[PATCH 0/3] ARM: shmobile: enable SMP Thumb2 kernel

[PATCH 0/3] ARM: shmobile: enable SMP Thumb2 kernel

[Tetsuyuki Kobayashi]

Hello,

I try to build SMP kernel for KZM-A9-GT board in CONFIG_THUMB2_KERNEL=y.
After some modification it successully boots in Thumb2 kernel.
In my case, Thumb2 kernel is 23% smaller than usual ARM kernel.

   text	   data	    bss	    dec	    hex	filename
4763561	 251580	 196164	5211305	 4f84a9	out.kzm9g/vmlinux

   text	   data	    bss	    dec	    hex	filename
3595265	 251668	 196164	4043097	 3db159	out.kzm9g_thumb/vmlinux


Useful info for Thumb2 kernel
https://wiki.linaro.org/WorkingGroups/KernelArchived/Thumb2Guide

This patch set is based on arm-soc git repositry, 
remotes/origin/renesas/soc-cleanup branch
53332005bfde9d2e3c9a66030c0e8c2598eaa1d5 ARM: shmobile: Remove Bonito board support

Tetsuyuki Kobayashi (3):
  ARM: shmobile: fix compile error when CONFIG_THUMB2_KERNEL=y
  ARM: shmobile: Force ARM mode to compile reset vector for secondary
    CPUs
  ARM: shmobile: Insert align directives before 4 bytes data

 arch/arm/mach-shmobile/headsmp-scu.S  |    4 +++-
 arch/arm/mach-shmobile/headsmp.S      |    6 +++++-
 arch/arm/mach-shmobile/sleep-sh7372.S |    2 ++
 3 files changed, 10 insertions(+), 2 deletions(-)

-- 
1.7.9.5

[PATCH 1/3] ARM: shmobile: fix compile error when CONFIG_THUMB2_KERNEL=y

[Tetsuyuki Kobayashi]

On KZM-A9-GT board (SMP), when CONFIG_THUMB2_KERNEL=y it fails to compile
 
  AS      arch/arm/mach-shmobile/headsmp-scu.o
/proj/koba/kernel/arm-soc/arch/arm/mach-shmobile/headsmp-scu.S: Assembler messages:
/proj/koba/kernel/arm-soc/arch/arm/mach-shmobile/headsmp-scu.S:41: Error: shift must be constant -- `bic r2,r2,r3,lsl r1'
make[2]: *** [arch/arm/mach-shmobile/headsmp-scu.o] Error 1
make[1]: *** [arch/arm/mach-shmobile] Error 2
make: *** [sub-make] Error 2

Instruction `bic r2,r2,r3,lsl r1' is not supported in thumb mode. This patch split it into 2 instructions.

Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
---
 arch/arm/mach-shmobile/headsmp-scu.S |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-shmobile/headsmp-scu.S b/arch/arm/mach-shmobile/headsmp-scu.S
index 6f98654..5ce416c 100644
--- a/arch/arm/mach-shmobile/headsmp-scu.S
+++ b/arch/arm/mach-shmobile/headsmp-scu.S
@@ -38,7 +38,8 @@ ENTRY(shmobile_boot_scu)
 	lsl	r1, r1, #3		@ we will shift by cpu_id * 8 bits
 	ldr	r2, [r0, #8]		@ SCU Power Status Register
 	mov	r3, #3
-	bic	r2, r2, r3, lsl r1	@ Clear bits of our CPU (Run Mode)
+	lsl	r3, r3, r1
+	bic	r2, r2, r3		@ Clear bits of our CPU (Run Mode)
 	str	r2, [r0, #8]		@ write back
 
 	b	shmobile_invalidate_start
-- 
1.7.9.5

[PATCH 2/3] ARM: shmobile: Force ARM mode to compile reset vector for secondary CPUs

[Tetsuyuki Kobayashi]

Instructions start from boot vector must be ARM mode.
This patch specify ARM mode explicitly and use 'bx' instruction to be
able to change to Thumb mode.

Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
---
 arch/arm/mach-shmobile/headsmp.S |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-shmobile/headsmp.S b/arch/arm/mach-shmobile/headsmp.S
index 559d1ce..afed58e 100644
--- a/arch/arm/mach-shmobile/headsmp.S
+++ b/arch/arm/mach-shmobile/headsmp.S
@@ -26,10 +26,13 @@ ENDPROC(shmobile_invalidate_start)
  * This will be mapped at address 0 by SBAR register.
  * We need _long_ jump to the physical address.
  */
+	.arm
 	.align  12
 ENTRY(shmobile_boot_vector)
 	ldr     r0, 2f
-	ldr     pc, 1f
+	ldr     r1, 1f
+	bx	r1
+
 ENDPROC(shmobile_boot_vector)
 
 	.globl	shmobile_boot_fn
-- 
1.7.9.5

[PATCH 3/3] ARM: shmobile: Insert align directives before 4 bytes data

[Tetsuyuki Kobayashi]

In thumb2 mode instructions are not align to 4 byte. This patch insert
align directives before putting 4 byte data.

Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
---
 arch/arm/mach-shmobile/headsmp-scu.S  |    1 +
 arch/arm/mach-shmobile/headsmp.S      |    1 +
 arch/arm/mach-shmobile/sleep-sh7372.S |    2 ++
 3 files changed, 4 insertions(+)

diff --git a/arch/arm/mach-shmobile/headsmp-scu.S b/arch/arm/mach-shmobile/headsmp-scu.S
index 5ce416c..0a77488 100644
--- a/arch/arm/mach-shmobile/headsmp-scu.S
+++ b/arch/arm/mach-shmobile/headsmp-scu.S
@@ -46,6 +46,7 @@ ENTRY(shmobile_boot_scu)
 ENDPROC(shmobile_boot_scu)
 
 	.text
+	.align	2
 	.globl	shmobile_scu_base
 shmobile_scu_base:
 	.space	4
diff --git a/arch/arm/mach-shmobile/headsmp.S b/arch/arm/mach-shmobile/headsmp.S
index afed58e..dfb41df 100644
--- a/arch/arm/mach-shmobile/headsmp.S
+++ b/arch/arm/mach-shmobile/headsmp.S
@@ -35,6 +35,7 @@ ENTRY(shmobile_boot_vector)
 
 ENDPROC(shmobile_boot_vector)
 
+	.align	2
 	.globl	shmobile_boot_fn
 shmobile_boot_fn:
 1:	.space	4
diff --git a/arch/arm/mach-shmobile/sleep-sh7372.S b/arch/arm/mach-shmobile/sleep-sh7372.S
index 53f4840..9782862 100644
--- a/arch/arm/mach-shmobile/sleep-sh7372.S
+++ b/arch/arm/mach-shmobile/sleep-sh7372.S
@@ -41,6 +41,7 @@
 sh7372_resume_core_standby_sysc:
 	ldr     pc, 1f
 
+	.align	2
 	.globl	sh7372_cpu_resume
 sh7372_cpu_resume:
 1:	.space	4
@@ -96,6 +97,7 @@ sh7372_do_idle_sysc:
 1:
 	b      1b
 
+	.align	2
 kernel_flush:
 	.word v7_flush_dcache_all
 #endif
-- 
1.7.9.5

[PATCH 0/3] ARM: shmobile: enable SMP Thumb2 kernel

[Magnus Damm]

Hi Kobayashi-san,

Your patch series looks fine to me. Thanks for your contribution.

Acked-by: Magnus Damm <damm@opensource.se>

On Wed, Jul 10, 2013 at 10:56 AM, Tetsuyuki Kobayashi <koba@kmckk.co.jp> wrote:
> Hello,
>
> I try to build SMP kernel for KZM-A9-GT board in CONFIG_THUMB2_KERNEL=y.
> After some modification it successully boots in Thumb2 kernel.
> In my case, Thumb2 kernel is 23% smaller than usual ARM kernel.
>
>    text    data     bss     dec     hex filename
> 4763561  251580  196164 5211305  4f84a9 out.kzm9g/vmlinux
>
>    text    data     bss     dec     hex filename
> 3595265  251668  196164 4043097  3db159 out.kzm9g_thumb/vmlinux
>
>
> Useful info for Thumb2 kernel
> https://wiki.linaro.org/WorkingGroups/KernelArchived/Thumb2Guide
>
> This patch set is based on arm-soc git repositry,
> remotes/origin/renesas/soc-cleanup branch
> 53332005bfde9d2e3c9a66030c0e8c2598eaa1d5 ARM: shmobile: Remove Bonito board support
>
> Tetsuyuki Kobayashi (3):
>   ARM: shmobile: fix compile error when CONFIG_THUMB2_KERNEL=y
>   ARM: shmobile: Force ARM mode to compile reset vector for secondary
>     CPUs
>   ARM: shmobile: Insert align directives before 4 bytes data
>
>  arch/arm/mach-shmobile/headsmp-scu.S  |    4 +++-
>  arch/arm/mach-shmobile/headsmp.S      |    6 +++++-
>  arch/arm/mach-shmobile/sleep-sh7372.S |    2 ++
>  3 files changed, 10 insertions(+), 2 deletions(-)
>
> --
> 1.7.9.5
>

