Commit | Line | Data |
---|---|---|
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 | 19 | #include <linux/mutex.h> |
6de1c933 | 20 | #include <linux/rpmsg.h> |
5f2f6b7d | 21 | #include <linux/rpmsg/byteorder.h> |
c435a041 | 22 | #include <linux/rpmsg/ns.h> |
bcabbcca | 23 | #include <linux/scatterlist.h> |
bcabbcca | 24 | #include <linux/slab.h> |
bcabbcca | 25 | #include <linux/sched.h> |
6de1c933 LP |
26 | #include <linux/virtio.h> |
27 | #include <linux/virtio_ids.h> | |
28 | #include <linux/virtio_config.h> | |
bcabbcca | 29 | #include <linux/wait.h> |
bcabbcca | 30 | |
8b881c07 BA |
31 | #include "rpmsg_internal.h" |
32 | ||
bcabbcca OBC |
33 | /** |
34 | * struct virtproc_info - virtual remote processor state | |
35 | * @vdev: the virtio device | |
36 | * @rvq: rx virtqueue | |
37 | * @svq: tx virtqueue | |
38 | * @rbufs: kernel address of rx buffers | |
39 | * @sbufs: kernel address of tx buffers | |
b1b98914 | 40 | * @num_bufs: total number of buffers for rx and tx |
f93848f9 | 41 | * @buf_size: size of one rx or tx buffer |
bcabbcca OBC |
42 | * @last_sbuf: index of last tx buffer used |
43 | * @bufs_dma: dma base addr of the buffers | |
44 | * @tx_lock: protects svq, sbufs and sleepers, to allow concurrent senders. | |
45 | * sending a message might require waking up a dozing remote | |
46 | * processor, which involves sleeping, hence the mutex. | |
47 | * @endpoints: idr of local endpoints, allows fast retrieval | |
48 | * @endpoints_lock: lock of the endpoints set | |
49 | * @sendq: wait queue of sending contexts waiting for a tx buffers | |
50 | * @sleepers: number of senders that are waiting for a tx buffer | |
bcabbcca OBC |
51 | * |
52 | * This structure stores the rpmsg state of a given virtio remote processor | |
53 | * device (there might be several virtio proc devices for each physical | |
54 | * remote processor). | |
55 | */ | |
56 | struct virtproc_info { | |
57 | struct virtio_device *vdev; | |
58 | struct virtqueue *rvq, *svq; | |
59 | void *rbufs, *sbufs; | |
b1b98914 | 60 | unsigned int num_bufs; |
f93848f9 | 61 | unsigned int buf_size; |
bcabbcca OBC |
62 | int last_sbuf; |
63 | dma_addr_t bufs_dma; | |
64 | struct mutex tx_lock; | |
65 | struct idr endpoints; | |
66 | struct mutex endpoints_lock; | |
67 | wait_queue_head_t sendq; | |
68 | atomic_t sleepers; | |
bcabbcca OBC |
69 | }; |
70 | ||
e88dae5d BA |
71 | /* The feature bitmap for virtio rpmsg */ |
72 | #define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ | |
73 | ||
74 | /** | |
75 | * struct rpmsg_hdr - common header for all rpmsg messages | |
76 | * @src: source address | |
77 | * @dst: destination address | |
78 | * @reserved: reserved for future use | |
79 | * @len: length of payload (in bytes) | |
80 | * @flags: message flags | |
81 | * @data: @len bytes of message payload data | |
82 | * | |
83 | * Every message sent(/received) on the rpmsg bus begins with this header. | |
84 | */ | |
85 | struct rpmsg_hdr { | |
5f2f6b7d MP |
86 | __rpmsg32 src; |
87 | __rpmsg32 dst; | |
88 | __rpmsg32 reserved; | |
89 | __rpmsg16 len; | |
90 | __rpmsg16 flags; | |
4f05fc33 | 91 | u8 data[]; |
e88dae5d BA |
92 | } __packed; |
93 | ||
e88dae5d | 94 | |
3bf950ff | 95 | /** |
6c09ea0b AP |
96 | * struct virtio_rpmsg_channel - rpmsg channel descriptor |
97 | * @rpdev: the rpmsg channel device | |
98 | * @vrp: the virtio remote processor device this channel belongs to | |
99 | * | |
100 | * This structure stores the channel that links the rpmsg device to the virtio | |
101 | * remote processor device. | |
3bf950ff BA |
102 | */ |
103 | struct virtio_rpmsg_channel { | |
104 | struct rpmsg_device rpdev; | |
105 | ||
106 | struct virtproc_info *vrp; | |
107 | }; | |
108 | ||
109 | #define to_virtio_rpmsg_channel(_rpdev) \ | |
110 | container_of(_rpdev, struct virtio_rpmsg_channel, rpdev) | |
111 | ||
bcabbcca | 112 | /* |
b1b98914 SA |
113 | * We're allocating buffers of 512 bytes each for communications. The |
114 | * number of buffers will be computed from the number of buffers supported | |
115 | * by the vring, upto a maximum of 512 buffers (256 in each direction). | |
bcabbcca OBC |
116 | * |
117 | * Each buffer will have 16 bytes for the msg header and 496 bytes for | |
118 | * the payload. | |
119 | * | |
b1b98914 | 120 | * This will utilize a maximum total space of 256KB for the buffers. |
bcabbcca OBC |
121 | * |
122 | * We might also want to add support for user-provided buffers in time. | |
123 | * This will allow bigger buffer size flexibility, and can also be used | |
124 | * to achieve zero-copy messaging. | |
125 | * | |
126 | * Note that these numbers are purely a decision of this driver - we | |
127 | * can change this without changing anything in the firmware of the remote | |
128 | * processor. | |
129 | */ | |
b1b98914 | 130 | #define MAX_RPMSG_NUM_BUFS (512) |
f93848f9 | 131 | #define MAX_RPMSG_BUF_SIZE (512) |
bcabbcca OBC |
132 | |
133 | /* | |
134 | * Local addresses are dynamically allocated on-demand. | |
135 | * We do not dynamically assign addresses from the low 1024 range, | |
136 | * in order to reserve that address range for predefined services. | |
137 | */ | |
138 | #define RPMSG_RESERVED_ADDRESSES (1024) | |
139 | ||
8a228ecf BA |
