Re: [RFC PATCH 24/33] irqchip/gic-v3-its: Add VPE scheduling

From: Auger Eric
Date: Thu Mar 16 2017 - 17:34:29 EST


Hi,

On 17/01/2017 11:20, Marc Zyngier wrote:
> When a VPE is scheduled to run, the corresponding redistributor must
> be told so, by setting VPROPBASER to the VM's property table, and
> VPENDBASER to the vcpu's pending table.
>
> When scheduled out, we preserve the IDAI and PendingLast bits. The
> latter is specially important, as it tells the hypervisor that
> there are pending interrupts for this vcpu.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 57 ++++++++++++++++++++++++++++++++++
> include/linux/irqchip/arm-gic-v3.h | 63 ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 120 insertions(+)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 598e25b..f918d59 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -143,6 +143,7 @@ static DEFINE_IDA(its_vpeid_ida);
>
> #define gic_data_rdist() (raw_cpu_ptr(gic_rdists->rdist))
> #define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base)
> +#define gic_data_rdist_vlpi_base() (gic_data_rdist_rd_base() + SZ_128K)
>
> static struct its_collection *dev_event_to_col(struct its_device *its_dev,
> u32 event)
> @@ -2039,8 +2040,64 @@ static const struct irq_domain_ops its_domain_ops = {
> .deactivate = its_irq_domain_deactivate,
> };
>
> +static int its_vpe_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
> +{
> + struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
> + struct its_cmd_info *info = vcpu_info;
> + u64 val;
> +
> + switch (info->cmd_type) {
> + case SCHEDULE_VPE:
> + {
> + void * __iomem vlpi_base = gic_data_rdist_vlpi_base();
> +
> + /* Schedule the VPE */
> + val = virt_to_phys(page_address(vpe->its_vm->vprop_page)) &
> + GENMASK_ULL(51, 12);
> + val |= (LPI_NRBITS - 1) & GICR_VPROPBASER_IDBITS_MASK;
> + val |= GICR_VPROPBASER_RaWb;
> + val |= GICR_VPROPBASER_InnerShareable;
> + gits_write_vpropbaser(val, vlpi_base + GICR_VPROPBASER);
> +
> + val = virt_to_phys(page_address(vpe->vpt_page)) & GENMASK(51, 16);
> + val |= GICR_VPENDBASER_WaWb;
> + val |= GICR_VPENDBASER_NonShareable;
> + val |= GICR_PENDBASER_PendingLast;
don't you want to restore the vpe->pending_last here? anyway I
understand this will force the HW to read the LPI pending table.

Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>

Eric

> + val |= vpe->idai ? GICR_PENDBASER_IDAI : 0;
> + val |= GICR_PENDBASER_Valid;
> + gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
> +
> + return 0;
> + }
> +
> + case DESCHEDULE_VPE:
> + {
> + void * __iomem vlpi_base = gic_data_rdist_vlpi_base();
> +
> + /* We're being scheduled out */
> + val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
> + val &= ~GICR_PENDBASER_Valid;
> + gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
> +
> + val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
> + while (val & GICR_PENDBASER_Dirty) {
> + cpu_relax();
> + val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
> + }
> +
> + vpe->idai = !!(val & GICR_PENDBASER_IDAI);
> + vpe->pending_last = !!(val & GICR_PENDBASER_PendingLast);
> + return 0;
> + }
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static struct irq_chip its_vpe_irq_chip = {
> .name = "GICv4-vpe",
> + .irq_set_vcpu_affinity = its_vpe_set_vcpu_affinity,
> };
>
> static int its_vpe_id_alloc(void)
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index 1b3a070..2789c9a 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -209,6 +209,69 @@
> #define LPI_PROP_ENABLED (1 << 0)
>
> /*
> + * Re-Distributor registers, offsets from VLPI_base
> + */
> +#define GICR_VPROPBASER 0x0070
> +
> +#define GICR_VPROPBASER_IDBITS_MASK 0x1f
> +
> +#define GICR_VPROPBASER_SHAREABILITY_SHIFT (10)
> +#define GICR_VPROPBASER_INNER_CACHEABILITY_SHIFT (7)
> +#define GICR_VPROPBASER_OUTER_CACHEABILITY_SHIFT (56)
> +
> +#define GICR_VPROPBASER_SHAREABILITY_MASK \
> + GIC_BASER_SHAREABILITY(GICR_VPROPBASER, SHAREABILITY_MASK)
> +#define GICR_VPROPBASER_INNER_CACHEABILITY_MASK \
> + GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, MASK)
> +#define GICR_VPROPBASER_OUTER_CACHEABILITY_MASK \
> + GIC_BASER_CACHEABILITY(GICR_VPROPBASER, OUTER, MASK)
> +#define GICR_VPROPBASER_CACHEABILITY_MASK \
> + GICR_VPROPBASER_INNER_CACHEABILITY_MASK
> +
> +#define GICR_VPROPBASER_InnerShareable \
> + GIC_BASER_SHAREABILITY(GICR_VPROPBASER, InnerShareable)
> +
> +#define GICR_VPROPBASER_nCnB GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, nCnB)
> +#define GICR_VPROPBASER_nC GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, nC)
> +#define GICR_VPROPBASER_RaWt GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, RaWt)
> +#define GICR_VPROPBASER_RaWb GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, RaWt)
> +#define GICR_VPROPBASER_WaWt GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, WaWt)
> +#define GICR_VPROPBASER_WaWb GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, WaWb)
> +#define GICR_VPROPBASER_RaWaWt GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, RaWaWt)
> +#define GICR_VPROPBASER_RaWaWb GIC_BASER_CACHEABILITY(GICR_VPROPBASER, INNER, RaWaWb)
> +
> +#define GICR_VPENDBASER 0x0078
> +
> +#define GICR_VPENDBASER_SHAREABILITY_SHIFT (10)
> +#define GICR_VPENDBASER_INNER_CACHEABILITY_SHIFT (7)
> +#define GICR_VPENDBASER_OUTER_CACHEABILITY_SHIFT (56)
> +#define GICR_VPENDBASER_SHAREABILITY_MASK \
> + GIC_BASER_SHAREABILITY(GICR_VPENDBASER, SHAREABILITY_MASK)
> +#define GICR_VPENDBASER_INNER_CACHEABILITY_MASK \
> + GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, MASK)
> +#define GICR_VPENDBASER_OUTER_CACHEABILITY_MASK \
> + GIC_BASER_CACHEABILITY(GICR_VPENDBASER, OUTER, MASK)
> +#define GICR_VPENDBASER_CACHEABILITY_MASK \
> + GICR_VPENDBASER_INNER_CACHEABILITY_MASK
> +
> +#define GICR_VPENDBASER_NonShareable \
> + GIC_BASER_SHAREABILITY(GICR_VPENDBASER, NonShareable)
> +
> +#define GICR_VPENDBASER_nCnB GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, nCnB)
> +#define GICR_VPENDBASER_nC GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, nC)
> +#define GICR_VPENDBASER_RaWt GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, RaWt)
> +#define GICR_VPENDBASER_RaWb GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, RaWt)
> +#define GICR_VPENDBASER_WaWt GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, WaWt)
> +#define GICR_VPENDBASER_WaWb GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, WaWb)
> +#define GICR_VPENDBASER_RaWaWt GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, RaWaWt)
> +#define GICR_VPENDBASER_RaWaWb GIC_BASER_CACHEABILITY(GICR_VPENDBASER, INNER, RaWaWb)
> +
> +#define GICR_PENDBASER_Dirty (1ULL << 60)
> +#define GICR_PENDBASER_PendingLast (1ULL << 61)
> +#define GICR_PENDBASER_IDAI (1ULL << 62)
> +#define GICR_PENDBASER_Valid (1ULL << 63)
> +
> +/*
> * ITS registers, offsets from ITS_base
> */
> #define GITS_CTLR 0x0000
>