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From: catalin.marinas@arm.com (Catalin Marinas)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 4/5] Cortex-M3: Add base support for Cortex-M3
Date: Thu, 8 Mar 2012 10:52:46 +0000	[thread overview]
Message-ID: <20120308105246.GC26727@arm.com> (raw)
In-Reply-To: <1330967042-25612-1-git-send-email-u.kleine-koenig@pengutronix.de>

Hi Uwe,

On Mon, Mar 05, 2012 at 05:04:01PM +0000, Uwe Kleine-K?nig wrote:
> --- a/arch/arm/include/asm/processor.h
> +++ b/arch/arm/include/asm/processor.h
> @@ -49,7 +49,15 @@ struct thread_struct {
>  #ifdef CONFIG_MMU
>  #define nommu_start_thread(regs) do { } while (0)
>  #else
> +#ifndef CONFIG_CPU_V7M
>  #define nommu_start_thread(regs) regs->ARM_r10 = current->mm->start_data
> +#else
> +#define nommu_start_thread(regs) do {                                  \
> +       regs->ARM_r10 = current->mm->start_data;                        \
> +       regs->ARM_sp -= 32;             /* exception return state */    \
> +       regs->ARM_EXCRET = 0xfffffffdL;                                 \
> +} while (0)
...
> --- a/arch/arm/include/asm/ptrace.h
> +++ b/arch/arm/include/asm/ptrace.h
> @@ -39,16 +39,25 @@
> @@ -127,7 +136,11 @@ struct pt_regs {
>  #define ARM_r2         uregs[2]
>  #define ARM_r1         uregs[1]
>  #define ARM_r0         uregs[0]
> +#if defined CONFIG_CPU_V7M
> +#define ARM_EXCRET     uregs[17]
> +#else
>  #define ARM_ORIG_r0    uregs[17]
> +#endif

Could we save the exception return somewhere in thread_info and preserve
ORIG_r0?

Alternatively, with some care, we could extend the kernel pt_regs
definition with two more registers and use one of them for exception
return. The user variant would remain the same as it's used by ptrace.

-- 
Catalin

  parent reply	other threads:[~2012-03-08 10:52 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-22 11:12 [RFC PATCH 00/11] Cortex-M3 support Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 01/11] ARM: only show modules in the memory layout for MODULES=y Uwe Kleine-König
2012-01-26  6:16   ` Linus Walleij
2012-01-22 11:13 ` [RFC PATCH 02/11] ARM: add device tree blobs to .gitignore Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 03/11] ARM: protect usage of cr_alignment by #ifdef CONFIG_CPU_CP15 Uwe Kleine-König
2012-01-23  5:43   ` Jean-Christophe PLAGNIOL-VILLARD
2012-01-23  8:14     ` Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 04/11] ARM: Add a printk loglevel modifier Uwe Kleine-König
2012-01-23  5:50   ` Jean-Christophe PLAGNIOL-VILLARD
2012-01-22 11:13 ` [RFC PATCH 05/11] ARM: provide XIP_VIRT_ADDR for no-MMU builds Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 06/11] Cortex-M3: Add base support for Cortex-M3 Uwe Kleine-König
2012-01-22 19:45   ` Michał Mirosław
2012-01-22 20:42     ` Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 07/11] Cortex-M3: Add support for exception handling Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 08/11] Cortex-M3: Add NVIC support Uwe Kleine-König
2012-01-31 19:39   ` Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 09/11] Cortex-M3: Allow the building of Cortex-M3 kernel port Uwe Kleine-König
2012-01-22 20:05   ` Michał Mirosław
2012-02-07 19:43     ` Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 10/11] Cortex-M3: Add VFP support Uwe Kleine-König
2012-01-22 11:13 ` [RFC PATCH 11/11] HACK! ARM: no, we don't enter in ARM Uwe Kleine-König
2012-02-07 20:18 ` [RFC PATCH 00/11] Cortex-M3 support Uwe Kleine-König
2012-02-16 20:01   ` Uwe Kleine-König
2012-02-16 20:18     ` [PATCH 1/5] ARM: protect usage of cr_alignment by #ifdef CONFIG_CPU_CP15 Uwe Kleine-König
2012-02-16 20:18       ` [PATCH 2/5] ARM: Add a printk loglevel modifier Uwe Kleine-König
2012-02-16 20:18       ` [PATCH 3/5] ARM: force branch instructions to use long distance encoding Uwe Kleine-König
2012-02-16 20:18       ` [PATCH 4/5] ARM: Cortex-M3: Add base support for Cortex-M3 Uwe Kleine-König
2012-02-16 20:18       ` [PATCH 5/5] ARM: Cortex-M3: Add support for exception handling Uwe Kleine-König
2012-02-16 22:20         ` Russell King - ARM Linux
2012-02-24 22:01           ` Uwe Kleine-König
2012-02-24 22:12             ` Catalin Marinas
2012-02-24 22:43               ` Russell King - ARM Linux
2012-02-25  8:49                 ` Catalin Marinas
2012-02-25 14:07               ` Uwe Kleine-König
2012-03-05 17:04               ` [PATCH v2 4/5] Cortex-M3: Add base support for Cortex-M3 Uwe Kleine-König
2012-03-05 17:04                 ` [PATCH v2 5/5] Cortex-M3: Add support for exception handling Uwe Kleine-König
2012-03-09 17:10                   ` Catalin Marinas
2012-03-13 20:39                     ` Uwe Kleine-König
2012-03-08 10:52                 ` Catalin Marinas [this message]
2012-02-17  0:28       ` [PATCH 1/5] ARM: protect usage of cr_alignment by #ifdef CONFIG_CPU_CP15 Ryan Mallon

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