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-mapping.h>
  13 #include <linux/export.h>
  14 #include <linux/of_reserved_mem.h>
  15 #include <linux/remoteproc.h>
  16 #include <linux/virtio.h>
  17 #include <linux/virtio_config.h>
  18 #include <linux/virtio_ids.h>
  19 #include <linux/virtio_ring.h>
  20 #include <linux/err.h>
  21 #include <linux/kref.h>
  22 #include <linux/slab.h>
  23
  24 #include "remoteproc_internal.h"
  25
  26 /* kick the remote processor, and let it know which virtqueue to poke at */
  27 static bool rproc_virtio_notify(struct virtqueue *vq)
  28 {
  29         struct rproc_vring *rvring = vq->priv;
  30         struct rproc *rproc = rvring->rvdev->rproc;
  31         int notifyid = rvring->notifyid;
  32
  33         dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);
  34
  35         rproc->ops->kick(rproc, notifyid);
  36         return true;
  37 }
  38
  39 /**
  40  * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
  41  * @rproc: handle to the remote processor
  42  * @notifyid: index of the signalled virtqueue (unique per this @rproc)
  43  *
  44  * This function should be called by the platform-specific rproc driver,
  45  * when the remote processor signals that a specific virtqueue has pending
  46  * messages available.
  47  *
  48  * Returns IRQ_NONE if no message was found in the @notifyid virtqueue,
  49  * and otherwise returns IRQ_HANDLED.
  50  */
  51 irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
  52 {
  53         struct rproc_vring *rvring;
  54
  55         dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid);
  56
  57         rvring = idr_find(&rproc->notifyids, notifyid);
  58         if (!rvring || !rvring->vq)
  59                 return IRQ_NONE;
  60
  61         return vring_interrupt(0, rvring->vq);
  62 }
  63 EXPORT_SYMBOL(rproc_vq_interrupt);
  64
  65 static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
  66                                     unsigned int id,
  67                                     void (*callback)(struct virtqueue *vq),
  68                                     const char *name, bool ctx)
  69 {
  70         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
  71         struct rproc *rproc = vdev_to_rproc(vdev);
  72         struct device *dev = &rproc->dev;
  73         struct rproc_mem_entry *mem;
  74         struct rproc_vring *rvring;
  75         struct fw_rsc_vdev *rsc;
  76         struct virtqueue *vq;
  77         void *addr;
  78         int len, size;
  79
  80         /* we're temporarily limited to two virtqueues per rvdev */
  81         if (id >= ARRAY_SIZE(rvdev->vring))
  82                 return ERR_PTR(-EINVAL);
  83
  84         if (!name)
  85                 return NULL;
  86
  87         /* Search allocated memory region by name */
  88         mem = rproc_find_carveout_by_name(rproc, "vdev%dvring%d", rvdev->index,
  89                                           id);
  90         if (!mem || !mem->va)
  91                 return ERR_PTR(-ENOMEM);
  92
  93         rvring = &rvdev->vring[id];
  94         addr = mem->va;
  95         len = rvring->len;
  96
  97         /* zero vring */
  98         size = vring_size(len, rvring->align);
  99         memset(addr, 0, size);
 100
 101         dev_dbg(dev, "vring%d: va %pK qsz %d notifyid %d\n",
 102                 id, addr, len, rvring->notifyid);
 103
 104         /*
 105          * Create the new vq, and tell virtio we're not interested in
 106          * the 'weak' smp barriers, since we're talking with a real device.
 107          */
 108         vq = vring_new_virtqueue(id, len, rvring->align, vdev, false, ctx,
 109                                  addr, rproc_virtio_notify, callback, name);
 110         if (!vq) {
 111                 dev_err(dev, "vring_new_virtqueue %s failed\n", name);
 112                 rproc_free_vring(rvring);
 113                 return ERR_PTR(-ENOMEM);
 114         }
 115
 116         rvring->vq = vq;
 117         vq->priv = rvring;
 118
 119         /* Update vring in resource table */
 120         rsc = (void *)rproc->table_ptr + rvdev->rsc_offset;
 121         rsc->vring[id].da = mem->da;
 122
 123         return vq;
 124 }
 125
 126 static void __rproc_virtio_del_vqs(struct virtio_device *vdev)
 127 {
 128         struct virtqueue *vq, *n;
 129         struct rproc_vring *rvring;
 130
 131         list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 132                 rvring = vq->priv;
 133                 rvring->vq = NULL;
 134                 vring_del_virtqueue(vq);
 135         }
 136 }
 137
 138 static void rproc_virtio_del_vqs(struct virtio_device *vdev)
 139 {
 140         __rproc_virtio_del_vqs(vdev);
 141 }
 142
 143 static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
 144                                  struct virtqueue *vqs[],
 145                                  vq_callback_t *callbacks[],
 146                                  const char * const names[],
 147                                  const bool * ctx,
 148                                  struct irq_affinity *desc)
 149 {
 150         int i, ret, queue_idx = 0;
 151
 152         for (i = 0; i < nvqs; ++i) {
 153                 if (!names[i]) {
 154                         vqs[i] = NULL;
 155                         continue;
 156                 }
 157
 158                 vqs[i] = rp_find_vq(vdev, queue_idx++, callbacks[i], names[i],
 159                                     ctx ? ctx[i] : false);
 160                 if (IS_ERR(vqs[i])) {
 161                         ret = PTR_ERR(vqs[i]);
 162                         goto error;
 163                 }
 164         }
 165
 166         return 0;
 167
 168 error:
 169         __rproc_virtio_del_vqs(vdev);
 170         return ret;
 171 }
 172
 173 static u8 rproc_virtio_get_status(struct virtio_device *vdev)
 174 {
 175         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 176         struct fw_rsc_vdev *rsc;
 177
 178         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 179
 180         return rsc->status;
 181 }
 182
 183 static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
 184 {
 185         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 186         struct fw_rsc_vdev *rsc;
 187
 188         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 189
 190         rsc->status = status;
 191         dev_dbg(&vdev->dev, "status: %d\n", status);
 192 }
 193
 194 static void rproc_virtio_reset(struct virtio_device *vdev)
 195 {
 196         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 197         struct fw_rsc_vdev *rsc;
 198
 199         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 200
 201         rsc->status = 0;
 202         dev_dbg(&vdev->dev, "reset !\n");
 203 }
 204
 205 /* provide the vdev features as retrieved from the firmware */
 206 static u64 rproc_virtio_get_features(struct virtio_device *vdev)
 207 {
 208         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 209         struct fw_rsc_vdev *rsc;
 210
 211         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 212
 213         return rsc->dfeatures;
 214 }
 215
 216 static void rproc_transport_features(struct virtio_device *vdev)
 217 {
 218         /*
 219          * Packed ring isn't enabled on remoteproc for now,
 220          * because remoteproc uses vring_new_virtqueue() which
 221          * creates virtio rings on preallocated memory.
 222          */
 223         __virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED);
 224 }
 225
 226 static int rproc_virtio_finalize_features(struct virtio_device *vdev)
 227 {
 228         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 229         struct fw_rsc_vdev *rsc;
 230
 231         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 232
 233         /* Give virtio_ring a chance to accept features */
 234         vring_transport_features(vdev);
 235
 236         /* Give virtio_rproc a chance to accept features. */
 237         rproc_transport_features(vdev);
 238
 239         /* Make sure we don't have any features > 32 bits! */
 240         BUG_ON((u32)vdev->features != vdev->features);
 241
 242         /*
 243          * Remember the finalized features of our vdev, and provide it
 244          * to the remote processor once it is powered on.
 245          */
 246         rsc->gfeatures = vdev->features;
 247
 248         return 0;
 249 }
 250
 251 static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset,
 252                              void *buf, unsigned int len)
 253 {
 254         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 255         struct fw_rsc_vdev *rsc;
 256         void *cfg;
 257
 258         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 259         cfg = &rsc->vring[rsc->num_of_vrings];
 260
 261         if (offset + len > rsc->config_len || offset + len < len) {
 262                 dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n");
 263                 return;
 264         }
 265
 266         memcpy(buf, cfg + offset, len);
 267 }
 268
 269 static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset,
 270                              const void *buf, unsigned int len)
 271 {
 272         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 273         struct fw_rsc_vdev *rsc;
 274         void *cfg;
 275
 276         rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 277         cfg = &rsc->vring[rsc->num_of_vrings];
 278
 279         if (offset + len > rsc->config_len || offset + len < len) {
 280                 dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n");
 281                 return;
 282         }
 283
 284         memcpy(cfg + offset, buf, len);
 285 }
 286
 287 static const struct virtio_config_ops rproc_virtio_config_ops = {
 288         .get_features   = rproc_virtio_get_features,
 289         .finalize_features = rproc_virtio_finalize_features,
 290         .find_vqs       = rproc_virtio_find_vqs,
 291         .del_vqs        = rproc_virtio_del_vqs,
 292         .reset          = rproc_virtio_reset,
 293         .set_status     = rproc_virtio_set_status,
 294         .get_status     = rproc_virtio_get_status,
 295         .get            = rproc_virtio_get,
 296         .set            = rproc_virtio_set,
 297 };
 298
 299 /*
 300  * This function is called whenever vdev is released, and is responsible
 301  * to decrement the remote processor's refcount which was taken when vdev was
 302  * added.
 303  *
 304  * Never call this function directly; it will be called by the driver
 305  * core when needed.
 306  */
 307 static void rproc_virtio_dev_release(struct device *dev)
 308 {
 309         struct virtio_device *vdev = dev_to_virtio(dev);
 310         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 311         struct rproc *rproc = vdev_to_rproc(vdev);
 312
 313         kfree(vdev);
 314
 315         kref_put(&rvdev->refcount, rproc_vdev_release);
 316
 317         put_device(&rproc->dev);
 318 }
 319
 320 /**
 321  * rproc_add_virtio_dev() - register an rproc-induced virtio device
 322  * @rvdev: the remote vdev
 323  * @id: the device type identification (used to match it with a driver).
 324  *
 325  * This function registers a virtio device. This vdev's partent is
 326  * the rproc device.
 327  *
 328  * Returns 0 on success or an appropriate error value otherwise.
 329  */
 330 int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
 331 {
 332         struct rproc *rproc = rvdev->rproc;
 333         struct device *dev = &rvdev->dev;
 334         struct virtio_device *vdev;
 335         struct rproc_mem_entry *mem;
 336         int ret;
 337
 338         if (rproc->ops->kick == NULL) {
 339                 ret = -EINVAL;
 340                 dev_err(dev, ".kick method not defined for %s\n", rproc->name);
 341                 goto out;
 342         }
 343
 344         /* Try to find dedicated vdev buffer carveout */
 345         mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
 346         if (mem) {
 347                 phys_addr_t pa;
 348
 349                 if (mem->of_resm_idx != -1) {
 350                         struct device_node *np = rproc->dev.parent->of_node;
 351
 352                         /* Associate reserved memory to vdev device */
 353                         ret = of_reserved_mem_device_init_by_idx(dev, np,
 354                                                                  mem->of_resm_idx);
 355                         if (ret) {
 356                                 dev_err(dev, "Can't associate reserved memory\n");
 357                                 goto out;
 358                         }
 359                 } else {
 360                         if (mem->va) {
 361                                 dev_warn(dev, "vdev %d buffer already mapped\n",
 362                                          rvdev->index);
 363                                 pa = rproc_va_to_pa(mem->va);
 364                         } else {
 365                                 /* Use dma address as carveout no memmapped yet */
 366                                 pa = (phys_addr_t)mem->dma;
 367                         }
 368
 369                         /* Associate vdev buffer memory pool to vdev subdev */
 370                         ret = dma_declare_coherent_memory(dev, pa,
 371                                                            mem->da,
 372                                                            mem->len);
 373                         if (ret < 0) {
 374                                 dev_err(dev, "Failed to associate buffer\n");
 375                                 goto out;
 376                         }
 377                 }
 378         } else {
 379                 struct device_node *np = rproc->dev.parent->of_node;
 380
 381                 /*
 382                  * If we don't have dedicated buffer, just attempt to re-assign
 383                  * the reserved memory from our parent. A default memory-region
 384                  * at index 0 from the parent's memory-regions is assigned for
 385                  * the rvdev dev to allocate from. Failure is non-critical and
 386                  * the allocations will fall back to global pools, so don't
 387                  * check return value either.
 388                  */
 389                 of_reserved_mem_device_init_by_idx(dev, np, 0);
 390         }
 391
 392         /* Allocate virtio device */
 393         vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
 394         if (!vdev) {
 395                 ret = -ENOMEM;
 396                 goto out;
 397         }
 398         vdev->id.device = id,
 399         vdev->config = &rproc_virtio_config_ops,
 400         vdev->dev.parent = dev;
 401         vdev->dev.release = rproc_virtio_dev_release;
 402
 403         /*
 404          * We're indirectly making a non-temporary copy of the rproc pointer
 405          * here, because drivers probed with this vdev will indirectly
 406          * access the wrapping rproc.
 407          *
 408          * Therefore we must increment the rproc refcount here, and decrement
 409          * it _only_ when the vdev is released.
 410          */
 411         get_device(&rproc->dev);
 412
 413         /* Reference the vdev and vring allocations */
 414         kref_get(&rvdev->refcount);
 415
 416         ret = register_virtio_device(vdev);
 417         if (ret) {
 418                 put_device(&vdev->dev);
 419                 dev_err(dev, "failed to register vdev: %d\n", ret);
 420                 goto out;
 421         }
 422
 423         dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);
 424
 425 out:
 426         return ret;
 427 }
 428
 429 /**
 430  * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
 431  * @dev: the virtio device
 432  * @data: must be null
 433  *
 434  * This function unregisters an existing virtio device.
 435  */
 436 int rproc_remove_virtio_dev(struct device *dev, void *data)
 437 {
 438         struct virtio_device *vdev = dev_to_virtio(dev);
 439
 440         unregister_virtio_device(vdev);
 441         return 0;
 442 }