[PATCH] firmware: meson_sm: Fix memcpy vs iomem type warnings

[Kees Cook]

Use memcpy_{toio,fromio}() instead of memcpy(). Silences warnings from
Sparse:

drivers/firmware/meson/meson_sm.c:170:17: warning: incorrect type in argument 1 (different address spaces)
drivers/firmware/meson/meson_sm.c:170:17:    expected void const *
drivers/firmware/meson/meson_sm.c:170:17:    got void [noderef] __iomem *sm_shmem_out_base
drivers/firmware/meson/meson_sm.c:170:17: warning: incorrect type in argument 2 (different address spaces)
drivers/firmware/meson/meson_sm.c:170:17:    expected void const *
drivers/firmware/meson/meson_sm.c:170:17:    got void [noderef] __iomem *sm_shmem_out_base
drivers/firmware/meson/meson_sm.c:206:9: warning: incorrect type in argument 1 (different address spaces)
drivers/firmware/meson/meson_sm.c:206:9:    expected void const *
drivers/firmware/meson/meson_sm.c:206:9:    got void [noderef] __iomem *sm_shmem_in_base
drivers/firmware/meson/meson_sm.c:206:9: warning: incorrect type in argument 1 (different address spaces)
drivers/firmware/meson/meson_sm.c:206:9:    expected void const *
drivers/firmware/meson/meson_sm.c:206:9:    got void [noderef] __iomem *sm_shmem_in_base
drivers/firmware/meson/meson_sm.c:206:9: warning: incorrect type in argument 1 (different address spaces)
drivers/firmware/meson/meson_sm.c:206:9:    expected void const *
drivers/firmware/meson/meson_sm.c:206:9:    got void [noderef] __iomem *sm_shmem_in_base
drivers/firmware/meson/meson_sm.c:206:9: warning: incorrect type in argument 1 (different address spaces)
drivers/firmware/meson/meson_sm.c:206:9:    expected void *
drivers/firmware/meson/meson_sm.c:206:9:    got void [noderef] __iomem *sm_shmem_in_base

While here, fix this warning as well:

drivers/firmware/meson/meson_sm.c:85:24: warning: Using plain integer as NULL pointer

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Link: https://lore.kernel.org/lkml/202210122023.zF56nCzM-lkp@xxxxxxxxx
Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Cc: Kevin Hilman <khilman@xxxxxxxxxxxx>
Cc: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Cc: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-amlogic@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/firmware/meson/meson_sm.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
index 77aa5c6398aa..4efde225a580 100644
--- a/drivers/firmware/meson/meson_sm.c
+++ b/drivers/firmware/meson/meson_sm.c
@@ -82,7 +82,7 @@ static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)
 
 	sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);
 	if (!sm_phy_base)
-		return 0;
+		return NULL;
 
 	return ioremap_cache(sm_phy_base, size);
 }
@@ -167,7 +167,7 @@ int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,
 		size = bsize;
 
 	if (buffer)
-		memcpy(buffer, fw->sm_shmem_out_base, size);
+		memcpy_fromio(buffer, fw->sm_shmem_out_base, size);
 
 	return ret;
 }
@@ -203,7 +203,7 @@ int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,
 	if (!fw->chip->cmd_shmem_in_base)
 		return -EINVAL;
 
-	memcpy(fw->sm_shmem_in_base, buffer, size);
+	memcpy_toio(fw->sm_shmem_in_base, buffer, size);
 
 	if (meson_sm_call(fw, cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0)
 		return -EINVAL;
-- 
2.34.1