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-rw-r--r--drivers/firmware/meson/meson_sm.c20
-rw-r--r--drivers/nvmem/meson-efuse.c2
-rw-r--r--include/linux/firmware/meson/meson_sm.h4
3 files changed, 19 insertions, 7 deletions
diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
index b0d254930ed3..ff204421117b 100644
--- a/drivers/firmware/meson/meson_sm.c
+++ b/drivers/firmware/meson/meson_sm.c
@@ -127,6 +127,7 @@ EXPORT_SYMBOL(meson_sm_call);
* meson_sm_call_read - retrieve data from secure-monitor
*
* @buffer: Buffer to store the retrieved data
+ * @bsize: Size of the buffer
* @cmd_index: Index of the SMC32 function ID
* @arg0: SMC32 Argument 0
* @arg1: SMC32 Argument 1
@@ -135,11 +136,14 @@ EXPORT_SYMBOL(meson_sm_call);
* @arg4: SMC32 Argument 4
*
* Return: size of read data on success, a negative value on error
+ * When 0 is returned there is no guarantee about the amount of
+ * data read and bsize bytes are copied in buffer.
*/
-int meson_sm_call_read(void *buffer, unsigned int cmd_index, u32 arg0,
- u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+int meson_sm_call_read(void *buffer, unsigned int bsize, unsigned int cmd_index,
+ u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
{
u32 size;
+ int ret;
if (!fw.chip)
return -ENOENT;
@@ -147,16 +151,24 @@ int meson_sm_call_read(void *buffer, unsigned int cmd_index, u32 arg0,
if (!fw.chip->cmd_shmem_out_base)
return -EINVAL;
+ if (bsize > fw.chip->shmem_size)
+ return -EINVAL;
+
if (meson_sm_call(cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
return -EINVAL;
- if (!size || size > fw.chip->shmem_size)
+ if (size > bsize)
return -EINVAL;
+ ret = size;
+
+ if (!size)
+ size = bsize;
+
if (buffer)
memcpy(buffer, fw.sm_shmem_out_base, size);
- return size;
+ return ret;
}
EXPORT_SYMBOL(meson_sm_call_read);
diff --git a/drivers/nvmem/meson-efuse.c b/drivers/nvmem/meson-efuse.c
index f207c3b10482..70bfc9839bb2 100644
--- a/drivers/nvmem/meson-efuse.c
+++ b/drivers/nvmem/meson-efuse.c
@@ -27,7 +27,7 @@ static int meson_efuse_read(void *context, unsigned int offset,
u8 *buf = val;
int ret;
- ret = meson_sm_call_read(buf, SM_EFUSE_READ, offset,
+ ret = meson_sm_call_read(buf, bytes, SM_EFUSE_READ, offset,
bytes, 0, 0, 0);
if (ret < 0)
return ret;
diff --git a/include/linux/firmware/meson/meson_sm.h b/include/linux/firmware/meson/meson_sm.h
index 8e953c6f394a..37a5eaea69dd 100644
--- a/include/linux/firmware/meson/meson_sm.h
+++ b/include/linux/firmware/meson/meson_sm.h
@@ -25,7 +25,7 @@ int meson_sm_call(unsigned int cmd_index, u32 *ret, u32 arg0, u32 arg1,
u32 arg2, u32 arg3, u32 arg4);
int meson_sm_call_write(void *buffer, unsigned int b_size, unsigned int cmd_index,
u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
-int meson_sm_call_read(void *buffer, unsigned int cmd_index, u32 arg0, u32 arg1,
- u32 arg2, u32 arg3, u32 arg4);
+int meson_sm_call_read(void *buffer, unsigned int bsize, unsigned int cmd_index,
+ u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
#endif /* _MESON_SM_FW_H_ */