[PATCH v2 1/2] boot: extlinux: Fix unaligned buffer for reading data from file system

[Nam Cao]

extlinux_read_bootflow() allocates a buffer to read from file system
without any alignment.

But for some block devices which transfer data via DMA, ARCH_DMA_MINALIGN
alignment is required. For example, due to misaligned buffer, the below
boot failure is observed.

=> boot
CACHE: Misaligned operation at range [9efa25f8, 9efa27f8]
CACHE: Misaligned operation at range [9efa25f8, 9efa27f8]
CACHE: Misaligned operation at range [9efa25f8, 9efa27f8]
CACHE: Misaligned operation at range [9efa25f8, 9efa27f8]
** Booting bootflow 'mmc at 2194000.bootdev.part_1' with extlinux
Ignoring unknown command: �D���D��
Boot failed (err=-14)

Change the buffer alignment to ARCH_DMA_MINALIGN.

Fixes: 31aefaf89a5b ("bootstd: Add an implementation of distro boot")
Signed-off-by: Nam Cao <namcao at linutronix.de>
Tested-by: Javier Fernandez Pastrana <javier.pastrana at linutronix.de>
---
v2:
  - use ARCH_DMA_MINALIGN to be consistent with bootmeth_script [Simon]

 boot/bootmeth_extlinux.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/boot/bootmeth_extlinux.c b/boot/bootmeth_extlinux.c
index ae0ad1d53e3..ac046705033 100644
--- a/boot/bootmeth_extlinux.c
+++ b/boot/bootmeth_extlinux.c
@@ -8,6 +8,7 @@
 
 #define LOG_CATEGORY UCLASS_BOOTSTD
 
+#include <asm/cache.h>
 #include <common.h>
 #include <bootdev.h>
 #include <bootflow.h>
@@ -127,7 +128,7 @@ static int extlinux_read_bootflow(struct udevice *dev, struct bootflow *bflow)
 		return log_msg_ret("try", ret);
 	size = bflow->size;
 
-	ret = bootmeth_alloc_file(bflow, 0x10000, 1);
+	ret = bootmeth_alloc_file(bflow, 0x10000, ARCH_DMA_MINALIGN);
 	if (ret)
 		return log_msg_ret("read", ret);
 
-- 
2.39.5