Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  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
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
 */

#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/wait.h>

#include <soc/qcom/rpmh.h>

#include "rpmh-internal.h"

#define RPMH_TIMEOUT_MS			msecs_to_jiffies(10000)

#define DEFINE_RPMH_MSG_ONSTACK(dev, s, q, name)	\
	struct rpmh_request name = {			\
		.msg = {				\
			.state = s,			\
			.cmds = name.cmd,		\
			.num_cmds = 0,			\
			.wait_for_compl = true,		\
		},					\
		.cmd = { { 0 } },			\
		.completion = q,			\
		.dev = dev,				\
		.needs_free = false,				\
	}

#define ctrlr_to_drv(ctrlr) container_of(ctrlr, struct rsc_drv, client)

/**
 * struct cache_req: the request object for caching
 *
 * @addr: the address of the resource
 * @sleep_val: the sleep vote
 * @wake_val: the wake vote
 * @list: linked list obj
 */
struct cache_req {
	u32 addr;
	u32 sleep_val;
	u32 wake_val;
	struct list_head list;
};

/**
 * struct batch_cache_req - An entry in our batch catch
 *
 * @list: linked list obj
 * @count: number of messages
 * @rpm_msgs: the messages
 */

struct batch_cache_req {
	struct list_head list;
	int count;
	struct rpmh_request rpm_msgs[];
};

static struct rpmh_ctrlr *get_rpmh_ctrlr(const struct device *dev)
{
	struct rsc_drv *drv = dev_get_drvdata(dev->parent);

	return &drv->client;
}

void rpmh_tx_done(const struct tcs_request *msg, int r)
{
	struct rpmh_request *rpm_msg = container_of(msg, struct rpmh_request,
						    msg);
	struct completion *compl = rpm_msg->completion;
	bool free = rpm_msg->needs_free;

	rpm_msg->err = r;

	if (r)
		dev_err(rpm_msg->dev, "RPMH TX fail in msg addr=%#x, err=%d\n",
			rpm_msg->msg.cmds[0].addr, r);

	if (!compl)
		goto exit;

	/* Signal the blocking thread we are done */
	complete(compl);

exit:
	if (free)
		kfree(rpm_msg);
}

static struct cache_req *__find_req(struct rpmh_ctrlr *ctrlr, u32 addr)
{
	struct cache_req *p, *req = NULL;

	list_for_each_entry(p, &ctrlr->cache, list) {
		if (p->addr == addr) {
			req = p;
			break;
		}
	}

	return req;
}

static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr,
					   enum rpmh_state state,
					   struct tcs_cmd *cmd)
{
	struct cache_req *req;
	unsigned long flags;

	spin_lock_irqsave(&ctrlr->cache_lock, flags);
	req = __find_req(ctrlr, cmd->addr);
	if (req)
		goto existing;

	req = kzalloc(sizeof(*req), GFP_ATOMIC);
	if (!req) {
		req = ERR_PTR(-ENOMEM);
		goto unlock;
	}

	req->addr = cmd->addr;
	req->sleep_val = req->wake_val = UINT_MAX;
	INIT_LIST_HEAD(&req->list);
	list_add_tail(&req->list, &ctrlr->cache);

existing:
	switch (state) {
	case RPMH_ACTIVE_ONLY_STATE:
		if (req->sleep_val != UINT_MAX)
			req->wake_val = cmd->data;
		break;
	case RPMH_WAKE_ONLY_STATE:
		req->wake_val = cmd->data;
		break;
	case RPMH_SLEEP_STATE:
		req->sleep_val = cmd->data;
		break;
	default:
		break;
	}

	ctrlr->dirty = true;
unlock:
	spin_unlock_irqrestore(&ctrlr->cache_lock, flags);

	return req;
}

/**
 * __rpmh_write: Cache and send the RPMH request
 *
 * @dev: The device making the request
 * @state: Active/Sleep request type
 * @rpm_msg: The data that needs to be sent (cmds).
 *
 * Cache the RPMH request and send if the state is ACTIVE_ONLY.
 * SLEEP/WAKE_ONLY requests are not sent to the controller at
 * this time. Use rpmh_flush() to send them to the controller.
 */
static int __rpmh_write(const struct device *dev, enum rpmh_state state,
			struct rpmh_request *rpm_msg)
{
	struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
	int ret = -EINVAL;
	struct cache_req *req;
	int i;

	rpm_msg->msg.state = state;

