2020-02-04 09:12:50

by Zenghui Yu

Subject: [PATCH 1/5] irqchip/gic-v4.1: Fix programming of GICR_VPROPBASER_4_1_SIZE

The Size field of GICv4.1 VPROPBASER register indicates number of
pages minus one and together Page_Size and Size control the vPEID
width. Let's respect this requirement of the architecture.

Signed-off-by: Zenghui Yu <[email protected]>
---
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 e5a25d97f8db..992bc72cab6f 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2531,7 +2531,7 @@ static int allocate_vpe_l1_table(void)
npg = 1;
}

- val |= FIELD_PREP(GICR_VPROPBASER_4_1_SIZE, npg);
+ val |= FIELD_PREP(GICR_VPROPBASER_4_1_SIZE, npg - 1);

/* Right, that's the number of CPU pages we need for L1 */
np = DIV_ROUND_UP(npg * psz, PAGE_SIZE);
--
2.19.1

2020-02-05 12:45:42

by Marc Zyngier

Subject: Re: [PATCH 1/5] irqchip/gic-v4.1: Fix programming of GICR_VPROPBASER_4_1_SIZE

On 2020-02-04 09:09, Zenghui Yu wrote:
> The Size field of GICv4.1 VPROPBASER register indicates number of
> pages minus one and together Page_Size and Size control the vPEID
> width. Let's respect this requirement of the architecture.
>
> Signed-off-by: Zenghui Yu <[email protected]>
> ---
> 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 e5a25d97f8db..992bc72cab6f 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -2531,7 +2531,7 @@ static int allocate_vpe_l1_table(void)
> npg = 1;
> }
>
> - val |= FIELD_PREP(GICR_VPROPBASER_4_1_SIZE, npg);
> + val |= FIELD_PREP(GICR_VPROPBASER_4_1_SIZE, npg - 1);
>
> /* Right, that's the number of CPU pages we need for L1 */
> np = DIV_ROUND_UP(npg * psz, PAGE_SIZE);

Indeed, nice catch.

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