2020-03-04 20:36:36

by Marc Zyngier

Subject: [PATCH v5 04/23] irqchip/gic-v4.1: Wait for completion of redistributor's INVALL operation

From: Zenghui Yu <[email protected]>

In GICv4.1, we emulate a guest-issued INVALL command by a direct write
to GICR_INVALLR. Before we finish the emulation and go back to guest,
let's make sure the physical invalidate operation is actually completed
and no stale data will be left in redistributor. Per the specification,
this can be achieved by polling the GICR_SYNCR.Busy bit (to zero).

Signed-off-by: Zenghui Yu <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
drivers/irqchip/irq-gic-v3-its.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1af713990123..c84370245bea 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3827,6 +3827,8 @@ static void its_vpe_4_1_invall(struct its_vpe *vpe)
/* Target the redistributor this vPE is currently known on */
rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
gic_write_lpir(val, rdbase + GICR_INVALLR);
+
+ wait_for_syncr(rdbase);
}

static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
--
2.20.1

2020-03-20 14:26:27

by Eric Auger

Subject: Re: [PATCH v5 04/23] irqchip/gic-v4.1: Wait for completion of redistributor's INVALL operation

Hi,

On 3/4/20 9:33 PM, Marc Zyngier wrote:
> From: Zenghui Yu <[email protected]>
>
> In GICv4.1, we emulate a guest-issued INVALL command by a direct write
> to GICR_INVALLR. Before we finish the emulation and go back to guest,
> let's make sure the physical invalidate operation is actually completed
> and no stale data will be left in redistributor. Per the specification,
> this can be achieved by polling the GICR_SYNCR.Busy bit (to zero).
>
> Signed-off-by: Zenghui Yu <[email protected]>
> Signed-off-by: Marc Zyngier <[email protected]>
> Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Eric Auger <[email protected]>

Thanks

Eric
> ---
> drivers/irqchip/irq-gic-v3-its.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 1af713990123..c84370245bea 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -3827,6 +3827,8 @@ static void its_vpe_4_1_invall(struct its_vpe *vpe)
> /* Target the redistributor this vPE is currently known on */
> rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
> gic_write_lpir(val, rdbase + GICR_INVALLR);
> +
> + wait_for_syncr(rdbase);
> }
>
> static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
>