140 | static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept); |
141 | static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); | |
142 | static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, | |
143 | u32 dst); | |
144 | static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, | |
145 | u32 dst, void *data, int len); | |
146 | static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); | |
147 | static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, | |
148 | int len, u32 dst); | |
149 | static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, | |
150 | u32 dst, void *data, int len); | |
e279317e | 151 | static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept); |
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, | |
e279317e | 163 | .get_mtu = virtio_rpmsg_get_mtu, |
8a228ecf BA |
164 | }; |
165 | ||
9dd87c2a LP |
166 | /** |
167 | * rpmsg_sg_init - initialize scatterlist according to cpu address location | |
168 | * @sg: scatterlist to fill | |
169 | * @cpu_addr: virtual address of the buffer | |
170 | * @len: buffer length | |
171 | * | |
172 | * An internal function filling scatterlist according to virtual address | |
173 | * location (in vmalloc or in kernel). | |
174 | */ | |
175 | static void | |
176 | rpmsg_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len) | |
177 | { | |
178 | if (is_vmalloc_addr(cpu_addr)) { | |
179 | sg_init_table(sg, 1); | |
180 | sg_set_page(sg, vmalloc_to_page(cpu_addr), len, | |
181 | offset_in_page(cpu_addr)); | |
182 | } else { | |
183 | WARN_ON(!virt_addr_valid(cpu_addr)); | |
184 | sg_init_one(sg, cpu_addr, len); | |
185 | } | |
186 | } | |
187 | ||
5a081caa OBC |
188 | /** |
189 | * __ept_release() - deallocate an rpmsg endpoint | |
190 | * @kref: the ept's reference count | |
191 | * | |
192 | * This function deallocates an ept, and is invoked when its @kref refcount | |
193 | * drops to zero. | |
194 | * | |
195 | * Never invoke this function directly! | |
196 | */ | |
197 | static void __ept_release(struct kref *kref) | |
198 | { | |
199 | struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, | |
200 | refcount); | |
201 | /* | |
202 | * At this point no one holds a reference to ept anymore, | |
203 | * so we can directly free it | |
204 | */ | |
205 | kfree(ept); | |
206 | } | |
207 | ||
bcabbcca OBC |
208 | /* for more info, see below documentation of rpmsg_create_ept() */ |
209 | static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp, | |
92e1de51 | 210 | struct rpmsg_device *rpdev, |
0963679c AS |
211 | rpmsg_rx_cb_t cb, |
212 | void *priv, u32 addr) | |
bcabbcca | 213 | { |
d0ffce77 | 214 | int id_min, id_max, id; |
bcabbcca OBC |
215 | struct rpmsg_endpoint *ept; |
216 | struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev; | |
217 | ||
bcabbcca | 218 | ept = kzalloc(sizeof(*ept), GFP_KERNEL); |
a8bb3fd9 | 219 | if (!ept) |
bcabbcca | 220 | return NULL; |
bcabbcca | 221 | |
5a081caa | 222 | kref_init(&ept->refcount); |
15fd943a | 223 | mutex_init(&ept->cb_lock); |
5a081caa | 224 | |
bcabbcca OBC |
225 | ept->rpdev = rpdev; |
226 | ept->cb = cb; | |
227 | ept->priv = priv; | |
8a228ecf | 228 | ept->ops = &virtio_endpoint_ops; |
bcabbcca OBC |
229 | |
230 | /* do we need to allocate a local address ? */ | |
d0ffce77 TH |
231 | if (addr == RPMSG_ADDR_ANY) { |
232 | id_min = RPMSG_RESERVED_ADDRESSES; | |
233 | id_max = 0; | |
234 | } else { | |
235 | id_min = addr; | |
236 | id_max = addr + 1; | |
237 | } | |
bcabbcca OBC |
238 | |
239 | mutex_lock(&vrp->endpoints_lock); | |
240 | ||
241 | /* bind the endpoint to an rpmsg address (and allocate one if needed) */ | |
d0ffce77 TH |
242 | id = idr_alloc(&vrp->endpoints, ept, id_min, id_max, GFP_KERNEL); |
243 | if (id < 0) { | |
244 | dev_err(dev, "idr_alloc failed: %d\n", id); | |
bcabbcca OBC |
245 | goto free_ept; |
246 | } | |
d0ffce77 | 247 | ept->addr = id; |
bcabbcca OBC |
248 | |
249 | mutex_unlock(&vrp->endpoints_lock); | |
250 | ||
251 | return ept; | |
252 | ||
bcabbcca OBC |
253 | free_ept: |
254 | mutex_unlock(&vrp->endpoints_lock); | |
5a081caa | 255 | kref_put(&ept->refcount, __ept_release); |
bcabbcca OBC |
256 | return NULL; |
257 | } | |
258 | ||
1ee1e5e1 AP |
259 | static struct rpmsg_device *virtio_rpmsg_create_channel(struct rpmsg_device *rpdev, |
260 | struct rpmsg_channel_info *chinfo) | |
261 | { | |
262 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); | |
263 | struct virtproc_info *vrp = vch->vrp; | |
264 | ||
265 | return __rpmsg_create_channel(vrp, chinfo); | |
266 | } | |
267 | ||
268 | static int virtio_rpmsg_release_channel(struct rpmsg_device *rpdev, | |
269 | struct rpmsg_channel_info *chinfo) | |
270 | { | |
271 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); | |
272 | struct virtproc_info *vrp = vch->vrp; | |
273 | ||
274 | return rpmsg_unregister_device(&vrp->vdev->dev, chinfo); | |
275 | } | |
276 | ||
36b72c7d BA |
277 | static struct rpmsg_endpoint *virtio_rpmsg_create_ept(struct rpmsg_device *rpdev, |
278 | rpmsg_rx_cb_t cb, | |
279 | void *priv, | |
280 | struct rpmsg_channel_info chinfo) | |
281 | { | |
3bf950ff BA |
282 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
283 | ||
284 | return __rpmsg_create_ept(vch->vrp, rpdev, cb, priv, chinfo.src); | |
36b72c7d BA |
