1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
|
/*
* Greybus Firmware Download Protocol Driver.
*
* Copyright 2016 Google Inc.
* Copyright 2016 Linaro Ltd.
*
* Released under the GPLv2 only.
*/
#include <linux/firmware.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include "firmware.h"
#include "greybus.h"
/* Estimated minimum buffer size, actual size can be smaller than this */
#define MIN_FETCH_SIZE 512
/* Timeout, in jiffies, within which fetch or release firmware must be called */
#define NEXT_REQ_TIMEOUT_J msecs_to_jiffies(1000)
struct fw_request {
u8 firmware_id;
bool disabled;
bool timedout;
char name[FW_NAME_SIZE];
const struct firmware *fw;
struct list_head node;
struct delayed_work dwork;
/* Timeout, in jiffies, within which the firmware shall download */
unsigned long release_timeout_j;
struct kref kref;
struct fw_download *fw_download;
};
struct fw_download {
struct device *parent;
struct gb_connection *connection;
struct list_head fw_requests;
struct ida id_map;
struct mutex mutex;
};
static void fw_req_release(struct kref *kref)
{
struct fw_request *fw_req = container_of(kref, struct fw_request, kref);
dev_dbg(fw_req->fw_download->parent, "firmware %s released\n",
fw_req->name);
release_firmware(fw_req->fw);
/*
* The request timed out and the module may send a fetch-fw or
* release-fw request later. Lets block the id we allocated for this
* request, so that the AP doesn't refer to a later fw-request (with
* same firmware_id) for the old timedout fw-request.
*
* NOTE:
*
* This also means that after 255 timeouts we will fail to service new
* firmware downloads. But what else can we do in that case anyway? Lets
* just hope that it never happens.
*/
if (!fw_req->timedout)
ida_simple_remove(&fw_req->fw_download->id_map,
fw_req->firmware_id);
kfree(fw_req);
}
/*
* Incoming requests are serialized for a connection, and the only race possible
* is between the timeout handler freeing this and an incoming request.
*
* The operations on the fw-request list are protected by the mutex and
* get_fw_req() increments the reference count before returning a fw_req pointer
* to the users.
*
* free_firmware() also takes the mutex while removing an entry from the list,
* it guarantees that every user of fw_req has taken a kref-reference by now and
* we wouldn't have any new users.
*
* Once the last user drops the reference, the fw_req structure is freed.
*/
static void put_fw_req(struct fw_request *fw_req)
{
kref_put(&fw_req->kref, fw_req_release);
}
/* Caller must call put_fw_req() after using struct fw_request */
static struct fw_request *get_fw_req(struct fw_download *fw_download,
u8 firmware_id)
{
struct fw_request *fw_req;
mutex_lock(&fw_download->mutex);
list_for_each_entry(fw_req, &fw_download->fw_requests, node) {
if (fw_req->firmware_id == firmware_id) {
kref_get(&fw_req->kref);
goto unlock;
}
}
fw_req = NULL;
unlock:
mutex_unlock(&fw_download->mutex);
return fw_req;
}
static void free_firmware(struct fw_download *fw_download,
struct fw_request *fw_req)
{
/* Already disabled from timeout handlers */
if (fw_req->disabled)
return;
mutex_lock(&fw_download->mutex);
list_del(&fw_req->node);
mutex_unlock(&fw_download->mutex);
fw_req->disabled = true;
put_fw_req(fw_req);
}
static void fw_request_timedout(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct fw_request *fw_req = container_of(dwork, struct fw_request, dwork);
struct fw_download *fw_download = fw_req->fw_download;
dev_err(fw_download->parent,
"Timed out waiting for fetch / release firmware requests: %u\n",
