1/* Copyright (c) 2010,2015, The Linux Foundation. All rights reserved.
  2 * Copyright (C) 2015 Linaro Ltd.
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License version 2 and
  6 * only version 2 as published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope that it will be useful,
  9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 11 * GNU General Public License for more details.
 12 *
 13 * You should have received a copy of the GNU General Public License
 14 * along with this program; if not, write to the Free Software
 15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 16 * 02110-1301, USA.
 17 */
 18
 19#include <linux/slab.h>
 20#include <linux/io.h>
 21#include <linux/module.h>
 22#include <linux/mutex.h>
 23#include <linux/errno.h>
 24#include <linux/err.h>
 25#include <linux/qcom_scm.h>
 26
 27#include <asm/cacheflush.h>
 28
 29#include "qcom_scm.h"
 30
 31#define QCOM_SCM_FLAG_COLDBOOT_CPU0	0x00
 32#define QCOM_SCM_FLAG_COLDBOOT_CPU1	0x01
 33#define QCOM_SCM_FLAG_COLDBOOT_CPU2	0x08
 34#define QCOM_SCM_FLAG_COLDBOOT_CPU3	0x20
 35
 36#define QCOM_SCM_FLAG_WARMBOOT_CPU0	0x04
 37#define QCOM_SCM_FLAG_WARMBOOT_CPU1	0x02
 38#define QCOM_SCM_FLAG_WARMBOOT_CPU2	0x10
 39#define QCOM_SCM_FLAG_WARMBOOT_CPU3	0x40
 40
 41struct qcom_scm_entry {
 42	int flag;
 43	void *entry;
 44};
 45
 46static struct qcom_scm_entry qcom_scm_wb[] = {
 47	{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU0 },
 48	{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU1 },
 49	{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU2 },
 50	{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU3 },
 51};
 52
 53static DEFINE_MUTEX(qcom_scm_lock);
 54
 55/**
 56 * struct qcom_scm_command - one SCM command buffer
 57 * @len: total available memory for command and response
 58 * @buf_offset: start of command buffer
 59 * @resp_hdr_offset: start of response buffer
 60 * @id: command to be executed
 61 * @buf: buffer returned from qcom_scm_get_command_buffer()
 62 *
 63 * An SCM command is laid out in memory as follows:
 64 *
 65 *	------------------- <--- struct qcom_scm_command
 66 *	| command header  |
 67 *	------------------- <--- qcom_scm_get_command_buffer()
 68 *	| command buffer  |
 69 *	------------------- <--- struct qcom_scm_response and
 70 *	| response header |      qcom_scm_command_to_response()
 71 *	------------------- <--- qcom_scm_get_response_buffer()
 72 *	| response buffer |
 73 *	-------------------
 74 *
 75 * There can be arbitrary padding between the headers and buffers so
 76 * you should always use the appropriate qcom_scm_get_*_buffer() routines
 77 * to access the buffers in a safe manner.
 78 */
 79struct qcom_scm_command {
 80	__le32 len;
 81	__le32 buf_offset;
 82	__le32 resp_hdr_offset;
 83	__le32 id;
 84	__le32 buf[0];
 85};
 86
 87/**
 88 * struct qcom_scm_response - one SCM response buffer
 89 * @len: total available memory for response
 90 * @buf_offset: start of response data relative to start of qcom_scm_response
 91 * @is_complete: indicates if the command has finished processing
 92 */
 93struct qcom_scm_response {
 94	__le32 len;
 95	__le32 buf_offset;
 96	__le32 is_complete;
 97};
 98
 99/**
100 * alloc_qcom_scm_command() - Allocate an SCM command
101 * @cmd_size: size of the command buffer
102 * @resp_size: size of the response buffer
103 *
104 * Allocate an SCM command, including enough room for the command
105 * and response headers as well as the command and response buffers.
106 *
107 * Returns a valid &qcom_scm_command on success or %NULL if the allocation fails.
108 */
109static struct qcom_scm_command *alloc_qcom_scm_command(size_t cmd_size, size_t resp_size)
110{
111	struct qcom_scm_command *cmd;
112	size_t len = sizeof(*cmd) + sizeof(struct qcom_scm_response) + cmd_size +
113		resp_size;
114	u32 offset;
115
116	cmd = kzalloc(PAGE_ALIGN(len), GFP_KERNEL);
117	if (cmd) {
118		cmd->len = cpu_to_le32(len);
119		offset = offsetof(struct qcom_scm_command, buf);
120		cmd->buf_offset = cpu_to_le32(offset);
121		cmd->resp_hdr_offset = cpu_to_le32(offset + cmd_size);
122	}
123	return cmd;
124}
125
126/**
127 * free_qcom_scm_command() - Free an SCM command
128 * @cmd: command to free
129 *
130 * Free an SCM command.
