summaryrefslogtreecommitdiff
path: root/package/kernel/mac80211/patches/600-0003-rt2x00-rt2800-serialize-shared-memory-access.patch
blob: c1e40d18eb3ede9335c2947c334676c41923366d (plain)
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
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
From 250a1b520cd7fdc0df4fc3fedea9066913f49ecf Mon Sep 17 00:00:00 2001
From: Gabor Juhos <juhosg@openwrt.org>
Date: Sat, 17 Aug 2013 19:31:42 +0200
Subject: [PATCH] rt2x00: rt2800: serialize shared memory access

The shared memory of the rt2800 devices is accessible
through the register offset range between 0x4000 and
0x8000. The size of this range is 16KB only and on
devices which have more than 16KB of shared memory either
the low or the high part of the memory is accessible at a
time.

Serialize all accesses to the shared memory by a mutex,
in order to avoid concurrent use of that.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
---
Changes since v1: ---
---
 drivers/net/wireless/rt2x00/rt2800lib.c  |   55 +++++++++++++++++++++++++++++-
 drivers/net/wireless/rt2x00/rt2800lib.h  |   32 +++++++++++++++++
 drivers/net/wireless/rt2x00/rt2800mmio.c |   26 ++++++++++++++
 drivers/net/wireless/rt2x00/rt2800mmio.h |    4 +++
 drivers/net/wireless/rt2x00/rt2800pci.c  |   14 ++++++++
 drivers/net/wireless/rt2x00/rt2800soc.c  |    3 ++
 drivers/net/wireless/rt2x00/rt2800usb.c  |   31 +++++++++++++++++
 7 files changed, 164 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -451,11 +451,13 @@ void rt2800_mcu_request(struct rt2x00_de
 		rt2x00_set_field32(&reg, H2M_MAILBOX_CSR_CMD_TOKEN, token);
 		rt2x00_set_field32(&reg, H2M_MAILBOX_CSR_ARG0, arg0);
 		rt2x00_set_field32(&reg, H2M_MAILBOX_CSR_ARG1, arg1);
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2800_register_write_lock(rt2x00dev, H2M_MAILBOX_CSR, reg);
 
 		reg = 0;
 		rt2x00_set_field32(&reg, HOST_CMD_CSR_HOST_COMMAND, command);
 		rt2800_register_write_lock(rt2x00dev, HOST_CMD_CSR, reg);
+		rt2800_shared_mem_unlock(rt2x00dev);
 	}
 
 	mutex_unlock(&rt2x00dev->csr_mutex);
@@ -674,7 +676,9 @@ int rt2800_load_firmware(struct rt2x00_d
 	 * Wait for device to stabilize.
 	 */
 	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2800_register_read(rt2x00dev, PBF_SYS_CTRL, &reg);
+		rt2800_shared_mem_unlock(rt2x00dev);
 		if (rt2x00_get_field32(reg, PBF_SYS_CTRL_READY))
 			break;
 		msleep(1);
@@ -694,10 +698,16 @@ int rt2800_load_firmware(struct rt2x00_d
 	/*
 	 * Initialize firmware.
 	 */
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_write(rt2x00dev, H2M_BBP_AGENT, 0);
 	rt2800_register_write(rt2x00dev, H2M_MAILBOX_CSR, 0);
+	rt2800_shared_mem_unlock(rt2x00dev);
+
 	if (rt2x00_is_usb(rt2x00dev)) {
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2800_register_write(rt2x00dev, H2M_INT_SRC, 0);
+		rt2800_shared_mem_unlock(rt2x00dev);
+
 		rt2800_mcu_request(rt2x00dev, MCU_BOOT_SIGNAL, 0, 0, 0);
 	}
 	msleep(1);
@@ -1035,8 +1045,10 @@ void rt2800_write_beacon(struct queue_en
 
 	beacon_base = rt2800_hw_beacon_base(rt2x00dev, entry->entry_idx);
 
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_multiwrite(rt2x00dev, beacon_base, entry->skb->data,
 				   entry->skb->len + padding_len);
+	rt2800_shared_mem_unlock(rt2x00dev);
 	__set_bit(ENTRY_BCN_ENABLED, &entry->flags);
 
