[deliverable/linux.git] / arch / arm / mach-msm / scm.c

/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
 *
 * 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 <asm/cacheflush.h>

#include "scm.h"

/* Cache line size for msm8x60 */
#define CACHELINESIZE 32

#define SCM_ENOMEM		-5
#define SCM_EOPNOTSUPP		-4
#define SCM_EINVAL_ADDR		-3
#define SCM_EINVAL_ARG		-2
#define SCM_ERROR		-1
#define SCM_INTERRUPTED		1

static DEFINE_MUTEX(scm_lock);

/**
 * struct 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 scm_get_command_buffer()
 *
 * An SCM command is laid out in memory as follows:
 *
 *	------------------- <--- struct scm_command
 *	| command header  |
 *	------------------- <--- scm_get_command_buffer()
 *	| command buffer  |
 *	------------------- <--- struct scm_response and
 *	| response header |      scm_command_to_response()
 *	------------------- <--- scm_get_response_buffer()
 *	| response buffer |
 *	-------------------
 *
 * There can be arbitrary padding between the headers and buffers so
 * you should always use the appropriate scm_get_*_buffer() routines
 * to access the buffers in a safe manner.
 */
struct scm_command {
	u32	len;
	u32	buf_offset;
	u32	resp_hdr_offset;
	u32	id;
	u32	buf[0];
};

/**
 * struct scm_response - one SCM response buffer
 * @len: total available memory for response
 * @buf_offset: start of response data relative to start of scm_response
 * @is_complete: indicates if the command has finished processing
 */
struct scm_response {
	u32	len;
	u32	buf_offset;
	u32	is_complete;
};

/**
 * alloc_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 &scm_command on success or %NULL if the allocation fails.
 */
static struct scm_command *alloc_scm_command(size_t cmd_size, size_t resp_size)
{
	struct scm_command *cmd;
	size_t len = sizeof(*cmd) + sizeof(struct scm_response) + cmd_size +
		resp_size;

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

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

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

/**
 * 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 *scm_get_command_buffer(const struct scm_command *cmd)
{
	return (void *)cmd->buf;
}

/**
 * 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 *scm_get_response_buffer(const struct scm_response *rsp)
{
	return (void *)rsp + rsp->buf_offset;
}

static int scm_remap_error(int err)
{
	switch (err) {
	case SCM_ERROR:
		return -EIO;
	case SCM_EINVAL_ADDR:
	case SCM_EINVAL_ARG:
		return -EINVAL;
	case SCM_EOPNOTSUPP:
		return -EOPNOTSUPP;
	case 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 == SCM_INTERRUPTED);

	return r0;
}

static int __scm_call(const struct scm_command *cmd)
{
	int ret;
	u32 cmd_addr = virt_to_phys(cmd);

	/*
	 * Flush the entire cache here so callers don't have to remember
	 * to flush the cache when passing physical addresses to the secure
	 * side in the buffer.
	 */
	flush_cache_all();
	ret = smc(cmd_addr);
	if (ret < 0)
		ret = scm_remap_error(ret);

	return ret;
}

/**
 * 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.
 */
int 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 scm_command *cmd;
	struct scm_response *rsp;

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

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

	mutex_lock(&scm_lock);
	ret = __scm_call(cmd);
	mutex_unlock(&scm_lock);
	if (ret)
		goto out;

	rsp = scm_command_to_response(cmd);
	do {
		u32 start = (u32)rsp;
		u32 end = (u32)scm_get_response_buffer(rsp) + resp_len;
		start &= ~(CACHELINESIZE - 1);
		while (start < end) {
			asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
			     : "memory");
			start += CACHELINESIZE;
		}
	} while (!rsp->is_complete);

	if (resp_buf)
		memcpy(resp_buf, scm_get_response_buffer(rsp), resp_len);
out:
	free_scm_command(cmd);
	return ret;
}
EXPORT_SYMBOL(scm_call);

u32 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(&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 == SCM_INTERRUPTED);

	version = r1;
	mutex_unlock(&scm_lock);

