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c3bab824 | 1 | // SPDX-License-Identifier: GPL-2.0 |
bcabbcca OBC |
2 | /* |
3 | * Virtio-based remote processor messaging bus | |
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> | |
bcabbcca OBC |
10 | */ |
11 | ||
12 | #define pr_fmt(fmt) "%s: " fmt, __func__ | |
13 | ||
6de1c933 LP |
14 | #include <linux/dma-mapping.h> |
15 | #include <linux/idr.h> | |
16 | #include <linux/jiffies.h> | |
bcabbcca OBC |
17 | #include <linux/kernel.h> |
18 | #include <linux/module.h> | |
6de1c933 LP |
19 | #include <linux/mutex.h> |
20 | #include <linux/of_device.h> | |
21 | #include <linux/rpmsg.h> | |
5f2f6b7d | 22 | #include <linux/rpmsg/byteorder.h> |
c435a041 | 23 | #include <linux/rpmsg/ns.h> |
bcabbcca | 24 | #include <linux/scatterlist.h> |
bcabbcca | 25 | #include <linux/slab.h> |
bcabbcca | 26 | #include <linux/sched.h> |
6de1c933 LP |
27 | #include <linux/virtio.h> |
28 | #include <linux/virtio_ids.h> | |
29 | #include <linux/virtio_config.h> | |
bcabbcca | 30 | #include <linux/wait.h> |
bcabbcca | 31 | |
8b881c07 BA |
32 | #include "rpmsg_internal.h" |
33 | ||
bcabbcca OBC |
34 | /** |
35 | * struct virtproc_info - virtual remote processor state | |
36 | * @vdev: the virtio device | |
37 | * @rvq: rx virtqueue | |
38 | * @svq: tx virtqueue | |
39 | * @rbufs: kernel address of rx buffers | |
40 | * @sbufs: kernel address of tx buffers | |
b1b98914 | 41 | * @num_bufs: total number of buffers for rx and tx |
f93848f9 | 42 | * @buf_size: size of one rx or tx buffer |
bcabbcca OBC |
43 | * @last_sbuf: index of last tx buffer used |
44 | * @bufs_dma: dma base addr of the buffers | |
45 | * @tx_lock: protects svq, sbufs and sleepers, to allow concurrent senders. | |
46 | * sending a message might require waking up a dozing remote | |
47 | * processor, which involves sleeping, hence the mutex. | |
48 | * @endpoints: idr of local endpoints, allows fast retrieval | |
49 | * @endpoints_lock: lock of the endpoints set | |
50 | * @sendq: wait queue of sending contexts waiting for a tx buffers | |
51 | * @sleepers: number of senders that are waiting for a tx buffer | |
bcabbcca OBC |
52 | * |
53 | * This structure stores the rpmsg state of a given virtio remote processor | |
54 | * device (there might be several virtio proc devices for each physical | |
55 | * remote processor). | |
56 | */ | |
57 | struct virtproc_info { | |
58 | struct virtio_device *vdev; | |
59 | struct virtqueue *rvq, *svq; | |
60 | void *rbufs, *sbufs; | |
b1b98914 | 61 | unsigned int num_bufs; |
f93848f9 | 62 | unsigned int buf_size; |
bcabbcca OBC |
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; | |
bcabbcca OBC |
70 | }; |
71 | ||
e88dae5d BA |
72 | /* The feature bitmap for virtio rpmsg */ |
73 | #define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ | |
74 | ||
75 | /** | |
76 | * struct rpmsg_hdr - common header for all rpmsg messages | |
77 | * @src: source address | |
78 | * @dst: destination address | |
79 | * @reserved: reserved for future use | |
80 | * @len: length of payload (in bytes) | |
81 | * @flags: message flags | |
82 | * @data: @len bytes of message payload data | |
83 | * | |
84 | * Every message sent(/received) on the rpmsg bus begins with this header. | |
85 | */ | |
86 | struct rpmsg_hdr { | |
5f2f6b7d MP |
87 | __rpmsg32 src; |
88 | __rpmsg32 dst; | |
89 | __rpmsg32 reserved; | |
90 | __rpmsg16 len; | |
91 | __rpmsg16 flags; | |
4f05fc33 | 92 | u8 data[]; |
e88dae5d BA |
93 | } __packed; |
94 | ||
e88dae5d | 95 | |
3bf950ff | 96 | /** |
6c09ea0b AP |
97 | * struct virtio_rpmsg_channel - rpmsg channel descriptor |
98 | * @rpdev: the rpmsg channel device | |
99 | * @vrp: the virtio remote processor device this channel belongs to | |
100 | * | |
101 | * This structure stores the channel that links the rpmsg device to the virtio | |
102 | * remote processor device. | |
3bf950ff BA |
103 | */ |
104 | struct virtio_rpmsg_channel { | |
105 | struct rpmsg_device rpdev; | |
106 | ||
107 | struct virtproc_info *vrp; | |
108 | }; | |
109 | ||
110 | #define to_virtio_rpmsg_channel(_rpdev) \ | |
111 | container_of(_rpdev, struct virtio_rpmsg_channel, rpdev) | |
112 | ||
bcabbcca | 113 | /* |
b1b98914 SA |
114 | * We're allocating buffers of 512 bytes each for communications. The |
115 | * number of buffers will be computed from the number of buffers supported | |
116 | * by the vring, upto a maximum of 512 buffers (256 in each direction). | |
bcabbcca OBC |
117 | * |
118 | * Each buffer will have 16 bytes for the msg header and 496 bytes for | |
119 | * the payload. | |
120 | * | |
b1b98914 | 121 | * This will utilize a maximum total space of 256KB for the buffers. |
bcabbcca OBC |
122 | * |
123 | * We might also want to add support for user-provided buffers in time. | |
124 | * This will allow bigger buffer size flexibility, and can also be used | |
125 | * to achieve zero-copy messaging. | |
126 | * | |
127 | * Note that these numbers are purely a decision of this driver - we | |