fw_req->firmware_id);
fw_req->timedout = true;
free_firmware(fw_download, fw_req);
}
static int exceeds_release_timeout(struct fw_request *fw_req)
{
struct fw_download *fw_download = fw_req->fw_download;
if (time_before(jiffies, fw_req->release_timeout_j))
return 0;
dev_err(fw_download->parent,
"Firmware download didn't finish in time, abort: %d\n",
fw_req->firmware_id);
fw_req->timedout = true;
free_firmware(fw_download, fw_req);
return -ETIMEDOUT;
}
/* This returns path of the firmware blob on the disk */
static struct fw_request *find_firmware(struct fw_download *fw_download,
const char *tag)
{
struct gb_interface *intf = fw_download->connection->bundle->intf;
struct fw_request *fw_req;
int ret, req_count;
fw_req = kzalloc(sizeof(*fw_req), GFP_KERNEL);
if (!fw_req)
return ERR_PTR(-ENOMEM);
/* Allocate ids from 1 to 255 (u8-max), 0 is an invalid id */
ret = ida_simple_get(&fw_download->id_map, 1, 256, GFP_KERNEL);
if (ret < 0) {
dev_err(fw_download->parent,
"failed to allocate firmware id (%d)\n", ret);
goto err_free_req;
}
fw_req->firmware_id = ret;
snprintf(fw_req->name, sizeof(fw_req->name),
FW_NAME_PREFIX "%08x_%08x_%08x_%08x_%s.tftf",
intf->ddbl1_manufacturer_id, intf->ddbl1_product_id,
intf->vendor_id, intf->product_id, tag);
dev_info(fw_download->parent, "Requested firmware package '%s'\n",
fw_req->name);
ret = request_firmware(&fw_req->fw, fw_req->name, fw_download->parent);
if (ret) {
dev_err(fw_download->parent,
"firmware request failed for %s (%d)\n", fw_req->name,
ret);
goto err_free_id;
}
fw_req->fw_download = fw_download;
kref_init(&fw_req->kref);
mutex_lock(&fw_download->mutex);
list_add(&fw_req->node, &fw_download->fw_requests);
mutex_unlock(&fw_download->mutex);
/* Timeout, in jiffies, within which firmware should get loaded */
req_count = DIV_ROUND_UP(fw_req->fw->size, MIN_FETCH_SIZE);
fw_req->release_timeout_j = jiffies + req_count * NEXT_REQ_TIMEOUT_J;
INIT_DELAYED_WORK(&fw_req->dwork, fw_request_timedout);
schedule_delayed_work(&fw_req->dwork, NEXT_REQ_TIMEOUT_J);
return fw_req;
err_free_id:
ida_simple_remove(&fw_download->id_map, fw_req->firmware_id);
err_free_req:
kfree(fw_req);
return ERR_PTR(ret);
}
static int fw_download_find_firmware(struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct fw_download *fw_download = gb_connection_get_data(connection);
struct gb_fw_download_find_firmware_request *request;
struct gb_fw_download_find_firmware_response *response;
struct fw_request *fw_req;
const char *tag;
if (op->request->payload_size != sizeof(*request)) {
dev_err(fw_download->parent,
"illegal size of find firmware request (%zu != %zu)\n",
op->request->payload_size, sizeof(*request));
return -EINVAL;
}
request = op->request->payload;
tag = (const char *)request->firmware_tag;
/* firmware_tag must be null-terminated */
if (strnlen(tag, GB_FIRMWARE_TAG_MAX_SIZE) == GB_FIRMWARE_TAG_MAX_SIZE) {
dev_err(fw_download->parent,
"firmware-tag is not null-terminated\n");
return -EINVAL;
}
fw_req = find_firmware(fw_download, tag);
if (IS_ERR(fw_req))
return PTR_ERR(fw_req);
if (!gb_operation_response_alloc(op, sizeof(*response), GFP_KERNEL)) {
dev_err(fw_download->parent, "error allocating response\n");
free_firmware(fw_download, fw_req);
return -ENOMEM;
}
response = op->response->payload;
response->firmware_id = fw_req->firmware_id;
response->size = cpu_to_le32(fw_req->fw->size);
dev_dbg(fw_download->parent,
"firmware size is %zu bytes\n", fw_req->fw->size);
return 0;
}
static int fw_download_fetch_firmware(struct gb_operation *op)
{
struct gb_connection *connection = op->
|