1 /* 2 * Remote processor messaging transport (OMAP platform-specific bits) 3 * 4 * Copyright (C) 2011 Texas Instruments, Inc. 5 * Copyright (C) 2011 Google, Inc. 6 * 7 * Ohad Ben-Cohen <ohad@wizery.com> 8 * Brian Swetland <swetland@google.com> 9 * 10 * This software is licensed under the terms of the GNU General Public 11 * License version 2, as published by the Free Software Foundation, and 12 * may be copied, distributed, and modified under those terms. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 */ 19 20 #include <linux/dma-mapping.h> 21 #include <linux/export.h> 22 #include <linux/of_reserved_mem.h> 23 #include <linux/remoteproc.h> 24 #include <linux/virtio.h> 25 #include <linux/virtio_config.h> 26 #include <linux/virtio_ids.h> 27 #include <linux/virtio_ring.h> 28 #include <linux/err.h> 29 #include <linux/kref.h> 30 #include <linux/slab.h> 31 32 #include "remoteproc_internal.h" 33 34 /* kick the remote processor, and let it know which virtqueue to poke at */ 35 static bool rproc_virtio_notify(struct virtqueue *vq) 36 { 37 struct rproc_vring *rvring = vq->priv; 38 struct rproc *rproc = rvring->rvdev->rproc; 39 int notifyid = rvring->notifyid; 40 41 dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid); 42 43 rproc->ops->kick(rproc, notifyid); 44 return true; 45 } 46 47 /** 48 * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted 49 * @rproc: handle to the remote processor 50 * @notifyid: index of the signalled virtqueue (unique per this @rproc) 51 * 52 * This function should be called by the platform-specific rproc driver, 53 * when the remote processor signals that a specific virtqueue has pending 54 * messages available. 55 * 56 * Returns IRQ_NONE if no message was found in the @notifyid virtqueue, 57 * and otherwise returns IRQ_HANDLED. 58 */ 59 irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid) 60 { 61 struct rproc_vring *rvring; 62 63 dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid); 64 65 rvring = idr_find(&rproc->notifyids, notifyid); 66 if (!rvring || !rvring->vq) 67 return IRQ_NONE; 68 69 return vring_interrupt(0, rvring->vq); 70 } 71 EXPORT_SYMBOL(rproc_vq_interrupt); 72 73 static struct virtqueue *rp_find_vq(struct virtio_device *vdev, 74 unsigned int id, 75 void (*callback)(struct virtqueue *vq), 76 const char *name, bool ctx) 77 { 78 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 79 struct rproc *rproc = vdev_to_rproc(vdev); 80 struct device *dev = &rproc->dev; 81 struct rproc_mem_entry *mem; 82 struct rproc_vring *rvring; 83 struct fw_rsc_vdev *rsc; 84 struct virtqueue *vq; 85 void *addr; 86 int len, size; 87 88 /* we're temporarily limited to two virtqueues per rvdev */ 89 if (id >= ARRAY_SIZE(rvdev->vring)) 90 return ERR_PTR(-EINVAL); 91 92 if (!name) 93 return NULL; 94 95 /* Search allocated memory region by name */ 96 mem = rproc_find_carveout_by_name(rproc, "vdev%dvring%d", rvdev->index, 97 id); 98 if (!mem || !mem->va) 99 return ERR_PTR(-ENOMEM); 100 101 rvring = &rvdev->vring[id]; 102 addr = mem->va; 103 len = rvring->len; 104 105 /* zero vring */ 106 size = vring_size(len, rvring->align); 107 memset(addr, 0, size); 108 109 dev_dbg(dev, "vring%d: va %pK qsz %d notifyid %d\n", 110 id, addr, len, rvring->notifyid); 111 112 /* 113 * Create the new vq, and tell virtio we're not interested in 114 * the 'weak' smp barriers, since we're talking with a real device. 115 */ 116 vq = vring_new_virtqueue(id, len, rvring->align, vdev, false, ctx, 117 addr, rproc_virtio_notify, callback, name); 118 if (!vq) { 119 dev_err(dev, "vring_new_virtqueue %s failed\n", name); 120 rproc_free_vring(rvring); 121 return ERR_PTR(-ENOMEM); 122 } 123 124 rvring->vq = vq; 125 vq->priv = rvring; 126 127 /* Update vring in resource table */ 128 rsc = (void *)rproc->table_ptr + rvdev->rsc_offset; 129 rsc->vring[id].da = mem->da; 130 131 return vq; 132 } 133 134 static void __rproc_virtio_del_vqs(struct virtio_device *vdev) 135 { 136 struct virtqueue *vq, *n; 137 struct rproc_vring *rvring; 138 139 list_for_each_entry_safe(vq, n, &vdev->vqs, list) { 140 rvring = vq->priv; 141 rvring->vq = NULL; 142 vring_del_virtqueue(vq); 143 } 144 } 145 146 static void rproc_virtio_del_vqs(struct virtio_device *vdev) 147 { 148 __rproc_virtio_del_vqs(vdev); 149 } 150 151 static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 152 struct virtqueue *vqs[], 153 vq_callback_t *callbacks[], 154 const char * const names[], 155 const bool * ctx, 156 struct irq_affinity *desc) 157 { 158 int i, ret, queue_idx = 0; 159 160 for (i = 0; i < nvqs; ++i) { 161 if (!names[i]) { 162 vqs[i] = NULL; 163 continue; 164 } 165 166 vqs[i] = rp_find_vq(vdev, queue_idx++, callbacks[i], names[i], 167 ctx ? ctx[i] : false); 168 if (IS_ERR(vqs[i])) { 169 ret = PTR_ERR(vqs[i]); 170 goto error; 171 } 172 } 173 174 return 0; 175 176 error: 177 __rproc_virtio_del_vqs(vdev); 178 return ret; 179 } 180 181 static u8 rproc_virtio_get_status(struct virtio_device *vdev) 182 { 183 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 184 struct fw_rsc_vdev *rsc; 185 186 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 187 188 return rsc->status; 189 } 190 191 static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status) 192 { 193 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 194 struct fw_rsc_vdev *rsc; 195 196 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 197 198 rsc->status = status; 199 dev_dbg(&vdev->dev, "status: %d\n", status); 200 } 201 202 static void rproc_virtio_reset(struct virtio_device *vdev) 203 { 204 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 205 struct fw_rsc_vdev *rsc; 206 207 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 208 209 rsc->status = 0; 210 dev_dbg(&vdev->dev, "reset !\n"); 211 } 212 213 /* provide the vdev features as retrieved from the firmware */ 214 static u64 rproc_virtio_get_features(struct virtio_device *vdev) 215 { 216 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 217 struct fw_rsc_vdev *rsc; 218 219 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 220 221 return rsc->dfeatures; 222 } 223 224 static void rproc_transport_features(struct virtio_device *vdev) 225 { 226 /* 227 * Packed ring isn't enabled on remoteproc for now, 228 * because remoteproc uses vring_new_virtqueue() which 229 * creates virtio rings on preallocated memory. 230 */ 231 __virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED); 232 } 233 234 static int rproc_virtio_finalize_features(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 /* Give virtio_ring a chance to accept features */ 242 vring_transport_features(vdev); 243 244 /* Give virtio_rproc a chance to accept features. */ 245 rproc_transport_features(vdev); 246 247 /* Make sure we don't have any features > 32 bits! */ 248 BUG_ON((u32)vdev->features != vdev->features); 249 250 /* 251 * Remember the finalized features of our vdev, and provide it 252 * to the remote processor once it is powered on. 253 */ 254 rsc->gfeatures = vdev->features; 255 256 return 0; 257 } 258 259 static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset, 260 void *buf, unsigned int len) 261 { 262 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 263 struct fw_rsc_vdev *rsc; 264 void *cfg; 265 266 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 267 cfg = &rsc->vring[rsc->num_of_vrings]; 268 269 if (offset + len > rsc->config_len || offset + len < len) { 270 dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n"); 271 return; 272 } 273 274 memcpy(buf, cfg + offset, len); 275 } 276 277 static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset, 278 const void *buf, unsigned int len) 279 { 280 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 281 struct fw_rsc_vdev *rsc; 282 void *cfg; 283 284 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 285 cfg = &rsc->vring[rsc->num_of_vrings]; 286 287 if (offset + len > rsc->config_len || offset + len < len) { 288 dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n"); 289 return; 