Hi Nicolas,

On Saturday 03 August 2013 09:10 AM, Nicolas Pitre wrote:

On Wed, 31 Jul 2013, Santosh Shilimkar wrote:

quoted

From: Sricharan R <redacted>

Update the runtime patching  code to support Thumb2. In testing the
64 bit patching code, the issue was uncovered.

For better review, the patch is kept separate. If needed it can be
merged into "ARM: LPAE: Correct virt_to_phys patching for 64 bit
physical addresses"

Cc: Nicolas Pitre <redacted>
Cc: Russell King <redacted>

Signed-off-by: Sricharan R <redacted>
[santosh.shilimkar at ti.com: reduced #ifdef, updated commit log]
Signed-off-by: Santosh Shilimkar <redacted>
---
 arch/arm/kernel/head.S |   69 ++++++++++++++++++++++++++++--------------------
 1 file changed, 40 insertions(+), 29 deletions(-)

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index aa3b0f7..a70d330 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S

@@ -573,62 +573,73 @@ ENDPROC(__fixup_pv_table)
 
 	.text
 __fixup_a_pv_table:
-#ifdef CONFIG_THUMB2_KERNEL
-	lsls	r6, #24
-	beq	2f
-	clz	r7, r6
-	lsr	r6, #24
-	lsl	r6, r7
-	bic	r6, #0x0080
-	lsrs	r7, #1
-	orrcs	r6, #0x0080
-	orr	r6, r6, r7, lsl #12
-	orr	r6, #0x4000
-	b	2f
-1:	add     r7, r3
-	ldrh	ip, [r7, #2]
-	and	ip, 0x8f00
-	orr	ip, r6	@ mask in offset bits 31-24
-	strh	ip, [r7, #2]
-2:	cmp	r4, r5
-	ldrcc	r7, [r4], #4	@ use branch for delay slot
-	bcc	1b
-	bx	lr
-#else
 	adr	r0, 5f
 	b	4f
 1:	ldr	ip, [r7, r3]
+ THUMB(	1:	add	r7, r3)
+ THUMB(	ldrh	ip, [r7])
+ THUMB(	ldrh	r6, [r7, #2])
+ THUMB(	orr	ip, r6, ip, lsl #16)
+ ARM( 1: ldr	ip, [r7, r3])
 	lsr	r6, ip, #20		@ extract opcode

Please don't do this.

- Remember my comment about using mnemonics such as "lsr" in an 
  ARM-mode compiled kernel when old binutils are used.

 Ok, i will remove this to be generic.

- There is rather little commonalities between the patching of ARM 
  instructions vs Thumb instructions.  Especially after you take into 
  account my previous comments.  Interlacing them makes it harder 
  to follow as well in this case.


Nicolas

 Ok, then i will keep it under #ifdef CONFIG_THUMB2_KERNEL
 as it was originally.

Regards,
 Sricharan