131 */
132static inline void free_qcom_scm_command(struct qcom_scm_command *cmd)
133{
134	kfree(cmd);
135}
136
137/**
138 * qcom_scm_command_to_response() - Get a pointer to a qcom_scm_response
139 * @cmd: command
140 *
141 * Returns a pointer to a response for a command.
142 */
143static inline struct qcom_scm_response *qcom_scm_command_to_response(
144		const struct qcom_scm_command *cmd)
145{
146	return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset);
147}
148
149/**
150 * qcom_scm_get_command_buffer() - Get a pointer to a command buffer
151 * @cmd: command
152 *
153 * Returns a pointer to the command buffer of a command.
154 */
155static inline void *qcom_scm_get_command_buffer(const struct qcom_scm_command *cmd)
156{
157	return (void *)cmd->buf;
158}
159
160/**
161 * qcom_scm_get_response_buffer() - Get a pointer to a response buffer
162 * @rsp: response
163 *
164 * Returns a pointer to a response buffer of a response.
165 */
166static inline void *qcom_scm_get_response_buffer(const struct qcom_scm_response *rsp)
167{
168	return (void *)rsp + le32_to_cpu(rsp->buf_offset);
169}
170
171static int qcom_scm_remap_error(int err)
172{
173	pr_err("qcom_scm_call failed with error code %d\n", err);
174	switch (err) {
175	case QCOM_SCM_ERROR:
176		return -EIO;
177	case QCOM_SCM_EINVAL_ADDR:
178	case QCOM_SCM_EINVAL_ARG:
179		return -EINVAL;
180	case QCOM_SCM_EOPNOTSUPP:
181		return -EOPNOTSUPP;
182	case QCOM_SCM_ENOMEM:
183		return -ENOMEM;
184	}
185	return -EINVAL;
186}
187
188static u32 smc(u32 cmd_addr)
189{
190	int context_id;
191	register u32 r0 asm("r0") = 1;
192	register u32 r1 asm("r1") = (u32)&context_id;
193	register u32 r2 asm("r2") = cmd_addr;
194	do {
195		asm volatile(
196			__asmeq("%0", "r0")
197			__asmeq("%1", "r0")
198			__asmeq("%2", "r1")
199			__asmeq("%3", "r2")
200#ifdef REQUIRES_SEC
201			".arch_extension sec\n"
202#endif
203			"smc	#0	@ switch to secure world\n"
204			: "=r" (r0)
205			: "r" (r0), "r" (r1), "r" (r2)
206			: "r3");
207	} while (r0 == QCOM_SCM_INTERRUPTED);
208
209	return r0;
210}
211
212static int __qcom_scm_call(const struct qcom_scm_command *cmd)
213{
214	int ret;
215	u32 cmd_addr = virt_to_phys(cmd);
216
217	/*
218	 * Flush the command buffer so that the secure world sees
219	 * the correct data.
220	 */
221	secure_flush_area(cmd, cmd->len);
222
223	ret = smc(cmd_addr);
224	if (ret < 0)
225		ret = qcom_scm_remap_error(ret);
226
227	return ret;
228}
229
230static void qcom_scm_inv_range(unsigned long start, unsigned long end)
231{
232	u32 cacheline_size, ctr;
233
234	asm volatile("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
235	cacheline_size = 4 << ((ctr >> 16) & 0xf);
236
237	start = round_down(start, cacheline_size);
238	end = round_up(end, cacheline_size);
239	outer_inv_range(start, end);
240	while (start < end) {
241		asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
242		     : "memory");
243		start += cacheline_size;
244	}
245	dsb();
246	isb();
247}
248
249/**
250 * qcom_scm_call() - Send an SCM command
251 * @svc_id: service identifier
252 * @cmd_id: command identifier
253 * @cmd_buf: command buffer
254 * @cmd_len: length of the command buffer
255 * @resp_buf: response buffer
256 * @resp_len: length of the response buffer
257 *
258 * Sends a command to the SCM and waits for the command to finish processing.
