Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Virtio-based remote processor messaging bus |
| 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 | #define pr_fmt(fmt) "%s: " fmt, __func__ |
| 21 | |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/virtio.h> |
| 25 | #include <linux/virtio_ids.h> |
| 26 | #include <linux/virtio_config.h> |
| 27 | #include <linux/scatterlist.h> |
| 28 | #include <linux/dma-mapping.h> |
| 29 | #include <linux/slab.h> |
| 30 | #include <linux/idr.h> |
| 31 | #include <linux/jiffies.h> |
| 32 | #include <linux/sched.h> |
| 33 | #include <linux/wait.h> |
| 34 | #include <linux/rpmsg.h> |
| 35 | #include <linux/mutex.h> |
| 36 | |
| 37 | /** |
| 38 | * struct virtproc_info - virtual remote processor state |
| 39 | * @vdev: the virtio device |
| 40 | * @rvq: rx virtqueue |
| 41 | * @svq: tx virtqueue |
| 42 | * @rbufs: kernel address of rx buffers |
| 43 | * @sbufs: kernel address of tx buffers |
| 44 | * @last_sbuf: index of last tx buffer used |
| 45 | * @bufs_dma: dma base addr of the buffers |
| 46 | * @tx_lock: protects svq, sbufs and sleepers, to allow concurrent senders. |
| 47 | * sending a message might require waking up a dozing remote |
| 48 | * processor, which involves sleeping, hence the mutex. |
| 49 | * @endpoints: idr of local endpoints, allows fast retrieval |
| 50 | * @endpoints_lock: lock of the endpoints set |
| 51 | * @sendq: wait queue of sending contexts waiting for a tx buffers |
| 52 | * @sleepers: number of senders that are waiting for a tx buffer |
| 53 | * @ns_ept: the bus's name service endpoint |
| 54 | * |
| 55 | * This structure stores the rpmsg state of a given virtio remote processor |
| 56 | * device (there might be several virtio proc devices for each physical |
| 57 | * remote processor). |
| 58 | */ |
| 59 | struct virtproc_info { |
| 60 | struct virtio_device *vdev; |
| 61 | struct virtqueue *rvq, *svq; |
| 62 | void *rbufs, *sbufs; |
| 63 | int last_sbuf; |
| 64 | dma_addr_t bufs_dma; |
| 65 | struct mutex tx_lock; |
| 66 | struct idr endpoints; |
| 67 | struct mutex endpoints_lock; |
| 68 | wait_queue_head_t sendq; |
| 69 | atomic_t sleepers; |
| 70 | struct rpmsg_endpoint *ns_ept; |
| 71 | }; |
| 72 | |
| 73 | /** |
| 74 | * struct rpmsg_channel_info - internal channel info representation |
| 75 | * @name: name of service |
| 76 | * @src: local address |
| 77 | * @dst: destination address |
| 78 | */ |
| 79 | struct rpmsg_channel_info { |
| 80 | char name[RPMSG_NAME_SIZE]; |
| 81 | u32 src; |
| 82 | u32 dst; |
| 83 | }; |
| 84 | |
| 85 | #define to_rpmsg_channel(d) container_of(d, struct rpmsg_channel, dev) |
| 86 | #define to_rpmsg_driver(d) container_of(d, struct rpmsg_driver, drv) |
| 87 | |
| 88 | /* |
| 89 | * We're allocating 512 buffers of 512 bytes for communications, and then |
| 90 | * using the first 256 buffers for RX, and the last 256 buffers for TX. |
| 91 | * |
| 92 | * Each buffer will have 16 bytes for the msg header and 496 bytes for |
| 93 | * the payload. |
| 94 | * |
| 95 | * This will require a total space of 256KB for the buffers. |
| 96 | * |
| 97 | * We might also want to add support for user-provided buffers in time. |
| 98 | * This will allow bigger buffer size flexibility, and can also be used |
| 99 | * to achieve zero-copy messaging. |
| 100 | * |
| 101 | * Note that these numbers are purely a decision of this driver - we |
| 102 | * can change this without changing anything in the firmware of the remote |
| 103 | * processor. |
| 104 | */ |
| 105 | #define RPMSG_NUM_BUFS (512) |
| 106 | #define RPMSG_BUF_SIZE (512) |
| 107 | #define RPMSG_TOTAL_BUF_SPACE (RPMSG_NUM_BUFS * RPMSG_BUF_SIZE) |
| 108 | |
| 109 | /* |
| 110 | * Local addresses are dynamically allocated on-demand. |
| 111 | * We do not dynamically assign addresses from the low 1024 range, |
| 112 | * in order to reserve that address range for predefined services. |
| 113 | */ |
| 114 | #define RPMSG_RESERVED_ADDRESSES (1024) |
| 115 | |
| 116 | /* Address 53 is reserved for advertising remote services */ |
| 117 | #define RPMSG_NS_ADDR (53) |
| 118 | |
| 119 | /* sysfs show configuration fields */ |
| 120 | #define rpmsg_show_attr(field, path, format_string) \ |
| 121 | static ssize_t \ |
| 122 | field##_show(struct device *dev, \ |
| 123 | struct device_attribute *attr, char *buf) \ |
| 124 | { \ |
| 125 | struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); \ |
| 126 | \ |
| 127 | return sprintf(buf, format_string, rpdev->path); \ |
| 128 | } |
| 129 | |
| 130 | /* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */ |
| 131 | rpmsg_show_attr(name, id.name, "%s\n"); |
| 132 | rpmsg_show_attr(src, src, "0x%x\n"); |
| 133 | rpmsg_show_attr(dst, dst, "0x%x\n"); |
| 134 | rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n"); |
| 135 | |
| 136 | /* |
| 137 | * Unique (and free running) index for rpmsg devices. |
| 138 | * |
| 139 | * Yeah, we're not recycling those numbers (yet?). will be easy |
| 140 | * to change if/when we want to. |
| 141 | */ |
| 142 | static unsigned int rpmsg_dev_index; |
| 143 | |
| 144 | static ssize_t modalias_show(struct device *dev, |
| 145 | struct device_attribute *attr, char *buf) |
| 146 | { |
| 147 | struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); |
| 148 | |
| 149 | return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name); |
| 150 | } |
| 151 | |