285 | } |
286 | ||
bcabbcca | 287 | /** |
fa2d7795 OBC |
288 | * __rpmsg_destroy_ept() - destroy an existing rpmsg endpoint |
289 | * @vrp: virtproc which owns this ept | |
bcabbcca OBC |
290 | * @ept: endpoing to destroy |
291 | * | |
fa2d7795 OBC |
292 | * An internal function which destroy an ept without assuming it is |
293 | * bound to an rpmsg channel. This is needed for handling the internal | |
294 | * name service endpoint, which isn't bound to an rpmsg channel. | |
295 | * See also __rpmsg_create_ept(). | |
bcabbcca | 296 | */ |
fa2d7795 OBC |
297 | static void |
298 | __rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept) | |
bcabbcca | 299 | { |
15fd943a | 300 | /* make sure new inbound messages can't find this ept anymore */ |
bcabbcca OBC |
301 | mutex_lock(&vrp->endpoints_lock); |
302 | idr_remove(&vrp->endpoints, ept->addr); | |
303 | mutex_unlock(&vrp->endpoints_lock); | |
304 | ||
15fd943a OBC |
305 | /* make sure in-flight inbound messages won't invoke cb anymore */ |
306 | mutex_lock(&ept->cb_lock); | |
307 | ept->cb = NULL; | |
308 | mutex_unlock(&ept->cb_lock); | |
309 | ||
5a081caa | 310 | kref_put(&ept->refcount, __ept_release); |
bcabbcca | 311 | } |
fa2d7795 | 312 | |
8a228ecf BA |
313 | static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept) |
314 | { | |
3bf950ff BA |
315 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(ept->rpdev); |
316 | ||
317 | __rpmsg_destroy_ept(vch->vrp, ept); | |
8a228ecf BA |
318 | } |
319 | ||
36b72c7d BA |
320 | static int virtio_rpmsg_announce_create(struct rpmsg_device *rpdev) |
321 | { | |
3bf950ff BA |
322 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
323 | struct virtproc_info *vrp = vch->vrp; | |
36b72c7d BA |
324 | struct device *dev = &rpdev->dev; |
325 | int err = 0; | |
326 | ||
bcabbcca | 327 | /* need to tell remote processor's name service about this channel ? */ |
b2599ebf | 328 | if (rpdev->announce && rpdev->ept && |
0963679c | 329 | virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { |
bcabbcca OBC |
330 | struct rpmsg_ns_msg nsm; |
331 | ||
332 | strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); | |
5f2f6b7d MP |
333 | nsm.addr = cpu_to_rpmsg32(rpdev, rpdev->ept->addr); |
334 | nsm.flags = cpu_to_rpmsg32(rpdev, RPMSG_NS_CREATE); | |
bcabbcca | 335 | |
2a48d732 | 336 | err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR); |
bcabbcca OBC |
337 | if (err) |
338 | dev_err(dev, "failed to announce service %d\n", err); | |
339 | } | |
340 | ||
bcabbcca OBC |
341 | return err; |
342 | } | |
343 | ||
36b72c7d | 344 | static int virtio_rpmsg_announce_destroy(struct rpmsg_device *rpdev) |
bcabbcca | 345 | { |
3bf950ff BA |
346 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
347 | struct virtproc_info *vrp = vch->vrp; | |
36b72c7d | 348 | struct device *dev = &rpdev->dev; |
bcabbcca OBC |
349 | int err = 0; |
350 | ||
351 | /* tell remote processor's name service we're removing this channel */ | |
b2599ebf | 352 | if (rpdev->announce && rpdev->ept && |
0963679c | 353 | virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { |
bcabbcca OBC |
354 | struct rpmsg_ns_msg nsm; |
355 | ||
356 | strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); | |
5f2f6b7d MP |
357 | nsm.addr = cpu_to_rpmsg32(rpdev, rpdev->ept->addr); |
358 | nsm.flags = cpu_to_rpmsg32(rpdev, RPMSG_NS_DESTROY); | |
bcabbcca | 359 | |
2a48d732 | 360 | err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR); |
bcabbcca OBC |
361 | if (err) |
362 | dev_err(dev, "failed to announce service %d\n", err); | |
363 | } | |
364 | ||
36b72c7d BA |
365 | return err; |
366 | } | |
367 | ||
36b72c7d | 368 | static const struct rpmsg_device_ops virtio_rpmsg_ops = { |
1ee1e5e1 AP |
369 | .create_channel = virtio_rpmsg_create_channel, |
370 | .release_channel = virtio_rpmsg_release_channel, | |
36b72c7d BA |
371 | .create_ept = virtio_rpmsg_create_ept, |
372 | .announce_create = virtio_rpmsg_announce_create, | |
373 | .announce_destroy = virtio_rpmsg_announce_destroy, | |
374 | }; | |
375 | ||
b0b03b81 BA |
376 | static void virtio_rpmsg_release_device(struct device *dev) |
377 | { | |
378 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); | |
379 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); | |
380 | ||
381 | kfree(vch); | |
382 | } | |
383 | ||
bcabbcca OBC |
384 | /* |
385 | * create an rpmsg channel using its name and address info. | |
386 | * this function will be used to create both static and dynamic | |
387 | * channels. | |
388 | */ | |
77d37298 AP |
389 | static struct rpmsg_device *__rpmsg_create_channel(struct virtproc_info *vrp, |
390 | struct rpmsg_channel_info *chinfo) | |
bcabbcca | 391 | { |
3bf950ff | 392 | struct virtio_rpmsg_channel *vch; |
92e1de51 | 393 | struct rpmsg_device *rpdev; |
bcabbcca OBC |
394 | struct device *tmp, *dev = &vrp->vdev->dev; |
395 | int ret; | |
396 | ||
397 | /* make sure a similar channel doesn't already exist */ | |
8b881c07 | 398 | tmp = rpmsg_find_device(dev, chinfo); |
bcabbcca OBC |
399 | if (tmp) { |
400 | /* decrement the matched device's refcount back */ | |
401 | put_device(tmp); | |
402 | dev_err(dev, "channel %s:%x:%x already exist\n", | |
403 | chinfo->name, chinfo->src, chinfo->dst); | |
404 | return NULL; | |
405 | } | |
