mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 18:39:59 +00:00
![Marc Zyngier](/assets/img/avatar_default.png)
CONFIG_MSM_SCM uses the smc instruction, which with some toolchains requires a ".arch_extension" directive. Cc: David Brown <davidb@codeaurora.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David Brown <davidb@codeaurora.org>
296 lines
7 KiB
C
296 lines
7 KiB
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")
|
|
"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);
|