	/* Cache the request in our store and link the payload */
	for (i = 0; i < rpm_msg->msg.num_cmds; i++) {
		req = cache_rpm_request(ctrlr, state, &rpm_msg->msg.cmds[i]);
		if (IS_ERR(req))
			return PTR_ERR(req);
	}

	rpm_msg->msg.state = state;

	if (state == RPMH_ACTIVE_ONLY_STATE) {
		WARN_ON(irqs_disabled());
		ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msg->msg);
	} else {
		/* Clean up our call by spoofing tx_done */
		ret = 0;
		rpmh_tx_done(&rpm_msg->msg, ret);
	}

	return ret;
}

static int __fill_rpmh_msg(struct rpmh_request *req, enum rpmh_state state,
		const struct tcs_cmd *cmd, u32 n)
{
	if (!cmd || !n || n > MAX_RPMH_PAYLOAD)
		return -EINVAL;

	memcpy(req->cmd, cmd, n * sizeof(*cmd));

	req->msg.state = state;
	req->msg.cmds = req->cmd;
	req->msg.num_cmds = n;

	return 0;
}

/**
 * rpmh_write_async: Write a set of RPMH commands
 *
 * @dev: The device making the request
 * @state: Active/sleep set
 * @cmd: The payload data
 * @n: The number of elements in payload
 *
 * Write a set of RPMH commands, the order of commands is maintained
 * and will be sent as a single shot.
 */
int rpmh_write_async(const struct device *dev, enum rpmh_state state,
		     const struct tcs_cmd *cmd, u32 n)
{
	struct rpmh_request *rpm_msg;
	int ret;

	rpm_msg = kzalloc(sizeof(*rpm_msg), GFP_ATOMIC);
	if (!rpm_msg)
		return -ENOMEM;
	rpm_msg->needs_free = true;

	ret = __fill_rpmh_msg(rpm_msg, state, cmd, n);
	if (ret) {
		kfree(rpm_msg);
		return ret;
	}

	return __rpmh_write(dev, state, rpm_msg);
}
EXPORT_SYMBOL(rpmh_write_async);

/**
 * rpmh_write: Write a set of RPMH commands and block until response
 *
 * @rc: The RPMH handle got from rpmh_get_client
 * @state: Active/sleep set
 * @cmd: The payload data
 * @n: The number of elements in @cmd
 *
 * May sleep. Do not call from atomic contexts.
 */
int rpmh_write(const struct device *dev, enum rpmh_state state,
	       const struct tcs_cmd *cmd, u32 n)
{
	DECLARE_COMPLETION_ONSTACK(compl);
	DEFINE_RPMH_MSG_ONSTACK(dev, state, &compl, rpm_msg);
	int ret;

	if (!cmd || !n || n > MAX_RPMH_PAYLOAD)
		return -EINVAL;

	memcpy(rpm_msg.cmd, cmd, n * sizeof(*cmd));
	rpm_msg.msg.num_cmds = n;

	ret = __rpmh_write(dev, state, &rpm_msg);
	if (ret)
		return ret;

	ret = wait_for_completion_timeout(&compl, RPMH_TIMEOUT_MS);
	WARN_ON(!ret);
	return (ret > 0) ? 0 : -ETIMEDOUT;
}
EXPORT_SYMBOL(rpmh_write);

static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req)
{
	unsigned long flags;

	spin_lock_irqsave(&ctrlr->cache_lock, flags);
	list_add_tail(&req->list, &ctrlr->batch_cache);
	spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
}

static int flush_batch(struct rpmh_ctrlr *ctrlr)
{
	struct batch_cache_req *req;
	const struct rpmh_request *rpm_msg;
	unsigned long flags;
	int ret = 0;
	int i;

	/* Send Sleep/Wake requests to the controller, expect no response */
	spin_lock_irqsave(&ctrlr->cache_lock, flags);
	list_for_each_entry(req, &ctrlr->batch_cache, list) {
		for (i = 0; i < req->count; i++) {
			rpm_msg = req->rpm_msgs + i;
			ret = rpmh_rsc_write_ctrl_data(ctrlr_to_drv(ctrlr),
						       &rpm_msg->msg);
			if (ret)
				break;
		}
	}
	spin_unlock_irqrestore(&ctrlr->cache_lock, flags);

	return ret;
}

static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
{
	struct batch_cache_req *req, *tmp;
	unsigned long flags;

	spin_lock_irqsave(&ctrlr->cache_lock, flags);
	list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
		kfree(req);
	INIT_LIST_HEAD(&ctrlr->batch_cache);
	spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
}

/**
 * rpmh_write_batch: Write multiple sets of RPMH commands and wait for the
 * batch to finish.
 *
 * @dev: the device making the request
 * @state: Active/sleep set
 * @cmd: The payload data
 * @n: The array of count of elements in each batch, 0 terminated.
 *
 * Write a request to the RSC controller without caching. If the request
 * state is ACTIVE, then the requests are treated as completion request
 * and sent to the controller immediately. The function waits until all the
 * commands are complete. If the request was to SLEEP or WAKE_ONLY, then the
 * request is sent as fire-n-forget and no ack is expected.
 *
 * May sleep. Do not call from atomic contexts for ACTIVE_ONLY requests.
 */
int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
		     const struct tcs_cmd *cmd, u32 *n)
{
	struct batch_cache_req *req;
	struct rpmh_request *rpm_msgs;
	struct completion *compls;
	struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
	unsigned long time_left;
	int count = 0;
	int ret, i;
	void *ptr;