406 | ||
3bf950ff BA |
407 | vch = kzalloc(sizeof(*vch), GFP_KERNEL); |
408 | if (!vch) | |
bcabbcca | 409 | return NULL; |
bcabbcca | 410 | |
3bf950ff BA |
411 | /* Link the channel to our vrp */ |
412 | vch->vrp = vrp; | |
413 | ||
3bf950ff BA |
414 | /* Assign public information to the rpmsg_device */ |
415 | rpdev = &vch->rpdev; | |
bcabbcca OBC |
416 | rpdev->src = chinfo->src; |
417 | rpdev->dst = chinfo->dst; | |
36b72c7d | 418 | rpdev->ops = &virtio_rpmsg_ops; |
5f2f6b7d | 419 | rpdev->little_endian = virtio_is_little_endian(vrp->vdev); |
bcabbcca OBC |
420 | |
421 | /* | |
422 | * rpmsg server channels has predefined local address (for now), | |
423 | * and their existence needs to be announced remotely | |
424 | */ | |
c8ced113 | 425 | rpdev->announce = rpdev->src != RPMSG_ADDR_ANY; |
bcabbcca OBC |
426 | |
427 | strncpy(rpdev->id.name, chinfo->name, RPMSG_NAME_SIZE); | |
428 | ||
6eed598a | 429 | rpdev->dev.parent = &vrp->vdev->dev; |
b0b03b81 | 430 | rpdev->dev.release = virtio_rpmsg_release_device; |
6eed598a BA |
431 | ret = rpmsg_register_device(rpdev); |
432 | if (ret) | |
433 | return NULL; | |
434 | ||
435 | return rpdev; | |
436 | } | |
437 | ||
bcabbcca OBC |
438 | /* super simple buffer "allocator" that is just enough for now */ |
439 | static void *get_a_tx_buf(struct virtproc_info *vrp) | |
440 | { | |
441 | unsigned int len; | |
442 | void *ret; | |
443 | ||
444 | /* support multiple concurrent senders */ | |
445 | mutex_lock(&vrp->tx_lock); | |
446 | ||
447 | /* | |
448 | * either pick the next unused tx buffer | |
449 | * (half of our buffers are used for sending messages) | |
450 | */ | |
b1b98914 | 451 | if (vrp->last_sbuf < vrp->num_bufs / 2) |
f93848f9 | 452 | ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++; |
bcabbcca OBC |
453 | /* or recycle a used one */ |
454 | else | |
455 | ret = virtqueue_get_buf(vrp->svq, &len); | |
456 | ||
457 | mutex_unlock(&vrp->tx_lock); | |
458 | ||
459 | return ret; | |
460 | } | |
461 | ||
462 | /** | |
463 | * rpmsg_upref_sleepers() - enable "tx-complete" interrupts, if needed | |
464 | * @vrp: virtual remote processor state | |
465 | * | |
466 | * This function is called before a sender is blocked, waiting for | |
467 | * a tx buffer to become available. | |
468 | * | |
469 | * If we already have blocking senders, this function merely increases | |
470 | * the "sleepers" reference count, and exits. | |
471 | * | |
472 | * Otherwise, if this is the first sender to block, we also enable | |
473 | * virtio's tx callbacks, so we'd be immediately notified when a tx | |
474 | * buffer is consumed (we rely on virtio's tx callback in order | |
475 | * to wake up sleeping senders as soon as a tx buffer is used by the | |
476 | * remote processor). | |
477 | */ | |
478 | static void rpmsg_upref_sleepers(struct virtproc_info *vrp) | |
479 | { | |
480 | /* support multiple concurrent senders */ | |
481 | mutex_lock(&vrp->tx_lock); | |
482 | ||
483 | /* are we the first sleeping context waiting for tx buffers ? */ | |
484 | if (atomic_inc_return(&vrp->sleepers) == 1) | |
485 | /* enable "tx-complete" interrupts before dozing off */ | |
486 | virtqueue_enable_cb(vrp->svq); | |
487 | ||
488 | mutex_unlock(&vrp->tx_lock); | |
489 | } | |
490 | ||
491 | /** | |
492 | * rpmsg_downref_sleepers() - disable "tx-complete" interrupts, if needed | |
493 | * @vrp: virtual remote processor state | |
494 | * | |
495 | * This function is called after a sender, that waited for a tx buffer | |
496 | * to become available, is unblocked. | |
497 | * | |
498 | * If we still have blocking senders, this function merely decreases | |
499 | * the "sleepers" reference count, and exits. | |
500 | * | |
501 | * Otherwise, if there are no more blocking senders, we also disable | |
502 | * virtio's tx callbacks, to avoid the overhead incurred with handling | |
503 | * those (now redundant) interrupts. | |
504 | */ | |
505 | static void rpmsg_downref_sleepers(struct virtproc_info *vrp) | |
506 | { | |
507 | /* support multiple concurrent senders */ | |
508 | mutex_lock(&vrp->tx_lock); | |
509 | ||
510 | /* are we the last sleeping context waiting for tx buffers ? */ | |
511 | if (atomic_dec_and_test(&vrp->sleepers)) | |
512 | /* disable "tx-complete" interrupts */ | |
513 | virtqueue_disable_cb(vrp->svq); | |
514 | ||
515 | mutex_unlock(&vrp->tx_lock); | |
516 | } | |
517 | ||
518 | /** | |
519 | * rpmsg_send_offchannel_raw() - send a message across to the remote processor | |
520 | * @rpdev: the rpmsg channel | |
521 | * @src: source address | |
522 | * @dst: destination address | |
523 | * @data: payload of message | |
524 | * @len: length of payload | |
525 | * @wait: indicates whether caller should block in case no TX buffers available | |
526 | * | |
527 | * This function is the base implementation for all of the rpmsg sending API. | |
528 | * | |
529 | * It will send @data of length @len to @dst, and say it's from @src. The | |
530 | * message will be sent to the remote processor which the @rpdev channel | |
531 | * belongs to. | |
532 | * | |
533 | * The message is sent using one of the TX buffers that are available for | |
534 | * communication with this remote processor. | |
535 | * | |
536 | * If @wait is true, the caller will be blocked until either a TX buffer is | |
