Re: [PATCH v5 08/23] irqchip/gic-v4.1: Plumb skeletal VSGI irqchip

Auger Eric
2020-03-16T17:34:55Z

Hi Marc,

On 3/4/20 9:33 PM, Marc Zyngier wrote:
> Since GICv4.1 has the capability to inject 16 SGIs into each VPE,
> and that I'm keen not to invent too many specific interfaces to
> manipulate these interrupts, let's pretend that each of these SGIs
> is an actual Linux interrupt.
>
> For that matter, let's introduce a minimal irqchip and irqdomain
> setup that will get fleshed up in the following patches.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 68 +++++++++++++++++++++++++++++-
> drivers/irqchip/irq-gic-v4.c | 8 +++-
> include/linux/irqchip/arm-gic-v4.h | 9 +++-
> 3 files changed, 81 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 54d6fdf7a28e..112b452fcb40 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -3870,6 +3870,67 @@ static struct irq_chip its_vpe_4_1_irq_chip = {
> .irq_set_vcpu_affinity = its_vpe_4_1_set_vcpu_affinity,
> };
>
> +static int its_sgi_set_affinity(struct irq_data *d,
> + const struct cpumask *mask_val,
> + bool force)
> +{
> + return -EINVAL;
> +}
> +
> +static struct irq_chip its_sgi_irq_chip = {
> + .name = "GICv4.1-sgi",
> + .irq_set_affinity = its_sgi_set_affinity,
> +};
nit: const?
> +
> +static int its_sgi_irq_domain_alloc(struct irq_domain *domain,
> + unsigned int virq, unsigned int nr_irqs,
> + void *args)
> +{
> + struct its_vpe *vpe = args;
> + int i;
> +
> + /* Yes, we do want 16 SGIs */
> + WARN_ON(nr_irqs != 16);
> +
> + for (i = 0; i < 16; i++) {
> + vpe->sgi_config[i].priority = 0;
> + vpe->sgi_config[i].enabled = false;
> + vpe->sgi_config[i].group = false;
> +
> + irq_domain_set_hwirq_and_chip(domain, virq + i, i,
> + &its_sgi_irq_chip, vpe);
> + irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> + }
> +
> + return 0;
> +}
> +
> +static void its_sgi_irq_domain_free(struct irq_domain *domain,
> + unsigned int virq,
> + unsigned int nr_irqs)
> +{
> + /* Nothing to do */
> +}
> +
> +static int its_sgi_irq_domain_activate(struct irq_domain *domain,
> + struct irq_data *d, bool reserve)
> +{
> + return 0;
> +}
> +
> +static void its_sgi_irq_domain_deactivate(struct irq_domain *domain,
> + struct irq_data *d)
> +{
> + /* Nothing to do */
> +}
> +
> +static struct irq_domain_ops its_sgi_domain_ops = {
> + .alloc = its_sgi_irq_domain_alloc,
> + .free = its_sgi_irq_domain_free,
> + .activate = its_sgi_irq_domain_activate,
> + .deactivate = its_sgi_irq_domain_deactivate,
> +};
nit: const?
> +
> static int its_vpe_id_alloc(void)
> {
> return ida_simple_get(&its_vpeid_ida, 0, ITS_MAX_VPEID, GFP_KERNEL);
> @@ -4912,8 +4973,13 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
> rdists->has_rvpeid = false;
>
> if (has_v4 & rdists->has_vlpis) {
> + struct irq_domain_ops *sgi_ops = NULL;
> +
> + if (has_v4_1)
> + sgi_ops = &its_sgi_domain_ops;
> +
> if (its_init_vpe_domain() ||
> - its_init_v4(parent_domain, &its_vpe_domain_ops)) {
> + its_init_v4(parent_domain, &its_vpe_domain_ops, sgi_ops)) {
> rdists->has_vlpis = false;
> pr_err("ITS: Disabling GICv4 support\n");
> }
> diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
> index 45969927cc81..c01910d53f9e 100644
> --- a/drivers/irqchip/irq-gic-v4.c
> +++ b/drivers/irqchip/irq-gic-v4.c
> @@ -85,6 +85,7 @@
>
> static struct irq_domain *gic_domain;
> static const struct irq_domain_ops *vpe_domain_ops;
> +static const struct irq_domain_ops *sgi_domain_ops;
>
> int its_alloc_vcpu_irqs(struct its_vm *vm)
> {
> @@ -216,12 +217,15 @@ int its_prop_update_vlpi(int irq, u8 config, bool inv)
> return irq_set_vcpu_affinity(irq, &info);
> }
>
> -int its_init_v4(struct irq_domain *domain, const struct irq_domain_ops *ops)
> +int its_init_v4(struct irq_domain *domain,
> + const struct irq_domain_ops *vpe_ops,
> + const struct irq_domain_ops *sgi_ops)
> {
> if (domain) {
> pr_info("ITS: Enabling GICv4 support\n");
> gic_domain = domain;
> - vpe_domain_ops = ops;
> + vpe_domain_ops = vpe_ops;
> + sgi_domain_ops = sgi_ops;
> return 0;
> }
>
> diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
> index 439963f4c66a..44e8c19e3d56 100644
> --- a/include/linux/irqchip/arm-gic-v4.h
> +++ b/include/linux/irqchip/arm-gic-v4.h
> @@ -49,6 +49,11 @@ struct its_vpe {
> };
> /* GICv4.1 implementations */
> struct {
> + struct {
> + u8 priority;
> + bool enabled;
> + bool group;
> + } sgi_config[16];
> atomic_t vmapp_count;
> };
> };
> @@ -123,6 +128,8 @@ int its_unmap_vlpi(int irq);
> int its_prop_update_vlpi(int irq, u8 config, bool inv);
>
> struct irq_domain_ops;
> -int its_init_v4(struct irq_domain *domain, const struct irq_domain_ops *ops);
> +int its_init_v4(struct irq_domain *domain,
> + const struct irq_domain_ops *vpe_ops,
> + const struct irq_domain_ops *sgi_ops);
>
> #endif
>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric