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 * 324 * This function registers a virtio device. This vdev's partent is 325 * the rproc device. 326 * 327 * Returns 0 on success or an appropriate error value otherwise. 328 */ 329 int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id) 330 { 331 struct rproc *rproc = rvdev->rproc; 332 struct device *dev = &rvdev->dev; 333 struct virtio_device *vdev; 334 struct rproc_mem_entry *mem; 335 int ret; 336 337 /* Try to find dedicated vdev buffer carveout */ 338 mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index); 339 if (mem) { 340 phys_addr_t pa; 341 342 if (mem->of_resm_idx != -1) { 343 struct device_node *np = rproc->dev.parent->of_node; 344 345 /* Associate reserved memory to vdev device */ 346 ret = of_reserved_mem_device_init_by_idx(dev, np, 347 mem->of_resm_idx); 348 if (ret) { 349 dev_err(dev, "Can't associate reserved memory\n"); 350 goto out; 351 } 352 } else { 353 if (mem->va) { 354 dev_warn(dev, "vdev %d buffer already mapped\n", 355 rvdev->index); 356 pa = rproc_va_to_pa(mem->va); 357 } else { 358 /* Use dma address as carveout no memmapped yet */ 359 pa = (phys_addr_t)mem->dma; 360 } 361 362 /* Associate vdev buffer memory pool to vdev subdev */ 363 ret = dma_declare_coherent_memory(dev, pa, 364 mem->da, 365 mem->len); 366 if (ret < 0) { 367 dev_err(dev, "Failed to associate buffer\n"); 368 goto out; 369 } 370 } 371 } 372 373 /* Allocate virtio device */ 374 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); 375 if (!vdev) { 376 ret = -ENOMEM; 377 goto out; 378 } 379 vdev->id.device = id, 380 vdev->config = &rproc_virtio_config_ops, 381 vdev->dev.parent = dev; 382 vdev->dev.release = rproc_virtio_dev_release; 383 384 /* 385 * We're indirectly making a non-temporary copy of the rproc pointer 386 * here, because drivers probed with this vdev will indirectly 387 * access the wrapping rproc. 388 * 389 * Therefore we must increment the rproc refcount here, and decrement 390 * it _only_ when the vdev is released. 391 */ 392 get_device(&rproc->dev); 393 394 /* Reference the vdev and vring allocations */ 395 kref_get(&rvdev->refcount); 396 397 ret = register_virtio_device(vdev); 398 if (ret) { 399 put_device(&vdev->dev); 400 dev_err(dev, "failed to register vdev: %d\n", ret); 401 goto out; 402 } 403 404 dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id); 405 406 out: 407 return ret; 408 } 409 410 /** 411 * rproc_remove_virtio_dev() - remove an rproc-induced virtio device 412 * @dev: the virtio device 413 * @data: must be null 414 * 415 * This function unregisters an existing virtio device. 416 */ 417 int rproc_remove_virtio_dev(struct device *dev, void *data) 418 { 419 struct virtio_device *vdev = dev_to_virtio(dev); 420 421 unregister_virtio_device(vdev); 422 return 0; 423 } 424