259 *
260 * A note on cache maintenance:
261 * Note that any buffers that are expected to be accessed by the secure world
262 * must be flushed before invoking qcom_scm_call and invalidated in the cache
263 * immediately after qcom_scm_call returns. Cache maintenance on the command
264 * and response buffers is taken care of by qcom_scm_call; however, callers are
265 * responsible for any other cached buffers passed over to the secure world.
266 */
267static int qcom_scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf,
268			size_t cmd_len, void *resp_buf, size_t resp_len)
269{
270	int ret;
271	struct qcom_scm_command *cmd;
272	struct qcom_scm_response *rsp;
273	unsigned long start, end;
274
275	cmd = alloc_qcom_scm_command(cmd_len, resp_len);
276	if (!cmd)
277		return -ENOMEM;
278
279	cmd->id = cpu_to_le32((svc_id << 10) | cmd_id);
280	if (cmd_buf)
281		memcpy(qcom_scm_get_command_buffer(cmd), cmd_buf, cmd_len);
282
283	mutex_lock(&qcom_scm_lock);
284	ret = __qcom_scm_call(cmd);
285	mutex_unlock(&qcom_scm_lock);
286	if (ret)
287		goto out;
288
289	rsp = qcom_scm_command_to_response(cmd);
290	start = (unsigned long)rsp;
291
292	do {
293		qcom_scm_inv_range(start, start + sizeof(*rsp));
294	} while (!rsp->is_complete);
295
296	end = (unsigned long)qcom_scm_get_response_buffer(rsp) + resp_len;
297	qcom_scm_inv_range(start, end);
298
299	if (resp_buf)
300		memcpy(resp_buf, qcom_scm_get_response_buffer(rsp), resp_len);
301out:
302	free_qcom_scm_command(cmd);
303	return ret;
304}
305
306#define SCM_CLASS_REGISTER	(0x2 << 8)
307#define SCM_MASK_IRQS		BIT(5)
308#define SCM_ATOMIC(svc, cmd, n) (((((svc) << 10)|((cmd) & 0x3ff)) << 12) | \
309				SCM_CLASS_REGISTER | \
310				SCM_MASK_IRQS | \
311				(n & 0xf))
312
313/**
314 * qcom_scm_call_atomic1() - Send an atomic SCM command with one argument
315 * @svc_id: service identifier
316 * @cmd_id: command identifier
317 * @arg1: first argument
318 *
319 * This shall only be used with commands that are guaranteed to be
320 * uninterruptable, atomic and SMP safe.
321 */
322static s32 qcom_scm_call_atomic1(u32 svc, u32 cmd, u32 arg1)
323{
324	int context_id;
325
326	register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 1);
327	register u32 r1 asm("r1") = (u32)&context_id;
328	register u32 r2 asm("r2") = arg1;
329
330	asm volatile(
331			__asmeq("%0", "r0")
332			__asmeq("%1", "r0")
333			__asmeq("%2", "r1")
334			__asmeq("%3", "r2")
335#ifdef REQUIRES_SEC
336			".arch_extension sec\n"
337#endif
338			"smc    #0      @ switch to secure world\n"
339			: "=r" (r0)
340			: "r" (r0), "r" (r1), "r" (r2)
341			: "r3");
342	return r0;
343}
344
345u32 qcom_scm_get_version(void)
346{
347	int context_id;
348	static u32 version = -1;
349	register u32 r0 asm("r0");
350	register u32 r1 asm("r1");
351
352	if (version != -1)
353		return version;
354
355	mutex_lock(&qcom_scm_lock);
356
357	r0 = 0x1 << 8;
358	r1 = (u32)&context_id;
359	do {
360		asm volatile(
361			__asmeq("%0", "r0")
362			__asmeq("%1", "r1")
363			__asmeq("%2", "r0")
364			__asmeq("%3", "r1")
365#ifdef REQUIRES_SEC
366			".arch_extension sec\n"
367#endif
368			"smc	#0	@ switch to secure world\n"
369			: "=r" (r0), "=r" (r1)
370			: "r" (r0), "r" (r1)
371			: "r2", "r3");
372	} while (r0 == QCOM_SCM_INTERRUPTED);
373
374	version = r1;
375	mutex_unlock(&qcom_scm_lock);
376
377	return version;
378}
379EXPORT_SYMBOL(qcom_scm_get_version);
380
381/*
382 * Set the cold/warm boot address for one of the CPU cores.
