On Thu, Jun 05, 2014 at 11:53:09AM +0200, Daniel Thompson wrote:
This patch registers two virqs for each interrupt source it supports. Using multiple virqs allows the GIC driver to automatically modify the group register, allowing the new virqs to be used as argument to enable_fiq(). This also allows FIQ resources to be described in the device tree's interrupt list using a special flag (currently 0x80).
Both these aspects combine and allow a driver to deploy a FIQ handler without any machine specific knowledge; it can be used effectively on multi-arch kernels.
Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Jason Cooper jason@lakedaemon.net Cc: Nicolas Pitre nicolas.pitre@linaro.org Cc: Christoffer Dall christoffer.dall@linaro.org Cc: Sricharan R r.sricharan@ti.com
drivers/irqchip/irq-gic.c | 62 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 56 insertions(+), 6 deletions(-)
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index aa8efe4..9a4712d 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -42,12 +42,17 @@ #include <linux/irqchip/chained_irq.h> #include <linux/irqchip/arm-gic.h> +#ifdef CONFIG_FIQ +#include <asm/fiq.h> +#endif #include <asm/irq.h> #include <asm/exception.h> #include <asm/smp_plat.h> #include "irqchip.h" +#define GIC_INTSPEC_IRQ_IS_FIQ (1 << 7)
union gic_base { void __iomem *common_base; void __percpu * __iomem *percpu_base; @@ -65,6 +70,7 @@ struct gic_chip_data { #endif struct irq_domain *domain; unsigned int gic_irqs;
- unsigned int fiq_shadow_offset;
#ifdef CONFIG_GIC_NON_BANKED void __iomem *(*get_base)(union gic_base *); #endif @@ -143,11 +149,34 @@ static inline void __iomem *gic_cpu_base(struct irq_data *d) return gic_data_cpu_base(gic_data); } +static inline bool gic_is_fiq(struct irq_data *d) +{
- struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
- return d->hwirq > gic_data->gic_irqs;
+}
static inline unsigned int gic_irq(struct irq_data *d) {
- struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
- if (gic_is_fiq(d))
return d->hwirq - gic_data->fiq_shadow_offset;} +static void gic_set_group_irq(struct irq_data *d, int group) +{
- unsigned int reg = gic_irq(d) / 32 * 4;
- u32 mask = 1 << (gic_irq(d) % 32);
- u32 val;
- val = readl_relaxed(gic_dist_base(d) + GIC_DIST_IGROUP + reg);
- if (group)
val |= mask;- else
val &= ~mask;- writel_relaxed(val, gic_dist_base(d) + GIC_DIST_IGROUP + reg);
+}
/*
- Routines to acknowledge, disable and enable interrupts
*/ @@ -159,6 +188,8 @@ static void gic_mask_irq(struct irq_data *d) writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_CLEAR + (gic_irq(d) / 32) * 4); if (gic_arch_extn.irq_mask) gic_arch_extn.irq_mask(d);
- if (gic_is_fiq(d))
gic_set_group_irq(d, 1);} @@ -167,6 +198,8 @@ static void gic_unmask_irq(struct irq_data *d) u32 mask = 1 << (gic_irq(d) % 32); raw_spin_lock(&irq_controller_lock);
- if (gic_is_fiq(d))
gic_set_group_irq(d, 0);@@ -940,7 +973,12 @@ static int gic_routable_irq_domain_xlate(struct irq_domain *d, unsigned long *out_hwirq, unsigned int *out_type) {
- struct gic_chip_data *gic_data = d->host_data; *out_hwirq += 16;
- if (intspec[2] & GIC_INTSPEC_IRQ_IS_FIQ)
*out_hwirq += gic_data->fiq_shadow_offset;- return 0;
} @@ -1026,10 +1064,11 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start, gic->gic_irqs = gic_irqs; gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
- gic->fiq_shadow_offset = gic_irqs;
if (of_property_read_u32(node, "arm,routable-irqs", &nr_routable_irqs)) {
irq_base = irq_alloc_descs(irq_start, 16, gic_irqs,
irq_base = irq_alloc_descs(irq_start, 16, 2 * gic_irqs, numa_node_id());@@ -1037,17 +1076,28 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start, irq_base = irq_start; }
gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,hwirq_base, &gic_irq_domain_ops, gic);
gic->domain =irq_domain_add_legacy(node, 2 * gic_irqs, irq_base,hwirq_base, &gic_irq_domain_ops, gic);
gic->domain = irq_domain_add_linear(node, nr_routable_irqs,&gic_irq_domain_ops,gic);
gic->domain = irq_domain_add_linear(node, 2 * nr_routable_irqs,&gic_irq_domain_ops, gic);if (WARN_ON(!gic->domain)) return; +#ifdef CONFIG_FIQ
- /* FIQ can only be supported on platforms without an extended irq_eoi
* method (otherwise we take a lock during irq_eoi handling).*/- if (!gic_arch_extn.irq_eoi)
fiq_add_mapping(irq_linear_revmap(gic->domain, hwirq_base),irq_linear_revmap(gic->domain, hwirq_base + gic_irqs),gic_irqs);+#endif
This is rather unfortunate. On Tegra for example we don't need a lock for the irq_eoi because the eoi ack can be handled with a single write to the appropriate irq ack register.
Cheers,
Peter.