ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)

The current cpu-private IRQ registration is ugly as it requires need to
expose arch_unmask_irq() outside of intc code.
So switch to percpu IRQ APIs:
  -request_percpu_irq [boot core]
  -enable_percpu_irq  [all cores]

Encapsulated in helper arc_request_percpu_irq()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

4 files changed, 37 insertions, 26 deletions

diff --git a/arch/arc/include/asm/irq.h b/arch/arc/include/asm/irq.h
index fb4efb648971..f38652fb2ed7 100644
--- a/arch/arc/include/asm/irq.h
+++ b/arch/arc/include/asm/irq.h
@@ -16,9 +16,13 @@
 #define TIMER0_IRQ      3
 #define TIMER1_IRQ      4
 
+#include <linux/interrupt.h>
 #include <asm-generic/irq.h>
 
 extern void arc_init_IRQ(void);
 void arc_local_timer_setup(void);
+void arc_request_percpu_irq(int irq, int cpu,
+                            irqreturn_t (*isr)(int irq, void *dev),
+                            const char *irq_nm, void *percpu_dev);
 
 #endif
diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c
index 7d653c0d0773..835fa5e71b62 100644
--- a/arch/arc/kernel/irq.c
+++ b/arch/arc/kernel/irq.c
@@ -150,6 +150,32 @@ void arch_do_IRQ(unsigned int irq, struct pt_regs *regs)
         set_irq_regs(old_regs);
 }
 
+void arc_request_percpu_irq(int irq, int cpu,
+                            irqreturn_t (*isr)(int irq, void *dev),
+                            const char *irq_nm,
+                            void *percpu_dev)
+{
+        /* Boot cpu calls request, all call enable */
+        if (!cpu) {
+                int rc;
+
+                /*
+                 * These 2 calls are essential to making percpu IRQ APIs work
+                 * Ideally these details could be hidden in irq chip map function
+                 * but the issue is IPIs IRQs being static (non-DT) and platform
+                 * specific, so we can't identify them there.
+                 */
+                irq_set_percpu_devid(irq);
+                irq_modify_status(irq, IRQ_NOAUTOEN, 0);  /* @irq, @clr, @set */
+
+                rc = request_percpu_irq(irq, isr, irq_nm, percpu_dev);
+                if (rc)
+                        panic("Percpu IRQ request failed for %d\n", irq);
+        }
+
+        enable_percpu_irq(irq, 0);
+}
+
 /*
  * arch_local_irq_enable - Enable interrupts.
  *
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index c802bb500602..1790c21760a1 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -136,7 +136,7 @@ void start_kernel_secondary(void)
         pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu);
 
         if (machine_desc->init_smp)
-                machine_desc->init_smp(smp_processor_id());
+                machine_desc->init_smp(cpu);
 
         arc_local_timer_setup();
 
@@ -338,18 +338,11 @@ irqreturn_t do_IPI(int irq, void *dev_id)
  */
 static DEFINE_PER_CPU(int, ipi_dev);
 
-static struct irqaction arc_ipi_irq = {
-        .name    = "IPI Interrupt",
-        .flags   = IRQF_PERCPU,
-        .handler = do_IPI,
-};
-
 int smp_ipi_irq_setup(int cpu, int irq)
 {
-        if (!cpu)
-                return setup_irq(irq, &arc_ipi_irq);
-        else
-                arch_unmask_irq(irq);
+        int *dev = per_cpu_ptr(&ipi_dev, cpu);
+
+        arc_request_percpu_irq(irq, cpu, do_IPI, "IPI Interrupt", dev);
 
         return 0;
 }
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 36c2aa99436f..f92cfb14ecd3 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -210,12 +210,6 @@ static irqreturn_t timer_irq_handler(int irq, void *dev_id)
         return IRQ_HANDLED;
 }
 
-static struct irqaction arc_timer_irq = {
-        .name    = "Timer0 (clock-evt-dev)",
-        .flags   = IRQF_TIMER | IRQF_PERCPU,
-        .handler = timer_irq_handler,
-};
-
 /*
  * Setup the local event timer for @cpu
  */
@@ -228,15 +222,9 @@ void arc_local_timer_setup()
         clockevents_config_and_register(evt, arc_get_core_freq(),
                                         0, ARC_TIMER_MAX);
 
-        /*
-         * setup the per-cpu timer IRQ handler - for all cpus
-         * For non boot CPU explicitly unmask at intc
-         * setup_irq() -> .. -> irq_startup() already does this on boot-cpu
-         */
-        if (!cpu)
-                setup_irq(TIMER0_IRQ, &arc_timer_irq);
-        else
-                arch_unmask_irq(TIMER0_IRQ);
+        /* setup the per-cpu timer IRQ handler - for all cpus */
+        arc_request_percpu_irq(TIMER0_IRQ, cpu, timer_irq_handler,
+                               "Timer0 (per-cpu-tick)", evt);
 }
 
 /*