Re: [PATCH 06/11] irqchip/gic-v3: Configure SGIs as standard interrupts

Sumit Garg
2020-05-20T09:52:29Z

Hi Marc,

On Tue, 19 May 2020 at 21:48, Marc Zyngier <maz@kernel.org> wrote:
>
> Change the way we deal with GICv3 SGIs by turning them into proper
> IRQs, and calling into the arch code to register the interrupt range
> instead of a callback.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/irqchip/irq-gic-v3.c | 91 +++++++++++++++++++++---------------
> 1 file changed, 53 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> index 23d7c87da407..d57289057b75 100644
> --- a/drivers/irqchip/irq-gic-v3.c
> +++ b/drivers/irqchip/irq-gic-v3.c
> @@ -36,6 +36,9 @@
> #define FLAGS_WORKAROUND_GICR_WAKER_MSM8996 (1ULL << 0)
> #define FLAGS_WORKAROUND_CAVIUM_ERRATUM_38539 (1ULL << 1)
>
> +#define GIC_IRQ_TYPE_PARTITION (GIC_IRQ_TYPE_LPI + 1)
> +#define GIC_IRQ_TYPE_SGI (GIC_IRQ_TYPE_LPI + 2)
> +
> struct redist_region {
> void __iomem *redist_base;
> phys_addr_t phys_base;
> @@ -657,38 +660,14 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs
> if ((irqnr >= 1020 && irqnr <= 1023))
> return;
>
> - /* Treat anything but SGIs in a uniform way */
> - if (likely(irqnr > 15)) {
> - int err;
> -
> - if (static_branch_likely(&supports_deactivate_key))
> - gic_write_eoir(irqnr);
> - else
> - isb();
> -
> - err = handle_domain_irq(gic_data.domain, irqnr, regs);
> - if (err) {
> - WARN_ONCE(true, "Unexpected interrupt received!\n");
> - gic_deactivate_unhandled(irqnr);
> - }
> - return;
> - }
> - if (irqnr < 16) {
> + if (static_branch_likely(&supports_deactivate_key))
> gic_write_eoir(irqnr);
> - if (static_branch_likely(&supports_deactivate_key))
> - gic_write_dir(irqnr);
> -#ifdef CONFIG_SMP
> - /*
> - * Unlike GICv2, we don't need an smp_rmb() here.
> - * The control dependency from gic_read_iar to
> - * the ISB in gic_write_eoir is enough to ensure
> - * that any shared data read by handle_IPI will
> - * be read after the ACK.
> - */
> - handle_IPI(irqnr, regs);
> -#else
> - WARN_ONCE(true, "Unexpected SGI received!\n");
> -#endif
> + else
> + isb();
> +
> + if (handle_domain_irq(gic_data.domain, irqnr, regs)) {
> + WARN_ONCE(true, "Unexpected interrupt received!\n");
> + gic_deactivate_unhandled(irqnr);
> }
> }
>
> @@ -1136,11 +1115,11 @@ static void gic_send_sgi(u64 cluster_id, u16 tlist, unsigned int irq)
> gic_write_sgi1r(val);
> }
>
> -static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
> +static void gic_ipi_send_mask(struct irq_data *d, const struct cpumask *mask)
> {
> int cpu;
>
> - if (WARN_ON(irq >= 16))
> + if (WARN_ON(d->hwirq >= 16))
> return;
>
> /*
> @@ -1154,7 +1133,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
> u16 tlist;
>
> tlist = gic_compute_target_list(&cpu, mask, cluster_id);
> - gic_send_sgi(cluster_id, tlist, irq);
> + gic_send_sgi(cluster_id, tlist, d->hwirq);
> }
>
> /* Force the above writes to ICC_SGI1R_EL1 to be executed */
> @@ -1163,10 +1142,36 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
>
> static void gic_smp_init(void)
> {
> - set_smp_cross_call(gic_raise_softirq);
> + struct irq_fwspec sgi_fwspec = {
> + .fwnode = gic_data.fwnode,
> + };
> + int base_sgi;
> +
> cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING,
> "irqchip/arm/gicv3:starting",
> gic_starting_cpu, NULL);
> +
> + if (is_of_node(gic_data.fwnode)) {
> + /* DT */
> + sgi_fwspec.param_count = 3;
> + sgi_fwspec.param[0] = GIC_IRQ_TYPE_SGI;
> + sgi_fwspec.param[1] = 0;
> + sgi_fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
> + } else {
> + /* ACPI */
> + sgi_fwspec.param_count = 2;
> + sgi_fwspec.param[0] = 0;
> + sgi_fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
> + }
> +
> + /* Register all 8 non-secure SGIs */
> + base_sgi = __irq_domain_alloc_irqs(gic_data.domain, -1, 8,
> + NUMA_NO_NODE, &sgi_fwspec,
> + false, NULL);
> + if (WARN_ON(base_sgi <= 0))
> + return;
> +
> + set_smp_ipi_range(base_sgi, 8);
> }
>
> static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
> @@ -1215,6 +1220,7 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
> }
> #else
> #define gic_set_affinity NULL
> +#define gic_ipi_send_mask NULL
> #define gic_smp_init() do { } while(0)
> #endif
>
> @@ -1257,6 +1263,7 @@ static struct irq_chip gic_chip = {
> .irq_set_irqchip_state = gic_irq_set_irqchip_state,
> .irq_nmi_setup = gic_irq_nmi_setup,
> .irq_nmi_teardown = gic_irq_nmi_teardown,
> + .ipi_send_mask = gic_ipi_send_mask,
> .flags = IRQCHIP_SET_TYPE_MASKED |
> IRQCHIP_SKIP_SET_WAKE |
> IRQCHIP_MASK_ON_SUSPEND,