 	/*
@@ -1066,6 +1078,8 @@ static inline void rt2800_clear_beacon_r
 
 	beacon_base = rt2800_hw_beacon_base(rt2x00dev, index);
 
+	rt2800_shared_mem_lock(rt2x00dev);
+
 	/*
 	 * For the Beacon base registers we only need to clear
 	 * the whole TXWI which (when set to 0) will invalidate
@@ -1073,6 +1087,8 @@ static inline void rt2800_clear_beacon_r
 	 */
 	for (i = 0; i < txwi_desc_size; i += sizeof(__le32))
 		rt2800_register_write(rt2x00dev, beacon_base + i, 0);
+
+	rt2800_shared_mem_unlock(rt2x00dev);
 }
 
 void rt2800_clear_beacon(struct queue_entry *entry)
@@ -1261,7 +1277,9 @@ static void rt2800_delete_wcid_attr(stru
 {
 	u32 offset;
 	offset = MAC_WCID_ATTR_ENTRY(wcid);
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_write(rt2x00dev, offset, 0);
+	rt2800_shared_mem_unlock(rt2x00dev);
 }
 
 static void rt2800_config_wcid_attr_bssidx(struct rt2x00_dev *rt2x00dev,
@@ -1274,11 +1292,13 @@ static void rt2800_config_wcid_attr_bssi
 	 * The BSS Idx numbers is split in a main value of 3 bits,
 	 * and a extended field for adding one additional bit to the value.
 	 */
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_read(rt2x00dev, offset, &reg);
 	rt2x00_set_field32(&reg, MAC_WCID_ATTRIBUTE_BSS_IDX, (bssidx & 0x7));
 	rt2x00_set_field32(&reg, MAC_WCID_ATTRIBUTE_BSS_IDX_EXT,
 			   (bssidx & 0x8) >> 3);
 	rt2800_register_write(rt2x00dev, offset, reg);
+	rt2800_shared_mem_unlock(rt2x00dev);
 }
 
 static void rt2800_config_wcid_attr_cipher(struct rt2x00_dev *rt2x00dev,
@@ -1291,6 +1311,7 @@ static void rt2800_config_wcid_attr_ciph
 
 	offset = MAC_WCID_ATTR_ENTRY(key->hw_key_idx);
 
+	rt2800_shared_mem_lock(rt2x00dev);
 	if (crypto->cmd == SET_KEY) {
 		rt2800_register_read(rt2x00dev, offset, &reg);
 		rt2x00_set_field32(&reg, MAC_WCID_ATTRIBUTE_KEYTAB,
@@ -1315,6 +1336,7 @@ static void rt2800_config_wcid_attr_ciph
 		rt2x00_set_field32(&reg, MAC_WCID_ATTRIBUTE_RX_WIUDF, 0);
 		rt2800_register_write(rt2x00dev, offset, reg);
 	}
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	offset = MAC_IVEIV_ENTRY(key->hw_key_idx);
 
@@ -1324,8 +1346,11 @@ static void rt2800_config_wcid_attr_ciph
 	    (crypto->cipher == CIPHER_AES))
 		iveiv_entry.iv[3] |= 0x20;
 	iveiv_entry.iv[3] |= key->keyidx << 6;
+
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_multiwrite(rt2x00dev, offset,
 				      &iveiv_entry, sizeof(iveiv_entry));
+	rt2800_shared_mem_unlock(rt2x00dev);
 }
 
 int rt2800_config_shared_key(struct rt2x00_dev *rt2x00dev,
@@ -1348,8 +1373,11 @@ int rt2800_config_shared_key(struct rt2x
 		       sizeof(key_entry.rx_mic));
 
 		offset = SHARED_KEY_ENTRY(key->hw_key_idx);
+
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2800_register_multiwrite(rt2x00dev, offset,
 					      &key_entry, sizeof(key_entry));
+		rt2800_shared_mem_unlock(rt2x00dev);
 	}
 
 	/*
@@ -1364,10 +1392,12 @@ int rt2800_config_shared_key(struct rt2x
 
 	offset = SHARED_KEY_MODE_ENTRY(key->hw_key_idx / 8);
 
