diff options
Diffstat (limited to 'drivers/soc/qcom/scm.c')
| -rw-r--r-- | drivers/soc/qcom/scm.c | 528 |
1 files changed, 528 insertions, 0 deletions
diff --git a/drivers/soc/qcom/scm.c b/drivers/soc/qcom/scm.c new file mode 100644 index 00000000000..45d15a075b2 --- /dev/null +++ b/drivers/soc/qcom/scm.c @@ -0,0 +1,528 @@ +/* Copyright (c) 2010-2013, The Linux Foundation. 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 <soc/qcom/scm.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); + +#define SCM_BUF_LEN(__cmd_size, __resp_size) \ + (sizeof(struct scm_command) + sizeof(struct scm_response) + \ + __cmd_size + __resp_size) +/** + * 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; +}; + +/** + * 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_common() - 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 + * @scm_buf: internal scm structure used for passing data + * @scm_buf_len: length of the internal scm structure + * + * Core function to scm call. Initializes the given cmd structure with + * appropriate values and makes the actual scm call. Validation of cmd + * pointer and length must occur in the calling function. + * + * Returns the appropriate error code from the scm call + */ + +static int scm_call_common(u32 svc_id, u32 cmd_id, const void *cmd_buf, + size_t cmd_len, void *resp_buf, size_t resp_len, + struct scm_command *scm_buf, + size_t scm_buf_length) +{ + int ret; + struct scm_response *rsp; + unsigned long start, end; + + scm_buf->len = scm_buf_length; + scm_buf->buf_offset = offsetof(struct scm_command, buf); + scm_buf->resp_hdr_offset = scm_buf->buf_offset + cmd_len; + scm_buf->id = (svc_id << 10) | cmd_id; + + if (cmd_buf) + memcpy(scm_get_command_buffer(scm_buf), cmd_buf, cmd_len); + + mutex_lock(&scm_lock); + ret = __scm_call(scm_buf); + mutex_unlock(&scm_lock); + if (ret) + return ret; + + rsp = scm_command_to_response(scm_buf); + 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); + + return ret; +} + +/** + * scm_call_noalloc - Send an SCM command + * + * Same as scm_call except clients pass in a buffer (@scm_buf) to be used for + * scm internal structures. The buffer should be allocated with + * DEFINE_SCM_BUFFER to account for the proper alignment and size. + */ +int scm_call_noalloc(u32 svc_id, u32 cmd_id, const void *cmd_buf, + size_t cmd_len, void *resp_buf, size_t resp_len, + void *scm_buf, size_t scm_buf_len) +{ + int ret; + size_t len = SCM_BUF_LEN(cmd_len, resp_len); + + if (cmd_len > scm_buf_len || resp_len > scm_buf_len || + len > scm_buf_len) + return -EINVAL; + + if (!IS_ALIGNED((unsigned long)scm_buf, PAGE_SIZE)) + return -EINVAL; + + memset(scm_buf, 0, scm_buf_len); + + ret = scm_call_common(svc_id, cmd_id, cmd_buf, cmd_len, resp_buf, + resp_len, scm_buf, len); + 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. + * + * 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) +{ + struct scm_command *cmd; + int ret; + size_t len = SCM_BUF_LEN(cmd_len, resp_len); + + if (cmd_len > len || resp_len > len) + return -EINVAL; + + cmd = kzalloc(PAGE_ALIGN(len), GFP_KERNEL); + if (!cmd) + return -ENOMEM; + + ret = scm_call_common(svc_id, cmd_id, cmd_buf, cmd_len, resp_buf, + resp_len, cmd, len); + kfree(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. + */ +s32 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") +#ifdef REQUIRES_SEC + ".arch_extension sec\n" +#endif + "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. + */ +s32 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") +#ifdef REQUIRES_SEC + ".arch_extension sec\n" +#endif + "smc #0 @ switch to secure world\n" + : "=r" (r0) + : "r" (r0), "r" (r1), "r" (r2), "r" (r3)); + return r0; +} +EXPORT_SYMBOL(scm_call_atomic2); + +/** + * scm_call_atomic3() - Send an atomic SCM command with three arguments + * @svc_id: service identifier + * @cmd_id: command identifier + * @arg1: first argument + * @arg2: second argument + * @arg3: third argument + * + * This shall only be used with commands that are guaranteed to be + * uninterruptable, atomic and SMP safe. + */ +s32 scm_call_atomic3(u32 svc, u32 cmd, u32 arg1, u32 arg2, u32 arg3) +{ + int context_id; + register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 3); + register u32 r1 asm("r1") = (u32)&context_id; + register u32 r2 asm("r2") = arg1; + register u32 r3 asm("r3") = arg2; + register u32 r4 asm("r4") = arg3; + + asm volatile( + __asmeq("%0", "r0") + __asmeq("%1", "r0") + __asmeq("%2", "r1") + __asmeq("%3", "r2") + __asmeq("%4", "r3") + __asmeq("%5", "r4") +#ifdef REQUIRES_SEC + ".arch_extension sec\n" +#endif + "smc #0 @ switch to secure world\n" + : "=r" (r0) + : "r" (r0), "r" (r1), "r" (r2), "r" (r3), "r" (r4)); + return r0; +} +EXPORT_SYMBOL(scm_call_atomic3); + +s32 scm_call_atomic4_3(u32 svc, u32 cmd, u32 arg1, u32 arg2, + u32 arg3, u32 arg4, u32 *ret1, u32 *ret2) +{ + int ret; + int context_id; + register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 4); + register u32 r1 asm("r1") = (u32)&context_id; + register u32 r2 asm("r2") = arg1; + register u32 r3 asm("r3") = arg2; + register u32 r4 asm("r4") = arg3; + register u32 r5 asm("r5") = arg4; + + asm volatile( + __asmeq("%0", "r0") + __asmeq("%1", "r1") + __asmeq("%2", "r2") + __asmeq("%3", "r0") + __asmeq("%4", "r1") + __asmeq("%5", "r2") + __asmeq("%6", "r3") +#ifdef REQUIRES_SEC + ".arch_extension sec\n" +#endif + "smc #0 @ switch to secure world\n" + : "=r" (r0), "=r" (r1), "=r" (r2) + : "r" (r0), "r" (r1), "r" (r2), "r" (r3), "r" (r4), "r" (r5)); + ret = r0; + if (ret1) + *ret1 = r1; + if (ret2) + *ret2 = r2; + return r0; +} +EXPORT_SYMBOL(scm_call_atomic4_3); + +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); + +#define IS_CALL_AVAIL_CMD 1 +int scm_is_call_available(u32 svc_id, u32 cmd_id) +{ + int ret; + u32 svc_cmd = (svc_id << 10) | cmd_id; + u32 ret_val = 0; + + ret = scm_call(SCM_SVC_INFO, IS_CALL_AVAIL_CMD, &svc_cmd, + sizeof(svc_cmd), &ret_val, sizeof(ret_val)); + if (ret) + return ret; + + return ret_val; +} +EXPORT_SYMBOL(scm_is_call_available); + +#define GET_FEAT_VERSION_CMD 3 +int scm_get_feat_version(u32 feat) +{ + if (scm_is_call_available(SCM_SVC_INFO, GET_FEAT_VERSION_CMD)) { + u32 version; + if (!scm_call(SCM_SVC_INFO, GET_FEAT_VERSION_CMD, &feat, + sizeof(feat), &version, sizeof(version))) + return version; + } + return 0; +} +EXPORT_SYMBOL(scm_get_feat_version); + |