diff options
Diffstat (limited to 'drivers/soc')
| -rw-r--r-- | drivers/soc/qcom/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/soc/qcom/Makefile | 2 | ||||
| -rw-r--r-- | drivers/soc/qcom/scm.c | 325 |
3 files changed, 329 insertions, 0 deletions
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig index 7bd2c94f54a4..7dcd554496c7 100644 --- a/drivers/soc/qcom/Kconfig +++ b/drivers/soc/qcom/Kconfig @@ -9,3 +9,5 @@ config QCOM_GSBI functions for connecting the underlying serial UART, SPI, and I2C devices to the output pins. +config QCOM_SCM + bool diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile index 438901257ac1..a39446d08ac6 100644 --- a/drivers/soc/qcom/Makefile +++ b/drivers/soc/qcom/Makefile @@ -1 +1,3 @@ obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o +CFLAGS_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1) +obj-$(CONFIG_QCOM_SCM) += scm.o diff --git a/drivers/soc/qcom/scm.c b/drivers/soc/qcom/scm.c new file mode 100644 index 000000000000..0ae8f97dc56e --- /dev/null +++ b/drivers/soc/qcom/scm.c @@ -0,0 +1,325 @@ +/* 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 <soc/qcom/scm.h> + +#include <asm/outercache.h> +#include <asm/cacheflush.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) +{ + pr_err("scm_call failed with error code %d\n", 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 command buffer so that the secure world sees + * the correct data. + */ + __cpuc_flush_dcache_area((void *)cmd, cmd->len); + outer_flush_range(cmd_addr, cmd_addr + cmd->len); + + ret = smc(cmd_addr); + if (ret < 0) + ret = scm_remap_error(ret); + + return ret; +} + +static void 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(); +} + +/** + * 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 scm_call and invalidated in the cache + * immediately after scm_call returns. Cache maintenance on the command and + * response buffers is taken care of by scm_call; however, callers are + * responsible for any other cached buffers passed over to the secure world. + */ +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); + +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); |