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_read(rt2x00dev, offset, &reg);
 	rt2x00_set_field32(&reg, field,
 			   (crypto->cmd == SET_KEY) * crypto->cipher);
 	rt2800_register_write(rt2x00dev, offset, reg);
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	/*
 	 * Update WCID information
@@ -1437,8 +1467,11 @@ int rt2800_config_pairwise_key(struct rt
 		       sizeof(key_entry.rx_mic));
 
 		offset = PAIRWISE_KEY_ENTRY(key->hw_key_idx);
+
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2800_register_multiwrite(rt2x00dev, offset,
 					      &key_entry, sizeof(key_entry));
+		rt2800_shared_mem_unlock(rt2x00dev);
 	}
 
 	/*
@@ -4901,14 +4934,19 @@ static int rt2800_init_registers(struct 
 	/*
 	 * ASIC will keep garbage value after boot, clear encryption keys.
 	 */
+	rt2800_shared_mem_lock(rt2x00dev);
 	for (i = 0; i < 4; i++)
 		rt2800_register_write(rt2x00dev,
 					 SHARED_KEY_MODE_ENTRY(i), 0);
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	for (i = 0; i < 256; i++) {
 		rt2800_config_wcid(rt2x00dev, NULL, i);
 		rt2800_delete_wcid_attr(rt2x00dev, i);
+
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2800_register_write(rt2x00dev, MAC_IVEIV_ENTRY(i), 0);
+		rt2800_shared_mem_unlock(rt2x00dev);
 	}
 
 	/*
@@ -5034,8 +5072,10 @@ static int rt2800_wait_bbp_ready(struct 
 	 * BBP was enabled after firmware was loaded,
 	 * but we need to reactivate it now.
 	 */
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_write(rt2x00dev, H2M_BBP_AGENT, 0);
 	rt2800_register_write(rt2x00dev, H2M_MAILBOX_CSR, 0);
+	rt2800_shared_mem_unlock(rt2x00dev);
 	msleep(1);
 
 	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
@@ -6731,11 +6771,19 @@ int rt2800_enable_radio(struct rt2x00_de
 	/*
 	 * Send signal during boot time to initialize firmware.
 	 */
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_write(rt2x00dev, H2M_BBP_AGENT, 0);
 	rt2800_register_write(rt2x00dev, H2M_MAILBOX_CSR, 0);
-	if (rt2x00_is_usb(rt2x00dev))
+	rt2800_shared_mem_unlock(rt2x00dev);
+
+	if (rt2x00_is_usb(rt2x00dev)) {
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2800_register_write(rt2x00dev, H2M_INT_SRC, 0);
+		rt2800_shared_mem_unlock(rt2x00dev);
+	}
+
 	rt2800_mcu_request(rt2x00dev, MCU_BOOT_SIGNAL, 0, 0, 0);
+
 	msleep(1);
 
 	/*
@@ -7744,6 +7792,8 @@ int rt2800_probe_hw(struct rt2x00_dev *r
 	int retval;
 	u32 reg;
 
+	rt2800_shared_mem_init_lock(rt2x00dev);
+
 	retval = rt2800_probe_rt(rt2x00dev);
 	if (retval)
 		return retval;
@@ -7823,8 +7873,11 @@ void rt2800_get_tkip_seq(struct ieee8021
 	u32 offset;
 
 	offset = MAC_IVEIV_ENTRY(hw_key_idx);
+
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2800_register_multiread(rt2x00dev, offset,
 				      &iveiv_entry, sizeof(iveiv_entry));
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	memcpy(iv16, &iveiv_entry.iv[0], sizeof(*iv16));
 	memcpy(iv32, &iveiv_entry.iv[4], sizeof(*iv32));
--- a/drivers/net/wireless/rt2x00/rt2800lib.h
+++ b/drivers/net/wireless/rt2x00/rt2800lib.h
@@ -35,6 +35,11 @@ struct rt2800_drv_data {
 	unsigned int tbtt_tick;
 
 	unsigned long rt2800_flags;
+
+	union {
+		spinlock_t spin;
+		struct mutex mutex;
+	} shmem_lock;
 };
 