	return version;
}
EXPORT_SYMBOL(scm_get_version);
Commit	Line	Data
2a1eb58a SB	1	/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
	2	*
	3	* This program is free software; you can redistribute it and/or modify
	4	* it under the terms of the GNU General Public License version 2 and
	5	* only version 2 as published by the Free Software Foundation.
	6	*
	7	* This program is distributed in the hope that it will be useful,
	8	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	9	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	10	* GNU General Public License for more details.
	11	*
	12	* You should have received a copy of the GNU General Public License
	13	* along with this program; if not, write to the Free Software
	14	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	15	* 02110-1301, USA.
	16	*/
	17
	18	#include <linux/slab.h>
	19	#include <linux/io.h>
	20	#include <linux/module.h>
	21	#include <linux/mutex.h>
	22	#include <linux/errno.h>
	23	#include <linux/err.h>
	24
	25	#include <asm/cacheflush.h>
	26
	27	#include "scm.h"
	28
	29	/* Cache line size for msm8x60 */
	30	#define CACHELINESIZE 32
	31
	32	#define SCM_ENOMEM -5
	33	#define SCM_EOPNOTSUPP -4
	34	#define SCM_EINVAL_ADDR -3
	35	#define SCM_EINVAL_ARG -2
	36	#define SCM_ERROR -1
	37	#define SCM_INTERRUPTED 1
	38
	39	static DEFINE_MUTEX(scm_lock);
	40
	41	/**
	42	* struct scm_command - one SCM command buffer
	43	* @len: total available memory for command and response
	44	* @buf_offset: start of command buffer
	45	* @resp_hdr_offset: start of response buffer
	46	* @id: command to be executed
	47	* @buf: buffer returned from scm_get_command_buffer()
	48	*
25985edc	49	* An SCM command is laid out in memory as follows:
2a1eb58a SB	50	*
	51	* ------------------- <--- struct scm_command
	52	* \| command header \|
	53	* ------------------- <--- scm_get_command_buffer()
	54	* \| command buffer \|
	55	* ------------------- <--- struct scm_response and
	56	* \| response header \| scm_command_to_response()
	57	* ------------------- <--- scm_get_response_buffer()
	58	* \| response buffer \|
	59	* -------------------
	60	*
	61	* There can be arbitrary padding between the headers and buffers so
	62	* you should always use the appropriate scm_get_*_buffer() routines
	63	* to access the buffers in a safe manner.
	64	*/
	65	struct scm_command {
	66	u32 len;
	67	u32 buf_offset;
	68	u32 resp_hdr_offset;
	69	u32 id;
	70	u32 buf[0];
	71	};
	72
	73	/**
	74	* struct scm_response - one SCM response buffer
	75	* @len: total available memory for response
	76	* @buf_offset: start of response data relative to start of scm_response
	77	* @is_complete: indicates if the command has finished processing
	78	*/
	79	struct scm_response {
	80	u32 len;
	81	u32 buf_offset;
	82	u32 is_complete;
	83	};
	84
	85	/**
	86	* alloc_scm_command() - Allocate an SCM command
	87	* @cmd_size: size of the command buffer
	88	* @resp_size: size of the response buffer
	89	*
	90	* Allocate an SCM command, including enough room for the command
	91	* and response headers as well as the command and response buffers.
	92	*
	93	* Returns a valid &scm_command on success or %NULL if the allocation fails.
	94	*/
	95	static struct scm_command *alloc_scm_command(size_t cmd_size, size_t resp_size)
	96	{
	97	struct scm_command *cmd;
	98	size_t len = sizeof(*cmd) + sizeof(struct scm_response) + cmd_size +
	99	resp_size;
	100
	101	cmd = kzalloc(PAGE_ALIGN(len), GFP_KERNEL);
	102	if (cmd) {
	103	cmd->len = len;
	104	cmd->buf_offset = offsetof(struct scm_command, buf);
	105	cmd->resp_hdr_offset = cmd->buf_offset + cmd_size;
	106	}
	107	return cmd;
	108	}
	109
	110	/**
	111	* free_scm_command() - Free an SCM command
	112	* @cmd: command to free
	113	*
114	* Free an SCM command.
115	*/
116	static inline void free_scm_command(struct scm_command *cmd)
117	{
118	kfree(cmd);
119	}
120
121	/**
122	* scm_command_to_response() - Get a pointer to a scm_response
123	* @cmd: command
124	*
125	* Returns a pointer to a response for a command.
126	*/
127	static inline struct scm_response *scm_command_to_response(
128	const struct scm_command *cmd)
129	{
130	return (void *)cmd + cmd->resp_hdr_offset;
131	}
132
133	/**