290 } 291 292 memcpy(cfg + offset, buf, len); 293 } 294 295 static const struct virtio_config_ops rproc_virtio_config_ops = { 296 .get_features = rproc_virtio_get_features, 297 .finalize_features = rproc_virtio_finalize_features, 298 .find_vqs = rproc_virtio_find_vqs, 299 .del_vqs = rproc_virtio_del_vqs, 300 .reset = rproc_virtio_reset, 301 .set_status = rproc_virtio_set_status, 302 .get_status = rproc_virtio_get_status, 303 .get = rproc_virtio_get, 304 .set = rproc_virtio_set, 305 }; 306 307 /* 308 * This function is called whenever vdev is released, and is responsible 309 * to decrement the remote processor's refcount which was taken when vdev was 310 * added. 311 * 312 * Never call this function directly; it will be called by the driver 313 * core when needed. 314 */ 315 static void rproc_virtio_dev_release(struct device *dev) 316 { 317 struct virtio_device *vdev = dev_to_virtio(dev); 318 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 319 struct rproc *rproc = vdev_to_rproc(vdev); 320 321 kfree(vdev); 322 323 kref_put(&rvdev->refcount, rproc_vdev_release); 324 325 put_device(&rproc->dev); 326 } 327 328 /** 329 * rproc_add_virtio_dev() - register an rproc-induced virtio device 330 * @rvdev: the remote vdev 331 * 332 * This function registers a virtio device. This vdev's partent is 333 * the rproc device. 334 * 335 * Returns 0 on success or an appropriate error value otherwise. 336 */ 337 int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id) 338 { 339 struct rproc *rproc = rvdev->rproc; 340 struct device *dev = &rvdev->dev; 341 struct virtio_device *vdev; 342 struct rproc_mem_entry *mem; 343 int ret; 344 345 /* Try to find dedicated vdev buffer carveout */ 346 mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index); 347 if (mem) { 348 phys_addr_t pa; 349 350 if (mem->of_resm_idx != -1) { 351 struct device_node *np = rproc->dev.parent->of_node; 352 353 /* Associate reserved memory to vdev device */ 354 ret = of_reserved_mem_device_init_by_idx(dev, np, 355 mem->of_resm_idx); 356 if (ret) { 357 dev_err(dev, "Can't associate reserved memory\n"); 358 goto out; 359 } 360 } else { 361 if (mem->va) { 362 dev_warn(dev, "vdev %d buffer already mapped\n", 363 rvdev->index); 364 pa = rproc_va_to_pa(mem->va); 365 } else { 366 /* Use dma address as carveout no memmapped yet */ 367 pa = (phys_addr_t)mem->dma; 368 } 369 370 /* Associate vdev buffer memory pool to vdev subdev */ 371 ret = dma_declare_coherent_memory(dev, pa, 372 mem->da, 373 mem->len); 374 if (ret < 0) { 375 dev_err(dev, "Failed to associate buffer\n"); 376 goto out; 377 } 378 } 379 } 380 381 /* Allocate virtio device */ 382 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); 383 if (!vdev) { 384 ret = -ENOMEM; 385 goto out; 386 } 387 vdev->id.device = id, 388 vdev->config = &rproc_virtio_config_ops, 389 vdev->dev.parent = dev; 390 vdev->dev.release = rproc_virtio_dev_release; 391 392 /* 393 * We're indirectly making a non-temporary copy of the rproc pointer 394 * here, because drivers probed with this vdev will indirectly 395 * access the wrapping rproc. 396 * 397 * Therefore we must increment the rproc refcount here, and decrement 398 * it _only_ when the vdev is released. 399 */ 400 get_device(&rproc->dev); 401 402 /* Reference the vdev and vring allocations */ 403 kref_get(&rvdev->refcount); 404 405 ret = register_virtio_device(vdev); 406 if (ret) { 407 put_device(&vdev->dev); 408 dev_err(dev, "failed to register vdev: %d\n", ret); 409 goto out; 410 } 411 412 dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id); 413 414 out: 415 return ret; 416 } 417 418 /** 419 * rproc_remove_virtio_dev() - remove an rproc-induced virtio device 420 * @dev: the virtio device 421 * @data: must be null 422 * 423 * This function unregisters an existing virtio device. 424 */ 425 int rproc_remove_virtio_dev(struct device *dev, void *data) 426 { 427 struct virtio_device *vdev = dev_to_virtio(dev); 428 429 unregister_virtio_device(vdev); 430 return 0; 431 } 432