[PATCH] Fix booting pre-ARM6 machines

[PATCH] Fix booting pre-ARM6 machines

[Uwe Kleine-König]

Commit 200b812d0084f800bc52465e273b118ff5f8141f includes the following
hunk:

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index a4eaf4f..e17e3c3 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -76,13 +76,25 @@
 #ifndef CONFIG_THUMB2_KERNEL
 	.macro	svc_exit, rpsr
 	msr	spsr_cxsf, \rpsr
+#if defined(CONFIG_CPU_32v6K)
+	clrex					@ clear the exclusive monitor
 	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
+#elif defined (CONFIG_CPU_V6)
+	ldr	r0, [sp]
+	strex	r1, r2, [sp]			@ clear the exclusive monitor
+	ldmib	sp, {r1 - pc}^			@ load r1 - pc, cpsr
+#endif
 	.endm

 	.macro	restore_user_regs, fast = 0, offset = 0

Having neither CONFIG_THUMB2_KERNEL nor CONFIG_CPU_32v6K nor
CONFIG_CPU_V6 this steals the ldmia instruction.  The result is that
svc_exit doesn't work at all.  So reintroduce it.

Signed-off-by: Uwe Kleine-K?nig <u.kleine-koenig@pengutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jamie Lokier <jamie@shareable.org>
---
 arch/arm/kernel/entry-header.S |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index e17e3c3..ac34c0d 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -83,6 +83,8 @@
 	ldr	r0, [sp]
 	strex	r1, r2, [sp]			@ clear the exclusive monitor
 	ldmib	sp, {r1 - pc}^			@ load r1 - pc, cpsr
+#else
+	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
 #endif
 	.endm
 
-- 
1.6.4.3

[PATCH] Fix booting pre-ARM6 machines

[Nicolas Pitre]

On Fri, 25 Sep 2009, Uwe Kleine-K?nig wrote:

> Commit 200b812d0084f800bc52465e273b118ff5f8141f includes the following
> hunk:
> 
> diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
> index a4eaf4f..e17e3c3 100644
> --- a/arch/arm/kernel/entry-header.S
> +++ b/arch/arm/kernel/entry-header.S
> @@ -76,13 +76,25 @@
>  #ifndef CONFIG_THUMB2_KERNEL
>  	.macro	svc_exit, rpsr
>  	msr	spsr_cxsf, \rpsr
> +#if defined(CONFIG_CPU_32v6K)
> +	clrex					@ clear the exclusive monitor
>  	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
> +#elif defined (CONFIG_CPU_V6)
> +	ldr	r0, [sp]
> +	strex	r1, r2, [sp]			@ clear the exclusive monitor
> +	ldmib	sp, {r1 - pc}^			@ load r1 - pc, cpsr
> +#endif
>  	.endm
> 
>  	.macro	restore_user_regs, fast = 0, offset = 0
> 

I've sent the same patch directly to Linus already in the hope that 
he'll merge it before -rc1.

Also you should avoid quoting patch hunks without indenting them or 
prefixing them with some quotation mark, otherwise the tools used to 
apply patches from emails will pick on that "diff" above as if it was 
the actual patch and discard everything that follows it.


Nicolas

[PATCH] Fix booting pre-ARM6 machines

[Uwe Kleine-König]

Hi Nicolas,

> I've sent the same patch directly to Linus already in the hope that 
> he'll merge it before -rc1.
OK.

> Also you should avoid quoting patch hunks without indenting them or 
> prefixing them with some quotation mark, otherwise the tools used to 
> apply patches from emails will pick on that "diff" above as if it was 
> the actual patch and discard everything that follows it.
ah, right.  Thanks for the hint.

Best regards
Uwe

-- 
Pengutronix e.K.                              | Uwe Kleine-K?nig            |
Industrial Linux Solutions                    | http://www.pengutronix.de/  |

[PATCH] Fix booting pre-ARM6 machines

[Ben Dooks]

On Fri, Sep 25, 2009 at 10:54:24PM +0200, Uwe Kleine-K?nig wrote:
> Commit 200b812d0084f800bc52465e273b118ff5f8141f includes the following
> hunk:
> 
> diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
> index a4eaf4f..e17e3c3 100644
> --- a/arch/arm/kernel/entry-header.S
> +++ b/arch/arm/kernel/entry-header.S
> @@ -76,13 +76,25 @@
>  #ifndef CONFIG_THUMB2_KERNEL
>  	.macro	svc_exit, rpsr
>  	msr	spsr_cxsf, \rpsr
> +#if defined(CONFIG_CPU_32v6K)
> +	clrex					@ clear the exclusive monitor
>  	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
> +#elif defined (CONFIG_CPU_V6)
> +	ldr	r0, [sp]
> +	strex	r1, r2, [sp]			@ clear the exclusive monitor
> +	ldmib	sp, {r1 - pc}^			@ load r1 - pc, cpsr
> +#endif

hmm, this really shouldn'y be selected at compile time as what if we have
a kernel which supports V6 or later and pre-V6 in one image?

>  	.endm
> 
>  	.macro	restore_user_regs, fast = 0, offset = 0
> 
> Having neither CONFIG_THUMB2_KERNEL nor CONFIG_CPU_32v6K nor
> CONFIG_CPU_V6 this steals the ldmia instruction.  The result is that
> svc_exit doesn't work at all.  So reintroduce it.
> 
> Signed-off-by: Uwe Kleine-K?nig <u.kleine-koenig@pengutronix.de>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Jamie Lokier <jamie@shareable.org>
> ---
>  arch/arm/kernel/entry-header.S |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
> index e17e3c3..ac34c0d 100644
> --- a/arch/arm/kernel/entry-header.S
> +++ b/arch/arm/kernel/entry-header.S
> @@ -83,6 +83,8 @@
>  	ldr	r0, [sp]
>  	strex	r1, r2, [sp]			@ clear the exclusive monitor
>  	ldmib	sp, {r1 - pc}^			@ load r1 - pc, cpsr
> +#else
> +	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
>  #endif
>  	.endm
>  
> -- 
> 1.6.4.3
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

-- 
-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.