[PATCH] ARM: qcom: Fix SCM interface for big-endian kernels

From: Stephen Boyd
Date: Mon Sep 22 2014 - 18:36:41 EST


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@xxxxxxxxxxxxxx>
---
drivers/soc/qcom/scm-boot.c | 8 ++++----
drivers/soc/qcom/scm.c | 34 ++++++++++++++++++----------------
2 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/drivers/soc/qcom/scm-boot.c b/drivers/soc/qcom/scm-boot.c
index 60ff7b482141..3e4d77b371c6 100644
--- a/drivers/soc/qcom/scm-boot.c
+++ b/drivers/soc/qcom/scm-boot.c
@@ -27,12 +27,12 @@
int scm_set_boot_addr(phys_addr_t addr, int flags)
{
struct {
- unsigned int flags;
- phys_addr_t 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/drivers/soc/qcom/scm.c b/drivers/soc/qcom/scm.c
index be1e2beec796..feeb4e4bb22d 100644
--- a/drivers/soc/qcom/scm.c
+++ b/drivers/soc/qcom/scm.c
@@ -62,11 +62,11 @@ 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];
};

/**
@@ -76,9 +76,9 @@ 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;
};

/**
@@ -96,12 +96,14 @@ 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;
}
@@ -126,7 +128,7 @@ 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);
}

/**
@@ -148,7 +150,7 @@ 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)
@@ -201,8 +203,8 @@ static int __scm_call(const struct scm_command *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);
+ __cpuc_flush_dcache_area((void *)cmd, le32_to_cpu(cmd->len));
+ outer_flush_range(cmd_addr, cmd_addr + le32_to_cpu(cmd->len));

ret = smc(cmd_addr);
if (ret < 0)
@@ -260,7 +262,7 @@ 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);

--
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