arch/arm/mach-msm/scm.c - kernel/msm - Gitiles

 /* Copyright (c) 2010-2011, 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.
  */

 #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/init.h>

 #include <asm/cacheflush.h>

 #include <mach/scm.h>

 #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")
 			"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;
 }

 static u32 cacheline_size;

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

 /**
  * 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;
 	unsigned long start, end;

 	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);
 	start = (unsigned long)rsp;

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

 	end = (unsigned long)scm_get_response_buffer(rsp) + resp_len;
 	scm_inv_range(start, end);

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

 #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))

 /**
  * 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.
  */
 u32 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")
 		"smc	#0	@ switch to secure world\n"
 		: "=r" (r0)
 		: "r" (r0), "r" (r1), "r" (r2)
 		: "r3");
 	return r0;
 }
 EXPORT_SYMBOL(scm_call_atomic1);

 /**
  * scm_call_atomic2() - Send an atomic SCM command with two arguments
  * @svc_id: service identifier
  * @cmd_id: command identifier
  * @arg1: first argument
  * @arg2: second argument
  *
  * This shall only be used with commands that are guaranteed to be
  * uninterruptable, atomic and SMP safe.
  */
 u32 scm_call_atomic2(u32 svc, u32 cmd, u32 arg1, u32 arg2)
 {
 	int context_id;
 	register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 2);
 	register u32 r1 asm("r1") = (u32)&context_id;
 	register u32 r2 asm("r2") = arg1;
 	register u32 r3 asm("r3") = arg2;

 	asm volatile(
 		__asmeq("%0", "r0")
 		__asmeq("%1", "r0")
 		__asmeq("%2", "r1")
 		__asmeq("%3", "r2")
 		__asmeq("%4", "r3")
 		"smc	#0	@ switch to secure world\n"
 		: "=r" (r0)
 		: "r" (r0), "r" (r1), "r" (r2), "r" (r3));
 	return r0;
 }
 EXPORT_SYMBOL(scm_call_atomic2);

 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")
 			"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);

 static int scm_init(void)
 {
 	u32 ctr;

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

 	return 0;
 }
 early_initcall(scm_init);
	/* Copyright (c) 2010-2011, 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.
	*/

	#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/init.h>

	#include <asm/cacheflush.h>

	#include <mach/scm.h>

	#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")
	"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;
	}

	static u32 cacheline_size;

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

	/**
	* 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;
	unsigned long start, end;

	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);
	start = (unsigned long)rsp;

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

	end = (unsigned long)scm_get_response_buffer(rsp) + resp_len;
	scm_inv_range(start, end);

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

	#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))

	/**
	* 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.
	*/
	u32 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")
	"smc #0 @ switch to secure world\n"
	: "=r" (r0)
	: "r" (r0), "r" (r1), "r" (r2)
	: "r3");
	return r0;
	}
	EXPORT_SYMBOL(scm_call_atomic1);

	/**
	* scm_call_atomic2() - Send an atomic SCM command with two arguments
	* @svc_id: service identifier
	* @cmd_id: command identifier
	* @arg1: first argument
	* @arg2: second argument
	*
	* This shall only be used with commands that are guaranteed to be
	* uninterruptable, atomic and SMP safe.
	*/
	u32 scm_call_atomic2(u32 svc, u32 cmd, u32 arg1, u32 arg2)
	{
	int context_id;
	register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 2);
	register u32 r1 asm("r1") = (u32)&context_id;
	register u32 r2 asm("r2") = arg1;
	register u32 r3 asm("r3") = arg2;

	asm volatile(
	__asmeq("%0", "r0")
	__asmeq("%1", "r0")
	__asmeq("%2", "r1")
	__asmeq("%3", "r2")
	__asmeq("%4", "r3")
	"smc #0 @ switch to secure world\n"
	: "=r" (r0)
	: "r" (r0), "r" (r1), "r" (r2), "r" (r3));
	return r0;
	}
	EXPORT_SYMBOL(scm_call_atomic2);

	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")
	"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);

	static int scm_init(void)
	{
	u32 ctr;

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

	return 0;
	}
	early_initcall(scm_init);