537 | * available, or 15 seconds elapses (we don't want callers to | |
538 | * sleep indefinitely due to misbehaving remote processors), and in that | |
539 | * case -ERESTARTSYS is returned. The number '15' itself was picked | |
540 | * arbitrarily; there's little point in asking drivers to provide a timeout | |
541 | * value themselves. | |
542 | * | |
543 | * Otherwise, if @wait is false, and there are no TX buffers available, | |
544 | * the function will immediately fail, and -ENOMEM will be returned. | |
545 | * | |
546 | * Normally drivers shouldn't use this function directly; instead, drivers | |
547 | * should use the appropriate rpmsg_{try}send{to, _offchannel} API | |
548 | * (see include/linux/rpmsg.h). | |
549 | * | |
631af6e0 | 550 | * Return: 0 on success and an appropriate error value on failure. |
bcabbcca | 551 | */ |
8a228ecf BA |
552 | static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev, |
553 | u32 src, u32 dst, | |
554 | void *data, int len, bool wait) | |
bcabbcca | 555 | { |
3bf950ff BA |
556 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
557 | struct virtproc_info *vrp = vch->vrp; | |
bcabbcca OBC |
558 | struct device *dev = &rpdev->dev; |
559 | struct scatterlist sg; | |
560 | struct rpmsg_hdr *msg; | |
561 | int err; | |
562 | ||
563 | /* bcasting isn't allowed */ | |
564 | if (src == RPMSG_ADDR_ANY || dst == RPMSG_ADDR_ANY) { | |
565 | dev_err(dev, "invalid addr (src 0x%x, dst 0x%x)\n", src, dst); | |
566 | return -EINVAL; | |
567 | } | |
568 | ||
569 | /* | |
570 | * We currently use fixed-sized buffers, and therefore the payload | |
571 | * length is limited. | |
572 | * | |
573 | * One of the possible improvements here is either to support | |
574 | * user-provided buffers (and then we can also support zero-copy | |
575 | * messaging), or to improve the buffer allocator, to support | |
576 | * variable-length buffer sizes. | |
577 | */ | |
f93848f9 | 578 | if (len > vrp->buf_size - sizeof(struct rpmsg_hdr)) { |
bcabbcca OBC |
579 | dev_err(dev, "message is too big (%d)\n", len); |
580 | return -EMSGSIZE; | |
581 | } | |
582 | ||
583 | /* grab a buffer */ | |
584 | msg = get_a_tx_buf(vrp); | |
585 | if (!msg && !wait) | |
586 | return -ENOMEM; | |
587 | ||
588 | /* no free buffer ? wait for one (but bail after 15 seconds) */ | |
589 | while (!msg) { | |
590 | /* enable "tx-complete" interrupts, if not already enabled */ | |
591 | rpmsg_upref_sleepers(vrp); | |
592 | ||
593 | /* | |
594 | * sleep until a free buffer is available or 15 secs elapse. | |
595 | * the timeout period is not configurable because there's | |
596 | * little point in asking drivers to specify that. | |
597 | * if later this happens to be required, it'd be easy to add. | |
598 | */ | |
599 | err = wait_event_interruptible_timeout(vrp->sendq, | |
600 | (msg = get_a_tx_buf(vrp)), | |
601 | msecs_to_jiffies(15000)); | |
602 | ||
603 | /* disable "tx-complete" interrupts if we're the last sleeper */ | |
604 | rpmsg_downref_sleepers(vrp); | |
605 | ||
606 | /* timeout ? */ | |
607 | if (!err) { | |
608 | dev_err(dev, "timeout waiting for a tx buffer\n"); | |
609 | return -ERESTARTSYS; | |
610 | } | |
611 | } | |
612 | ||
5f2f6b7d | 613 | msg->len = cpu_to_rpmsg16(rpdev, len); |
bcabbcca | 614 | msg->flags = 0; |
5f2f6b7d MP |
615 | msg->src = cpu_to_rpmsg32(rpdev, src); |
616 | msg->dst = cpu_to_rpmsg32(rpdev, dst); | |
bcabbcca OBC |
617 | msg->reserved = 0; |
618 | memcpy(msg->data, data, len); | |
619 | ||
620 | dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Reserved %d\n", | |
111d1089 | 621 | src, dst, len, msg->flags, msg->reserved); |
211e3a93 AS |
622 | #if defined(CONFIG_DYNAMIC_DEBUG) |
623 | dynamic_hex_dump("rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1, | |
111d1089 | 624 | msg, sizeof(*msg) + len, true); |
211e3a93 | 625 | #endif |
bcabbcca | 626 | |
9dd87c2a | 627 | rpmsg_sg_init(&sg, msg, sizeof(*msg) + len); |
bcabbcca OBC |
628 | |
629 | mutex_lock(&vrp->tx_lock); | |
630 | ||
631 | /* add message to the remote processor's virtqueue */ | |
cee51d69 | 632 | err = virtqueue_add_outbuf(vrp->svq, &sg, 1, msg, GFP_KERNEL); |
57e1a373 | 633 | if (err) { |
bcabbcca OBC |
634 | /* |
635 | * need to reclaim the buffer here, otherwise it's lost | |
636 | * (memory won't leak, but rpmsg won't use it again for TX). | |
637 | * this will wait for a buffer management overhaul. | |
638 | */ | |
cee51d69 | 639 | dev_err(dev, "virtqueue_add_outbuf failed: %d\n", err); |
bcabbcca OBC |
640 | goto out; |
641 | } | |
642 | ||
643 | /* tell the remote processor it has a pending message to read */ | |
644 | virtqueue_kick(vrp->svq); | |
bcabbcca OBC |
645 | out: |
646 | mutex_unlock(&vrp->tx_lock); | |
647 | return err; | |
648 | } | |
bcabbcca | 649 | |
8a228ecf BA |
650 | static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) |
651 | { | |
652 | struct rpmsg_device *rpdev = ept->rpdev; | |
653 | u32 src = ept->addr, dst = rpdev->dst; | |
654 | ||
655 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
656 | } | |
657 | ||
658 | static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, | |
659 | u32 dst) | |
660 | { | |
661 | struct rpmsg_device *rpdev = ept->rpdev; | |
662 | u32 src = ept->addr; | |
