aboutsummaryrefslogtreecommitdiff
path: root/drivers/firmware/qcom_scm-32.c
blob: 29e6850665eb344cbbc946273343ec13cef81e12 (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
/* Copyright (c) 2010,2015, The Linux Foundation. All rights reserved.
 * Copyright (C) 2015 Linaro Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include <linux/slab.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/qcom_scm.h>

#include <asm/cacheflush.h>

#include "qcom_scm.h"

#define QCOM_SCM_FLAG_COLDBOOT_CPU0	0x00
#define QCOM_SCM_FLAG_COLDBOOT_CPU1	0x01
#define QCOM_SCM_FLAG_COLDBOOT_CPU2	0x08
#define QCOM_SCM_FLAG_COLDBOOT_CPU3	0x20

#define QCOM_SCM_FLAG_WARMBOOT_CPU0	0x04
#define QCOM_SCM_FLAG_WARMBOOT_CPU1	0x02
#define QCOM_SCM_FLAG_WARMBOOT_CPU2	0x10
#define QCOM_SCM_FLAG_WARMBOOT_CPU3	0x40

struct qcom_scm_entry {
	int flag;
	void *entry;
};

static struct qcom_scm_entry qcom_scm_wb[] = {
	{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU0 },
	{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU1 },
	{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU2 },
	{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU3 },
};

static DEFINE_MUTEX(qcom_scm_lock);

/**
 * struct qcom_scm_command - one SCM command buffer
 * @len: total available memory for command and response
 * @buf_offset: start of command buffer
 * @resp_hdr_offset: start of response buffer
 * @id: command to be executed
 * @buf: buffer returned from qcom_scm_get_command_buffer()
 *
 * An SCM command is laid out in memory as follows:
 *
 *	------------------- <--- struct qcom_scm_command
 *	| command header  |
 *	------------------- <--- qcom_scm_get_command_buffer()
 *	| command buffer  |
 *	------------------- <--- struct qcom_scm_response and
 *	| response header |      qcom_scm_command_to_response()
 *	------------------- <--- qcom_scm_get_response_buffer()
 *	| response buffer |
 *	-------------------
 *
 * There can be arbitrary padding between the headers and buffers so
 * you should always use the appropriate qcom_scm_get_*_buffer() routines
 * to access the buffers in a safe manner.
 */
struct qcom_scm_command {
	__le32 len;
	__le32 buf_offset;
	__le32 resp_hdr_offset;
	__le32 id;
	__le32 buf[0];
};

/**
 * struct qcom_scm_response - one SCM response buffer
 * @len: total available memory for response
 * @buf_offset: start of response data relative to start of qcom_scm_response
 * @is_complete: indicates if the command has finished processing
 */
struct qcom_scm_response {
	__le32 len;
	__le32 buf_offset;
	__le32 is_complete;
};

/**
 * alloc_qcom_scm_command() - Allocate an SCM command
 * @cmd_size: size of the command buffer
 * @resp_size: size of the response buffer
 *
 * Allocate an SCM command, including enough room for the command
 * and response headers as well as the command and response buffers.
 *
 * Returns a valid &qcom_scm_command on success or %NULL if the allocation fails.
 */
static struct qcom_scm_command *alloc_qcom_scm_command(size_t cmd_size, size_t resp_size)
{
	struct qcom_scm_command *cmd;
	size_t len = sizeof(*cmd) + sizeof(struct qcom_scm_response) + cmd_size +
		resp_size;
	u32 offset;

	cmd = kzalloc(PAGE_ALIGN(len), GFP_KERNEL);
	if (cmd) {
		cmd->len = cpu_to_le32(len);
		offset = offsetof(struct qcom_scm_command, buf);
		cmd->buf_offset = cpu_to_le32(offset);
		cmd->resp_hdr_offset = cpu_to_le32(offset + cmd_size);
	}
	return cmd;
}

/**
 * free_qcom_scm_command() - Free an SCM command
 * @cmd: command to free
 *
 * Free an SCM command.
 */
static inline void free_qcom_scm_command(struct qcom_scm_command *cmd)
{
	kfree(cmd);
}

/**
 * qcom_scm_command_to_response() - Get a pointer to a qcom_scm_response
 * @cmd: command
 *
 * Returns a pointer to a response for a command.
 */
static inline struct qcom_scm_response *qcom_scm_command_to_response(
		const struct qcom_scm_command *cmd)
{
	return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset);
}

/**
 * qcom_scm_get_command_buffer() - Get a pointer to a command buffer
 * @cmd: command
 *
 * Returns a pointer to the command buffer of a command.
 */
static inline void *qcom_scm_get_command_buffer(const struct qcom_scm_command *cmd)
{
	return (void *)cmd->buf;
}

/**
 * qcom_scm_get_response_buffer() - Get a pointer to a response buffer
 * @rsp: response
 *
 * Returns a pointer to a response buffer of a response.
 */
static inline void *qcom_scm_get_response_buffer(const struct qcom_scm_response *rsp)
{
	return (void *)rsp + le32_to_cpu(rsp->buf_offset);
}

static int qcom_scm_remap_error(int err)
{
	pr_err("qcom_scm_call failed with error code %d\n", err);
	switch (err) {
	case QCOM_SCM_ERROR:
		return -EIO;
	case QCOM_SCM_EINVAL_ADDR:
	case QCOM_SCM_EINVAL_ARG:
		return -EINVAL;
	case QCOM_SCM_EOPNOTSUPP:
		return -EOPNOTSUPP;
	case QCOM_SCM_ENOMEM:
		return -ENOMEM;
	}
	return -EINVAL;
}

static u32 smc(u32 cmd_addr)
{
	int context_id;
	register u32 r0 asm("r0") = 1;
	register u32 r1 asm("r1") = (u32)&context_id;
	register u32 r2 asm("r2") = cmd_addr;
	do {
		asm volatile(
			__asmeq("%0", "r0")
			__asmeq("%1", "r0")
			__asmeq("%2", "r1")
			__asmeq("%3", "r2")
#ifdef REQUIRES_SEC
			".arch_extension sec\n"
#endif
			"smc	#0	@ switch to secure world\n"
			: "=r" (r0)
			: "r" (r0), "r" (r1), "r" (r2)
			: "r3");
	} while (r0 == QCOM_SCM_INTERRUPTED);

	return r0;
}

static int __qcom_scm_call(const struct qcom_scm_command *cmd)
{
	int ret;
	u32 cmd_addr = virt_to_phys(cmd);

	/*
	 * Flush the command buffer so that the secure world sees
	 * the correct data.
	 */
	secure_flush_area(cmd, cmd->len);

	ret = smc(cmd_addr);
	if (ret < 0)
		ret = qcom_scm_remap_error(ret);

	return ret;
}

static void qcom_scm_inv_range(unsigned long start, unsigned long end)
{
	u32 cacheline_size, ctr;

	asm volatile("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
	cacheline_size = 4 << ((ctr >> 16) & 0xf);

	start = round_down(start, cacheline_size);
	end = round_up(end, cacheline_size);
	outer_inv_range(start, end);
	while (start < end) {
		asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
		     : "memory");
		start += cacheline_size;
	}
	dsb();
	isb();
}