128 | * can change this without changing anything in the firmware of the remote | |
129 | * processor. | |
130 | */ | |
b1b98914 | 131 | #define MAX_RPMSG_NUM_BUFS (512) |
f93848f9 | 132 | #define MAX_RPMSG_BUF_SIZE (512) |
bcabbcca OBC |
133 | |
134 | /* | |
135 | * Local addresses are dynamically allocated on-demand. | |
136 | * We do not dynamically assign addresses from the low 1024 range, | |
137 | * in order to reserve that address range for predefined services. | |
138 | */ | |
139 | #define RPMSG_RESERVED_ADDRESSES (1024) | |
140 | ||
8a228ecf BA |
141 | static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept); |
142 | static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); | |
143 | static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, | |
144 | u32 dst); | |
145 | static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, | |
146 | u32 dst, void *data, int len); | |
147 | static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); | |
148 | static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, | |
149 | int len, u32 dst); | |
150 | static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, | |
151 | u32 dst, void *data, int len); | |
1ee1e5e1 AP |
152 | static struct rpmsg_device *__rpmsg_create_channel(struct virtproc_info *vrp, |
153 | struct rpmsg_channel_info *chinfo); | |
bcabbcca | 154 | |
8a228ecf BA |
155 | static const struct rpmsg_endpoint_ops virtio_endpoint_ops = { |
156 | .destroy_ept = virtio_rpmsg_destroy_ept, | |
157 | .send = virtio_rpmsg_send, | |
158 | .sendto = virtio_rpmsg_sendto, | |
159 | .send_offchannel = virtio_rpmsg_send_offchannel, | |
160 | .trysend = virtio_rpmsg_trysend, | |
161 | .trysendto = virtio_rpmsg_trysendto, | |
162 | .trysend_offchannel = virtio_rpmsg_trysend_offchannel, | |
163 | }; | |
164 | ||
9dd87c2a LP |
165 | /** |
166 | * rpmsg_sg_init - initialize scatterlist according to cpu address location | |
167 | * @sg: scatterlist to fill | |
168 | * @cpu_addr: virtual address of the buffer | |
169 | * @len: buffer length | |
170 | * | |
171 | * An internal function filling scatterlist according to virtual address | |
172 | * location (in vmalloc or in kernel). | |
173 | */ | |
174 | static void | |
175 | rpmsg_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len) | |
176 | { | |
177 | if (is_vmalloc_addr(cpu_addr)) { | |
178 | sg_init_table(sg, 1); | |
179 | sg_set_page(sg, vmalloc_to_page(cpu_addr), len, | |
180 | offset_in_page(cpu_addr)); | |
181 | } else { | |
182 | WARN_ON(!virt_addr_valid(cpu_addr)); | |
183 | sg_init_one(sg, cpu_addr, len); | |
184 | } | |
185 | } | |
186 | ||
5a081caa OBC |
187 | /** |
188 | * __ept_release() - deallocate an rpmsg endpoint | |
189 | * @kref: the ept's reference count | |
190 | * | |
191 | * This function deallocates an ept, and is invoked when its @kref refcount | |
192 | * drops to zero. | |
193 | * | |
194 | * Never invoke this function directly! | |
195 | */ | |
196 | static void __ept_release(struct kref *kref) | |
197 | { | |
198 | struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, | |
199 | refcount); | |
200 | /* | |
201 | * At this point no one holds a reference to ept anymore, | |
202 | * so we can directly free it | |
203 | */ | |
204 | kfree(ept); | |
205 | } | |
206 | ||
bcabbcca OBC |
207 | /* for more info, see below documentation of rpmsg_create_ept() */ |
208 | static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp, | |
92e1de51 | 209 | struct rpmsg_device *rpdev, |
0963679c AS |
210 | rpmsg_rx_cb_t cb, |
211 | void *priv, u32 addr) | |
bcabbcca | 212 | { |
d0ffce77 | 213 | int id_min, id_max, id; |
bcabbcca OBC |
214 | struct rpmsg_endpoint *ept; |
215 | struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev; | |
216 | ||
bcabbcca | 217 | ept = kzalloc(sizeof(*ept), GFP_KERNEL); |
a8bb3fd9 | 218 | if (!ept) |
bcabbcca | 219 | return NULL; |
bcabbcca | 220 | |
5a081caa | 221 | kref_init(&ept->refcount); |
15fd943a | 222 | mutex_init(&ept->cb_lock); |
5a081caa | 223 | |
bcabbcca OBC |
224 | ept->rpdev = rpdev; |
225 | ept->cb = cb; | |
226 | ept->priv = priv; | |
8a228ecf | 227 | ept->ops = &virtio_endpoint_ops; |
bcabbcca OBC |
228 | |
229 | /* do we need to allocate a local address ? */ | |
d0ffce77 TH |
230 | if (addr == RPMSG_ADDR_ANY) { |
231 | id_min = RPMSG_RESERVED_ADDRESSES; | |
232 | id_max = 0; | |
233 | } else { | |
234 | id_min = addr; | |
235 | id_max = addr + 1; | |
236 | } | |
bcabbcca OBC |
237 | |
238 | mutex_lock(&vrp->endpoints_lock); | |
239 | ||
240 | /* bind the endpoint to an rpmsg address (and allocate one if needed) */ | |
d0ffce77 TH |
241 | id = idr_alloc(&vrp->endpoints, ept, id_min, id_max, GFP_KERNEL); |
242 | if (id < 0) { | |
243 | dev_err(dev, "idr_alloc failed: %d\n", id); | |
bcabbcca OBC |
244 | goto free_ept; |
245 | } | |
d0ffce77 | 246 | ept->addr = id; |
bcabbcca OBC |
247 | |
248 | mutex_unlock(&vrp->endpoints_lock); | |
249 | ||
250 | return ept; | |
251 | ||
bcabbcca OBC |
252 | free_ept: |
253 | mutex_unlock(&vrp->endpoints_lock); | |
5a081caa | 254 | kref_put(&ept->refcount, __ept_release); |
