diff mbox series

irqchip/gic-v4.1: Wait for completion of redistributor's INVALL operation

Message ID 20200302092145.899-1-yuzenghui@huawei.com (mailing list archive)
State Mainlined
Commit b978c25f6ee7d4c79cbe918eed684e53887ec001
Headers show
Series irqchip/gic-v4.1: Wait for completion of redistributor's INVALL operation | expand

Commit Message

Zenghui Yu March 2, 2020, 9:21 a.m. UTC
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 <yuzenghui@huawei.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Marc Zyngier March 2, 2020, 12:12 p.m. UTC | #1
On 2020-03-02 09:21, Zenghui Yu wrote:
> 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 <yuzenghui@huawei.com>
> ---
>  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 83b1186ffcad..fc8c2970cee4 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -3784,6 +3784,8 @@ 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)

Yup, well spotted. I'll add that to the series.

Thanks,

         M.
diff mbox series

Patch

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 83b1186ffcad..fc8c2970cee4 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3784,6 +3784,8 @@  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)