[PATCH 1/3] ARM: shmobile: fix compile error when CONFIG_THUMB2_KERNEL=y

[Simon Horman]

On Wed, Jul 10, 2013 at 10:56:35AM +0900, Tetsuyuki Kobayashi wrote:
> On KZM-A9-GT board (SMP), when CONFIG_THUMB2_KERNEL=y it fails to compile
>  
>   AS      arch/arm/mach-shmobile/headsmp-scu.o
> /proj/koba/kernel/arm-soc/arch/arm/mach-shmobile/headsmp-scu.S: Assembler messages:
> /proj/koba/kernel/arm-soc/arch/arm/mach-shmobile/headsmp-scu.S:41: Error: shift must be constant -- `bic r2,r2,r3,lsl r1'
> make[2]: *** [arch/arm/mach-shmobile/headsmp-scu.o] Error 1
> make[1]: *** [arch/arm/mach-shmobile] Error 2
> make: *** [sub-make] Error 2
> 
> Instruction `bic r2,r2,r3,lsl r1' is not supported in thumb mode. This patch split it into 2 instructions.
> 
> Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
> ---
>  arch/arm/mach-shmobile/headsmp-scu.S |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Thanks, I have queued this up with Magnus's ack in the thumb-fixes
branch of my renesas tree on kernel.org. It should be
included in the renesas-next-20130710v2 tag.

[PATCH 2/3] ARM: shmobile: Force ARM mode to compile reset vector for secondary CPUs

[Simon Horman]

On Wed, Jul 10, 2013 at 10:56:36AM +0900, Tetsuyuki Kobayashi wrote:
> Instructions start from boot vector must be ARM mode.
> This patch specify ARM mode explicitly and use 'bx' instruction to be
> able to change to Thumb mode.
> 
> Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
> ---
>  arch/arm/mach-shmobile/headsmp.S |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Thanks, I have queued this up with Magnus's ack in the thumb-fixes
branch of my renesas tree on kernel.org. It should be
included in the renesas-next-20130710v2 tag.

[PATCH 3/3] ARM: shmobile: Insert align directives before 4 bytes data

[Simon Horman]

On Wed, Jul 10, 2013 at 10:56:37AM +0900, Tetsuyuki Kobayashi wrote:
> In thumb2 mode instructions are not align to 4 byte. This patch insert
> align directives before putting 4 byte data.
> 
> Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
> ---
>  arch/arm/mach-shmobile/headsmp-scu.S  |    1 +
>  arch/arm/mach-shmobile/headsmp.S      |    1 +
>  arch/arm/mach-shmobile/sleep-sh7372.S |    2 ++
>  3 files changed, 4 insertions(+)

Thanks, I have queued this up with Magnus's ack in the thumb-fixes
branch of my renesas tree on kernel.org. It should be
included in the renesas-next-20130710v2 tag.

[PATCH 2/3] ARM: shmobile: Force ARM mode to compile reset vector for secondary CPUs

[Tetsuyuki Kobayashi]

Thank you, Simon-san.

I will post the backport patch to next LTSI kernel.

(2013/07/10 22:20), Simon Horman wrote:
> On Wed, Jul 10, 2013 at 10:56:36AM +0900, Tetsuyuki Kobayashi wrote:
>> Instructions start from boot vector must be ARM mode.
>> This patch specify ARM mode explicitly and use 'bx' instruction to be
>> able to change to Thumb mode.
>>
>> Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
>> ---
>>   arch/arm/mach-shmobile/headsmp.S |    5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> Thanks, I have queued this up with Magnus's ack in the thumb-fixes
> branch of my renesas tree on kernel.org. It should be
> included in the renesas-next-20130710v2 tag.
>