Re: [PATCH 3/5] irqchip: gicv3-its: use 64KB page as default granule

From: Marc Zyngier
Date: Fri Jan 30 2015 - 14:18:43 EST


On 30/01/15 07:46, Yun Wu wrote:
> The field of page size in register GITS_BASERn might be read-only
> if an implementation only supports a single, fixed page size. But
> currently the ITS driver will throw out an error when PAGE_SIZE
> is less than the minimum size supported by an ITS. So addressing
> this problem by using 64KB pages as default granule for all the
> ITS base tables.

Do you actually know of an implementation with such a behaviour?

> Signed-off-by: Yun Wu <wuyun.wu@xxxxxxxxxx>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 2a08d85..430bc92 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -801,7 +801,7 @@ static int its_alloc_tables(struct its_node *its)
> int err;
> int i;
> int size;
> - int psz = PAGE_SIZE;
> + int psz = SZ_64K;
> u64 shr = GITS_BASER_InnerShareable;
>
> for (i = 0; i < GITS_BASER_NR_REGS; i++) {

Assuming such an implementation exists, you'll have to rebase this on
top of the patch I mentioned in my reply to patch #1.

Thanks,

M.
--
Jazz is not dead. It just smells funny...
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