| 152 | static struct device_attribute rpmsg_dev_attrs[] = { |
| 153 | __ATTR_RO(name), |
| 154 | __ATTR_RO(modalias), |
| 155 | __ATTR_RO(dst), |
| 156 | __ATTR_RO(src), |
| 157 | __ATTR_RO(announce), |
| 158 | __ATTR_NULL |
| 159 | }; |
| 160 | |
| 161 | /* rpmsg devices and drivers are matched using the service name */ |
| 162 | static inline int rpmsg_id_match(const struct rpmsg_channel *rpdev, |
| 163 | const struct rpmsg_device_id *id) |
| 164 | { |
| 165 | return strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE) == 0; |
| 166 | } |
| 167 | |
| 168 | /* match rpmsg channel and rpmsg driver */ |
| 169 | static int rpmsg_dev_match(struct device *dev, struct device_driver *drv) |
| 170 | { |
| 171 | struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); |
| 172 | struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv); |
| 173 | const struct rpmsg_device_id *ids = rpdrv->id_table; |
| 174 | unsigned int i; |
| 175 | |
| 176 | for (i = 0; ids[i].name[0]; i++) |
| 177 | if (rpmsg_id_match(rpdev, &ids[i])) |
| 178 | return 1; |
| 179 | |
| 180 | return 0; |
| 181 | } |
| 182 | |
| 183 | static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env) |
| 184 | { |
| 185 | struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); |
| 186 | |
| 187 | return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT, |
| 188 | rpdev->id.name); |
| 189 | } |
| 190 | |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 191 | /** |
| 192 | * __ept_release() - deallocate an rpmsg endpoint |
| 193 | * @kref: the ept's reference count |
| 194 | * |
| 195 | * This function deallocates an ept, and is invoked when its @kref refcount |
| 196 | * drops to zero. |
| 197 | * |
| 198 | * Never invoke this function directly! |
| 199 | */ |
| 200 | static void __ept_release(struct kref *kref) |
| 201 | { |
| 202 | struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, |
| 203 | refcount); |
| 204 | /* |
| 205 | * At this point no one holds a reference to ept anymore, |
| 206 | * so we can directly free it |
| 207 | */ |
| 208 | kfree(ept); |
| 209 | } |
| 210 | |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 211 | /* for more info, see below documentation of rpmsg_create_ept() */ |
| 212 | static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp, |
| 213 | struct rpmsg_channel *rpdev, rpmsg_rx_cb_t cb, |
| 214 | void *priv, u32 addr) |
| 215 | { |
| 216 | int err, tmpaddr, request; |
| 217 | struct rpmsg_endpoint *ept; |
| 218 | struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev; |
| 219 | |
| 220 | if (!idr_pre_get(&vrp->endpoints, GFP_KERNEL)) |
| 221 | return NULL; |
| 222 | |
| 223 | ept = kzalloc(sizeof(*ept), GFP_KERNEL); |
| 224 | if (!ept) { |
| 225 | dev_err(dev, "failed to kzalloc a new ept\n"); |
| 226 | return NULL; |
| 227 | } |
| 228 | |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 229 | kref_init(&ept->refcount); |
Ohad Ben-Cohen | d87127d | 2012-06-07 15:39:35 +0300 | [diff] [blame] | 230 | mutex_init(&ept->cb_lock); |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 231 | |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 232 | ept->rpdev = rpdev; |
| 233 | ept->cb = cb; |
| 234 | ept->priv = priv; |
| 235 | |
| 236 | /* do we need to allocate a local address ? */ |
| 237 | request = addr == RPMSG_ADDR_ANY ? RPMSG_RESERVED_ADDRESSES : addr; |
| 238 | |
| 239 | mutex_lock(&vrp->endpoints_lock); |
| 240 | |
| 241 | /* bind the endpoint to an rpmsg address (and allocate one if needed) */ |
| 242 | err = idr_get_new_above(&vrp->endpoints, ept, request, &tmpaddr); |
| 243 | if (err) { |
| 244 | dev_err(dev, "idr_get_new_above failed: %d\n", err); |
| 245 | goto free_ept; |
| 246 | } |
| 247 | |
| 248 | /* make sure the user's address request is fulfilled, if relevant */ |
| 249 | if (addr != RPMSG_ADDR_ANY && tmpaddr != addr) { |
| 250 | dev_err(dev, "address 0x%x already in use\n", addr); |
| 251 | goto rem_idr; |
| 252 | } |
| 253 | |
| 254 | ept->addr = tmpaddr; |
| 255 | |
| 256 | mutex_unlock(&vrp->endpoints_lock); |
| 257 | |
| 258 | return ept; |
| 259 | |
| 260 | rem_idr: |
| 261 | idr_remove(&vrp->endpoints, request); |
| 262 | free_ept: |
| 263 | mutex_unlock(&vrp->endpoints_lock); |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 264 | kref_put(&ept->refcount, __ept_release); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 265 | return NULL; |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * rpmsg_create_ept() - create a new rpmsg_endpoint |
| 270 | * @rpdev: rpmsg channel device |
| 271 | * @cb: rx callback handler |
| 272 | * @priv: private data for the driver's use |
| 273 | * @addr: local rpmsg address to bind with @cb |
| 274 | * |
| 275 | * Every rpmsg address in the system is bound to an rx callback (so when |
| 276 | * inbound messages arrive, they are dispatched by the rpmsg bus using the |
| 277 | * appropriate callback handler) by means of an rpmsg_endpoint struct. |
| 278 | * |
| 279 | * This function allows drivers to create such an endpoint, and by that, |
| 280 | * bind a callback, and possibly some private data too, to an rpmsg address |
| 281 | * (either one that is known in advance, or one that will be dynamically |
| 282 | * assigned for them). |
| 283 | * |
| 284 | * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint |
| 285 | * is already created for them when they are probed by the rpmsg bus |