bcabbcca OBC |
255 | return NULL; |
256 | } | |
257 | ||
1ee1e5e1 AP |
258 | static struct rpmsg_device *virtio_rpmsg_create_channel(struct rpmsg_device *rpdev, |
259 | struct rpmsg_channel_info *chinfo) | |
260 | { | |
261 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); | |
262 | struct virtproc_info *vrp = vch->vrp; | |
263 | ||
264 | return __rpmsg_create_channel(vrp, chinfo); | |
265 | } | |
266 | ||
267 | static int virtio_rpmsg_release_channel(struct rpmsg_device *rpdev, | |
268 | struct rpmsg_channel_info *chinfo) | |
269 | { | |
270 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); | |
271 | struct virtproc_info *vrp = vch->vrp; | |
272 | ||
273 | return rpmsg_unregister_device(&vrp->vdev->dev, chinfo); | |
274 | } | |
275 | ||
36b72c7d BA |
276 | static struct rpmsg_endpoint *virtio_rpmsg_create_ept(struct rpmsg_device *rpdev, |
277 | rpmsg_rx_cb_t cb, | |
278 | void *priv, | |
279 | struct rpmsg_channel_info chinfo) | |
280 | { | |
3bf950ff BA |
281 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
282 | ||
283 | return __rpmsg_create_ept(vch->vrp, rpdev, cb, priv, chinfo.src); | |
36b72c7d BA |
284 | } |
285 | ||
bcabbcca | 286 | /** |
fa2d7795 OBC |
287 | * __rpmsg_destroy_ept() - destroy an existing rpmsg endpoint |
288 | * @vrp: virtproc which owns this ept | |
bcabbcca OBC |
289 | * @ept: endpoing to destroy |
290 | * | |
fa2d7795 OBC |
291 | * An internal function which destroy an ept without assuming it is |
292 | * bound to an rpmsg channel. This is needed for handling the internal | |
293 | * name service endpoint, which isn't bound to an rpmsg channel. | |
294 | * See also __rpmsg_create_ept(). | |
bcabbcca | 295 | */ |
fa2d7795 OBC |
296 | static void |
297 | __rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept) | |
bcabbcca | 298 | { |
15fd943a | 299 | /* make sure new inbound messages can't find this ept anymore */ |
bcabbcca OBC |
300 | mutex_lock(&vrp->endpoints_lock); |
301 | idr_remove(&vrp->endpoints, ept->addr); | |
302 | mutex_unlock(&vrp->endpoints_lock); | |
303 | ||
15fd943a OBC |
304 | /* make sure in-flight inbound messages won't invoke cb anymore */ |
305 | mutex_lock(&ept->cb_lock); | |
306 | ept->cb = NULL; | |
307 | mutex_unlock(&ept->cb_lock); | |
308 | ||
5a081caa | 309 | kref_put(&ept->refcount, __ept_release); |
bcabbcca | 310 | } |
fa2d7795 | 311 | |
8a228ecf BA |
312 | static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept) |
313 | { | |
3bf950ff BA |
314 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(ept->rpdev); |
315 | ||
316 | __rpmsg_destroy_ept(vch->vrp, ept); | |
8a228ecf BA |
317 | } |
318 | ||
36b72c7d BA |
319 | static int virtio_rpmsg_announce_create(struct rpmsg_device *rpdev) |
320 | { | |
3bf950ff BA |
321 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
322 | struct virtproc_info *vrp = vch->vrp; | |
36b72c7d BA |
323 | struct device *dev = &rpdev->dev; |
324 | int err = 0; | |
325 | ||
bcabbcca | 326 | /* need to tell remote processor's name service about this channel ? */ |
b2599ebf | 327 | if (rpdev->announce && rpdev->ept && |
0963679c | 328 | virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { |
bcabbcca OBC |
329 | struct rpmsg_ns_msg nsm; |
330 | ||
331 | strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); | |
5f2f6b7d MP |
332 | nsm.addr = cpu_to_rpmsg32(rpdev, rpdev->ept->addr); |
333 | nsm.flags = cpu_to_rpmsg32(rpdev, RPMSG_NS_CREATE); | |
bcabbcca | 334 | |
2a48d732 | 335 | err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR); |
bcabbcca OBC |
336 | if (err) |
337 | dev_err(dev, "failed to announce service %d\n", err); | |
338 | } | |
339 | ||
bcabbcca OBC |
340 | return err; |
341 | } | |
342 | ||
36b72c7d | 343 | static int virtio_rpmsg_announce_destroy(struct rpmsg_device *rpdev) |
bcabbcca | 344 | { |
3bf950ff BA |
345 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
346 | struct virtproc_info *vrp = vch->vrp; | |
36b72c7d | 347 | struct device *dev = &rpdev->dev; |
bcabbcca OBC |
348 | int err = 0; |
349 | ||
350 | /* tell remote processor's name service we're removing this channel */ | |
b2599ebf | 351 | if (rpdev->announce && rpdev->ept && |
0963679c | 352 | virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { |
bcabbcca OBC |
353 | struct rpmsg_ns_msg nsm; |
354 | ||
355 | strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); | |
5f2f6b7d MP |
356 | nsm.addr = cpu_to_rpmsg32(rpdev, rpdev->ept->addr); |
357 | nsm.flags = cpu_to_rpmsg32(rpdev, RPMSG_NS_DESTROY); | |
bcabbcca | 358 | |
2a48d732 | 359 | err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR); |
bcabbcca OBC |
360 | if (err) |
361 | dev_err(dev, "failed to announce service %d\n", err); | |
362 | } | |
363 | ||
36b72c7d BA |
364 | return err; |
365 | } | |
366 | ||
36b72c7d | 367 | static const struct rpmsg_device_ops virtio_rpmsg_ops = { |
1ee1e5e1 AP |
368 | .create_channel = virtio_rpmsg_create_channel, |
369 | .release_channel = virtio_rpmsg_release_channel, | |
36b72c7d BA |
370 | .create_ept = virtio_rpmsg_create_ept, |
