[PATCH 3/5] ARM: ensure irqs are disabled at barebox exit
Sascha Hauer
s.hauer at pengutronix.de
Sun Oct 14 04:57:33 EDT 2012
On Sat, Oct 13, 2012 at 04:03:25PM +0200, Vicente wrote:
>
> Signed-off-by: Vicente <vicencb at gmail.com>
> ---
> arch/arm/cpu/cpu.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/arch/arm/cpu/cpu.c b/arch/arm/cpu/cpu.c
> index 51da3b5..2bfd3ed 100644
> --- a/arch/arm/cpu/cpu.c
> +++ b/arch/arm/cpu/cpu.c
> @@ -31,6 +31,7 @@
> #include <asm/system_info.h>
> #include <asm/cputype.h>
> #include <asm/cache.h>
> +#include <asm/ptrace.h>
>
> /**
> * Enable processor's instruction cache
> @@ -78,6 +79,16 @@ void arch_shutdown(void)
> mmu_disable();
> #endif
> flush_icache();
> + /*
> + * barebox normally does not use interrupts, but some functionalities
> + * (eg. OMAP4_USBBOOT) require them enabled. So be sure interrupts are
> + * disabled before exiting.
> + */
> +#if __LINUX_ARM_ARCH__ >= 6
> + __asm__ __volatile__("cpsid i");
> +#else
> + __asm__ __volatile__("msr cpsr_c, %0" : : "I"(PSR_I_BIT | SVC_MODE));
> +#endif
This won't work with multi ARM architecture support and also does not
compile in Thumb2 mode. So I suggest to do:
diff --git a/arch/arm/cpu/cpu.c b/arch/arm/cpu/cpu.c
index 25a0893..1328f0e 100644
--- a/arch/arm/cpu/cpu.c
+++ b/arch/arm/cpu/cpu.c
@@ -87,6 +87,23 @@ void arch_shutdown(void)
: "r0", "r1", "r2", "r3", "r6", "r10", "r12", "lr", "cc", "memory"
);
#endif
+
+ /*
+ * barebox normally does not use interrupts, but some functionalities
+ * (eg. OMAP4_USBBOOT) require them enabled. So be sure interrupts are
+ * disabled before exiting.
+ */
+ if (cpu_architecture() >= CPU_ARCH_ARMv6) {
+#if __LINUX_ARM_ARCH__ >= 6
+ __asm__ __volatile__("cpsid i");
+#endif
+ } else {
+ uint32_t r;
+
+ __asm__ __volatile__("mrs %0, cpsr":"=r"(r));
+ r |= PSR_I_BIT;
+ __asm__ __volatile__("msr cpsr, %0" : : "r"(r));
+ }
}
#ifdef CONFIG_THUMB2_BAREBOX
Or the following which is simpler as it doesn't use the cpsid
instruction which is only available on >= ARMv6:
diff --git a/arch/arm/cpu/cpu.c b/arch/arm/cpu/cpu.c
index 25a0893..bfad49d 100644
--- a/arch/arm/cpu/cpu.c
+++ b/arch/arm/cpu/cpu.c
@@ -73,6 +73,8 @@ int icache_status(void)
*/
void arch_shutdown(void)
{
+ uint32_t r;
+
#ifdef CONFIG_MMU
/* nearly the same as below, but this could also disable
* second level cache.
@@ -87,6 +89,15 @@ void arch_shutdown(void)
: "r0", "r1", "r2", "r3", "r6", "r10", "r12", "lr", "cc", "memory"
);
#endif
+
+ /*
+ * barebox normally does not use interrupts, but some functionalities
+ * (eg. OMAP4_USBBOOT) require them enabled. So be sure interrupts are
+ * disabled before exiting.
+ */
+ __asm__ __volatile__("mrs %0, cpsr":"=r"(r));
+ r |= PSR_I_BIT;
+ __asm__ __volatile__("msr cpsr, %0" : : "r"(r));
}
#ifdef CONFIG_THUMB2_BAREBOX
Sascha
--
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