ARM: qcom: Fix SCM interface for big-endian kernels

The secure environment only runs in little-endian mode, so any
buffers shared with the secure environment should have their
contents converted to little-endian. We also mark such elements
with __le32 to allow sparse to catch such problems.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kumar Gala <galak@codeaurora.org>

2 files changed, 20 insertions, 18 deletions

diff --git a/arch/arm/mach-qcom/scm-boot.c b/arch/arm/mach-qcom/scm-boot.c
index f2fa32834631..e8ff7beb6218 100644
--- a/arch/arm/mach-qcom/scm-boot.c
+++ b/arch/arm/mach-qcom/scm-boot.c
@@ -27,12 +27,12 @@
 int scm_set_boot_addr(u32 addr, int flags)
 {
         struct {
-                unsigned int flags;
-                u32 addr;
+                __le32 flags;
+                __le32 addr;
         } cmd;
 
-        cmd.addr = addr;
-        cmd.flags = flags;
+        cmd.addr = cpu_to_le32(addr);
+        cmd.flags = cpu_to_le32(flags);
         return scm_call(SCM_SVC_BOOT, SCM_BOOT_ADDR,
                         &cmd, sizeof(cmd), NULL, 0);
 }
diff --git a/arch/arm/mach-qcom/scm.c b/arch/arm/mach-qcom/scm.c
index a77349d34e78..1d9cf18c7091 100644
--- a/arch/arm/mach-qcom/scm.c
+++ b/arch/arm/mach-qcom/scm.c
@@ -61,11 +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];
 };
 
 /**
@@ -75,9 +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;
 };
 
 /**
@@ -95,12 +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;
 }
@@ -125,7 +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);
 }
 
 /**
@@ -147,7 +149,7 @@ 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)
@@ -259,7 +261,7 @@ int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_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);