| 286 | * (using the rx callback provided when they registered to the rpmsg bus). |
| 287 | * |
| 288 | * So things should just work for simple drivers: they already have an |
| 289 | * endpoint, their rx callback is bound to their rpmsg address, and when |
| 290 | * relevant inbound messages arrive (i.e. messages which their dst address |
| 291 | * equals to the src address of their rpmsg channel), the driver's handler |
| 292 | * is invoked to process it. |
| 293 | * |
| 294 | * That said, more complicated drivers might do need to allocate |
| 295 | * additional rpmsg addresses, and bind them to different rx callbacks. |
| 296 | * To accomplish that, those drivers need to call this function. |
| 297 | * |
| 298 | * Drivers should provide their @rpdev channel (so the new endpoint would belong |
| 299 | * to the same remote processor their channel belongs to), an rx callback |
| 300 | * function, an optional private data (which is provided back when the |
| 301 | * rx callback is invoked), and an address they want to bind with the |
| 302 | * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will |
| 303 | * dynamically assign them an available rpmsg address (drivers should have |
| 304 | * a very good reason why not to always use RPMSG_ADDR_ANY here). |
| 305 | * |
| 306 | * Returns a pointer to the endpoint on success, or NULL on error. |
| 307 | */ |
| 308 | struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *rpdev, |
| 309 | rpmsg_rx_cb_t cb, void *priv, u32 addr) |
| 310 | { |
| 311 | return __rpmsg_create_ept(rpdev->vrp, rpdev, cb, priv, addr); |
| 312 | } |
| 313 | EXPORT_SYMBOL(rpmsg_create_ept); |
| 314 | |
| 315 | /** |
Ohad Ben-Cohen | fa2d779 | 2012-02-09 15:16:41 +0200 | [diff] [blame] | 316 | * __rpmsg_destroy_ept() - destroy an existing rpmsg endpoint |
| 317 | * @vrp: virtproc which owns this ept |
| 318 | * @ept: endpoing to destroy |
| 319 | * |
| 320 | * An internal function which destroy an ept without assuming it is |
| 321 | * bound to an rpmsg channel. This is needed for handling the internal |
| 322 | * name service endpoint, which isn't bound to an rpmsg channel. |
| 323 | * See also __rpmsg_create_ept(). |
| 324 | */ |
| 325 | static void |
| 326 | __rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept) |
| 327 | { |
Ohad Ben-Cohen | d87127d | 2012-06-07 15:39:35 +0300 | [diff] [blame] | 328 | /* make sure new inbound messages can't find this ept anymore */ |
Ohad Ben-Cohen | fa2d779 | 2012-02-09 15:16:41 +0200 | [diff] [blame] | 329 | mutex_lock(&vrp->endpoints_lock); |
| 330 | idr_remove(&vrp->endpoints, ept->addr); |
| 331 | mutex_unlock(&vrp->endpoints_lock); |
| 332 | |
Ohad Ben-Cohen | d87127d | 2012-06-07 15:39:35 +0300 | [diff] [blame] | 333 | /* make sure in-flight inbound messages won't invoke cb anymore */ |
| 334 | mutex_lock(&ept->cb_lock); |
| 335 | ept->cb = NULL; |
| 336 | mutex_unlock(&ept->cb_lock); |
| 337 | |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 338 | kref_put(&ept->refcount, __ept_release); |
Ohad Ben-Cohen | fa2d779 | 2012-02-09 15:16:41 +0200 | [diff] [blame] | 339 | } |
| 340 | |
| 341 | /** |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 342 | * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint |
| 343 | * @ept: endpoing to destroy |
| 344 | * |
| 345 | * Should be used by drivers to destroy an rpmsg endpoint previously |
| 346 | * created with rpmsg_create_ept(). |
| 347 | */ |
| 348 | void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) |
| 349 | { |
Ohad Ben-Cohen | fa2d779 | 2012-02-09 15:16:41 +0200 | [diff] [blame] | 350 | __rpmsg_destroy_ept(ept->rpdev->vrp, ept); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 351 | } |
| 352 | EXPORT_SYMBOL(rpmsg_destroy_ept); |
| 353 | |
| 354 | /* |
| 355 | * when an rpmsg driver is probed with a channel, we seamlessly create |
| 356 | * it an endpoint, binding its rx callback to a unique local rpmsg |
| 357 | * address. |
| 358 | * |
| 359 | * if we need to, we also announce about this channel to the remote |
| 360 | * processor (needed in case the driver is exposing an rpmsg service). |
| 361 | */ |
| 362 | static int rpmsg_dev_probe(struct device *dev) |
| 363 | { |
| 364 | struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); |
| 365 | struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); |
| 366 | struct virtproc_info *vrp = rpdev->vrp; |
| 367 | struct rpmsg_endpoint *ept; |
| 368 | int err; |
| 369 | |
| 370 | ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, rpdev->src); |
| 371 | if (!ept) { |
| 372 | dev_err(dev, "failed to create endpoint\n"); |
| 373 | err = -ENOMEM; |
| 374 | goto out; |
| 375 | } |
| 376 | |
| 377 | rpdev->ept = ept; |
| 378 | rpdev->src = ept->addr; |
| 379 | |
| 380 | err = rpdrv->probe(rpdev); |
| 381 | if (err) { |
| 382 | dev_err(dev, "%s: failed: %d\n", __func__, err); |
| 383 | rpmsg_destroy_ept(ept); |
| 384 | goto out; |
| 385 | } |
| 386 | |
| 387 | /* need to tell remote processor's name service about this channel ? */ |
| 388 | if (rpdev->announce && |
| 389 | virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { |
| 390 | struct rpmsg_ns_msg nsm; |
| 391 | |
| 392 | strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); |
| 393 | nsm.addr = rpdev->src; |
| 394 | nsm.flags = RPMSG_NS_CREATE; |
| 395 | |
| 396 | err = rpmsg_sendto(rpdev, &nsm, sizeof(nsm), RPMSG_NS_ADDR); |
| 397 | if (err) |
