Re: [PATCH 11/16] xen: arm: Add debug keyhandler to dump the physical GIC state.

[Julien Grall <julien.grall@linaro.org>]

On 11/20/2013 02:48 PM, Ian Campbell wrote:
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>  xen/arch/arm/gic.c |   75 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 75 insertions(+)
> 
> diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
> index ab49106..185a6b8 100644
> --- a/xen/arch/arm/gic.c
> +++ b/xen/arch/arm/gic.c
> @@ -28,6 +28,7 @@
>  #include <xen/softirq.h>
>  #include <xen/list.h>
>  #include <xen/device_tree.h>
> +#include <xen/keyhandler.h>
>  #include <asm/p2m.h>
>  #include <asm/domain.h>
>  
> @@ -385,6 +386,77 @@ int gic_irq_xlate(const u32 *intspec, unsigned int intsize,
>      return 0;
>  }
>  
> +
> +static void do_dump_gic(unsigned char key)
> +{
> +    int irq;
> +    printk("'%c' pressed -> dumping GIC state\n", key);
> +
> +    for ( irq = 0; irq < gic.lines; irq++ )
> +    {
> +        const char *type;
> +        int type_nr, enable, pend, active, priority, target;
> +        struct irq_desc *desc = irq_to_desc(irq);
> +        uint8_t *bytereg;
> +        uint32_t wordreg;
> +
> +        bytereg = (uint8_t *) (GICD + GICD_ITARGETSR);
> +        target = bytereg[irq];
> +
> +        bytereg = (uint8_t *) (GICD + GICD_IPRIORITYR);
> +        priority = bytereg[irq];
> +
> +        switch ( irq )
> +        {
> +        case 0 ... 15:
> +            type = "SGI";
> +            type_nr = irq;
> +            target = 0x00; /* these are per-CPU */
> +            break;
> +        case 16 ... 31:
> +            type = "PPI";
> +            type_nr = irq - 16;
> +            break;

I think it's a bit stupid to print SGI and PPI as it's per-CPU
interrupt. With your solution, you don't know which CPU call the keyhandler.

Perhaps, you need to an SGI to each CPU?

-- 
Julien Grall