/**
 * qcom_scm_call() - Send an SCM command
 * @svc_id: service identifier
 * @cmd_id: command identifier
 * @cmd_buf: command buffer
 * @cmd_len: length of the command buffer
 * @resp_buf: response buffer
 * @resp_len: length of the response buffer
 *
 * Sends a command to the SCM and waits for the command to finish processing.
 *
 * A note on cache maintenance:
 * Note that any buffers that are expected to be accessed by the secure world
 * must be flushed before invoking qcom_scm_call and invalidated in the cache
 * immediately after qcom_scm_call returns. Cache maintenance on the command
 * and response buffers is taken care of by qcom_scm_call; however, callers are
 * responsible for any other cached buffers passed over to the secure world.
 */
static int qcom_scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf,
			size_t cmd_len, void *resp_buf, size_t resp_len)
{
	int ret;
	struct qcom_scm_command *cmd;
	struct qcom_scm_response *rsp;
	unsigned long start, end;

	cmd = alloc_qcom_scm_command(cmd_len, resp_len);
	if (!cmd)
		return -ENOMEM;

	cmd->id = cpu_to_le32((svc_id << 10) | cmd_id);
	if (cmd_buf)
		memcpy(qcom_scm_get_command_buffer(cmd), cmd_buf, cmd_len);

	mutex_lock(&qcom_scm_lock);
	ret = __qcom_scm_call(cmd);
	mutex_unlock(&qcom_scm_lock);
	if (ret)
		goto out;

	rsp = qcom_scm_command_to_response(cmd);
	start = (unsigned long)rsp;

	do {
		qcom_scm_inv_range(start, start + sizeof(*rsp));
	} while (!rsp->is_complete);

	end = (unsigned long)qcom_scm_get_response_buffer(rsp) + resp_len;
	qcom_scm_inv_range(start, end);

	if (resp_buf)
		memcpy(resp_buf, qcom_scm_get_response_buffer(rsp), resp_len);
out:
	free_qcom_scm_command(cmd);
	return ret;
}

#define SCM_CLASS_REGISTER	(0x2 << 8)
#define SCM_MASK_IRQS		BIT(5)
#define SCM_ATOMIC(svc, cmd, n) (((((svc) << 10)|((cmd) & 0x3ff)) << 12) | \
				SCM_CLASS_REGISTER | \
				SCM_MASK_IRQS | \
				(n & 0xf))

/**
 * qcom_scm_call_atomic1() - Send an atomic SCM command with one argument
 * @svc_id: service identifier
 * @cmd_id: command identifier
 * @arg1: first argument
 *
 * This shall only be used with commands that are guaranteed to be
 * uninterruptable, atomic and SMP safe.
 */
static s32 qcom_scm_call_atomic1(u32 svc, u32 cmd, u32 arg1)
{
	int context_id;

	register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 1);
	register u32 r1 asm("r1") = (u32)&context_id;
	register u32 r2 asm("r2") = arg1;

	asm volatile(
			__asmeq("%0", "r0")
			__asmeq("%1", "r0")
			__asmeq("%2", "r1")
			__asmeq("%3", "r2")
#ifdef REQUIRES_SEC
			".arch_extension sec\n"
#endif
			"smc    #0      @ switch to secure world\n"
			: "=r" (r0)
			: "r" (r0), "r" (r1), "r" (r2)
			: "r3");
	return r0;
}

u32 qcom_scm_get_version(void)
{
	int context_id;
	static u32 version = -1;
	register u32 r0 asm("r0");
	register u32 r1 asm("r1");

	if (version != -1)
		return version;

	mutex_lock(&qcom_scm_lock);

	r0 = 0x1 << 8;
	r1 = (u32)&context_id;
	do {
		asm volatile(
			__asmeq("%0", "r0")
			__asmeq("%1", "r1")
			__asmeq("%2", "r0")
			__asmeq("%3", "r1")
#ifdef REQUIRES_SEC
			".arch_extension sec\n"
#endif
			"smc	#0	@ switch to secure world\n"
			: "=r" (r0), "=r" (r1)
			: "r" (r0), "r" (r1)
			: "r2", "r3");
	} while (r0 == QCOM_SCM_INTERRUPTED);

	version = r1;
	mutex_unlock(&qcom_scm_lock);

	return version;
}
EXPORT_SYMBOL(qcom_scm_get_version);