 struct rt2800_ops {
@@ -65,6 +70,10 @@ struct rt2800_ops {
 				  const u8 *data, const size_t len);
 	int (*drv_init_registers)(struct rt2x00_dev *rt2x00dev);
 	__le32 *(*drv_get_txwi)(struct queue_entry *entry);
+
+	void (*shmem_init_lock)(struct rt2x00_dev *rt2x00dev);
+	void (*shmem_lock)(struct rt2x00_dev *rt2x00dev);
+	void (*shmem_unlock)(struct rt2x00_dev *rt2x00dev);
 };
 
 static inline bool rt2800_has_high_shared_mem(struct rt2x00_dev *rt2x00dev)
@@ -74,6 +83,29 @@ static inline bool rt2800_has_high_share
 	return test_bit(RT2800_HAS_HIGH_SHARED_MEM, &drv_data->rt2800_flags);
 }
 
+static inline void rt2800_shared_mem_init_lock(struct rt2x00_dev *rt2x00dev)
+{
+	const struct rt2800_ops *rt2800ops = rt2x00dev->ops->drv;
+
+	rt2800ops->shmem_init_lock(rt2x00dev);
+}
+
+static inline void rt2800_shared_mem_lock(struct rt2x00_dev *rt2x00dev)
+{
+	const struct rt2800_ops *rt2800ops = rt2x00dev->ops->drv;
+
+	if (rt2800_has_high_shared_mem(rt2x00dev))
+		rt2800ops->shmem_lock(rt2x00dev);
+}
+
+static inline void rt2800_shared_mem_unlock(struct rt2x00_dev *rt2x00dev)
+{
+	const struct rt2800_ops *rt2800ops = rt2x00dev->ops->drv;
+
+	if (rt2800_has_high_shared_mem(rt2x00dev))
+		rt2800ops->shmem_unlock(rt2x00dev);
+}
+
 static inline void rt2800_register_read(struct rt2x00_dev *rt2x00dev,
 					const unsigned int offset,
 					u32 *value)
--- a/drivers/net/wireless/rt2x00/rt2800mmio.c
+++ b/drivers/net/wireless/rt2x00/rt2800mmio.c
@@ -820,8 +820,10 @@ int rt2800mmio_init_registers(struct rt2
 	rt2x00_set_field32(&reg, WPDMA_RST_IDX_DRX_IDX0, 1);
 	rt2x00mmio_register_write(rt2x00dev, WPDMA_RST_IDX, reg);
 
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2x00mmio_register_write(rt2x00dev, PBF_SYS_CTRL, 0x00000e1f);
 	rt2x00mmio_register_write(rt2x00dev, PBF_SYS_CTRL, 0x00000e00);
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	if (rt2x00_is_pcie(rt2x00dev) &&
 	    (rt2x00_rt(rt2x00dev, RT3090) ||
@@ -865,6 +867,30 @@ int rt2800mmio_enable_radio(struct rt2x0
 }
 EXPORT_SYMBOL_GPL(rt2800mmio_enable_radio);
 
+void rt2800mmio_shmem_init_lock(struct rt2x00_dev *rt2x00dev)
+{
+	struct rt2800_drv_data *drv_data = rt2x00dev->drv_data;
+
+	spin_lock_init(&drv_data->shmem_lock.spin);
+}
+EXPORT_SYMBOL_GPL(rt2800mmio_shmem_init_lock);
+
+void rt2800mmio_shmem_lock(struct rt2x00_dev *rt2x00dev)
+{
+	struct rt2800_drv_data *drv_data = rt2x00dev->drv_data;
+
+	spin_lock_bh(&drv_data->shmem_lock.spin);
+}
+EXPORT_SYMBOL_GPL(rt2800mmio_shmem_lock);
+
+void rt2800mmio_shmem_unlock(struct rt2x00_dev *rt2x00dev)
+{
+	struct rt2800_drv_data *drv_data = rt2x00dev->drv_data;
+
+	spin_unlock_bh(&drv_data->shmem_lock.spin);
+}
+EXPORT_SYMBOL_GPL(rt2800mmio_shmem_unlock);
+
 MODULE_AUTHOR(DRV_PROJECT);
 MODULE_VERSION(DRV_VERSION);
 MODULE_DESCRIPTION("rt2800 MMIO library");
--- a/drivers/net/wireless/rt2x00/rt2800mmio.h
+++ b/drivers/net/wireless/rt2x00/rt2800mmio.h
@@ -160,4 +160,8 @@ int rt2800mmio_init_registers(struct rt2
 /* Device state switch handlers. */
 int rt2800mmio_enable_radio(struct rt2x00_dev *rt2x00dev);
 