	if (!cmd || !n)
		return -EINVAL;

	while (n[count] > 0)
		count++;
	if (!count)
		return -EINVAL;

	ptr = kzalloc(sizeof(*req) +
		      count * (sizeof(req->rpm_msgs[0]) + sizeof(*compls)),
		      GFP_ATOMIC);
	if (!ptr)
		return -ENOMEM;

	req = ptr;
	compls = ptr + sizeof(*req) + count * sizeof(*rpm_msgs);

	req->count = count;
	rpm_msgs = req->rpm_msgs;

	for (i = 0; i < count; i++) {
		__fill_rpmh_msg(rpm_msgs + i, state, cmd, n[i]);
		cmd += n[i];
	}

	if (state != RPMH_ACTIVE_ONLY_STATE) {
		cache_batch(ctrlr, req);
		return 0;
	}

	for (i = 0; i < count; i++) {
		struct completion *compl = &compls[i];

		init_completion(compl);
		rpm_msgs[i].completion = compl;
		ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msgs[i].msg);
		if (ret) {
			pr_err("Error(%d) sending RPMH message addr=%#x\n",
			       ret, rpm_msgs[i].msg.cmds[0].addr);
			break;
		}
	}

	time_left = RPMH_TIMEOUT_MS;
	while (i--) {
		time_left = wait_for_completion_timeout(&compls[i], time_left);
		if (!time_left) {
			/*
			 * Better hope they never finish because they'll signal
			 * the completion that we're going to free once
			 * we've returned from this function.
			 */
			WARN_ON(1);
			ret = -ETIMEDOUT;
			goto exit;
		}
	}

exit:
	kfree(ptr);

	return ret;
}
EXPORT_SYMBOL(rpmh_write_batch);

static int is_req_valid(struct cache_req *req)
{
	return (req->sleep_val != UINT_MAX &&
		req->wake_val != UINT_MAX &&
		req->sleep_val != req->wake_val);
}

static int send_single(const struct device *dev, enum rpmh_state state,
		       u32 addr, u32 data)
{
	DEFINE_RPMH_MSG_ONSTACK(dev, state, NULL, rpm_msg);
	struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);

	/* Wake sets are always complete and sleep sets are not */
	rpm_msg.msg.wait_for_compl = (state == RPMH_WAKE_ONLY_STATE);
	rpm_msg.cmd[0].addr = addr;
	rpm_msg.cmd[0].data = data;
	rpm_msg.msg.num_cmds = 1;

	return rpmh_rsc_write_ctrl_data(ctrlr_to_drv(ctrlr), &rpm_msg.msg);
}

/**
 * rpmh_flush: Flushes the buffered active and sleep sets to TCS
 *
 * @dev: The device making the request
 *
 * Return: -EBUSY if the controller is busy, probably waiting on a response
 * to a RPMH request sent earlier.
 *
 * This function is always called from the sleep code from the last CPU
 * that is powering down the entire system. Since no other RPMH API would be
 * executing at this time, it is safe to run lockless.
 */
int rpmh_flush(const struct device *dev)
{
	struct cache_req *p;
	struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
	int ret;

	if (!ctrlr->dirty) {
		pr_debug("Skipping flush, TCS has latest data.\n");
		return 0;
	}

	/* First flush the cached batch requests */
	ret = flush_batch(ctrlr);
	if (ret)
		return ret;

	/*
	 * Nobody else should be calling this function other than system PM,
	 * hence we can run without locks.
	 */
	list_for_each_entry(p, &ctrlr->cache, list) {
		if (!is_req_valid(p)) {
			pr_debug("%s: skipping RPMH req: a:%#x s:%#x w:%#x",
				 __func__, p->addr, p->sleep_val, p->wake_val);
			continue;
		}
		ret = send_single(dev, RPMH_SLEEP_STATE, p->addr, p->sleep_val);
		if (ret)
			return ret;
		ret = send_single(dev, RPMH_WAKE_ONLY_STATE,
				  p->addr, p->wake_val);
		if (ret)
			return ret;
	}

	ctrlr->dirty = false;

	return 0;
}
EXPORT_SYMBOL(rpmh_flush);

/**
 * rpmh_invalidate: Invalidate all sleep and active sets
 * sets.
 *
 * @dev: The device making the request
 *
 * Invalidate the sleep and active values in the TCS blocks.
 */
int rpmh_invalidate(const struct device *dev)
{
	struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
	int ret;

	invalidate_batch(ctrlr);
	ctrlr->dirty = true;

	do {
		ret = rpmh_rsc_invalidate(ctrlr_to_drv(ctrlr));
	} while (ret == -EAGAIN);

	return ret;
}
EXPORT_SYMBOL(rpmh_invalidate);