/*
 * Set the cold/warm boot address for one of the CPU cores.
 */
static int qcom_scm_set_boot_addr(u32 addr, int flags)
{
	struct {
		__le32 flags;
		__le32 addr;
	} cmd;

	cmd.addr = cpu_to_le32(addr);
	cmd.flags = cpu_to_le32(flags);
	return qcom_scm_call(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_ADDR,
			&cmd, sizeof(cmd), NULL, 0);
}

/**
 * qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
 * @entry: Entry point function for the cpus
 * @cpus: The cpumask of cpus that will use the entry point
 *
 * Set the cold boot address of the cpus. Any cpu outside the supported
 * range would be removed from the cpu present mask.
 */
int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
{
	int flags = 0;
	int cpu;
	int scm_cb_flags[] = {
		QCOM_SCM_FLAG_COLDBOOT_CPU0,
		QCOM_SCM_FLAG_COLDBOOT_CPU1,
		QCOM_SCM_FLAG_COLDBOOT_CPU2,
		QCOM_SCM_FLAG_COLDBOOT_CPU3,
	};

	if (!cpus || (cpus && cpumask_empty(cpus)))
		return -EINVAL;

	for_each_cpu(cpu, cpus) {
		if (cpu < ARRAY_SIZE(scm_cb_flags))
			flags |= scm_cb_flags[cpu];
		else
			set_cpu_present(cpu, false);
	}

	return qcom_scm_set_boot_addr(virt_to_phys(entry), flags);
}

/**
 * qcom_scm_set_warm_boot_addr() - Set the warm boot address for cpus
 * @entry: Entry point function for the cpus
 * @cpus: The cpumask of cpus that will use the entry point
 *
 * Set the Linux entry point for the SCM to transfer control to when coming
 * out of a power down. CPU power down may be executed on cpuidle or hotplug.
 */
int __qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus)
{
	int ret;
	int flags = 0;
	int cpu;

	/*
	 * Reassign only if we are switching from hotplug entry point
	 * to cpuidle entry point or vice versa.
	 */
	for_each_cpu(cpu, cpus) {
		if (entry == qcom_scm_wb[cpu].entry)
			continue;
		flags |= qcom_scm_wb[cpu].flag;
	}

	/* No change in entry function */
	if (!flags)
		return 0;

	ret = qcom_scm_set_boot_addr(virt_to_phys(entry), flags);
	if (!ret) {
		for_each_cpu(cpu, cpus)
			qcom_scm_wb[cpu].entry = entry;
	}

	return ret;
}

/**
 * qcom_scm_cpu_power_down() - Power down the cpu
 * @flags - Flags to flush cache
 *
 * This is an end point to power down cpu. If there was a pending interrupt,
 * the control would return from this function, otherwise, the cpu jumps to the
 * warm boot entry point set for this cpu upon reset.
 */
void __qcom_scm_cpu_power_down(u32 flags)
{
	qcom_scm_call_atomic1(QCOM_SCM_SVC_BOOT, QCOM_SCM_CMD_TERMINATE_PC,
			flags & QCOM_SCM_FLUSH_FLAG_MASK);
}

int __qcom_scm_is_call_available(u32 svc_id, u32 cmd_id)
{
	int ret;
	u32 svc_cmd = (svc_id << 10) | cmd_id;
	u32 ret_val = 0;

	ret = qcom_scm_call(QCOM_SCM_SVC_INFO, QCOM_IS_CALL_AVAIL_CMD, &svc_cmd,
			sizeof(svc_cmd), &ret_val, sizeof(ret_val));
	if (ret)
		return ret;

	return ret_val;
}

int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
{
	if (req_cnt > QCOM_SCM_HDCP_MAX_REQ_CNT)
		return -ERANGE;

	return qcom_scm_call(QCOM_SCM_SVC_HDCP, QCOM_SCM_CMD_HDCP,
		req, req_cnt * sizeof(*req), resp, sizeof(*resp));
}