ARM: gic: add irq_domain support

Convert the gic interrupt controller to use irq domains in preparation
for device-tree binding and MULTI_IRQ. This allows for translation between
GIC interrupt IDs and Linux irq numbers.

The meaning of irq_offset has changed. It now is just the number of skipped
GIC interrupt IDs for the controller. It will be 16 for primary GIC and 32
for secondary GICs.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index 4b71766..74df9ca 100644 (file)
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -1,4 +1,5 @@
 config ARM_GIC
+       select IRQ_DOMAIN
        bool
 
 config ARM_VIC

diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 016c1ae..ccaa1ab 100644 (file)
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -24,11 +24,13 @@
  */
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/export.h>
 #include <linux/list.h>
 #include <linux/smp.h>
 #include <linux/cpu_pm.h>
 #include <linux/cpumask.h>
 #include <linux/io.h>
+#include <linux/irqdomain.h>
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
 #include <linux/slab.h>
@@ -75,8 +77,7 @@ static inline void __iomem *gic_cpu_base(struct irq_data *d)
 
 static inline unsigned int gic_irq(struct irq_data *d)
 {
-       struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
-       return d->irq - gic_data->irq_offset;
+       return d->hwirq;
 }
 
 /*
@@ -84,7 +85,7 @@ static inline unsigned int gic_irq(struct irq_data *d)
  */
 static void gic_mask_irq(struct irq_data *d)
 {
-       u32 mask = 1 << (d->irq % 32);
+       u32 mask = 1 << (gic_irq(d) % 32);
 
        spin_lock(&irq_controller_lock);
        writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_CLEAR + (gic_irq(d) / 32) * 4);
@@ -95,7 +96,7 @@ static void gic_mask_irq(struct irq_data *d)
 
 static void gic_unmask_irq(struct irq_data *d)
 {
-       u32 mask = 1 << (d->irq % 32);
+       u32 mask = 1 << (gic_irq(d) % 32);
 
        spin_lock(&irq_controller_lock);
        if (gic_arch_extn.irq_unmask)
@@ -176,7 +177,7 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
                            bool force)
 {
        void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
-       unsigned int shift = (d->irq % 4) * 8;
+       unsigned int shift = (gic_irq(d) % 4) * 8;
        unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
        u32 val, mask, bit;
 
@@ -227,7 +228,7 @@ static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
        if (gic_irq == 1023)
                goto out;
 
-       cascade_irq = gic_irq + chip_data->irq_offset;
+       cascade_irq = irq_domain_to_irq(&chip_data->domain, gic_irq);
        if (unlikely(gic_irq < 32 || gic_irq > 1020 || cascade_irq >= NR_IRQS))
                do_bad_IRQ(cascade_irq, desc);
        else
@@ -259,14 +260,14 @@ void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
        irq_set_chained_handler(irq, gic_handle_cascade_irq);
 }
 
-static void __init gic_dist_init(struct gic_chip_data *gic,
-       unsigned int irq_start)
+static void __init gic_dist_init(struct gic_chip_data *gic)
 {
-       unsigned int gic_irqs, irq_limit, i;
+       unsigned int i, irq;
        u32 cpumask;
+       unsigned int gic_irqs = gic->gic_irqs;
+       struct irq_domain *domain = &gic->domain;
        void __iomem *base = gic->dist_base;
        u32 cpu = 0;
-       u32 nrppis = 0, ppi_base = 0;
 
 #ifdef CONFIG_SMP
        cpu = cpu_logical_map(smp_processor_id());
@@ -278,34 +279,6 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
 
        writel_relaxed(0, base + GIC_DIST_CTRL);
 
-       /*
-        * Find out how many interrupts are supported.
-        * The GIC only supports up to 1020 interrupt sources.
-        */
-       gic_irqs = readl_relaxed(base + GIC_DIST_CTR) & 0x1f;
-       gic_irqs = (gic_irqs + 1) * 32;
-       if (gic_irqs > 1020)
-               gic_irqs = 1020;
-
-       gic->gic_irqs = gic_irqs;
-
-       /*
-        * Nobody would be insane enough to use PPIs on a secondary
-        * GIC, right?
-        */
-       if (gic == &gic_data[0]) {
-               nrppis = (32 - irq_start) & 31;
-
-               /* The GIC only supports up to 16 PPIs. */
-               if (nrppis > 16)
-                       BUG();
-
-               ppi_base = gic->irq_offset + 32 - nrppis;
-       }
-
-       pr_info("Configuring GIC with %d sources (%d PPIs)\n",
-               gic_irqs, (gic == &gic_data[0]) ? nrppis : 0);
-
        /*
         * Set all global interrupts to be level triggered, active low.
         */
@@ -331,30 +304,21 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
        for (i = 32; i < gic_irqs; i += 32)
                writel_relaxed(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32);
 