371 | .announce_create = virtio_rpmsg_announce_create, | |
372 | .announce_destroy = virtio_rpmsg_announce_destroy, | |
373 | }; | |
374 | ||
b0b03b81 BA |
375 | static void virtio_rpmsg_release_device(struct device *dev) |
376 | { | |
377 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
378 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); | |
379 | ||
380 | kfree(vch); | |
381 | } | |
382 | ||
bcabbcca OBC |
383 | /* |
384 | * create an rpmsg channel using its name and address info. | |
385 | * this function will be used to create both static and dynamic | |
386 | * channels. | |
387 | */ | |
77d37298 AP |
388 | static struct rpmsg_device *__rpmsg_create_channel(struct virtproc_info *vrp, |
389 | struct rpmsg_channel_info *chinfo) | |
bcabbcca | 390 | { |
3bf950ff | 391 | struct virtio_rpmsg_channel *vch; |
92e1de51 | 392 | struct rpmsg_device *rpdev; |
bcabbcca OBC |
393 | struct device *tmp, *dev = &vrp->vdev->dev; |
394 | int ret; | |
395 | ||
396 | /* make sure a similar channel doesn't already exist */ | |
8b881c07 | 397 | tmp = rpmsg_find_device(dev, chinfo); |
bcabbcca OBC |
398 | if (tmp) { |
399 | /* decrement the matched device's refcount back */ | |
400 | put_device(tmp); | |
401 | dev_err(dev, "channel %s:%x:%x already exist\n", | |
402 | chinfo->name, chinfo->src, chinfo->dst); | |
403 | return NULL; | |
404 | } | |
405 | ||
3bf950ff BA |
406 | vch = kzalloc(sizeof(*vch), GFP_KERNEL); |
407 | if (!vch) | |
bcabbcca | 408 | return NULL; |
bcabbcca | 409 | |
3bf950ff BA |
410 | /* Link the channel to our vrp */ |
411 | vch->vrp = vrp; | |
412 | ||
3bf950ff BA |
413 | /* Assign public information to the rpmsg_device */ |
414 | rpdev = &vch->rpdev; | |
bcabbcca OBC |
415 | rpdev->src = chinfo->src; |
416 | rpdev->dst = chinfo->dst; | |
36b72c7d | 417 | rpdev->ops = &virtio_rpmsg_ops; |
5f2f6b7d | 418 | rpdev->little_endian = virtio_is_little_endian(vrp->vdev); |
bcabbcca OBC |
419 | |
420 | /* | |
421 | * rpmsg server channels has predefined local address (for now), | |
422 | * and their existence needs to be announced remotely | |
423 | */ | |
c8ced113 | 424 | rpdev->announce = rpdev->src != RPMSG_ADDR_ANY; |
bcabbcca OBC |
425 | |
426 | strncpy(rpdev->id.name, chinfo->name, RPMSG_NAME_SIZE); | |
427 | ||
6eed598a | 428 | rpdev->dev.parent = &vrp->vdev->dev; |
b0b03b81 | 429 | rpdev->dev.release = virtio_rpmsg_release_device; |
6eed598a BA |
430 | ret = rpmsg_register_device(rpdev); |
431 | if (ret) | |
432 | return NULL; | |
433 | ||
434 | return rpdev; | |
435 | } | |
436 | ||
bcabbcca OBC |
437 | /* super simple buffer "allocator" that is just enough for now */ |
438 | static void *get_a_tx_buf(struct virtproc_info *vrp) | |
439 | { | |
440 | unsigned int len; | |
441 | void *ret; | |
442 | ||
443 | /* support multiple concurrent senders */ | |
444 | mutex_lock(&vrp->tx_lock); | |
445 | ||
446 | /* | |
447 | * either pick the next unused tx buffer | |
448 | * (half of our buffers are used for sending messages) | |
449 | */ | |
b1b98914 | 450 | if (vrp->last_sbuf < vrp->num_bufs / 2) |
f93848f9 | 451 | ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++; |
bcabbcca OBC |
452 | /* or recycle a used one */ |
453 | else | |
454 | ret = virtqueue_get_buf(vrp->svq, &len); | |
455 | ||
456 | mutex_unlock(&vrp->tx_lock); | |
457 | ||
458 | return ret; | |
459 | } | |
460 | ||
461 | /** | |
462 | * rpmsg_upref_sleepers() - enable "tx-complete" interrupts, if needed | |
463 | * @vrp: virtual remote processor state | |
464 | * | |
465 | * This function is called before a sender is blocked, waiting for | |
466 | * a tx buffer to become available. | |
467 | * | |
468 | * If we already have blocking senders, this function merely increases | |
469 | * the "sleepers" reference count, and exits. | |
470 | * | |
471 | * Otherwise, if this is the first sender to block, we also enable | |
472 | * virtio's tx callbacks, so we'd be immediately notified when a tx | |
473 | * buffer is consumed (we rely on virtio's tx callback in order | |
474 | * to wake up sleeping senders as soon as a tx buffer is used by the | |
475 | * remote processor). | |
476 | */ | |
477 | static void rpmsg_upref_sleepers(struct virtproc_info *vrp) | |
478 | { | |
479 | /* support multiple concurrent senders */ | |
480 | mutex_lock(&vrp->tx_lock); | |
481 | ||
482 | /* are we the first sleeping context waiting for tx buffers ? */ | |
483 | if (atomic_inc_return(&vrp->sleepers) == 1) | |
484 | /* enable "tx-complete" interrupts before dozing off */ | |
485 | virtqueue_enable_cb(vrp->svq); | |
486 | ||
487 | mutex_unlock(&vrp->tx_lock); | |
488 | } | |
489 | ||
490 | /** | |
491 | * rpmsg_downref_sleepers() - disable "tx-complete" interrupts, if needed | |
492 | * @vrp: virtual remote processor state | |
493 | * | |
494 | * This function is called after a sender, that waited for a tx buffer | |
495 | * to become available, is unblocked. | |
496 | * | |
497 | * If we still have blocking senders, this function merely decreases | |
498 | * the "sleepers" reference count, and exits. | |
499 | * | |