663 | ||
664 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
665 | } | |
666 | ||
667 | static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, | |
668 | u32 dst, void *data, int len) | |
669 | { | |
670 | struct rpmsg_device *rpdev = ept->rpdev; | |
671 | ||
672 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | |
673 | } | |
674 | ||
675 | static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) | |
676 | { | |
677 | struct rpmsg_device *rpdev = ept->rpdev; | |
678 | u32 src = ept->addr, dst = rpdev->dst; | |
679 | ||
680 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
681 | } | |
682 | ||
683 | static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, | |
684 | int len, u32 dst) | |
685 | { | |
686 | struct rpmsg_device *rpdev = ept->rpdev; | |
687 | u32 src = ept->addr; | |
688 | ||
689 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
690 | } | |
691 | ||
692 | static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, | |
693 | u32 dst, void *data, int len) | |
694 | { | |
695 | struct rpmsg_device *rpdev = ept->rpdev; | |
696 | ||
697 | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | |
698 | } | |
699 | ||
e279317e AP |
700 | static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept) |
701 | { | |
702 | struct rpmsg_device *rpdev = ept->rpdev; | |
703 | struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); | |
704 | ||
705 | return vch->vrp->buf_size - sizeof(struct rpmsg_hdr); | |
706 | } | |
707 | ||
1aa7d6a5 RT |
708 | static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev, |
709 | struct rpmsg_hdr *msg, unsigned int len) | |
bcabbcca | 710 | { |
bcabbcca OBC |
711 | struct rpmsg_endpoint *ept; |
712 | struct scatterlist sg; | |
5f2f6b7d MP |
713 | bool little_endian = virtio_is_little_endian(vrp->vdev); |
714 | unsigned int msg_len = __rpmsg16_to_cpu(little_endian, msg->len); | |
bcabbcca OBC |
715 | int err; |
716 | ||
bcabbcca | 717 | dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Reserved: %d\n", |
5f2f6b7d MP |
718 | __rpmsg32_to_cpu(little_endian, msg->src), |
719 | __rpmsg32_to_cpu(little_endian, msg->dst), msg_len, | |
720 | __rpmsg16_to_cpu(little_endian, msg->flags), | |
721 | __rpmsg32_to_cpu(little_endian, msg->reserved)); | |
211e3a93 AS |
722 | #if defined(CONFIG_DYNAMIC_DEBUG) |
723 | dynamic_hex_dump("rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1, | |
111d1089 | 724 | msg, sizeof(*msg) + msg_len, true); |
211e3a93 | 725 | #endif |
bcabbcca | 726 | |
9648224e OBC |
727 | /* |
728 | * We currently use fixed-sized buffers, so trivially sanitize | |
729 | * the reported payload length. | |
730 | */ | |
f93848f9 | 731 | if (len > vrp->buf_size || |
111d1089 GL |
732 | msg_len > (len - sizeof(struct rpmsg_hdr))) { |
733 | dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg_len); | |
1aa7d6a5 | 734 | return -EINVAL; |
9648224e OBC |
735 | } |
736 | ||
bcabbcca OBC |
737 | /* use the dst addr to fetch the callback of the appropriate user */ |
738 | mutex_lock(&vrp->endpoints_lock); | |
5a081caa | 739 | |
5f2f6b7d | 740 | ept = idr_find(&vrp->endpoints, __rpmsg32_to_cpu(little_endian, msg->dst)); |
5a081caa OBC |
741 | |
742 | /* let's make sure no one deallocates ept while we use it */ | |
743 | if (ept) | |
744 | kref_get(&ept->refcount); | |
745 | ||
bcabbcca OBC |
746 | mutex_unlock(&vrp->endpoints_lock); |
747 | ||
15fd943a OBC |
748 | if (ept) { |
749 | /* make sure ept->cb doesn't go away while we use it */ | |
750 | mutex_lock(&ept->cb_lock); | |
bcabbcca | 751 | |
15fd943a | 752 | if (ept->cb) |
111d1089 | 753 | ept->cb(ept->rpdev, msg->data, msg_len, ept->priv, |
5f2f6b7d | 754 | __rpmsg32_to_cpu(little_endian, msg->src)); |
15fd943a OBC |
755 | |
756 | mutex_unlock(&ept->cb_lock); | |
757 | ||
758 | /* farewell, ept, we don't need you anymore */ | |
5a081caa | 759 | kref_put(&ept->refcount, __ept_release); |
15fd943a | 760 | } else |
63b8d799 | 761 | dev_warn_ratelimited(dev, "msg received with no recipient\n"); |
5a081caa | 762 | |
f1d9e9c7 | 763 | /* publish the real size of the buffer */ |
9dd87c2a | 764 | rpmsg_sg_init(&sg, msg, vrp->buf_size); |
bcabbcca OBC |
765 | |
766 | /* add the buffer back to the remote processor's virtqueue */ | |
cee51d69 | 767 | err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL); |
bcabbcca OBC |
768 | if (err < 0) { |
769 | dev_err(dev, "failed to add a virtqueue buffer: %d\n", err); | |
1aa7d6a5 RT |
770 | return err; |
771 | } | |
772 | ||
773 | return 0; | |
774 | } | |
775 | ||
776 | /* called when an rx buffer is used, and it's time to digest a message */ | |
777 | static void rpmsg_recv_done(struct virtqueue *rvq) | |
778 | { | |
779 | struct virtproc_info *vrp = rvq->vdev->priv; | |
780 | struct device *dev = &rvq->vdev->dev; | |
781 | struct rpmsg_hdr *msg; | |
782 | unsigned int len, msgs_received = 0; | |
783 | int err; | |
784 | ||
785 | msg = virtqueue_get_buf(rvq, &len); | |
786 | if (!msg) { | |
787 | dev_err(dev, "uhm, incoming signal, but no used buffer ?\n"); | |
bcabbcca OBC |
788 | return; |
789 | } | |
790 | ||
1aa7d6a5 RT |
791 | while (msg) { |
792 | err = rpmsg_recv_single(vrp, dev, msg, len); | |
793 | if (err) | |
794 | break; | |
795 | ||
796 | msgs_received++; | |
797 | ||