| 398 | dev_err(dev, "failed to announce service %d\n", err); |
| 399 | } |
| 400 | |
| 401 | out: |
| 402 | return err; |
| 403 | } |
| 404 | |
| 405 | static int rpmsg_dev_remove(struct device *dev) |
| 406 | { |
| 407 | struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); |
| 408 | struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); |
| 409 | struct virtproc_info *vrp = rpdev->vrp; |
| 410 | int err = 0; |
| 411 | |
| 412 | /* tell remote processor's name service we're removing this channel */ |
| 413 | if (rpdev->announce && |
| 414 | virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { |
| 415 | struct rpmsg_ns_msg nsm; |
| 416 | |
| 417 | strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); |
| 418 | nsm.addr = rpdev->src; |
| 419 | nsm.flags = RPMSG_NS_DESTROY; |
| 420 | |
| 421 | err = rpmsg_sendto(rpdev, &nsm, sizeof(nsm), RPMSG_NS_ADDR); |
| 422 | if (err) |
| 423 | dev_err(dev, "failed to announce service %d\n", err); |
| 424 | } |
| 425 | |
| 426 | rpdrv->remove(rpdev); |
| 427 | |
| 428 | rpmsg_destroy_ept(rpdev->ept); |
| 429 | |
| 430 | return err; |
| 431 | } |
| 432 | |
| 433 | static struct bus_type rpmsg_bus = { |
| 434 | .name = "rpmsg", |
| 435 | .match = rpmsg_dev_match, |
| 436 | .dev_attrs = rpmsg_dev_attrs, |
| 437 | .uevent = rpmsg_uevent, |
| 438 | .probe = rpmsg_dev_probe, |
| 439 | .remove = rpmsg_dev_remove, |
| 440 | }; |
| 441 | |
| 442 | /** |
| 443 | * register_rpmsg_driver() - register an rpmsg driver with the rpmsg bus |
| 444 | * @rpdrv: pointer to a struct rpmsg_driver |
| 445 | * |
| 446 | * Returns 0 on success, and an appropriate error value on failure. |
| 447 | */ |
| 448 | int register_rpmsg_driver(struct rpmsg_driver *rpdrv) |
| 449 | { |
| 450 | rpdrv->drv.bus = &rpmsg_bus; |
| 451 | return driver_register(&rpdrv->drv); |
| 452 | } |
| 453 | EXPORT_SYMBOL(register_rpmsg_driver); |
| 454 | |
| 455 | /** |
| 456 | * unregister_rpmsg_driver() - unregister an rpmsg driver from the rpmsg bus |
| 457 | * @rpdrv: pointer to a struct rpmsg_driver |
| 458 | * |
| 459 | * Returns 0 on success, and an appropriate error value on failure. |
| 460 | */ |
| 461 | void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv) |
| 462 | { |
| 463 | driver_unregister(&rpdrv->drv); |
| 464 | } |
| 465 | EXPORT_SYMBOL(unregister_rpmsg_driver); |
| 466 | |
| 467 | static void rpmsg_release_device(struct device *dev) |
| 468 | { |
| 469 | struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); |
| 470 | |
| 471 | kfree(rpdev); |
| 472 | } |
| 473 | |
| 474 | /* |
| 475 | * match an rpmsg channel with a channel info struct. |
| 476 | * this is used to make sure we're not creating rpmsg devices for channels |
| 477 | * that already exist. |
| 478 | */ |
| 479 | static int rpmsg_channel_match(struct device *dev, void *data) |
| 480 | { |
| 481 | struct rpmsg_channel_info *chinfo = data; |
| 482 | struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); |
| 483 | |
| 484 | if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src) |
| 485 | return 0; |
| 486 | |
| 487 | if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst) |
| 488 | return 0; |
| 489 | |
| 490 | if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE)) |
| 491 | return 0; |
| 492 | |
| 493 | /* found a match ! */ |
| 494 | return 1; |
| 495 | } |
| 496 | |
| 497 | /* |
| 498 | * create an rpmsg channel using its name and address info. |
| 499 | * this function will be used to create both static and dynamic |
| 500 | * channels. |
| 501 | */ |
| 502 | static struct rpmsg_channel *rpmsg_create_channel(struct virtproc_info *vrp, |
| 503 | struct rpmsg_channel_info *chinfo) |
| 504 | { |
| 505 | struct rpmsg_channel *rpdev; |
| 506 | struct device *tmp, *dev = &vrp->vdev->dev; |
| 507 | int ret; |
| 508 | |
| 509 | /* make sure a similar channel doesn't already exist */ |
| 510 | tmp = device_find_child(dev, chinfo, rpmsg_channel_match); |
| 511 | if (tmp) { |
| 512 | /* decrement the matched device's refcount back */ |
| 513 | put_device(tmp); |
| 514 | dev_err(dev, "channel %s:%x:%x already exist\n", |
| 515 | chinfo->name, chinfo->src, chinfo->dst); |
| 516 | return NULL; |
| 517 | } |
| 518 | |
| 519 | rpdev = kzalloc(sizeof(struct rpmsg_channel), GFP_KERNEL); |
| 520 | if (!rpdev) { |
| 521 | pr_err("kzalloc failed\n"); |
| 522 | return NULL; |
| 523 | } |
| 524 | |
| 525 | rpdev->vrp = vrp; |
| 526 | rpdev->src = chinfo->src; |
| 527 | rpdev->dst = chinfo->dst; |
| 528 | |
| 529 | /* |
| 530 | * rpmsg server channels has predefined local address (for now), |
| 531 | * and their existence needs to be announced remotely |
| 532 | */ |
| 533 | rpdev->announce = rpdev->src != RPMSG_ADDR_ANY ? true : false; |
| 534 | |
| 535 | strncpy(rpdev->id.name, chinfo->name, RPMSG_NAME_SIZE); |
| 536 | |
| 537 | /* very simple device indexing plumbing which is enough for now */ |
| 538 | dev_set_name(&rpdev->dev, "rpmsg%d", rpmsg_dev_index++); |
| 539 | |
| 540 | rpdev->dev.parent = &vrp->vdev->dev; |
| 541 | rpdev->dev.bus = &rpmsg_bus; |
| 542 | rpdev->dev.release = rpmsg_release_device; |
| 543 | |
| 544 | ret = device_register(&rpdev->dev); |
| 545 | if (ret) { |
| 546 | dev_err(dev, "device_register failed: %d\n", ret); |
| 547 | put_device(&rpdev->dev); |
| 548 | return NULL; |
| 549 | } |
| 550 | |
| 551 | return rpdev; |
| 552 | } |
| 553 | |
| 554 | /* |
| 555 | * find an existing channel using its name + address properties, |