It looks like you missed to update "struct irq_chip gic_eoimode1_chip"
with similar change as follows:

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 2a09634..ceef63b 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1291,6 +1291,7 @@ static struct irq_chip gic_eoimode1_chip = {
.irq_set_vcpu_affinity = gic_irq_set_vcpu_affinity,
.irq_nmi_setup = gic_irq_nmi_setup,
.irq_nmi_teardown = gic_irq_nmi_teardown,
+ .ipi_send_mask = gic_ipi_send_mask,
.flags = IRQCHIP_SET_TYPE_MASKED |
IRQCHIP_SKIP_SET_WAKE |
IRQCHIP_MASK_ON_SUSPEND,

After incorporating this change, your patch-set works fine on my
Developerbox machine.

-Sumit

> @@ -1289,6 +1296,13 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
>
> switch (__get_intid_range(hw)) {
> case SGI_RANGE:
> + irq_set_percpu_devid(irq);
> + irq_domain_set_info(d, irq, hw, chip, d->host_data,
> + handle_percpu_devid_fasteoi_ipi,
> + NULL, NULL);
> + irq_set_status_flags(irq, IRQ_NOAUTOEN);
> + break;
> +
> case PPI_RANGE:
> case EPPI_RANGE:
> irq_set_percpu_devid(irq);
> @@ -1319,8 +1333,6 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
> return 0;
> }
>
> -#define GIC_IRQ_TYPE_PARTITION (GIC_IRQ_TYPE_LPI + 1)
> -
> static int gic_irq_domain_translate(struct irq_domain *d,
> struct irq_fwspec *fwspec,
> unsigned long *hwirq,
> @@ -1353,6 +1365,9 @@ static int gic_irq_domain_translate(struct irq_domain *d,
> else
> *hwirq += 16;
> break;
> + case GIC_IRQ_TYPE_SGI:
> + *hwirq = fwspec->param[1];
> + break;
> default:
> return -EINVAL;
> }
> @@ -1657,9 +1672,9 @@ static int __init gic_init_bases(void __iomem *dist_base,
>
> gic_update_rdist_properties();
>
> - gic_smp_init();
> gic_dist_init();
> gic_cpu_init();
> + gic_smp_init();
> gic_cpu_pm_init();
>
> if (gic_dist_supports_lpis()) {
> --
> 2.26.2
>