[U-Boot] [PATCH v4 4/4] arm: interrupt_init: set sp in IRQ/FIQ modes

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hello Georges,

On Tue, 28 Oct 2014 23:16:12 +0100, Georges Savoundararadj <savoundg@gmail.com> wrote:
> Before this commit, the stack addresses for IRQ and FIQ modes,
> IRQ_STACK_START and FIQ_STACK_START, were computed in interrupt_init but
> they were not used.
> 
> This commit sets the stack pointers for IRQ and FIQ modes.
> 
> Signed-off-by: Georges Savoundararadj <savoundg@gmail.com>
> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
> 
> ---
> 
> Changes in v4:
> - Restore initial CPSR value after configuring SP in IRQ and FIQ modes
> 
> Changes in v3: None
> Changes in v2:
> - Reword the commit message
> 
>  arch/arm/lib/interrupts.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/arch/arm/lib/interrupts.c b/arch/arm/lib/interrupts.c
> index 9019736..4dacfd9 100644
> --- a/arch/arm/lib/interrupts.c
> +++ b/arch/arm/lib/interrupts.c
> @@ -28,6 +28,8 @@ DECLARE_GLOBAL_DATA_PTR;
>  #ifdef CONFIG_USE_IRQ
>  int interrupt_init (void)
>  {
> +	unsigned long cpsr;
> +
>  	/*
>  	 * setup up stacks if necessary
>  	 */
> @@ -35,6 +37,31 @@ int interrupt_init (void)
>  	IRQ_STACK_START_IN = gd->irq_sp + 8;
>  	FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ;
>  
> +
> +	__asm__ __volatile__("mrs %0, cpsr\n"
> +			     : "=r" (cpsr)
> +			     :
> +			     : "memory");
> +
> +	__asm__ __volatile__("msr cpsr_c, %0\n"
> +			     "mov sp, %1\n"
> +			     :
> +			     : "r" (IRQ_MODE | I_BIT | F_BIT | (cpsr & ~FIQ_MODE)),
> +			       "r" (IRQ_STACK_START)
> +			     : "memory");
> +
> +	__asm__ __volatile__("msr cpsr_c, %0\n"
> +			     "mov sp, %1\n"
> +			     :
> +			     : "r" (FIQ_MODE | I_BIT | F_BIT | (cpsr & ~IRQ_MODE)),
> +			       "r" (FIQ_STACK_START)
> +			     : "memory");
> +
> +	__asm__ __volatile__("msr cpsr_c, %0"
> +			     :
> +			     : "r" (cpsr)
> +			     : "memory");
> +
>  	return arch_interrupt_init();
>  }
>  
> -- 
> 2.1.2
> 

Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net>

Amicalement,
-- 
Albert.