| 556 | * and destroy it |
| 557 | */ |
| 558 | static int rpmsg_destroy_channel(struct virtproc_info *vrp, |
| 559 | struct rpmsg_channel_info *chinfo) |
| 560 | { |
| 561 | struct virtio_device *vdev = vrp->vdev; |
| 562 | struct device *dev; |
| 563 | |
| 564 | dev = device_find_child(&vdev->dev, chinfo, rpmsg_channel_match); |
| 565 | if (!dev) |
| 566 | return -EINVAL; |
| 567 | |
| 568 | device_unregister(dev); |
| 569 | |
| 570 | put_device(dev); |
| 571 | |
| 572 | return 0; |
| 573 | } |
| 574 | |
| 575 | /* super simple buffer "allocator" that is just enough for now */ |
| 576 | static void *get_a_tx_buf(struct virtproc_info *vrp) |
| 577 | { |
| 578 | unsigned int len; |
| 579 | void *ret; |
| 580 | |
| 581 | /* support multiple concurrent senders */ |
| 582 | mutex_lock(&vrp->tx_lock); |
| 583 | |
| 584 | /* |
| 585 | * either pick the next unused tx buffer |
| 586 | * (half of our buffers are used for sending messages) |
| 587 | */ |
| 588 | if (vrp->last_sbuf < RPMSG_NUM_BUFS / 2) |
| 589 | ret = vrp->sbufs + RPMSG_BUF_SIZE * vrp->last_sbuf++; |
| 590 | /* or recycle a used one */ |
| 591 | else |
| 592 | ret = virtqueue_get_buf(vrp->svq, &len); |
| 593 | |
| 594 | mutex_unlock(&vrp->tx_lock); |
| 595 | |
| 596 | return ret; |
| 597 | } |
| 598 | |
| 599 | /** |
| 600 | * rpmsg_upref_sleepers() - enable "tx-complete" interrupts, if needed |
| 601 | * @vrp: virtual remote processor state |
| 602 | * |
| 603 | * This function is called before a sender is blocked, waiting for |
| 604 | * a tx buffer to become available. |
| 605 | * |
| 606 | * If we already have blocking senders, this function merely increases |
| 607 | * the "sleepers" reference count, and exits. |
| 608 | * |
| 609 | * Otherwise, if this is the first sender to block, we also enable |
| 610 | * virtio's tx callbacks, so we'd be immediately notified when a tx |
| 611 | * buffer is consumed (we rely on virtio's tx callback in order |
| 612 | * to wake up sleeping senders as soon as a tx buffer is used by the |
| 613 | * remote processor). |
| 614 | */ |
| 615 | static void rpmsg_upref_sleepers(struct virtproc_info *vrp) |
| 616 | { |
| 617 | /* support multiple concurrent senders */ |
| 618 | mutex_lock(&vrp->tx_lock); |
| 619 | |
| 620 | /* are we the first sleeping context waiting for tx buffers ? */ |
| 621 | if (atomic_inc_return(&vrp->sleepers) == 1) |
| 622 | /* enable "tx-complete" interrupts before dozing off */ |
| 623 | virtqueue_enable_cb(vrp->svq); |
| 624 | |
| 625 | mutex_unlock(&vrp->tx_lock); |
| 626 | } |
| 627 | |
| 628 | /** |
| 629 | * rpmsg_downref_sleepers() - disable "tx-complete" interrupts, if needed |
| 630 | * @vrp: virtual remote processor state |
| 631 | * |
| 632 | * This function is called after a sender, that waited for a tx buffer |
| 633 | * to become available, is unblocked. |
| 634 | * |
| 635 | * If we still have blocking senders, this function merely decreases |
| 636 | * the "sleepers" reference count, and exits. |
| 637 | * |
| 638 | * Otherwise, if there are no more blocking senders, we also disable |
| 639 | * virtio's tx callbacks, to avoid the overhead incurred with handling |
| 640 | * those (now redundant) interrupts. |
| 641 | */ |
| 642 | static void rpmsg_downref_sleepers(struct virtproc_info *vrp) |
| 643 | { |
| 644 | /* support multiple concurrent senders */ |
| 645 | mutex_lock(&vrp->tx_lock); |
| 646 | |
| 647 | /* are we the last sleeping context waiting for tx buffers ? */ |
| 648 | if (atomic_dec_and_test(&vrp->sleepers)) |
| 649 | /* disable "tx-complete" interrupts */ |
| 650 | virtqueue_disable_cb(vrp->svq); |
| 651 | |
| 652 | mutex_unlock(&vrp->tx_lock); |
| 653 | } |
| 654 | |
| 655 | /** |
| 656 | * rpmsg_send_offchannel_raw() - send a message across to the remote processor |
| 657 | * @rpdev: the rpmsg channel |
| 658 | * @src: source address |
| 659 | * @dst: destination address |
| 660 | * @data: payload of message |
| 661 | * @len: length of payload |
| 662 | * @wait: indicates whether caller should block in case no TX buffers available |
| 663 | * |
| 664 | * This function is the base implementation for all of the rpmsg sending API. |
| 665 | * |
| 666 | * It will send @data of length @len to @dst, and say it's from @src. The |
| 667 | * message will be sent to the remote processor which the @rpdev channel |
| 668 | * belongs to. |
| 669 | * |
| 670 | * The message is sent using one of the TX buffers that are available for |
| 671 | * communication with this remote processor. |
| 672 | * |
| 673 | * If @wait is true, the caller will be blocked until either a TX buffer is |
| 674 | * available, or 15 seconds elapses (we don't want callers to |
| 675 | * sleep indefinitely due to misbehaving remote processors), and in that |
| 676 | * case -ERESTARTSYS is returned. The number '15' itself was picked |
| 677 | * arbitrarily; there's little point in asking drivers to provide a timeout |
| 678 | * value themselves. |
| 679 | * |
| 680 | * Otherwise, if @wait is false, and there are no TX buffers available, |
| 681 | * the function will immediately fail, and -ENOMEM will be returned. |
| 682 | * |
| 683 | * Normally drivers shouldn't use this function directly; instead, drivers |
| 684 | * should use the appropriate rpmsg_{try}send{to, _offchannel} API |
| 685 | * (see include/linux/rpmsg.h). |
| 686 | * |
