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/export.h> 21 #include <linux/remoteproc.h> 22 #include <linux/virtio.h> 23 #include <linux/virtio_config.h> 24 #include <linux/virtio_ids.h> 25 #include <linux/virtio_ring.h> 26 #include <linux/err.h> 27 #include <linux/kref.h> 28 #include <linux/slab.h> 29 30 #include "remoteproc_internal.h" 31 32 /* kick the remote processor, and let it know which virtqueue to poke at */ 33 static bool rproc_virtio_notify(struct virtqueue *vq) 34 { 35 struct rproc_vring *rvring = vq->priv; 36 struct rproc *rproc = rvring->rvdev->rproc; 37 int notifyid = rvring->notifyid; 38 39 dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid); 40 41 rproc->ops->kick(rproc, notifyid); 42 return true; 43 } 44 45 /** 46 * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted 47 * @rproc: handle to the remote processor 48 * @notifyid: index of the signalled virtqueue (unique per this @rproc) 49 * 50 * This function should be called by the platform-specific rproc driver, 51 * when the remote processor signals that a specific virtqueue has pending 52 * messages available. 53 * 54 * Returns IRQ_NONE if no message was found in the @notifyid virtqueue, 55 * and otherwise returns IRQ_HANDLED. 56 */ 57 irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid) 58 { 59 struct rproc_vring *rvring; 60 61 dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid); 62 63 rvring = idr_find(&rproc->notifyids, notifyid); 64 if (!rvring || !rvring->vq) 65 return IRQ_NONE; 66 67 return vring_interrupt(0, rvring->vq); 68 } 69 EXPORT_SYMBOL(rproc_vq_interrupt); 70 71 static struct virtqueue *rp_find_vq(struct virtio_device *vdev, 72 unsigned int id, 73 void (*callback)(struct virtqueue *vq), 74 const char *name) 75 { 76 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 77 struct rproc *rproc = vdev_to_rproc(vdev); 78 struct device *dev = &rproc->dev; 79 struct rproc_vring *rvring; 80 struct virtqueue *vq; 81 void *addr; 82 int len, size, ret; 83 84 /* we're temporarily limited to two virtqueues per rvdev */ 85 if (id >= ARRAY_SIZE(rvdev->vring)) 86 return ERR_PTR(-EINVAL); 87 88 if (!name) 89 return NULL; 90 91 ret = rproc_alloc_vring(rvdev, id); 92 if (ret) 93 return ERR_PTR(ret); 94 95 rvring = &rvdev->vring[id]; 96 addr = rvring->va; 97 len = rvring->len; 98 99 /* zero vring */ 100 size = vring_size(len, rvring->align); 101 memset(addr, 0, size); 102 103 dev_dbg(dev, "vring%d: va %p qsz %d notifyid %d\n", 104 id, addr, len, rvring->notifyid); 105 106 /* 107 * Create the new vq, and tell virtio we're not interested in 108 * the 'weak' smp barriers, since we're talking with a real device. 109 */ 110 vq = vring_new_virtqueue(id, len, rvring->align, vdev, false, addr, 111 rproc_virtio_notify, callback, name); 112 if (!vq) { 113 dev_err(dev, "vring_new_virtqueue %s failed\n", name); 114 rproc_free_vring(rvring); 115 return ERR_PTR(-ENOMEM); 116 } 117 118 rvring->vq = vq; 119 vq->priv = rvring; 120 121 return vq; 122 } 123 124 static void __rproc_virtio_del_vqs(struct virtio_device *vdev) 125 { 126 struct virtqueue *vq, *n; 127 struct rproc_vring *rvring; 128 129 list_for_each_entry_safe(vq, n, &vdev->vqs, list) { 130 rvring = vq->priv; 131 rvring->vq = NULL; 132 vring_del_virtqueue(vq); 133 rproc_free_vring(rvring); 134 } 135 } 136 137 static void rproc_virtio_del_vqs(struct virtio_device *vdev) 138 { 139 __rproc_virtio_del_vqs(vdev); 140 } 141 142 static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 143 struct virtqueue *vqs[], 144 vq_callback_t *callbacks[], 145 const char * const names[]) 146 { 147 int i, ret; 148 149 for (i = 0; i < nvqs; ++i) { 150 vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]); 151 if (IS_ERR(vqs[i])) { 152 ret = PTR_ERR(vqs[i]); 153 goto error; 154 } 155 } 156 157 return 0; 158 159 error: 160 __rproc_virtio_del_vqs(vdev); 161 return ret; 162 } 163 164 static u8 rproc_virtio_get_status(struct virtio_device *vdev) 165 { 166 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 167 struct fw_rsc_vdev *rsc; 168 169 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 170 171 return rsc->status; 172 } 173 174 static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status) 175 { 176 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 177 struct fw_rsc_vdev *rsc; 178 179 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 180 181 rsc->status = status; 182 dev_dbg(&vdev->dev, "status: %d\n", status); 183 } 184 185 static void rproc_virtio_reset(struct virtio_device *vdev) 186 { 187 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 188 struct fw_rsc_vdev *rsc; 189 190 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 191 192 rsc->status = 0; 193 dev_dbg(&vdev->dev, "reset !