798 | msg = virtqueue_get_buf(rvq, &len); | |
6c49fbe3 | 799 | } |
1aa7d6a5 RT |
800 | |
801 | dev_dbg(dev, "Received %u messages\n", msgs_received); | |
802 | ||
bcabbcca | 803 | /* tell the remote processor we added another available rx buffer */ |
1aa7d6a5 RT |
804 | if (msgs_received) |
805 | virtqueue_kick(vrp->rvq); | |
bcabbcca OBC |
806 | } |
807 | ||
808 | /* | |
809 | * This is invoked whenever the remote processor completed processing | |
810 | * a TX msg we just sent it, and the buffer is put back to the used ring. | |
811 | * | |
812 | * Normally, though, we suppress this "tx complete" interrupt in order to | |
813 | * avoid the incurred overhead. | |
814 | */ | |
815 | static void rpmsg_xmit_done(struct virtqueue *svq) | |
816 | { | |
817 | struct virtproc_info *vrp = svq->vdev->priv; | |
818 | ||
819 | dev_dbg(&svq->vdev->dev, "%s\n", __func__); | |
820 | ||
821 | /* wake up potential senders that are waiting for a tx buffer */ | |
822 | wake_up_interruptible(&vrp->sendq); | |
823 | } | |
824 | ||
c486682a AP |
825 | /* |
826 | * Called to expose to user a /dev/rpmsg_ctrlX interface allowing to | |
827 | * create endpoint-to-endpoint communication without associated RPMsg channel. | |
828 | * The endpoints are rattached to the ctrldev RPMsg device. | |
829 | */ | |
830 | static struct rpmsg_device *rpmsg_virtio_add_ctrl_dev(struct virtio_device *vdev) | |
831 | { | |
832 | struct virtproc_info *vrp = vdev->priv; | |
833 | struct virtio_rpmsg_channel *vch; | |
834 | struct rpmsg_device *rpdev_ctrl; | |
835 | int err = 0; | |
836 | ||
837 | vch = kzalloc(sizeof(*vch), GFP_KERNEL); | |
838 | if (!vch) | |
839 | return ERR_PTR(-ENOMEM); | |
840 | ||
841 | /* Link the channel to the vrp */ | |
842 | vch->vrp = vrp; | |
843 | ||
844 | /* Assign public information to the rpmsg_device */ | |
845 | rpdev_ctrl = &vch->rpdev; | |
846 | rpdev_ctrl->ops = &virtio_rpmsg_ops; | |
847 | ||
848 | rpdev_ctrl->dev.parent = &vrp->vdev->dev; | |
849 | rpdev_ctrl->dev.release = virtio_rpmsg_release_device; | |
850 | rpdev_ctrl->little_endian = virtio_is_little_endian(vrp->vdev); | |
851 | ||
472f84ee | 852 | err = rpmsg_ctrldev_register_device(rpdev_ctrl); |
c486682a | 853 | if (err) { |
1680939e | 854 | /* vch will be free in virtio_rpmsg_release_device() */ |
c486682a AP |
855 | return ERR_PTR(err); |
856 | } | |
857 | ||
858 | return rpdev_ctrl; | |
859 | } | |
860 | ||
861 | static void rpmsg_virtio_del_ctrl_dev(struct rpmsg_device *rpdev_ctrl) | |
862 | { | |
863 | if (!rpdev_ctrl) | |
864 | return; | |
df191796 | 865 | device_unregister(&rpdev_ctrl->dev); |
c486682a AP |
866 | } |
867 | ||
bcabbcca OBC |
868 | static int rpmsg_probe(struct virtio_device *vdev) |
869 | { | |
870 | vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done }; | |
f7ad26ff | 871 | static const char * const names[] = { "input", "output" }; |
bcabbcca OBC |
872 | struct virtqueue *vqs[2]; |
873 | struct virtproc_info *vrp; | |
c486682a AP |
874 | struct virtio_rpmsg_channel *vch = NULL; |
875 | struct rpmsg_device *rpdev_ns, *rpdev_ctrl; | |
bcabbcca OBC |
876 | void *bufs_va; |
877 | int err = 0, i; | |
b1b98914 | 878 | size_t total_buf_space; |
71e4b8bf | 879 | bool notify; |
bcabbcca OBC |
880 | |
881 | vrp = kzalloc(sizeof(*vrp), GFP_KERNEL); | |
882 | if (!vrp) | |
883 | return -ENOMEM; | |
884 | ||
885 | vrp->vdev = vdev; | |
886 | ||
887 | idr_init(&vrp->endpoints); | |
888 | mutex_init(&vrp->endpoints_lock); | |
889 | mutex_init(&vrp->tx_lock); | |
890 | init_waitqueue_head(&vrp->sendq); | |
891 | ||
892 | /* We expect two virtqueues, rx and tx (and in this order) */ | |
9b2bbdb2 | 893 | err = virtio_find_vqs(vdev, 2, vqs, vq_cbs, names, NULL); |
bcabbcca OBC |
894 | if (err) |
895 | goto free_vrp; | |
896 | ||
897 | vrp->rvq = vqs[0]; | |
898 | vrp->svq = vqs[1]; | |
899 | ||
b1b98914 SA |
900 | /* we expect symmetric tx/rx vrings */ |
901 | WARN_ON(virtqueue_get_vring_size(vrp->rvq) != | |
902 | virtqueue_get_vring_size(vrp->svq)); | |
903 | ||
904 | /* we need less buffers if vrings are small */ | |
905 | if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS / 2) | |
906 | vrp->num_bufs = virtqueue_get_vring_size(vrp->rvq) * 2; | |
907 | else | |
908 | vrp->num_bufs = MAX_RPMSG_NUM_BUFS; | |
909 | ||
f93848f9 LP |
910 | vrp->buf_size = MAX_RPMSG_BUF_SIZE; |
911 | ||
912 | total_buf_space = vrp->num_bufs * vrp->buf_size; | |
b1b98914 | 913 | |
bcabbcca | 914 | /* allocate coherent memory for the buffers */ |
d999b622 | 915 | bufs_va = dma_alloc_coherent(vdev->dev.parent, |
b1b98914 SA |
916 | total_buf_space, &vrp->bufs_dma, |
917 | GFP_KERNEL); | |
3119b487 WY |
918 | if (!bufs_va) { |
919 | err = -ENOMEM; | |
bcabbcca | 920 | goto vqs_del; |
3119b487 | 921 | } |
bcabbcca | 922 | |
de4064af | 923 | dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n", |
8d95b322 | 924 | bufs_va, &vrp->bufs_dma); |
bcabbcca OBC |
925 | |
926 | /* half of the buffers is dedicated for RX */ | |
927 | vrp->rbufs = bufs_va; | |
928 | ||
929 | /* and half is dedicated for TX */ | |
b1b98914 | 930 | vrp->sbufs = bufs_va + total_buf_space / 2; |
bcabbcca OBC |
931 | |
932 | /* set up the receive buffers */ | |
b1b98914 | 933 | for (i = 0; i < vrp->num_bufs / 2; i++) { |
bcabbcca | 934 | struct scatterlist sg; |
