595         .probe          = rproc_virtio_probe,
 596         .remove         = rproc_virtio_remove,
 597         .driver         = {
 598                 .name   = "rproc-virtio",
 599         },
 600 };
 601 builtin_platform_driver(rproc_virtio_driver);