| 687 | * Returns 0 on success and an appropriate error value on failure. |
| 688 | */ |
| 689 | int rpmsg_send_offchannel_raw(struct rpmsg_channel *rpdev, u32 src, u32 dst, |
| 690 | void *data, int len, bool wait) |
| 691 | { |
| 692 | struct virtproc_info *vrp = rpdev->vrp; |
| 693 | struct device *dev = &rpdev->dev; |
| 694 | struct scatterlist sg; |
| 695 | struct rpmsg_hdr *msg; |
| 696 | int err; |
| 697 | |
| 698 | /* bcasting isn't allowed */ |
| 699 | if (src == RPMSG_ADDR_ANY || dst == RPMSG_ADDR_ANY) { |
| 700 | dev_err(dev, "invalid addr (src 0x%x, dst 0x%x)\n", src, dst); |
| 701 | return -EINVAL; |
| 702 | } |
| 703 | |
| 704 | /* |
| 705 | * We currently use fixed-sized buffers, and therefore the payload |
| 706 | * length is limited. |
| 707 | * |
| 708 | * One of the possible improvements here is either to support |
| 709 | * user-provided buffers (and then we can also support zero-copy |
| 710 | * messaging), or to improve the buffer allocator, to support |
| 711 | * variable-length buffer sizes. |
| 712 | */ |
| 713 | if (len > RPMSG_BUF_SIZE - sizeof(struct rpmsg_hdr)) { |
| 714 | dev_err(dev, "message is too big (%d)\n", len); |
| 715 | return -EMSGSIZE; |
| 716 | } |
| 717 | |
| 718 | /* grab a buffer */ |
| 719 | msg = get_a_tx_buf(vrp); |
| 720 | if (!msg && !wait) |
| 721 | return -ENOMEM; |
| 722 | |
| 723 | /* no free buffer ? wait for one (but bail after 15 seconds) */ |
| 724 | while (!msg) { |
| 725 | /* enable "tx-complete" interrupts, if not already enabled */ |
| 726 | rpmsg_upref_sleepers(vrp); |
| 727 | |
| 728 | /* |
| 729 | * sleep until a free buffer is available or 15 secs elapse. |
| 730 | * the timeout period is not configurable because there's |
| 731 | * little point in asking drivers to specify that. |
| 732 | * if later this happens to be required, it'd be easy to add. |
| 733 | */ |
| 734 | err = wait_event_interruptible_timeout(vrp->sendq, |
| 735 | (msg = get_a_tx_buf(vrp)), |
| 736 | msecs_to_jiffies(15000)); |
| 737 | |
| 738 | /* disable "tx-complete" interrupts if we're the last sleeper */ |
| 739 | rpmsg_downref_sleepers(vrp); |
| 740 | |
| 741 | /* timeout ? */ |
| 742 | if (!err) { |
| 743 | dev_err(dev, "timeout waiting for a tx buffer\n"); |
| 744 | return -ERESTARTSYS; |
| 745 | } |
| 746 | } |
| 747 | |
| 748 | msg->len = len; |
| 749 | msg->flags = 0; |
| 750 | msg->src = src; |
| 751 | msg->dst = dst; |
| 752 | msg->reserved = 0; |
| 753 | memcpy(msg->data, data, len); |
| 754 | |
| 755 | dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Reserved %d\n", |
| 756 | msg->src, msg->dst, msg->len, |
| 757 | msg->flags, msg->reserved); |
| 758 | print_hex_dump(KERN_DEBUG, "rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1, |
| 759 | msg, sizeof(*msg) + msg->len, true); |
| 760 | |
| 761 | sg_init_one(&sg, msg, sizeof(*msg) + len); |
| 762 | |
| 763 | mutex_lock(&vrp->tx_lock); |
| 764 | |
| 765 | /* add message to the remote processor's virtqueue */ |
Axel Lin | b719587 | 2012-01-12 09:00:27 +0200 | [diff] [blame] | 766 | err = virtqueue_add_buf(vrp->svq, &sg, 1, 0, msg, GFP_KERNEL); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 767 | if (err < 0) { |
| 768 | /* |
| 769 | * need to reclaim the buffer here, otherwise it's lost |
| 770 | * (memory won't leak, but rpmsg won't use it again for TX). |
| 771 | * this will wait for a buffer management overhaul. |
| 772 | */ |
Axel Lin | b719587 | 2012-01-12 09:00:27 +0200 | [diff] [blame] | 773 | dev_err(dev, "virtqueue_add_buf failed: %d\n", err); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 774 | goto out; |
| 775 | } |
| 776 | |
| 777 | /* tell the remote processor it has a pending message to read */ |
| 778 | virtqueue_kick(vrp->svq); |
| 779 | |
| 780 | err = 0; |
| 781 | out: |
| 782 | mutex_unlock(&vrp->tx_lock); |
| 783 | return err; |
| 784 | } |
| 785 | EXPORT_SYMBOL(rpmsg_send_offchannel_raw); |
| 786 | |
| 787 | /* called when an rx buffer is used, and it's time to digest a message */ |
| 788 | static void rpmsg_recv_done(struct virtqueue *rvq) |
| 789 | { |
| 790 | struct rpmsg_hdr *msg; |
| 791 | unsigned int len; |
| 792 | struct rpmsg_endpoint *ept; |
| 793 | struct scatterlist sg; |
| 794 | struct virtproc_info *vrp = rvq->vdev->priv; |
| 795 | struct device *dev = &rvq->vdev->dev; |
| 796 | int err; |
| 797 | |
| 798 | msg = virtqueue_get_buf(rvq, &len); |
| 799 | if (!msg) { |
| 800 | dev_err(dev, "uhm, incoming signal, but no used buffer ?\n"); |
| 801 | return; |
| 802 | } |
| 803 | |
| 804 | dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Reserved: %d\n", |
| 805 | msg->src, msg->dst, msg->len, |
| 806 | msg->flags, msg->reserved); |
| 807 | print_hex_dump(KERN_DEBUG, "rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1, |
| 808 | msg, sizeof(*msg) + msg->len, true); |
| 809 | |
Ohad Ben-Cohen | 9648224 | 2012-02-28 16:16:48 +0200 | [diff] [blame] | 810 | /* |
| 811 | * We currently use fixed-sized buffers, so trivially sanitize |
| 812 | * the reported payload length. |
| 813 | */ |
| 814 | if (len > RPMSG_BUF_SIZE || |
| 815 | msg->len > (len - sizeof(struct rpmsg_hdr))) { |
| 816 | dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg->len); |
| 817 | return; |
| 818 | } |
| 819 | |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 820 | /* use the dst addr to fetch the callback of the appropriate user */ |