f93848f9 | 935 | void *cpu_addr = vrp->rbufs + i * vrp->buf_size; |
bcabbcca | 936 | |
9dd87c2a | 937 | rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size); |
bcabbcca | 938 | |
cee51d69 | 939 | err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr, |
0963679c | 940 | GFP_KERNEL); |
57e1a373 | 941 | WARN_ON(err); /* sanity check; this can't really happen */ |
bcabbcca OBC |
942 | } |
943 | ||
944 | /* suppress "tx-complete" interrupts */ | |
945 | virtqueue_disable_cb(vrp->svq); | |
946 | ||
947 | vdev->priv = vrp; | |
948 | ||
c486682a AP |
949 | rpdev_ctrl = rpmsg_virtio_add_ctrl_dev(vdev); |
950 | if (IS_ERR(rpdev_ctrl)) { | |
951 | err = PTR_ERR(rpdev_ctrl); | |
952 | goto free_coherent; | |
953 | } | |
954 | ||
bcabbcca OBC |
955 | /* if supported by the remote processor, enable the name service */ |
956 | if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) { | |
950a7388 AP |
957 | vch = kzalloc(sizeof(*vch), GFP_KERNEL); |
958 | if (!vch) { | |
bcabbcca | 959 | err = -ENOMEM; |
c486682a | 960 | goto free_ctrldev; |
bcabbcca | 961 | } |
950a7388 AP |
962 | |
963 | /* Link the channel to our vrp */ | |
964 | vch->vrp = vrp; | |
965 | ||
966 | /* Assign public information to the rpmsg_device */ | |
967 | rpdev_ns = &vch->rpdev; | |
968 | rpdev_ns->ops = &virtio_rpmsg_ops; | |
969 | rpdev_ns->little_endian = virtio_is_little_endian(vrp->vdev); | |
970 | ||
971 | rpdev_ns->dev.parent = &vrp->vdev->dev; | |
972 | rpdev_ns->dev.release = virtio_rpmsg_release_device; | |
973 | ||
974 | err = rpmsg_ns_register_device(rpdev_ns); | |
975 | if (err) | |
c2eecefe HH |
976 | /* vch will be free in virtio_rpmsg_release_device() */ |
977 | goto free_ctrldev; | |
bcabbcca OBC |
978 | } |
979 | ||
71e4b8bf MT |
980 | /* |
981 | * Prepare to kick but don't notify yet - we can't do this before | |
982 | * device is ready. | |
983 | */ | |
984 | notify = virtqueue_kick_prepare(vrp->rvq); | |
985 | ||
986 | /* From this point on, we can notify and get callbacks. */ | |
987 | virtio_device_ready(vdev); | |
988 | ||
bcabbcca | 989 | /* tell the remote processor it can start sending messages */ |
71e4b8bf MT |
990 | /* |
991 | * this might be concurrent with callbacks, but we are only | |
992 | * doing notify, not a full kick here, so that's ok. | |
993 | */ | |
994 | if (notify) | |
995 | virtqueue_notify(vrp->rvq); | |
bcabbcca OBC |
996 | |
997 | dev_info(&vdev->dev, "rpmsg host is online\n"); | |
998 | ||
999 | return 0; | |
1000 | ||
c486682a AP |
1001 | free_ctrldev: |
1002 | rpmsg_virtio_del_ctrl_dev(rpdev_ctrl); | |
1003 | free_coherent: | |
d999b622 | 1004 | dma_free_coherent(vdev->dev.parent, total_buf_space, |
b1b98914 | 1005 | bufs_va, vrp->bufs_dma); |
bcabbcca OBC |
1006 | vqs_del: |
1007 | vdev->config->del_vqs(vrp->vdev); | |
1008 | free_vrp: | |
1009 | kfree(vrp); | |
1010 | return err; | |
1011 | } | |
1012 | ||
1013 | static int rpmsg_remove_device(struct device *dev, void *data) | |
1014 | { | |
1015 | device_unregister(dev); | |
1016 | ||
1017 | return 0; | |
1018 | } | |
1019 | ||
0fe763c5 | 1020 | static void rpmsg_remove(struct virtio_device *vdev) |
bcabbcca OBC |
1021 | { |
1022 | struct virtproc_info *vrp = vdev->priv; | |
f93848f9 | 1023 | size_t total_buf_space = vrp->num_bufs * vrp->buf_size; |
bcabbcca OBC |
1024 | int ret; |
1025 | ||
d9679d00 | 1026 | virtio_reset_device(vdev); |
bcabbcca OBC |
1027 | |
1028 | ret = device_for_each_child(&vdev->dev, NULL, rpmsg_remove_device); | |
1029 | if (ret) | |
1030 | dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret); | |
1031 | ||
bcabbcca OBC |
1032 | idr_destroy(&vrp->endpoints); |
1033 | ||
1034 | vdev->config->del_vqs(vrp->vdev); | |
1035 | ||
d999b622 | 1036 | dma_free_coherent(vdev->dev.parent, total_buf_space, |
b1b98914 | 1037 | vrp->rbufs, vrp->bufs_dma); |
bcabbcca OBC |
1038 | |
1039 | kfree(vrp); | |
1040 | } | |
1041 | ||
1042 | static struct virtio_device_id id_table[] = { | |
1043 | { VIRTIO_ID_RPMSG, VIRTIO_DEV_ANY_ID }, | |
1044 | { 0 }, | |
1045 | }; | |
1046 | ||
1047 | static unsigned int features[] = { | |
1048 | VIRTIO_RPMSG_F_NS, | |
1049 | }; | |
1050 | ||
1051 | static struct virtio_driver virtio_ipc_driver = { | |
1052 | .feature_table = features, | |
1053 | .feature_table_size = ARRAY_SIZE(features), | |
1054 | .driver.name = KBUILD_MODNAME, | |
1055 | .driver.owner = THIS_MODULE, | |
1056 | .id_table = id_table, | |
1057 | .probe = rpmsg_probe, | |
0fe763c5 | 1058 | .remove = rpmsg_remove, |
bcabbcca OBC |
1059 | }; |
1060 | ||
1061 | static int __init rpmsg_init(void) | |
1062 | { | |
1063 | int ret; | |
1064 | ||
bcabbcca | 1065 | ret = register_virtio_driver(&virtio_ipc_driver); |
5e619b48 | 1066 | if (ret) |
bcabbcca | 1067 | pr_err("failed to register virtio driver: %d\n", ret); |
bcabbcca OBC |
1068 | |
1069 | return ret; | |
1070 | } | |
96342526 | 1071 | subsys_initcall(rpmsg_init); |
bcabbcca OBC |
1072 | |
1073 | static void __exit rpmsg_fini(void) | |
1074 | { | |
1075 | unregister_virtio_driver(&virtio_ipc_driver); | |
bcabbcca OBC |
1076 | } |
1077 | module_exit(rpmsg_fini); | |
1078 | ||
1079 | MODULE_DEVICE_TABLE(virtio, id_table); | |
1080 | MODULE_DESCRIPTION("Virtio-based remote processor messaging bus"); | |
1081 | MODULE_LICENSE("GPL v2"); |