irqchip/mips-gic: Add a IPI hierarchy domain

Add a new ipi domain on top of the normal domain.

MIPS GIC now supports dynamic allocation of an IPI.

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: <jiang.liu@linux.intel.com>
Cc: <linux-mips@linux-mips.org>
Cc: <lisa.parratt@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Link: http://lkml.kernel.org/r/1449580830-23652-13-git-send-email-qais.yousef@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 0ffbdfd..71e648a 100644 (file)
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -209,6 +209,7 @@ config KEYSTONE_IRQ
 
 config MIPS_GIC
        bool
+       select IRQ_DOMAIN_HIERARCHY
        select MIPS_CM
 
 config INGENIC_IRQ

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 9e17ef2..99f01ca 100644 (file)
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -29,16 +29,31 @@ struct gic_pcpu_mask {
        DECLARE_BITMAP(pcpu_mask, GIC_MAX_INTRS);
 };
 
+struct gic_irq_spec {
+       enum {
+               GIC_DEVICE,
+               GIC_IPI
+       } type;
+
+       union {
+               struct cpumask *ipimask;
+               unsigned int hwirq;
+       };
+};
+
 static unsigned long __gic_base_addr;
+
 static void __iomem *gic_base;
 static struct gic_pcpu_mask pcpu_masks[NR_CPUS];
 static DEFINE_SPINLOCK(gic_lock);
 static struct irq_domain *gic_irq_domain;
+static struct irq_domain *gic_ipi_domain;
 static int gic_shared_intrs;
 static int gic_vpes;
 static unsigned int gic_cpu_pin;
 static unsigned int timer_cpu_pin;
 static struct irq_chip gic_level_irq_controller, gic_edge_irq_controller;
+DECLARE_BITMAP(ipi_resrv, GIC_MAX_INTRS);
 
 static void __gic_irq_dispatch(void);
 
@@ -753,7 +768,7 @@ static int gic_local_irq_domain_map(struct irq_domain *d, unsigned int virq,
 }
 
 static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq,
-                                    irq_hw_number_t hw)
+                                    irq_hw_number_t hw, unsigned int vpe)
 {
        int intr = GIC_HWIRQ_TO_SHARED(hw);
        unsigned long flags;
@@ -763,9 +778,8 @@ static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq,
 
        spin_lock_irqsave(&gic_lock, flags);
        gic_map_to_pin(intr, gic_cpu_pin);
-       /* Map to VPE 0 by default */
-       gic_map_to_vpe(intr, 0);
-       set_bit(intr, pcpu_masks[0].pcpu_mask);
+       gic_map_to_vpe(intr, vpe);
+       set_bit(intr, pcpu_masks[vpe].pcpu_mask);
        spin_unlock_irqrestore(&gic_lock, flags);
 
        return 0;
@@ -776,7 +790,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
 {
        if (GIC_HWIRQ_TO_LOCAL(hw) < GIC_NUM_LOCAL_INTRS)
                return gic_local_irq_domain_map(d, virq, hw);
-       return gic_shared_irq_domain_map(d, virq, hw);
+       return gic_shared_irq_domain_map(d, virq, hw, 0);
 }
 
 static int gic_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
@@ -798,9 +812,157 @@ static int gic_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
        return 0;
 }
 