500 | * Otherwise, if there are no more blocking senders, we also disable | |
501 | * virtio's tx callbacks, to avoid the overhead incurred with handling | |
502 | * those (now redundant) interrupts. | |
503 | */ | |
504 | static void rpmsg_downref_sleepers(struct virtproc_info *vrp) | |
505 | { | |
506 | /* support multiple concurrent senders */ | |
507 | mutex_lock(&vrp->tx_lock); | |
508 | ||
509 | /* are we the last sleeping context waiting for tx buffers ? */ | |
510 | if (atomic_dec_and_test(&vrp->sleepers)) | |
511 | /* disable "tx-complete" interrupts */ | |
512 | virtqueue_disable_cb(vrp->svq); | |
513 | ||
514 | mutex_unlock(&vrp->tx_lock); | |
515 | } | |
516 | ||
517 | /** | |
518 | * rpmsg_send_offchannel_raw() - send a message across to the remote processor | |
519 | * @rpdev: the rpmsg channel | |
520 | * @src: source address | |
521 | * @dst: destination address | |
522 | * @data: payload of message | |
523 | * @len: length of payload | |
524 | * @wait: indicates whether caller should block in case no TX buffers available | |
525 | * | |
526 | * This function is the base implementation for all of the rpmsg sending API. | |
527 | * | |
528 | * It will send @data of length @len to @dst, and say it's from @src. The | |
529 | * message will be sent to the remote processor which the @rpdev channel | |
530 | * belongs to. | |
531 | * | |
532 | * The message is sent using one of the TX buffers that are available for | |
533 | * communication with this remote processor. | |
534 | * | |
535 | * If @wait is true, the caller will be blocked until either a TX buffer is | |
536 | * available, or 15 seconds elapses (we don't want callers to | |
537 | * sleep indefinitely due to misbehaving remote processors), and in that | |
538 | * case -ERESTARTSYS is returned. The number '15' itself was picked | |
539 | * arbitrarily; there's little point in asking drivers to provide a timeout | |
540 | * value themselves. | |
541 | * | |
542 | * Otherwise, if @wait is false, and there are no TX buffers available, | |
543 | * the function will immediately fail, and -ENOMEM will be returned. | |
544 | * | |
545 | * Normally drivers shouldn't use this function directly; instead, drivers | |
546 | * should use the appropriate rpmsg_{try}send{to, _offchannel} API | |
547 | * (see include/linux/rpmsg.h). | |
548 | * | |
549 | * Returns 0 on success and an appropriate error value on failure. | |
550 | */ | |
8a228ecf BA |
551 | static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev, |
552 | u32 src, u32 dst, | |
553 | void *data, int len, bool wait) | |
bcabbcca | 554 | { |
3bf950ff BA |
555 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
556 | struct virtproc_info *vrp = vch->vrp; | |
bcabbcca OBC |
557 | struct device *dev = &rpdev->dev; |
558 | struct scatterlist sg; | |
559 | struct rpmsg_hdr *msg; | |
560 | int err; | |
561 | ||
562 | /* bcasting isn't allowed */ | |
563 | if (src == RPMSG_ADDR_ANY || dst == RPMSG_ADDR_ANY) { | |
564 | dev_err(dev, "invalid addr (src 0x%x, dst 0x%x)\n", src, dst); | |
565 | return -EINVAL; | |
566 | } | |
567 | ||
568 | /* | |
569 | * We currently use fixed-sized buffers, and therefore the payload | |
570 | * length is limited. | |
571 | * | |
572 | * One of the possible improvements here is either to support | |
573 | * user-provided buffers (and then we can also support zero-copy | |
574 | * messaging), or to improve the buffer allocator, to support | |
575 | * variable-length buffer sizes. | |
576 | */ | |
f93848f9 | 577 | if (len > vrp->buf_size - sizeof(struct rpmsg_hdr)) { |
bcabbcca OBC |
578 | dev_err(dev, "message is too big (%d)\n", len); |
579 | return -EMSGSIZE; | |
580 | } | |
581 | ||
582 | /* grab a buffer */ | |
583 | msg = get_a_tx_buf(vrp); | |
584 | if (!msg && !wait) | |
585 | return -ENOMEM; | |
586 | ||
587 | /* no free buffer ? wait for one (but bail after 15 seconds) */ | |
588 | while (!msg) { | |
589 | /* enable "tx-complete" interrupts, if not already enabled */ | |
590 | rpmsg_upref_sleepers(vrp); | |
591 | ||
592 | /* | |
593 | * sleep until a free buffer is available or 15 secs elapse. | |
594 | * the timeout period is not configurable because there's | |
595 | * little point in asking drivers to specify that. | |
596 | * if later this happens to be required, it'd be easy to add. | |
597 | */ | |
598 | err = wait_event_interruptible_timeout(vrp->sendq, | |
599 | (msg = get_a_tx_buf(vrp)), | |
600 | msecs_to_jiffies(15000)); | |
601 | ||
602 | /* disable "tx-complete" interrupts if we're the last sleeper */ | |
603 | rpmsg_downref_sleepers(vrp); | |
604 | ||
605 | /* timeout ? */ | |
606 | if (!err) { | |
607 | dev_err(dev, "timeout waiting for a tx buffer\n"); | |
608 | return -ERESTARTSYS; | |
609 | } | |
610 | } | |
611 | ||
5f2f6b7d | 612 | msg->len = cpu_to_rpmsg16(rpdev, len); |
bcabbcca | 613 | msg->flags = 0; |
5f2f6b7d MP |
614 | msg->src = cpu_to_rpmsg32(rpdev, src); |
615 | msg->dst = cpu_to_rpmsg32(rpdev, dst); | |
bcabbcca OBC |
616 | msg->reserved = 0; |
617 | memcpy(msg->data, data, len); | |