+void rt2800mmio_shmem_init_lock(struct rt2x00_dev *rt2x00dev);
+void rt2800mmio_shmem_lock(struct rt2x00_dev *rt2x00dev);
+void rt2800mmio_shmem_unlock(struct rt2x00_dev *rt2x00dev);
+
 #endif /* RT2800MMIO_H */
--- a/drivers/net/wireless/rt2x00/rt2800pci.c
+++ b/drivers/net/wireless/rt2x00/rt2800pci.c
@@ -69,7 +69,9 @@ static void rt2800pci_mcu_status(struct 
 		return;
 
 	for (i = 0; i < 200; i++) {
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2x00mmio_register_read(rt2x00dev, H2M_MAILBOX_CID, &reg);
+		rt2800_shared_mem_unlock(rt2x00dev);
 
 		if ((rt2x00_get_field32(reg, H2M_MAILBOX_CID_CMD0) == token) ||
 		    (rt2x00_get_field32(reg, H2M_MAILBOX_CID_CMD1) == token) ||
@@ -83,8 +85,10 @@ static void rt2800pci_mcu_status(struct 
 	if (i == 200)
 		rt2x00_err(rt2x00dev, "MCU request failed, no response from hardware\n");
 
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2x00mmio_register_write(rt2x00dev, H2M_MAILBOX_STATUS, ~0);
 	rt2x00mmio_register_write(rt2x00dev, H2M_MAILBOX_CID, ~0);
+	rt2800_shared_mem_unlock(rt2x00dev);
 }
 
 static void rt2800pci_eepromregister_read(struct eeprom_93cx6 *eeprom)
@@ -184,6 +188,8 @@ static int rt2800pci_write_firmware(stru
 	 */
 	reg = 0;
 	rt2x00_set_field32(&reg, PBF_SYS_CTRL_HOST_RAM_WRITE, 1);
+
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2x00mmio_register_write(rt2x00dev, PBF_SYS_CTRL, reg);
 
 	/*
@@ -197,6 +203,7 @@ static int rt2800pci_write_firmware(stru
 
 	rt2x00mmio_register_write(rt2x00dev, H2M_BBP_AGENT, 0);
 	rt2x00mmio_register_write(rt2x00dev, H2M_MAILBOX_CSR, 0);
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	return 0;
 }
@@ -213,8 +220,10 @@ static int rt2800pci_enable_radio(struct
 		return retval;
 
 	/* After resume MCU_BOOT_SIGNAL will trash these. */
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2x00mmio_register_write(rt2x00dev, H2M_MAILBOX_STATUS, ~0);
 	rt2x00mmio_register_write(rt2x00dev, H2M_MAILBOX_CID, ~0);
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	rt2800_mcu_request(rt2x00dev, MCU_SLEEP, TOKEN_RADIO_OFF, 0xff, 0x02);
 	rt2800pci_mcu_status(rt2x00dev, TOKEN_RADIO_OFF);
@@ -233,10 +242,12 @@ static int rt2800pci_set_state(struct rt
 				   0, 0x02);
 		rt2800pci_mcu_status(rt2x00dev, TOKEN_WAKEUP);
 	} else if (state == STATE_SLEEP) {
+		rt2800_shared_mem_lock(rt2x00dev);
 		rt2x00mmio_register_write(rt2x00dev, H2M_MAILBOX_STATUS,
 					  0xffffffff);
 		rt2x00mmio_register_write(rt2x00dev, H2M_MAILBOX_CID,
 					  0xffffffff);
+		rt2800_shared_mem_unlock(rt2x00dev);
 		rt2800_mcu_request(rt2x00dev, MCU_SLEEP, TOKEN_SLEEP,
 				   0xff, 0x01);
 	}
@@ -337,6 +348,9 @@ static const struct rt2800_ops rt2800pci
 	.drv_write_firmware	= rt2800pci_write_firmware,
 	.drv_init_registers	= rt2800mmio_init_registers,
 	.drv_get_txwi		= rt2800mmio_get_txwi,
+	.shmem_init_lock	= rt2800mmio_shmem_init_lock,
+	.shmem_lock		= rt2800mmio_shmem_lock,
+	.shmem_unlock		= rt2800mmio_shmem_unlock,
 };
 