383 */
384static int qcom_scm_set_boot_addr(u32 addr, int flags)
385{
386	struct {
387		__le32 flags;
388		__le32 addr;
389	} cmd;
390
391	cmd.addr = cpu_to_le32(addr);
392	cmd.flags = cpu_to_le32(flags);
393	return qcom_scm_call(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_ADDR,
394			&cmd, sizeof(cmd), NULL, 0);
395}
396
397/**
398 * qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
399 * @entry: Entry point function for the cpus
400 * @cpus: The cpumask of cpus that will use the entry point
401 *
402 * Set the cold boot address of the cpus. Any cpu outside the supported
403 * range would be removed from the cpu present mask.
404 */
405int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
406{
407	int flags = 0;
408	int cpu;
409	int scm_cb_flags[] = {
410		QCOM_SCM_FLAG_COLDBOOT_CPU0,
411		QCOM_SCM_FLAG_COLDBOOT_CPU1,
412		QCOM_SCM_FLAG_COLDBOOT_CPU2,
413		QCOM_SCM_FLAG_COLDBOOT_CPU3,
414	};
415
416	if (!cpus || (cpus && cpumask_empty(cpus)))
417		return -EINVAL;
418
419	for_each_cpu(cpu, cpus) {
420		if (cpu < ARRAY_SIZE(scm_cb_flags))
421			flags |= scm_cb_flags[cpu];
422		else
423			set_cpu_present(cpu, false);
424	}
425
426	return qcom_scm_set_boot_addr(virt_to_phys(entry), flags);
427}
428
429/**
430 * qcom_scm_set_warm_boot_addr() - Set the warm boot address for cpus
431 * @entry: Entry point function for the cpus
432 * @cpus: The cpumask of cpus that will use the entry point
433 *
434 * Set the Linux entry point for the SCM to transfer control to when coming
435 * out of a power down. CPU power down may be executed on cpuidle or hotplug.
436 */
437int __qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus)
438{
439	int ret;
440	int flags = 0;
441	int cpu;
442
443	/*
444	 * Reassign only if we are switching from hotplug entry point
445	 * to cpuidle entry point or vice versa.
446	 */
447	for_each_cpu(cpu, cpus) {
448		if (entry == qcom_scm_wb[cpu].entry)
449			continue;
450		flags |= qcom_scm_wb[cpu].flag;
451	}
452
453	/* No change in entry function */
454	if (!flags)
455		return 0;
456
457	ret = qcom_scm_set_boot_addr(virt_to_phys(entry), flags);
458	if (!ret) {
459		for_each_cpu(cpu, cpus)
460			qcom_scm_wb[cpu].entry = entry;
461	}
462
463	return ret;
464}
465
466/**
467 * qcom_scm_cpu_power_down() - Power down the cpu
468 * @flags - Flags to flush cache
469 *
470 * This is an end point to power down cpu. If there was a pending interrupt,
471 * the control would return from this function, otherwise, the cpu jumps to the
472 * warm boot entry point set for this cpu upon reset.
473 */
474void __qcom_scm_cpu_power_down(u32 flags)
475{
476	qcom_scm_call_atomic1(QCOM_SCM_SVC_BOOT, QCOM_SCM_CMD_TERMINATE_PC,
477			flags & QCOM_SCM_FLUSH_FLAG_MASK);
478}
479
480int __qcom_scm_is_call_available(u32 svc_id, u32 cmd_id)
481{
482	int ret;
483	__le32 svc_cmd = cpu_to_le32((svc_id << 10) | cmd_id);
484	__le32 ret_val = 0;
485
486	ret = qcom_scm_call(QCOM_SCM_SVC_INFO, QCOM_IS_CALL_AVAIL_CMD, &svc_cmd,
487			sizeof(svc_cmd), &ret_val, sizeof(ret_val));
488	if (ret)
489		return ret;
490
491	return le32_to_cpu(ret_val);
492}
493
494int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
495{
496	if (req_cnt > QCOM_SCM_HDCP_MAX_REQ_CNT)
497		return -ERANGE;
498
499	return qcom_scm_call(QCOM_SCM_SVC_HDCP, QCOM_SCM_CMD_HDCP,
500		req, req_cnt * sizeof(*req), resp, sizeof(*resp));
501}