618 | ||
619 | dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Reserved %d\n", | |
111d1089 | 620 | src, dst, len, msg->flags, msg->reserved); |
211e3a93 AS |
621 | #if defined(CONFIG_DYNAMIC_DEBUG) |
622 | dynamic_hex_dump("rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1, | |
111d1089 | 623 | msg, sizeof(*msg) + len, true); |
211e3a93 | 624 | #endif |
bcabbcca | 625 | |
9dd87c2a | 626 | rpmsg_sg_init(&sg, msg, sizeof(*msg) + len); |
bcabbcca OBC |
627 | |
628 | mutex_lock(&vrp->tx_lock); | |
629 | ||
630 | /* add message to the remote processor's virtqueue */ | |
cee51d69 | 631 | err = virtqueue_add_outbuf(vrp->svq, &sg, 1, msg, GFP_KERNEL); |
57e1a373 | 632 | if (err) { |
bcabbcca OBC |
633 | /* |
634 | * need to reclaim the buffer here, otherwise it's lost | |
635 | * (memory won't leak, but rpmsg won't use it again for TX). | |
636 | * this will wait for a buffer management overhaul. | |
637 | */ | |
cee51d69 | 638 | dev_err(dev, "virtqueue_add_outbuf failed: %d\n", err); |
bcabbcca OBC |
639 | goto out; |
640 | } | |
641 | ||
642 | /* tell the remote processor it has a pending message to read */ | |
643 | virtqueue_kick(vrp->svq); | |
bcabbcca OBC |
644 | out: |
645 | mutex_unlock(&vrp->tx_lock); | |
646 | return err; | |
647 | } | |
bcabbcca | 648 | |
8a228ecf BA |
649 | static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) |
650 | { | |
651 | struct rpmsg_device *rpdev = ept->rpdev; | |
652 | u32 src = ept->addr, dst = rpdev->dst; | |
653 | ||
654 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
655 | } | |
656 | ||
657 | static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, | |
658 | u32 dst) | |
659 | { | |
660 | struct rpmsg_device *rpdev = ept->rpdev; | |
661 | u32 src = ept->addr; | |
662 | ||
663 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
664 | } | |
665 | ||
666 | static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, | |
667 | u32 dst, void *data, int len) | |
668 | { | |
669 | struct rpmsg_device *rpdev = ept->rpdev; | |
670 | ||
671 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
672 | } | |
673 | ||
674 | static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) | |
675 | { | |
676 | struct rpmsg_device *rpdev = ept->rpdev; | |
677 | u32 src = ept->addr, dst = rpdev->dst; | |
678 | ||
679 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
680 | } | |
681 | ||
682 | static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, | |
683 | int len, u32 dst) | |
684 | { | |
685 | struct rpmsg_device *rpdev = ept->rpdev; | |
686 | u32 src = ept->addr; | |
687 | ||
688 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
689 | } | |
690 | ||
691 | static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, | |
692 | u32 dst, void *data, int len) | |
693 | { | |
694 | struct rpmsg_device *rpdev = ept->rpdev; | |
695 | ||
696 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
697 | } | |
698 | ||
1aa7d6a5 RT |
699 | static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev, |
700 | struct rpmsg_hdr *msg, unsigned int len) | |
bcabbcca | 701 | { |
bcabbcca OBC |
702 | struct rpmsg_endpoint *ept; |
703 | struct scatterlist sg; | |
5f2f6b7d MP |
704 | bool little_endian = virtio_is_little_endian(vrp->vdev); |
705 | unsigned int msg_len = __rpmsg16_to_cpu(little_endian, msg->len); | |
bcabbcca OBC |
706 | int err; |
707 | ||
bcabbcca | 708 | dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Reserved: %d\n", |
5f2f6b7d MP |
709 | __rpmsg32_to_cpu(little_endian, msg->src), |
710 | __rpmsg32_to_cpu(little_endian, msg->dst), msg_len, | |
711 | __rpmsg16_to_cpu(little_endian, msg->flags), | |
712 | __rpmsg32_to_cpu(little_endian, msg->reserved)); | |
211e3a93 AS |
713 | #if defined(CONFIG_DYNAMIC_DEBUG) |
714 | dynamic_hex_dump("rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1, | |
111d1089 | 715 | msg, sizeof(*msg) + msg_len, true); |
211e3a93 | 716 | #endif |
bcabbcca | 717 | |
9648224e OBC |
718 | /* |
719 | * We currently use fixed-sized buffers, so trivially sanitize | |
720 | * the reported payload length. | |
721 | */ | |
f93848f9 | 722 | if (len > vrp->buf_size || |
111d1089 GL |
723 | msg_len > (len - sizeof(struct rpmsg_hdr))) { |
724 | dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg_len); | |
1aa7d6a5 | 725 | return -EINVAL; |
9648224e OBC |
726 | } |
727 | ||
bcabbcca OBC |
728 | /* use the dst addr to fetch the callback of the appropriate user */ |
729 | mutex_lock(&vrp->endpoints_lock); | |
5a081caa | 730 | |
5f2f6b7d | 731 | ept = idr_find(&vrp->endpoints, __rpmsg32_to_cpu(little_endian, msg->dst)); |
5a081caa OBC |
732 | |
733 | /* let's make sure no one deallocates ept while we use it */ | |
734 | if (ept) | |
735 | kref_get(&ept->refcount); | |
736 | ||
bcabbcca OBC |
737 | mutex_unlock(&vrp->endpoints_lock); |
738 | ||
15fd943a OBC |
739 | if (ept) { |
740 | /* make sure ept->cb doesn't go away while we use it */ | |
741 | mutex_lock(&ept->cb_lock); | |
bcabbcca | 742 | |
15fd943a | 743 | if (ept->cb) |
111d1089 | 744 | ept->cb(ept->rpdev, msg->data, msg_len, ept->priv, |