\n"); 194 } 195 196 /* provide the vdev features as retrieved from the firmware */ 197 static u64 rproc_virtio_get_features(struct virtio_device *vdev) 198 { 199 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 200 struct fw_rsc_vdev *rsc; 201 202 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 203 204 return rsc->dfeatures; 205 } 206 207 static int rproc_virtio_finalize_features(struct virtio_device *vdev) 208 { 209 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 210 struct fw_rsc_vdev *rsc; 211 212 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 213 214 /* Give virtio_ring a chance to accept features */ 215 vring_transport_features(vdev); 216 217 /* Make sure we don't have any features > 32 bits! */ 218 BUG_ON((u32)vdev->features != vdev->features); 219 220 /* 221 * Remember the finalized features of our vdev, and provide it 222 * to the remote processor once it is powered on. 223 */ 224 rsc->gfeatures = vdev->features; 225 226 return 0; 227 } 228 229 static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset, 230 void *buf, unsigned int len) 231 { 232 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 233 struct fw_rsc_vdev *rsc; 234 void *cfg; 235 236 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 237 cfg = &rsc->vring[rsc->num_of_vrings]; 238 239 if (offset + len > rsc->config_len || offset + len < len) { 240 dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n"); 241 return; 242 } 243 244 memcpy(buf, cfg + offset, len); 245 } 246 247 static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset, 248 const void *buf, unsigned int len) 249 { 250 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 251 struct fw_rsc_vdev *rsc; 252 void *cfg; 253 254 rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; 255 cfg = &rsc->vring[rsc->num_of_vrings]; 256 257 if (offset + len > rsc->config_len || offset + len < len) { 258 dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n"); 259 return; 260 } 261 262 memcpy(cfg + offset, buf, len); 263 } 264 265 static const struct virtio_config_ops rproc_virtio_config_ops = { 266 .get_features = rproc_virtio_get_features, 267 .finalize_features = rproc_virtio_finalize_features, 268 .find_vqs = rproc_virtio_find_vqs, 269 .del_vqs = rproc_virtio_del_vqs, 270 .reset = rproc_virtio_reset, 271 .set_status = rproc_virtio_set_status, 272 .get_status = rproc_virtio_get_status, 273 .get = rproc_virtio_get, 274 .set = rproc_virtio_set, 275 }; 276 277 /* 278 * This function is called whenever vdev is released, and is responsible 279 * to decrement the remote processor's refcount which was taken when vdev was 280 * added. 281 * 282 * Never call this function directly; it will be called by the driver 283 * core when needed. 284 */ 285 static void rproc_vdev_release(struct device *dev) 286 { 287 struct virtio_device *vdev = dev_to_virtio(dev); 288 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); 289 struct rproc *rproc = vdev_to_rproc(vdev); 290 291 list_del(&rvdev->node); 292 kfree(rvdev); 293 294 put_device(&rproc->dev); 295 } 296 297 /** 298 * rproc_add_virtio_dev() - register an rproc-induced virtio device 299 * @rvdev: the remote vdev 300 * 301 * This function registers a virtio device. This vdev's partent is 302 * the rproc device. 303 * 304 * Returns 0 on success or an appropriate error value otherwise. 305 */ 306 int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id) 307 { 308 struct rproc *rproc = rvdev->rproc; 309 struct device *dev = &rproc->dev; 310 struct virtio_device *vdev = &rvdev->vdev; 311 int ret; 312 313 vdev->id.device = id, 314 vdev->config = &rproc_virtio_config_ops, 315 vdev->dev.parent = dev; 316 vdev->dev.release = rproc_vdev_release; 317 318 /* 319 * We're indirectly making a non-temporary copy of the rproc pointer 320 * here, because drivers probed with this vdev will indirectly 321 * access the wrapping rproc. 322 * 323 * Therefore we must increment the rproc refcount here, and decrement 324 * it _only_ when the vdev is released. 325 */ 326 get_device(&rproc->dev); 327 328 ret = register_virtio_device(vdev); 329 if (ret) { 330 put_device(&rproc->dev); 331 dev_err(dev, "failed to register vdev: %d\n", ret); 332 goto out; 333 } 334 335 dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id); 336 337 out: 338 return ret; 339 } 340 341 /** 342 * rproc_remove_virtio_dev() - remove an rproc-induced virtio device 343 * @rvdev: the remote vdev 344 * 345 * This function unregisters an existing virtio device. 346 */ 347 void rproc_remove_virtio_dev(struct rproc_vdev *rvdev) 348 { 349 unregister_virtio_device(&rvdev->vdev); 350 } 351