MIPS: Add generic SMP IPI support

Use the new generic IPI layer to provide generic SMP IPI support if the irqchip
supports it.

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/1449580830-23652-17-git-send-email-qais.yousef@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index bd4385a8e6e86f7fbb9ca6d988f5eee155b9a8c7..c012e1903f6b88fc9befb3fca877687e419d1e5b 100644 (file)
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -33,12 +33,16 @@
 #include <linux/cpu.h>
 #include <linux/err.h>
 #include <linux/ftrace.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
 
 #include <linux/atomic.h>
 #include <asm/cpu.h>
 #include <asm/processor.h>
 #include <asm/idle.h>
 #include <asm/r4k-timer.h>
+#include <asm/mips-cpc.h>
 #include <asm/mmu_context.h>
 #include <asm/time.h>
 #include <asm/setup.h>
@@ -79,6 +83,11 @@ static cpumask_t cpu_core_setup_map;
 
 cpumask_t cpu_coherent_mask;
 
+#ifdef CONFIG_GENERIC_IRQ_IPI
+static struct irq_desc *call_desc;
+static struct irq_desc *sched_desc;
+#endif
+
 static inline void set_cpu_sibling_map(int cpu)
 {
        int i;
@@ -145,6 +154,133 @@ void register_smp_ops(struct plat_smp_ops *ops)
        mp_ops = ops;
 }
 
+#ifdef CONFIG_GENERIC_IRQ_IPI
+void mips_smp_send_ipi_single(int cpu, unsigned int action)
+{
+       mips_smp_send_ipi_mask(cpumask_of(cpu), action);
+}
+
+void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
+{
+       unsigned long flags;
+       unsigned int core;
+       int cpu;
+
+       local_irq_save(flags);
+
+       switch (action) {
+       case SMP_CALL_FUNCTION:
+               __ipi_send_mask(call_desc, mask);
+               break;
+
+       case SMP_RESCHEDULE_YOURSELF:
+               __ipi_send_mask(sched_desc, mask);
+               break;
+
+       default:
+               BUG();
+       }
+
+       if (mips_cpc_present()) {
+               for_each_cpu(cpu, mask) {
+                       core = cpu_data[cpu].core;
+
+                       if (core == current_cpu_data.core)
+                               continue;
+
+                       while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) {
+                               mips_cpc_lock_other(core);
+                               write_cpc_co_cmd(CPC_Cx_CMD_PWRUP);
+                               mips_cpc_unlock_other();
+                       }
+               }
+       }
+
+       local_irq_restore(flags);
+}
+
+
+static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
+{
+       scheduler_ipi();
+
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
+{
+       generic_smp_call_function_interrupt();
+
+       return IRQ_HANDLED;
+}
+
+static struct irqaction irq_resched = {
+       .handler        = ipi_resched_interrupt,
+       .flags          = IRQF_PERCPU,
+       .name           = "IPI resched"
+};
+
+static struct irqaction irq_call = {
+       .handler        = ipi_call_interrupt,
+       .flags          = IRQF_PERCPU,
+       .name           = "IPI call"
+};
+
+static __init void smp_ipi_init_one(unsigned int virq,
+                                   struct irqaction *action)
+{
+       int ret;
+
+       irq_set_handler(virq, handle_percpu_irq);
+       ret = setup_irq(virq, action);
+       BUG_ON(ret);
+}
+
+static int __init mips_smp_ipi_init(void)
+{
+       unsigned int call_virq, sched_virq;
+       struct irq_domain *ipidomain;
+       struct device_node *node;
+
+       node = of_irq_find_parent(of_root);
+       ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
+
+       /*
+        * Some platforms have half DT setup. So if we found irq node but
+        * didn't find an ipidomain, try to search for one that is not in the
+        * DT.
+        */
+       if (node && !ipidomain)
+               ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);
+
+       BUG_ON(!ipidomain);
+
+       call_virq = irq_reserve_ipi(ipidomain, cpu_possible_mask);
+       BUG_ON(!call_virq);
+
+       sched_virq = irq_reserve_ipi(ipidomain, cpu_possible_mask);
+       BUG_ON(!sched_virq);
+
+       if (irq_domain_is_ipi_per_cpu(ipidomain)) {
+               int cpu;
+
+               for_each_cpu(cpu, cpu_possible_mask) {
+                       smp_ipi_init_one(call_virq + cpu, &irq_call);
+                       smp_ipi_init_one(sched_virq + cpu, &irq_resched);
+               }
+       } else {
+               smp_ipi_init_one(call_virq, &irq_call);
+               smp_ipi_init_one(sched_virq, &irq_resched);
+       }
+
+       call_desc = irq_to_desc(call_virq);
+       sched_desc = irq_to_desc(sched_virq);
+
+       return 0;
+}
+early_initcall(mips_smp_ipi_init);
+#endif
+
 /*
  * First C code run on the secondary CPUs after being started up by
  * the master.