5f2f6b7d | 745 | __rpmsg32_to_cpu(little_endian, msg->src)); |
15fd943a OBC |
746 | |
747 | mutex_unlock(&ept->cb_lock); | |
748 | ||
749 | /* farewell, ept, we don't need you anymore */ | |
5a081caa | 750 | kref_put(&ept->refcount, __ept_release); |
15fd943a | 751 | } else |
8a168ca7 | 752 | dev_warn(dev, "msg received with no recipient\n"); |
5a081caa | 753 | |
f1d9e9c7 | 754 | /* publish the real size of the buffer */ |
9dd87c2a | 755 | rpmsg_sg_init(&sg, msg, vrp->buf_size); |
bcabbcca OBC |
756 | |
757 | /* add the buffer back to the remote processor's virtqueue */ | |
cee51d69 | 758 | err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL); |
bcabbcca OBC |
759 | if (err < 0) { |
760 | dev_err(dev, "failed to add a virtqueue buffer: %d\n", err); | |
1aa7d6a5 RT |
761 | return err; |
762 | } | |
763 | ||
764 | return 0; | |
765 | } | |
766 | ||
767 | /* called when an rx buffer is used, and it's time to digest a message */ | |
768 | static void rpmsg_recv_done(struct virtqueue *rvq) | |
769 | { | |
770 | struct virtproc_info *vrp = rvq->vdev->priv; | |
771 | struct device *dev = &rvq->vdev->dev; | |
772 | struct rpmsg_hdr *msg; | |
773 | unsigned int len, msgs_received = 0; | |
774 | int err; | |
775 | ||
776 | msg = virtqueue_get_buf(rvq, &len); | |
777 | if (!msg) { | |
778 | dev_err(dev, "uhm, incoming signal, but no used buffer ?\n"); | |
bcabbcca OBC |
779 | return; |
780 | } | |
781 | ||
1aa7d6a5 RT |
782 | while (msg) { |
783 | err = rpmsg_recv_single(vrp, dev, msg, len); | |
784 | if (err) | |
785 | break; | |
786 | ||
787 | msgs_received++; | |
788 | ||
789 | msg = virtqueue_get_buf(rvq, &len); | |
6c49fbe3 | 790 | } |
1aa7d6a5 RT |
791 | |
792 | dev_dbg(dev, "Received %u messages\n", msgs_received); | |
793 | ||
bcabbcca | 794 | /* tell the remote processor we added another available rx buffer */ |
1aa7d6a5 RT |
795 | if (msgs_received) |
796 | virtqueue_kick(vrp->rvq); | |
bcabbcca OBC |
797 | } |
798 | ||
799 | /* | |
800 | * This is invoked whenever the remote processor completed processing | |
801 | * a TX msg we just sent it, and the buffer is put back to the used ring. | |
802 | * | |
803 | * Normally, though, we suppress this "tx complete" interrupt in order to | |
804 | * avoid the incurred overhead. | |
805 | */ | |
806 | static void rpmsg_xmit_done(struct virtqueue *svq) | |
807 | { | |
808 | struct virtproc_info *vrp = svq->vdev->priv; | |
809 | ||
810 | dev_dbg(&svq->vdev->dev, "%s\n", __func__); | |
811 | ||
812 | /* wake up potential senders that are waiting for a tx buffer */ | |
813 | wake_up_interruptible(&vrp->sendq); | |
814 | } | |
815 | ||
bcabbcca OBC |
816 | static int rpmsg_probe(struct virtio_device *vdev) |
817 | { | |
818 | vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done }; | |
f7ad26ff | 819 | static const char * const names[] = { "input", "output" }; |
bcabbcca OBC |
820 | struct virtqueue *vqs[2]; |
821 | struct virtproc_info *vrp; | |
950a7388 AP |
822 | struct virtio_rpmsg_channel *vch; |
823 | struct rpmsg_device *rpdev_ns; | |
bcabbcca OBC |
824 | void *bufs_va; |
825 | int err = 0, i; | |
b1b98914 | 826 | size_t total_buf_space; |
71e4b8bf | 827 | bool notify; |
bcabbcca OBC |
828 | |
829 | vrp = kzalloc(sizeof(*vrp), GFP_KERNEL); | |
830 | if (!vrp) | |
831 | return -ENOMEM; | |
832 | ||
833 | vrp->vdev = vdev; | |
834 | ||
835 | idr_init(&vrp->endpoints); | |
836 | mutex_init(&vrp->endpoints_lock); | |
837 | mutex_init(&vrp->tx_lock); | |
838 | init_waitqueue_head(&vrp->sendq); | |
839 | ||
840 | /* We expect two virtqueues, rx and tx (and in this order) */ | |
9b2bbdb2 | 841 | err = virtio_find_vqs(vdev, 2, vqs, vq_cbs, names, NULL); |
bcabbcca OBC |
842 | if (err) |
843 | goto free_vrp; | |
844 | ||
845 | vrp->rvq = vqs[0]; | |
846 | vrp->svq = vqs[1]; | |
847 | ||
b1b98914 SA |
848 | /* we expect symmetric tx/rx vrings */ |
849 | WARN_ON(virtqueue_get_vring_size(vrp->rvq) != | |
850 | virtqueue_get_vring_size(vrp->svq)); | |
851 | ||
852 | /* we need less buffers if vrings are small */ | |
853 | if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS / 2) | |
854 | vrp->num_bufs = virtqueue_get_vring_size(vrp->rvq) * 2; | |
855 | else | |
856 | vrp->num_bufs = MAX_RPMSG_NUM_BUFS; | |
857 | ||
f93848f9 LP |
858 | vrp->buf_size = MAX_RPMSG_BUF_SIZE; |
859 | ||
860 | total_buf_space = vrp->num_bufs * vrp->buf_size; | |
b1b98914 | 861 | |
bcabbcca | 862 | /* allocate coherent memory for the buffers */ |
d999b622 | 863 | bufs_va = dma_alloc_coherent(vdev->dev.parent, |
b1b98914 SA |
864 | total_buf_space, &vrp->bufs_dma, |
865 | GFP_KERNEL); | |
3119b487 WY |
866 | if (!bufs_va) { |
867 | err = -ENOMEM; | |
bcabbcca | 868 | goto vqs_del; |
3119b487 | 869 | } |
bcabbcca | 870 | |
de4064af | 871 | dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n", |
8d95b322 | 872 | bufs_va, &vrp->bufs_dma); |
bcabbcca OBC |
873 | |
874 | /* half of the buffers is dedicated for RX */ | |
875 | vrp->rbufs = bufs_va; | |
876 | ||
877 | /* and half is dedicated for TX */ | |
