diff options
Diffstat (limited to 'arch/arm/mach-qcom/scm.c')
| -rw-r--r-- | arch/arm/mach-qcom/scm.c | 85 |
1 files changed, 56 insertions, 29 deletions
diff --git a/arch/arm/mach-qcom/scm.c b/arch/arm/mach-qcom/scm.c index c536fd6bf827..1d9cf18c7091 100644 --- a/arch/arm/mach-qcom/scm.c +++ b/arch/arm/mach-qcom/scm.c @@ -22,13 +22,11 @@ #include <linux/errno.h> #include <linux/err.h> +#include <asm/outercache.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 @@ -63,11 +61,11 @@ static DEFINE_MUTEX(scm_lock); * 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]; + __le32 len; + __le32 buf_offset; + __le32 resp_hdr_offset; + __le32 id; + __le32 buf[0]; }; /** @@ -77,9 +75,9 @@ struct scm_command { * @is_complete: indicates if the command has finished processing */ struct scm_response { - u32 len; - u32 buf_offset; - u32 is_complete; + __le32 len; + __le32 buf_offset; + __le32 is_complete; }; /** @@ -97,12 +95,14 @@ 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; + u32 offset; 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; + cmd->len = cpu_to_le32(len); + offset = offsetof(struct scm_command, buf); + cmd->buf_offset = cpu_to_le32(offset); + cmd->resp_hdr_offset = cpu_to_le32(offset + cmd_size); } return cmd; } @@ -127,7 +127,7 @@ static inline void free_scm_command(struct scm_command *cmd) static inline struct scm_response *scm_command_to_response( const struct scm_command *cmd) { - return (void *)cmd + cmd->resp_hdr_offset; + return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset); } /** @@ -149,11 +149,12 @@ static inline void *scm_get_command_buffer(const struct scm_command *cmd) */ static inline void *scm_get_response_buffer(const struct scm_response *rsp) { - return (void *)rsp + rsp->buf_offset; + return (void *)rsp + le32_to_cpu(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; @@ -198,11 +199,12 @@ static int __scm_call(const struct scm_command *cmd) 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 the command buffer so that the secure world sees + * the correct data. */ - flush_cache_all(); + __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); @@ -210,6 +212,25 @@ static int __scm_call(const struct scm_command *cmd) 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 @@ -220,6 +241,13 @@ static int __scm_call(const struct scm_command *cmd) * @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) @@ -227,12 +255,13 @@ int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_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; + cmd->id = cpu_to_le32((svc_id << 10) | cmd_id); if (cmd_buf) memcpy(scm_get_command_buffer(cmd), cmd_buf, cmd_len); @@ -243,17 +272,15 @@ int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_len, goto out; rsp = scm_command_to_response(cmd); + start = (unsigned long)rsp; + 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; - } + 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: |