[PATCH v10 1/3] ARM: uncompress: Add be32tocpu macro

Geert Uytterhoeven geert+renesas at glider.be
Thu Dec 3 07:19:14 EST 2020


DTB stores all values as 32-bit big-endian integers.
Add a macro to convert such values to native CPU endianness, to reduce
duplication.

Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
---
v10:
  - New.
---
 arch/arm/boot/compressed/head.S | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 835ce64f1674c9a2..aabdc544c03aafdc 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -165,6 +165,16 @@
 		orr	\res, \res, \tmp1, lsl #24
 		.endm
 
+		.macro	be32tocpu, val, tmp
+#ifndef __ARMEB__
+		/* convert to little endian */
+		eor	\tmp, \val, \val, ror #16
+		bic	\tmp, \tmp, #0x00ff0000
+		mov	\val, \val, ror #8
+		eor	\val, \val, \tmp, lsr #8
+#endif
+		.endm
+
 		.section ".start", "ax"
 /*
  * sort out different calling conventions
@@ -345,13 +355,7 @@ restart:	adr	r0, LC1
 
 		/* Get the initial DTB size */
 		ldr	r5, [r6, #4]
-#ifndef __ARMEB__
-		/* convert to little endian */
-		eor	r1, r5, r5, ror #16
-		bic	r1, r1, #0x00ff0000
-		mov	r5, r5, ror #8
-		eor	r5, r5, r1, lsr #8
-#endif
+		be32tocpu r5, r1
 		dbgadtb	r6, r5
 		/* 50% DTB growth should be good enough */
 		add	r5, r5, r5, lsr #1
@@ -403,13 +407,7 @@ restart:	adr	r0, LC1
 
 		/* Get the current DTB size */
 		ldr	r5, [r6, #4]
-#ifndef __ARMEB__
-		/* convert r5 (dtb size) to little endian */
-		eor	r1, r5, r5, ror #16
-		bic	r1, r1, #0x00ff0000
-		mov	r5, r5, ror #8
-		eor	r5, r5, r1, lsr #8
-#endif
+		be32tocpu r5, r1
 
 		/* preserve 64-bit alignment */
 		add	r5, r5, #7
-- 
2.25.1




More information about the linux-arm-kernel mailing list