From 0d423c4a78984dd02f6596d6fd9dd40446eec517 Mon Sep 17 00:00:00 2001 From: Alexey Romanov Date: Wed, 30 Aug 2023 17:08:50 +0300 Subject: drivers: meson: sm: correct meson_sm_* API retval handling 1. Following the ARM SMC32 calling convention, the return value from secure monitor is a 32-bit signed integer. This patch changes the type of the return value of the function meson_sm_call(). 2. Now, when meson_sm_call() returns a 32-bit signed integer, we need to ensure that this value is not negative. It is important to check that the return value is not negative in both the meson_sm_call_read() and meson_sm_call_write() functions. 3. Add a comment explaining why it is necessary to check if the SMC return value is equal to 0 in the function meson_sm_call_read(). It is not obvious when reading this code. Signed-off-by: Alexey Romanov Reviewed-by: Neil Armstrong Link: https://lore.kernel.org/r/20230830140850.17130-1-avromanov@salutedevices.com Signed-off-by: Neil Armstrong --- include/linux/firmware/meson/meson_sm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/firmware/meson/meson_sm.h b/include/linux/firmware/meson/meson_sm.h index 95b0da2326a9..8eaf8922ab02 100644 --- a/include/linux/firmware/meson/meson_sm.h +++ b/include/linux/firmware/meson/meson_sm.h @@ -19,7 +19,7 @@ enum { struct meson_sm_firmware; int meson_sm_call(struct meson_sm_firmware *fw, unsigned int cmd_index, - u32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4); + s32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4); int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer, unsigned int b_size, unsigned int cmd_index, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4); -- cgit v1.2.3