-       /*
-        * Limit number of interrupts registered to the platform maximum
-        */
-       irq_limit = gic->irq_offset + gic_irqs;
-       if (WARN_ON(irq_limit > NR_IRQS))
-               irq_limit = NR_IRQS;
-
        /*
         * Setup the Linux IRQ subsystem.
         */
-       for (i = 0; i < nrppis; i++) {
-               int ppi = i + ppi_base;
-
-               irq_set_percpu_devid(ppi);
-               irq_set_chip_and_handler(ppi, &gic_chip,
-                                        handle_percpu_devid_irq);
-               irq_set_chip_data(ppi, gic);
-               set_irq_flags(ppi, IRQF_VALID | IRQF_NOAUTOEN);
-       }
-
-       for (i = irq_start + nrppis; i < irq_limit; i++) {
-               irq_set_chip_and_handler(i, &gic_chip, handle_fasteoi_irq);
-               irq_set_chip_data(i, gic);
-               set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
+       irq_domain_for_each_irq(domain, i, irq) {
+               if (i < 32) {
+                       irq_set_percpu_devid(irq);
+                       irq_set_chip_and_handler(irq, &gic_chip,
+                                                handle_percpu_devid_irq);
+                       set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
+               } else {
+                       irq_set_chip_and_handler(irq, &gic_chip,
+                                                handle_fasteoi_irq);
+                       set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+               }
+               irq_set_chip_data(irq, gic);
        }
 
        writel_relaxed(1, base + GIC_DIST_CTRL);
@@ -566,23 +530,53 @@ static void __init gic_pm_init(struct gic_chip_data *gic)
 }
 #endif
 
+const struct irq_domain_ops gic_irq_domain_ops = {
+};
+
 void __init gic_init(unsigned int gic_nr, unsigned int irq_start,
        void __iomem *dist_base, void __iomem *cpu_base)
 {
        struct gic_chip_data *gic;
+       struct irq_domain *domain;
+       int gic_irqs;
 
        BUG_ON(gic_nr >= MAX_GIC_NR);
 
        gic = &gic_data[gic_nr];
+       domain = &gic->domain;
        gic->dist_base = dist_base;
        gic->cpu_base = cpu_base;
-       gic->irq_offset = (irq_start - 1) & ~31;
 
-       if (gic_nr == 0)
+       /*
+        * For primary GICs, skip over SGIs.
+        * For secondary GICs, skip over PPIs, too.
+        */
+       if (gic_nr == 0) {
                gic_cpu_base_addr = cpu_base;
+               domain->hwirq_base = 16;
+               irq_start = (irq_start & ~31) + 16;
+       } else
+               domain->hwirq_base = 32;
+
+       /*
+        * Find out how many interrupts are supported.
+        * The GIC only supports up to 1020 interrupt sources.
+        */
+       gic_irqs = readl_relaxed(dist_base + GIC_DIST_CTR) & 0x1f;
+       gic_irqs = (gic_irqs + 1) * 32;
+       if (gic_irqs > 1020)
+               gic_irqs = 1020;
+       gic->gic_irqs = gic_irqs;
+
+       domain->nr_irq = gic_irqs - domain->hwirq_base;
+       domain->irq_base = irq_alloc_descs(-1, irq_start, domain->nr_irq,
+                                          numa_node_id());
+       domain->priv = gic;
+       domain->ops = &gic_irq_domain_ops;
+       irq_domain_add(domain);
 
        gic_chip.flags |= gic_arch_extn.flags;
-       gic_dist_init(gic, irq_start);
+       gic_dist_init(gic);
        gic_cpu_init(gic);
        gic_pm_init(gic);
 }

diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h
index 14867e1..43a05d9 100644 (file)
--- a/arch/arm/include/asm/hardware/gic.h
+++ b/arch/arm/include/asm/hardware/gic.h
@@ -33,6 +33,9 @@
 #define GIC_DIST_SOFTINT               0xf00
 
 #ifndef __ASSEMBLY__
+#include <linux/irqdomain.h>
+struct device_node;
+
 extern void __iomem *gic_cpu_base_addr;
 extern struct irq_chip gic_arch_extn;
 
@@ -42,7 +45,6 @@ void gic_cascade_irq(unsigned int gic_nr, unsigned int irq);
 void gic_raise_softirq(const struct cpumask *mask, unsigned int irq);
 
 struct gic_chip_data {
-       unsigned int irq_offset;
        void __iomem *dist_base;
        void __iomem *cpu_base;
 #ifdef CONFIG_CPU_PM
@@ -51,6 +53,9 @@ struct gic_chip_data {
        u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
        u32 __percpu *saved_ppi_enable;
        u32 __percpu *saved_ppi_conf;
+#endif
+#ifdef CONFIG_IRQ_DOMAIN
+       struct irq_domain domain;
 #endif
        unsigned int gic_irqs;
 };