MIPS: Octeon: Fix fixup_irqs for HOTPLUG_CPU

The original version went behind the back of everything, leaving
things in an inconsistent state.

Now we use the irq_set_affinity() to do the work for us.  This has the
advantage that the IRQ core's view of the affinity stays consistent.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1486/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 69 insertions, 39 deletions

diff --git a/arch/mips/cavium-octeon/octeon-irq.c b/arch/mips/cavium-octeon/octeon-irq.c
index 8fb9fb667779..ce7500cdf5b7 100644
--- a/arch/mips/cavium-octeon/octeon-irq.c
+++ b/arch/mips/cavium-octeon/octeon-irq.c
@@ -788,54 +788,84 @@ asmlinkage void plat_irq_dispatch(void)
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
-static int is_irq_enabled_on_cpu(unsigned int irq, unsigned int cpu)
-{
-        unsigned int isset;
-        int coreid = octeon_coreid_for_cpu(cpu);
-        int bit = (irq < OCTEON_IRQ_WDOG0) ?
-                   irq - OCTEON_IRQ_WORKQ0 : irq - OCTEON_IRQ_WDOG0;
-       if (irq < 64) {
-                isset = (cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2)) &
-                        (1ull << bit)) >> bit;
-       } else {
-               isset = (cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1)) &
-                        (1ull << bit)) >> bit;
-       }
-       return isset;
-}
 
 void fixup_irqs(void)
 {
-       int irq;
+        int irq;
+        struct irq_desc *desc;
+        cpumask_t new_affinity;
+        unsigned long flags;
+        int do_set_affinity;
+        int cpu;
+
+        cpu = smp_processor_id();
 
         for (irq = OCTEON_IRQ_SW0; irq <= OCTEON_IRQ_TIMER; irq++)
                 octeon_irq_core_disable_local(irq);
 
-        for (irq = OCTEON_IRQ_WORKQ0; irq <= OCTEON_IRQ_GPIO15; irq++) {
-                if (is_irq_enabled_on_cpu(irq, smp_processor_id())) {
-                        /* ciu irq migrates to next cpu */
-                        octeon_irq_chip_ciu0.disable(irq);
-                        octeon_irq_ciu0_set_affinity(irq, &cpu_online_map);
-                }
-        }
+        for (irq = OCTEON_IRQ_WORKQ0; irq < OCTEON_IRQ_LAST; irq++) {
+                desc = irq_to_desc(irq);
+                switch (irq) {
+                case OCTEON_IRQ_MBOX0:
+                case OCTEON_IRQ_MBOX1:
+                        /* The eoi function will disable them on this CPU. */
+                        desc->chip->eoi(irq);
+                        break;
+                case OCTEON_IRQ_WDOG0:
+                case OCTEON_IRQ_WDOG1:
+                case OCTEON_IRQ_WDOG2:
+                case OCTEON_IRQ_WDOG3:
+                case OCTEON_IRQ_WDOG4:
+                case OCTEON_IRQ_WDOG5:
+                case OCTEON_IRQ_WDOG6:
+                case OCTEON_IRQ_WDOG7:
+                case OCTEON_IRQ_WDOG8:
+                case OCTEON_IRQ_WDOG9:
+                case OCTEON_IRQ_WDOG10:
+                case OCTEON_IRQ_WDOG11:
+                case OCTEON_IRQ_WDOG12:
+                case OCTEON_IRQ_WDOG13:
+                case OCTEON_IRQ_WDOG14:
+                case OCTEON_IRQ_WDOG15:
+                        /*
+                         * These have special per CPU semantics and
+                         * are handled in the watchdog driver.
+                         */
+                        break;
+                default:
+                        raw_spin_lock_irqsave(&desc->lock, flags);
+                        /*
+                         * If this irq has an action, it is in use and
+                         * must be migrated if it has affinity to this
+                         * cpu.
+                         */
+                        if (desc->action && cpumask_test_cpu(cpu, desc->affinity)) {
+                                if (cpumask_weight(desc->affinity) > 1) {
+                                        /*
+                                         * It has multi CPU affinity,
+                                         * just remove this CPU from
+                                         * the affinity set.
+                                         */
+                                        cpumask_copy(&new_affinity, desc->affinity);
+                                        cpumask_clear_cpu(cpu, &new_affinity);
+                                } else {
+                                        /*
+                                         * Otherwise, put it on lowest
+                                         * numbered online CPU.
+                                         */
+                                        cpumask_clear(&new_affinity);
+                                        cpumask_set_cpu(cpumask_first(cpu_online_mask), &new_affinity);
+                                }
+                                do_set_affinity = 1;
+                        } else {
+                                do_set_affinity = 0;
+                        }
+                        raw_spin_unlock_irqrestore(&desc->lock, flags);
 
-#if 0
-        for (irq = OCTEON_IRQ_MBOX0; irq <= OCTEON_IRQ_MBOX1; irq++)
-                octeon_irq_mailbox_mask(irq);
-#endif
-        for (irq = OCTEON_IRQ_UART0; irq <= OCTEON_IRQ_BOOTDMA; irq++) {
-                if (is_irq_enabled_on_cpu(irq, smp_processor_id())) {
-                        /* ciu irq migrates to next cpu */
-                        octeon_irq_chip_ciu0.disable(irq);
-                        octeon_irq_ciu0_set_affinity(irq, &cpu_online_map);
-                }
-        }
+                        if (do_set_affinity)
+                                irq_set_affinity(irq, &new_affinity);
 
-        for (irq = OCTEON_IRQ_UART2; irq <= OCTEON_IRQ_RESERVED135; irq++) {
-                if (is_irq_enabled_on_cpu(irq, smp_processor_id())) {
-                        /* ciu irq migrates to next cpu */
-                        octeon_irq_chip_ciu1.disable(irq);
-                        octeon_irq_ciu1_set_affinity(irq, &cpu_online_map);
+                        break;
                 }
         }
 }