134	* scm_get_command_buffer() - Get a pointer to a command buffer
135	* @cmd: command
136	*
137	* Returns a pointer to the command buffer of a command.
138	*/
139	static inline void scm_get_command_buffer(const struct scm_command cmd)
140	{
141	return (void *)cmd->buf;
142	}
143
144	/**
145	* scm_get_response_buffer() - Get a pointer to a response buffer
146	* @rsp: response
147	*
148	* Returns a pointer to a response buffer of a response.
149	*/
150	static inline void scm_get_response_buffer(const struct scm_response rsp)
151	{
152	return (void *)rsp + rsp->buf_offset;
153	}
154
155	static int scm_remap_error(int err)
156	{
157	switch (err) {
158	case SCM_ERROR:
159	return -EIO;
160	case SCM_EINVAL_ADDR:
161	case SCM_EINVAL_ARG:
162	return -EINVAL;
163	case SCM_EOPNOTSUPP:
164	return -EOPNOTSUPP;
165	case SCM_ENOMEM:
166	return -ENOMEM;
167	}
168	return -EINVAL;
169	}
170
171	static u32 smc(u32 cmd_addr)
172	{
173	int context_id;
174	register u32 r0 asm("r0") = 1;
175	register u32 r1 asm("r1") = (u32)&context_id;
176	register u32 r2 asm("r2") = cmd_addr;
8e76a809 SB	177	do {
	178	asm volatile(
	179	__asmeq("%0", "r0")
	180	__asmeq("%1", "r0")
	181	__asmeq("%2", "r1")
	182	__asmeq("%3", "r2")
eca55f4d MZ	183	#ifdef REQUIRES_SEC
	184	".arch_extension sec\n"
	185	#endif
8e76a809 SB	186	"smc #0 @ switch to secure world\n"
	187	: "=r" (r0)
	188	: "r" (r0), "r" (r1), "r" (r2)
	189	: "r3");
	190	} while (r0 == SCM_INTERRUPTED);
	191
2a1eb58a SB	192	return r0;
	193	}
	194
	195	static int __scm_call(const struct scm_command *cmd)
	196	{
	197	int ret;
	198	u32 cmd_addr = virt_to_phys(cmd);
	199
	200	/*
	201	* Flush the entire cache here so callers don't have to remember
	202	* to flush the cache when passing physical addresses to the secure
	203	* side in the buffer.
	204	*/
	205	flush_cache_all();
8e76a809 SB	206	ret = smc(cmd_addr);
	207	if (ret < 0)
	208	ret = scm_remap_error(ret);
2a1eb58a SB	209
	210	return ret;
	211	}
	212
	213	/**
	214	* scm_call() - Send an SCM command
	215	* @svc_id: service identifier
	216	* @cmd_id: command identifier
	217	* @cmd_buf: command buffer
	218	* @cmd_len: length of the command buffer
	219	* @resp_buf: response buffer
	220	* @resp_len: length of the response buffer
	221	*
	222	* Sends a command to the SCM and waits for the command to finish processing.
	223	*/
	224	int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_len,
	225	void *resp_buf, size_t resp_len)
	226	{
	227	int ret;
	228	struct scm_command *cmd;
	229	struct scm_response *rsp;
	230
	231	cmd = alloc_scm_command(cmd_len, resp_len);
	232	if (!cmd)
	233	return -ENOMEM;
	234
	235	cmd->id = (svc_id << 10) \| cmd_id;
	236	if (cmd_buf)
	237	memcpy(scm_get_command_buffer(cmd), cmd_buf, cmd_len);
	238
	239	mutex_lock(&scm_lock);
	240	ret = __scm_call(cmd);
	241	mutex_unlock(&scm_lock);
	242	if (ret)
	243	goto out;
	244
	245	rsp = scm_command_to_response(cmd);
	246	do {
	247	u32 start = (u32)rsp;
	248	u32 end = (u32)scm_get_response_buffer(rsp) + resp_len;
	249	start &= ~(CACHELINESIZE - 1);
	250	while (start < end) {
	251	asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
	252	: "memory");
	253	start += CACHELINESIZE;
	254	}
	255	} while (!rsp->is_complete);
	256
	257	if (resp_buf)
	258	memcpy(resp_buf, scm_get_response_buffer(rsp), resp_len);
	259	out:
	260	free_scm_command(cmd);
	261	return ret;
	262	}
	263	EXPORT_SYMBOL(scm_call);
	264
	265	u32 scm_get_version(void)
	266	{
	267	int context_id;
	268	static u32 version = -1;
98d4ded6 SB	269	register u32 r0 asm("r0");
98d4ded6 SB	270	register u32 r1 asm("r1");
2a1eb58a SB	271
	272	if (version != -1)
	273	return version;
	274
	275	mutex_lock(&scm_lock);
98d4ded6 SB	276
	277	r0 = 0x1 << 8;
	278	r1 = (u32)&context_id;
8e76a809 SB	279	do {
	280	asm volatile(
	281	__asmeq("%0", "r0")
	282	__asmeq("%1", "r1")
	283	__asmeq("%2", "r0")
	284	__asmeq("%3", "r1")
26e87b13 SB	285	#ifdef REQUIRES_SEC
	286	".arch_extension sec\n"
	287	#endif
8e76a809 SB	288	"smc #0 @ switch to secure world\n"
	289	: "=r" (r0), "=r" (r1)
	290	: "r" (r0), "r" (r1)
	291	: "r2", "r3");
	292	} while (r0 == SCM_INTERRUPTED);
	293
2a1eb58a SB	294	version = r1;
	295	mutex_unlock(&scm_lock);
	296
	297	return version;
	298	}
	299	EXPORT_SYMBOL(scm_get_version);