b1b98914 | 878 | vrp->sbufs = bufs_va + total_buf_space / 2; |
bcabbcca OBC |
879 | |
880 | /* set up the receive buffers */ | |
b1b98914 | 881 | for (i = 0; i < vrp->num_bufs / 2; i++) { |
bcabbcca | 882 | struct scatterlist sg; |
f93848f9 | 883 | void *cpu_addr = vrp->rbufs + i * vrp->buf_size; |
bcabbcca | 884 | |
9dd87c2a | 885 | rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size); |
bcabbcca | 886 | |
cee51d69 | 887 | err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr, |
0963679c | 888 | GFP_KERNEL); |
57e1a373 | 889 | WARN_ON(err); /* sanity check; this can't really happen */ |
bcabbcca OBC |
890 | } |
891 | ||
892 | /* suppress "tx-complete" interrupts */ | |
893 | virtqueue_disable_cb(vrp->svq); | |
894 | ||
895 | vdev->priv = vrp; | |
896 | ||
897 | /* if supported by the remote processor, enable the name service */ | |
898 | if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) { | |
950a7388 AP |
899 | vch = kzalloc(sizeof(*vch), GFP_KERNEL); |
900 | if (!vch) { | |
bcabbcca OBC |
901 | err = -ENOMEM; |
902 | goto free_coherent; | |
903 | } | |
950a7388 AP |
904 | |
905 | /* Link the channel to our vrp */ | |
906 | vch->vrp = vrp; | |
907 | ||
908 | /* Assign public information to the rpmsg_device */ | |
909 | rpdev_ns = &vch->rpdev; | |
910 | rpdev_ns->ops = &virtio_rpmsg_ops; | |
911 | rpdev_ns->little_endian = virtio_is_little_endian(vrp->vdev); | |
912 | ||
913 | rpdev_ns->dev.parent = &vrp->vdev->dev; | |
914 | rpdev_ns->dev.release = virtio_rpmsg_release_device; | |
915 | ||
916 | err = rpmsg_ns_register_device(rpdev_ns); | |
917 | if (err) | |
918 | goto free_coherent; | |
bcabbcca OBC |
919 | } |
920 | ||
71e4b8bf MT |
921 | /* |
922 | * Prepare to kick but don't notify yet - we can't do this before | |
923 | * device is ready. | |
924 | */ | |
925 | notify = virtqueue_kick_prepare(vrp->rvq); | |
926 | ||
927 | /* From this point on, we can notify and get callbacks. */ | |
928 | virtio_device_ready(vdev); | |
929 | ||
bcabbcca | 930 | /* tell the remote processor it can start sending messages */ |
71e4b8bf MT |
931 | /* |
932 | * this might be concurrent with callbacks, but we are only | |
933 | * doing notify, not a full kick here, so that's ok. | |
934 | */ | |
935 | if (notify) | |
936 | virtqueue_notify(vrp->rvq); | |
bcabbcca OBC |
937 | |
938 | dev_info(&vdev->dev, "rpmsg host is online\n"); | |
939 | ||
940 | return 0; | |
941 | ||
942 | free_coherent: | |
950a7388 | 943 | kfree(vch); |
d999b622 | 944 | dma_free_coherent(vdev->dev.parent, total_buf_space, |
b1b98914 | 945 | bufs_va, vrp->bufs_dma); |
bcabbcca OBC |
946 | vqs_del: |
947 | vdev->config->del_vqs(vrp->vdev); | |
948 | free_vrp: | |
949 | kfree(vrp); | |
950 | return err; | |
951 | } | |
952 | ||
953 | static int rpmsg_remove_device(struct device *dev, void *data) | |
954 | { | |
955 | device_unregister(dev); | |
956 | ||
957 | return 0; | |
958 | } | |
959 | ||
0fe763c5 | 960 | static void rpmsg_remove(struct virtio_device *vdev) |
bcabbcca OBC |
961 | { |
962 | struct virtproc_info *vrp = vdev->priv; | |
f93848f9 | 963 | size_t total_buf_space = vrp->num_bufs * vrp->buf_size; |
bcabbcca OBC |
964 | int ret; |
965 | ||
966 | vdev->config->reset(vdev); | |
967 | ||
968 | ret = device_for_each_child(&vdev->dev, NULL, rpmsg_remove_device); | |
969 | if (ret) | |
970 | dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret); | |
971 | ||
bcabbcca OBC |
972 | idr_destroy(&vrp->endpoints); |
973 | ||
974 | vdev->config->del_vqs(vrp->vdev); | |
975 | ||
d999b622 | 976 | dma_free_coherent(vdev->dev.parent, total_buf_space, |
b1b98914 | 977 | vrp->rbufs, vrp->bufs_dma); |
bcabbcca OBC |
978 | |
979 | kfree(vrp); | |
980 | } | |
981 | ||
982 | static struct virtio_device_id id_table[] = { | |
983 | { VIRTIO_ID_RPMSG, VIRTIO_DEV_ANY_ID }, | |
984 | { 0 }, | |
985 | }; | |
986 | ||
987 | static unsigned int features[] = { | |
988 | VIRTIO_RPMSG_F_NS, | |
989 | }; | |
990 | ||
991 | static struct virtio_driver virtio_ipc_driver = { | |
992 | .feature_table = features, | |
993 | .feature_table_size = ARRAY_SIZE(features), | |
994 | .driver.name = KBUILD_MODNAME, | |
995 | .driver.owner = THIS_MODULE, | |
996 | .id_table = id_table, | |
997 | .probe = rpmsg_probe, | |
0fe763c5 | 998 | .remove = rpmsg_remove, |
bcabbcca OBC |
999 | }; |
1000 | ||
1001 | static int __init rpmsg_init(void) | |
1002 | { | |
1003 | int ret; | |
1004 | ||
bcabbcca | 1005 | ret = register_virtio_driver(&virtio_ipc_driver); |
5e619b48 | 1006 | if (ret) |
bcabbcca | 1007 | pr_err("failed to register virtio driver: %d\n", ret); |
bcabbcca OBC |
1008 | |
1009 | return ret; | |
1010 | } | |
96342526 | 1011 | subsys_initcall(rpmsg_init); |
bcabbcca OBC |
1012 | |
1013 | static void __exit rpmsg_fini(void) | |
1014 | { | |
1015 | unregister_virtio_driver(&virtio_ipc_driver); | |
bcabbcca OBC |
1016 | } |
1017 | module_exit(rpmsg_fini); | |
1018 | ||
1019 | MODULE_DEVICE_TABLE(virtio, id_table); | |
1020 | MODULE_DESCRIPTION("Virtio-based remote processor messaging bus"); | |
1021 | MODULE_LICENSE("GPL v2"); |