| 821 | mutex_lock(&vrp->endpoints_lock); |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 822 | |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 823 | ept = idr_find(&vrp->endpoints, msg->dst); |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 824 | |
| 825 | /* let's make sure no one deallocates ept while we use it */ |
| 826 | if (ept) |
| 827 | kref_get(&ept->refcount); |
| 828 | |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 829 | mutex_unlock(&vrp->endpoints_lock); |
| 830 | |
Ohad Ben-Cohen | d87127d | 2012-06-07 15:39:35 +0300 | [diff] [blame] | 831 | if (ept) { |
| 832 | /* make sure ept->cb doesn't go away while we use it */ |
| 833 | mutex_lock(&ept->cb_lock); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 834 | |
Ohad Ben-Cohen | d87127d | 2012-06-07 15:39:35 +0300 | [diff] [blame] | 835 | if (ept->cb) |
| 836 | ept->cb(ept->rpdev, msg->data, msg->len, ept->priv, |
| 837 | msg->src); |
| 838 | |
| 839 | mutex_unlock(&ept->cb_lock); |
| 840 | |
| 841 | /* farewell, ept, we don't need you anymore */ |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 842 | kref_put(&ept->refcount, __ept_release); |
Ohad Ben-Cohen | d87127d | 2012-06-07 15:39:35 +0300 | [diff] [blame] | 843 | } else |
| 844 | dev_warn(dev, "msg received with no recepient\n"); |
Ohad Ben-Cohen | a299827 | 2012-06-06 10:09:25 +0300 | [diff] [blame] | 845 | |
Ohad Ben-Cohen | f1d9e9c | 2012-02-28 16:11:28 +0200 | [diff] [blame] | 846 | /* publish the real size of the buffer */ |
| 847 | sg_init_one(&sg, msg, RPMSG_BUF_SIZE); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 848 | |
| 849 | /* add the buffer back to the remote processor's virtqueue */ |
Axel Lin | b719587 | 2012-01-12 09:00:27 +0200 | [diff] [blame] | 850 | err = virtqueue_add_buf(vrp->rvq, &sg, 0, 1, msg, GFP_KERNEL); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 851 | if (err < 0) { |
| 852 | dev_err(dev, "failed to add a virtqueue buffer: %d\n", err); |
| 853 | return; |
| 854 | } |
| 855 | |
| 856 | /* tell the remote processor we added another available rx buffer */ |
| 857 | virtqueue_kick(vrp->rvq); |
| 858 | } |
| 859 | |
| 860 | /* |
| 861 | * This is invoked whenever the remote processor completed processing |
| 862 | * a TX msg we just sent it, and the buffer is put back to the used ring. |
| 863 | * |
| 864 | * Normally, though, we suppress this "tx complete" interrupt in order to |
| 865 | * avoid the incurred overhead. |
| 866 | */ |
| 867 | static void rpmsg_xmit_done(struct virtqueue *svq) |
| 868 | { |
| 869 | struct virtproc_info *vrp = svq->vdev->priv; |
| 870 | |
| 871 | dev_dbg(&svq->vdev->dev, "%s\n", __func__); |
| 872 | |
| 873 | /* wake up potential senders that are waiting for a tx buffer */ |
| 874 | wake_up_interruptible(&vrp->sendq); |
| 875 | } |
| 876 | |
| 877 | /* invoked when a name service announcement arrives */ |
| 878 | static void rpmsg_ns_cb(struct rpmsg_channel *rpdev, void *data, int len, |
| 879 | void *priv, u32 src) |
| 880 | { |
| 881 | struct rpmsg_ns_msg *msg = data; |
| 882 | struct rpmsg_channel *newch; |
| 883 | struct rpmsg_channel_info chinfo; |
| 884 | struct virtproc_info *vrp = priv; |
| 885 | struct device *dev = &vrp->vdev->dev; |
| 886 | int ret; |
| 887 | |
| 888 | print_hex_dump(KERN_DEBUG, "NS announcement: ", |
| 889 | DUMP_PREFIX_NONE, 16, 1, |
| 890 | data, len, true); |
| 891 | |
| 892 | if (len != sizeof(*msg)) { |
| 893 | dev_err(dev, "malformed ns msg (%d)\n", len); |
| 894 | return; |
| 895 | } |
| 896 | |
| 897 | /* |
| 898 | * the name service ept does _not_ belong to a real rpmsg channel, |
| 899 | * and is handled by the rpmsg bus itself. |
| 900 | * for sanity reasons, make sure a valid rpdev has _not_ sneaked |
| 901 | * in somehow. |
| 902 | */ |
| 903 | if (rpdev) { |
| 904 | dev_err(dev, "anomaly: ns ept has an rpdev handle\n"); |
| 905 | return; |
| 906 | } |
| 907 | |
| 908 | /* don't trust the remote processor for null terminating the name */ |
| 909 | msg->name[RPMSG_NAME_SIZE - 1] = '\0'; |
| 910 | |
| 911 | dev_info(dev, "%sing channel %s addr 0x%x\n", |
| 912 | msg->flags & RPMSG_NS_DESTROY ? "destroy" : "creat", |
| 913 | msg->name, msg->addr); |
| 914 | |
| 915 | strncpy(chinfo.name, msg->name, sizeof(chinfo.name)); |
| 916 | chinfo.src = RPMSG_ADDR_ANY; |
| 917 | chinfo.dst = msg->addr; |
| 918 | |
| 919 | if (msg->flags & RPMSG_NS_DESTROY) { |
| 920 | ret = rpmsg_destroy_channel(vrp, &chinfo); |
| 921 | if (ret) |
| 922 | dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret); |
| 923 | } else { |
| 924 | newch = rpmsg_create_channel(vrp, &chinfo); |
| 925 | if (!newch) |
| 926 | dev_err(dev, "rpmsg_create_channel failed\n"); |
| 927 | } |
| 928 | } |
| 929 | |
| 930 | static int rpmsg_probe(struct virtio_device *vdev) |
| 931 | { |
| 932 | vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done }; |
| 933 | const char *names[] = { "input", "output" }; |
| 934 | struct virtqueue *vqs[2]; |
| 935 | struct virtproc_info *vrp; |
| 936 | void *bufs_va; |
| 937 | int err = 0, i; |
| 938 | |
| 939 | vrp = kzalloc(sizeof(*vrp), GFP_KERNEL); |
| 940 | if (!vrp) |
| 941 | return -ENOMEM; |
| 942 | |
| 943 | vrp->vdev = vdev; |
| 944 | |
| 945 | idr_init(&vrp->endpoints); |
| 946 | mutex_init(&vrp->endpoints_lock); |
| 947 | mutex_init(&vrp->tx_lock); |
| 948 | init_waitqueue_head(&vrp->sendq); |
| 949 | |
| 950 | /* We expect two virtqueues, rx and tx (and in this order) */ |