 static const struct rt2x00lib_ops rt2800pci_rt2x00_ops = {
--- a/drivers/net/wireless/rt2x00/rt2800soc.c
+++ b/drivers/net/wireless/rt2x00/rt2800soc.c
@@ -176,6 +176,9 @@ static const struct rt2800_ops rt2800soc
 	.drv_write_firmware	= rt2800soc_write_firmware,
 	.drv_init_registers	= rt2800mmio_init_registers,
 	.drv_get_txwi		= rt2800mmio_get_txwi,
+	.shmem_init_lock	= rt2800mmio_shmem_init_lock,
+	.shmem_lock		= rt2800mmio_shmem_lock,
+	.shmem_unlock		= rt2800mmio_shmem_unlock,
 };
 
 static const struct rt2x00lib_ops rt2800soc_rt2x00_ops = {
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -51,6 +51,27 @@ static bool rt2800usb_hwcrypt_disabled(s
 	return modparam_nohwcrypt;
 }
 
+static void rt2800usb_shmem_init_lock(struct rt2x00_dev *rt2x00dev)
+{
+	struct rt2800_drv_data *drv_data = rt2x00dev->drv_data;
+
+	mutex_init(&drv_data->shmem_lock.mutex);
+}
+
+static void rt2800usb_shmem_lock(struct rt2x00_dev *rt2x00dev)
+{
+	struct rt2800_drv_data *drv_data = rt2x00dev->drv_data;
+
+	mutex_lock(&drv_data->shmem_lock.mutex);
+}
+
+static void rt2800usb_shmem_unlock(struct rt2x00_dev *rt2x00dev)
+{
+	struct rt2800_drv_data *drv_data = rt2x00dev->drv_data;
+
+	mutex_unlock(&drv_data->shmem_lock.mutex);
+}
+
 /*
  * Queue handlers.
  */
@@ -294,8 +315,10 @@ static int rt2800usb_write_firmware(stru
 					      data + offset, length);
 	}
 
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2x00usb_register_write(rt2x00dev, H2M_MAILBOX_CID, ~0);
 	rt2x00usb_register_write(rt2x00dev, H2M_MAILBOX_STATUS, ~0);
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	/*
 	 * Send firmware request to device to load firmware,
@@ -310,7 +333,10 @@ static int rt2800usb_write_firmware(stru
 	}
 
 	msleep(10);
+
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2x00usb_register_write(rt2x00dev, H2M_MAILBOX_CSR, 0);
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	return 0;
 }
@@ -328,8 +354,10 @@ static int rt2800usb_init_registers(stru
 	if (rt2800_wait_csr_ready(rt2x00dev))
 		return -EBUSY;
 
+	rt2800_shared_mem_lock(rt2x00dev);
 	rt2x00usb_register_read(rt2x00dev, PBF_SYS_CTRL, &reg);
 	rt2x00usb_register_write(rt2x00dev, PBF_SYS_CTRL, reg & ~0x00002000);
+	rt2800_shared_mem_unlock(rt2x00dev);
 
 	reg = 0;
 	rt2x00_set_field32(&reg, MAC_SYS_CTRL_RESET_CSR, 1);
@@ -859,6 +887,9 @@ static const struct rt2800_ops rt2800usb
 	.drv_write_firmware	= rt2800usb_write_firmware,
 	.drv_init_registers	= rt2800usb_init_registers,
 	.drv_get_txwi		= rt2800usb_get_txwi,
+	.shmem_init_lock	= rt2800usb_shmem_init_lock,
+	.shmem_lock		= rt2800usb_shmem_lock,
+	.shmem_unlock		= rt2800usb_shmem_unlock,
 };
 
 static const struct rt2x00lib_ops rt2800usb_rt2x00_ops = {