Subject: [PATCH v2] ARM: Add imprecise abort enable/disable macro

From: [email-masked] (Fabrice GASNIER)
Date: Wed, 12 Feb 2014 14:05:39 +0100

Hi,

Any comments on this patch ?

Russell, can I add this patch to your patch tracker system ?

Thanks,
Fabrice

On 02/10/2014 05:45 PM, Fabrice GASNIER wrote:
> This patch adds imprecise abort enable/disable macros.
> It also enables imprecise aborts when starting kernel.
>
> Changes in v2:
> Only ARMv6 and later have CPSR.A bit. On earlier CPUs,
> and ARMv7M this should be a no-op.
>
> Signed-off-by: Fabrice Gasnier <[email-masked]>
> ---
>   arch/arm/include/asm/irqflags.h |   10 ++++++++++
>   arch/arm/kernel/smp.c           |    1 +
>   arch/arm/kernel/traps.c         |    4 ++++
>   3 files changed, 15 insertions(+)
>
> diff --git a/arch/arm/include/asm/irqflags.h b/arch/arm/include/asm/irqflags.h
> index 3b763d6..8301f87 100644
> --- a/arch/arm/include/asm/irqflags.h
> +++ b/arch/arm/include/asm/irqflags.h
> @@ -51,6 +51,14 @@ static inline void arch_local_irq_disable(void)
>   
>   #define local_fiq_enable()  __asm__("cpsie f	@ __stf" : : : "memory", "cc")
>   #define local_fiq_disable() __asm__("cpsid f	@ __clf" : : : "memory", "cc")
> +
> +#ifndef CONFIG_CPU_V7M
> +#define local_abt_enable()  __asm__("cpsie a	@ __sta" : : : "memory", "cc")
> +#define local_abt_disable() __asm__("cpsid a	@ __cla" : : : "memory", "cc")
> +#else
> +#define local_abt_enable()	do { } while (0)
> +#define local_abt_disable()	do { } while (0)
> +#endif
>   #else
>   
>   /*
> @@ -130,6 +138,8 @@ static inline void arch_local_irq_disable(void)
>   	: "memory", "cc");					\
>   	})
>   
> +#define local_abt_enable()	do { } while (0)
> +#define local_abt_disable()	do { } while (0)
>   #endif
>   
>   /*
> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
> index dc894ab..c2093cb 100644
> --- a/arch/arm/kernel/smp.c
> +++ b/arch/arm/kernel/smp.c
> @@ -377,6 +377,7 @@ asmlinkage void secondary_start_kernel(void)
>   
>   	local_irq_enable();
>   	local_fiq_enable();
> +	local_abt_enable();
>   
>   	/*
>   	 * OK, it's off to the idle thread for us
> diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
> index 4636d56..ef15709 100644
> --- a/arch/arm/kernel/traps.c
> +++ b/arch/arm/kernel/traps.c
> @@ -900,6 +900,10 @@ void __init early_trap_init(void *vectors_base)
>   
>   	flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
>   	modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
> +
> +	/* Enable imprecise aborts */
> +	local_abt_enable();
> +
>   #else /* ifndef CONFIG_CPU_V7M */
>   	/*
>   	 * on V7-M there is no need to copy the vector table to a dedicated