+static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq,
+                               unsigned int nr_irqs, void *arg)
+{
+       struct gic_irq_spec *spec = arg;
+       irq_hw_number_t hwirq, base_hwirq;
+       int cpu, ret, i;
+
+       if (spec->type == GIC_DEVICE) {
+               /* verify that it doesn't conflict with an IPI irq */
+               if (test_bit(spec->hwirq, ipi_resrv))
+                       return -EBUSY;
+       } else {
+               base_hwirq = find_first_bit(ipi_resrv, gic_shared_intrs);
+               if (base_hwirq == gic_shared_intrs) {
+                       return -ENOMEM;
+               }
+
+               /* check that we have enough space */
+               for (i = base_hwirq; i < nr_irqs; i++) {
+                       if (!test_bit(i, ipi_resrv))
+                               return -EBUSY;
+               }
+               bitmap_clear(ipi_resrv, base_hwirq, nr_irqs);
+
+               /* map the hwirq for each cpu consecutively */
+               i = 0;
+               for_each_cpu(cpu, spec->ipimask) {
+                       hwirq = GIC_SHARED_TO_HWIRQ(base_hwirq + i);
+
+                       ret = irq_domain_set_hwirq_and_chip(d, virq + i, hwirq,
+                                                           &gic_edge_irq_controller,
+                                                           NULL);
+                       if (ret)
+                               goto error;
+
+                       ret = gic_shared_irq_domain_map(d, virq + i, hwirq, cpu);
+                       if (ret)
+                               goto error;
+
+                       i++;
+               }
+
+               /*
+                * tell the parent about the base hwirq we allocated so it can
+                * set its own domain data
+                */
+               spec->hwirq = base_hwirq;
+       }
+
+       return 0;
+error:
+       bitmap_set(ipi_resrv, base_hwirq, nr_irqs);
+       return ret;
+}
+
+void gic_irq_domain_free(struct irq_domain *d, unsigned int virq,
+                        unsigned int nr_irqs)
+{
+       irq_hw_number_t base_hwirq;
+       struct irq_data *data;
+
+       data = irq_get_irq_data(virq);
+       if (!data)
+               return;
+
+       base_hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(data));
+       bitmap_set(ipi_resrv, base_hwirq, nr_irqs);
+}
+
 static const struct irq_domain_ops gic_irq_domain_ops = {
        .map = gic_irq_domain_map,
        .xlate = gic_irq_domain_xlate,
+       .alloc = gic_irq_domain_alloc,
+       .free = gic_irq_domain_free,
+};
+
+static int gic_ipi_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
+                               const u32 *intspec, unsigned int intsize,
+                               irq_hw_number_t *out_hwirq,
+                               unsigned int *out_type)
+{
+       /*
+        * There's nothing to translate here. hwirq is dynamically allocated and
+        * the irq type is always edge triggered.
+        * */
+       *out_hwirq = 0;
+       *out_type = IRQ_TYPE_EDGE_RISING;
+
+       return 0;
+}
+
+static int gic_ipi_domain_alloc(struct irq_domain *d, unsigned int virq,
+                               unsigned int nr_irqs, void *arg)
+{
+       struct cpumask *ipimask = arg;
+       struct gic_irq_spec spec = {
+               .type = GIC_IPI,
+               .ipimask = ipimask
+       };
+       int ret, i;
+
+       ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &spec);
+       if (ret)
+               return ret;
+
+       /* the parent should have set spec.hwirq to the base_hwirq it allocated */
+       for (i = 0; i < nr_irqs; i++) {
+               ret = irq_domain_set_hwirq_and_chip(d, virq + i,
+                                                   GIC_SHARED_TO_HWIRQ(spec.hwirq + i),
+                                                   &gic_edge_irq_controller,
+                                                   NULL);
+               if (ret)
+                       goto error;
+
+               ret = irq_set_irq_type(virq + i, IRQ_TYPE_EDGE_RISING);
+               if (ret)
+                       goto error;
+       }
+
+       return 0;
+error:
+       irq_domain_free_irqs_parent(d, virq, nr_irqs);
+       return ret;
+}
+
+void gic_ipi_domain_free(struct irq_domain *d, unsigned int virq,
+                        unsigned int nr_irqs)
+{
+       irq_domain_free_irqs_parent(d, virq, nr_irqs);
+}
+
+int gic_ipi_domain_match(struct irq_domain *d, struct device_node *node,
+                        enum irq_domain_bus_token bus_token)
+{
+       bool is_ipi;
+
+       switch (bus_token) {
+       case DOMAIN_BUS_IPI:
+               is_ipi = d->bus_token == bus_token;
+               return to_of_node(d->fwnode) == node && is_ipi;
+               break;
+       default:
+               return 0;
+       }
+}
+
+static struct irq_domain_ops gic_ipi_domain_ops = {
+       .xlate = gic_ipi_domain_xlate,
+       .alloc = gic_ipi_domain_alloc,
+       .free = gic_ipi_domain_free,
+       .match = gic_ipi_domain_match,
 };
 
 static void __init __gic_init(unsigned long gic_base_addr,
@@ -864,6 +1026,18 @@ static void __init __gic_init(unsigned long gic_base_addr,
        if (!gic_irq_domain)
                panic("Failed to add GIC IRQ domain");
 
+       gic_ipi_domain = irq_domain_add_hierarchy(gic_irq_domain,
+                                                 IRQ_DOMAIN_FLAG_IPI_PER_CPU,
+                                                 GIC_NUM_LOCAL_INTRS + gic_shared_intrs,
+                                                 node, &gic_ipi_domain_ops, NULL);
+       if (!gic_ipi_domain)
+               panic("Failed to add GIC IPI domain");
+
+       gic_ipi_domain->bus_token = DOMAIN_BUS_IPI;
+
+       /* Make the last 2 * NR_CPUS available for IPIs */
+       bitmap_set(ipi_resrv, gic_shared_intrs - 2 * NR_CPUS, 2 * NR_CPUS);
+
        gic_basic_init();
 
        gic_ipi_init();