| 951 | err = vdev->config->find_vqs(vdev, 2, vqs, vq_cbs, names); |
| 952 | if (err) |
| 953 | goto free_vrp; |
| 954 | |
| 955 | vrp->rvq = vqs[0]; |
| 956 | vrp->svq = vqs[1]; |
| 957 | |
| 958 | /* allocate coherent memory for the buffers */ |
| 959 | bufs_va = dma_alloc_coherent(vdev->dev.parent, RPMSG_TOTAL_BUF_SPACE, |
| 960 | &vrp->bufs_dma, GFP_KERNEL); |
| 961 | if (!bufs_va) |
| 962 | goto vqs_del; |
| 963 | |
Mark Asselstine | 9d8ae5c | 2012-03-04 13:33:28 +0200 | [diff] [blame] | 964 | dev_dbg(&vdev->dev, "buffers: va %p, dma 0x%llx\n", bufs_va, |
| 965 | (unsigned long long)vrp->bufs_dma); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 966 | |
| 967 | /* half of the buffers is dedicated for RX */ |
| 968 | vrp->rbufs = bufs_va; |
| 969 | |
| 970 | /* and half is dedicated for TX */ |
| 971 | vrp->sbufs = bufs_va + RPMSG_TOTAL_BUF_SPACE / 2; |
| 972 | |
| 973 | /* set up the receive buffers */ |
| 974 | for (i = 0; i < RPMSG_NUM_BUFS / 2; i++) { |
| 975 | struct scatterlist sg; |
| 976 | void *cpu_addr = vrp->rbufs + i * RPMSG_BUF_SIZE; |
| 977 | |
| 978 | sg_init_one(&sg, cpu_addr, RPMSG_BUF_SIZE); |
| 979 | |
Axel Lin | b719587 | 2012-01-12 09:00:27 +0200 | [diff] [blame] | 980 | err = virtqueue_add_buf(vrp->rvq, &sg, 0, 1, cpu_addr, |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 981 | GFP_KERNEL); |
| 982 | WARN_ON(err < 0); /* sanity check; this can't really happen */ |
| 983 | } |
| 984 | |
| 985 | /* suppress "tx-complete" interrupts */ |
| 986 | virtqueue_disable_cb(vrp->svq); |
| 987 | |
| 988 | vdev->priv = vrp; |
| 989 | |
| 990 | /* if supported by the remote processor, enable the name service */ |
| 991 | if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) { |
| 992 | /* a dedicated endpoint handles the name service msgs */ |
| 993 | vrp->ns_ept = __rpmsg_create_ept(vrp, NULL, rpmsg_ns_cb, |
| 994 | vrp, RPMSG_NS_ADDR); |
| 995 | if (!vrp->ns_ept) { |
| 996 | dev_err(&vdev->dev, "failed to create the ns ept\n"); |
| 997 | err = -ENOMEM; |
| 998 | goto free_coherent; |
| 999 | } |
| 1000 | } |
| 1001 | |
| 1002 | /* tell the remote processor it can start sending messages */ |
| 1003 | virtqueue_kick(vrp->rvq); |
| 1004 | |
| 1005 | dev_info(&vdev->dev, "rpmsg host is online\n"); |
| 1006 | |
| 1007 | return 0; |
| 1008 | |
| 1009 | free_coherent: |
| 1010 | dma_free_coherent(vdev->dev.parent, RPMSG_TOTAL_BUF_SPACE, bufs_va, |
| 1011 | vrp->bufs_dma); |
| 1012 | vqs_del: |
| 1013 | vdev->config->del_vqs(vrp->vdev); |
| 1014 | free_vrp: |
| 1015 | kfree(vrp); |
| 1016 | return err; |
| 1017 | } |
| 1018 | |
| 1019 | static int rpmsg_remove_device(struct device *dev, void *data) |
| 1020 | { |
| 1021 | device_unregister(dev); |
| 1022 | |
| 1023 | return 0; |
| 1024 | } |
| 1025 | |
| 1026 | static void __devexit rpmsg_remove(struct virtio_device *vdev) |
| 1027 | { |
| 1028 | struct virtproc_info *vrp = vdev->priv; |
| 1029 | int ret; |
| 1030 | |
| 1031 | vdev->config->reset(vdev); |
| 1032 | |
| 1033 | ret = device_for_each_child(&vdev->dev, NULL, rpmsg_remove_device); |
| 1034 | if (ret) |
| 1035 | dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret); |
| 1036 | |
Ohad Ben-Cohen | fa2d779 | 2012-02-09 15:16:41 +0200 | [diff] [blame] | 1037 | if (vrp->ns_ept) |
| 1038 | __rpmsg_destroy_ept(vrp, vrp->ns_ept); |
| 1039 | |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 1040 | idr_remove_all(&vrp->endpoints); |
| 1041 | idr_destroy(&vrp->endpoints); |
| 1042 | |
| 1043 | vdev->config->del_vqs(vrp->vdev); |
| 1044 | |
| 1045 | dma_free_coherent(vdev->dev.parent, RPMSG_TOTAL_BUF_SPACE, |
| 1046 | vrp->rbufs, vrp->bufs_dma); |
| 1047 | |
| 1048 | kfree(vrp); |
| 1049 | } |
| 1050 | |
| 1051 | static struct virtio_device_id id_table[] = { |
| 1052 | { VIRTIO_ID_RPMSG, VIRTIO_DEV_ANY_ID }, |
| 1053 | { 0 }, |
| 1054 | }; |
| 1055 | |
| 1056 | static unsigned int features[] = { |
| 1057 | VIRTIO_RPMSG_F_NS, |
| 1058 | }; |
| 1059 | |
| 1060 | static struct virtio_driver virtio_ipc_driver = { |
| 1061 | .feature_table = features, |
| 1062 | .feature_table_size = ARRAY_SIZE(features), |
| 1063 | .driver.name = KBUILD_MODNAME, |
| 1064 | .driver.owner = THIS_MODULE, |
| 1065 | .id_table = id_table, |
| 1066 | .probe = rpmsg_probe, |
| 1067 | .remove = __devexit_p(rpmsg_remove), |
| 1068 | }; |
| 1069 | |
| 1070 | static int __init rpmsg_init(void) |
| 1071 | { |
| 1072 | int ret; |
| 1073 | |
| 1074 | ret = bus_register(&rpmsg_bus); |
| 1075 | if (ret) { |
| 1076 | pr_err("failed to register rpmsg bus: %d\n", ret); |
| 1077 | return ret; |
| 1078 | } |
| 1079 | |
| 1080 | ret = register_virtio_driver(&virtio_ipc_driver); |
| 1081 | if (ret) { |
| 1082 | pr_err("failed to register virtio driver: %d\n", ret); |
| 1083 | bus_unregister(&rpmsg_bus); |
| 1084 | } |
| 1085 | |
| 1086 | return ret; |
| 1087 | } |
Federico Fuga | 4bdf4f0 | 2012-07-16 10:36:51 +0300 | [diff] [blame] | 1088 | subsys_initcall(rpmsg_init); |
Ohad Ben-Cohen | bcabbcc | 2011-10-20 21:10:55 +0200 | [diff] [blame] | 1089 | |
| 1090 | static void __exit rpmsg_fini(void) |
| 1091 | { |
| 1092 | unregister_virtio_driver(&virtio_ipc_driver); |
| 1093 | bus_unregister(&rpmsg_bus); |
| 1094 | } |
| 1095 | module_exit(rpmsg_fini); |
| 1096 | |
| 1097 | MODULE_DEVICE_TABLE(virtio, id_table); |
| 1098 | MODULE_DESCRIPTION("Virtio-based remote processor messaging bus"); |
| 1099 | MODULE_LICENSE("GPL v2"); |