powerpc/smp: Remove migrate_irq() custom implementation

Some powerpc platforms use this to move IRQs away from a CPU being
unplugged. This function has several bugs such as not taking the right
locks or failing to NULL check pointers.

There's a new generic function doing exactly the same thing without all
the bugs, so let's use it instead.

mpe: The obvious place for the select of GENERIC_IRQ_MIGRATION is on
HOTPLUG_CPU, but that doesn't work. On some configs PM_SLEEP_SMP will
select HOTPLUG_CPU even though its dependencies are not met, which means
the select of GENERIC_IRQ_MIGRATION doesn't happen. That leads to the
build breaking. Fix it by moving the select of GENERIC_IRQ_MIGRATION to
SMP.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 2f8e36f91acdf2eb940aa2d3e85e1da17726d290..63fa780b71a0b2c39a9e25c61362527e7a62c26e 100644 (file)
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -62,7 +62,6 @@ extern void smp_generic_take_timebase(void);
 DECLARE_PER_CPU(unsigned int, cpu_pvr);
 
 #ifdef CONFIG_HOTPLUG_CPU
-extern void migrate_irqs(void);
 int generic_cpu_disable(void);
 void generic_cpu_die(unsigned int cpu);
 void generic_set_cpu_dead(unsigned int cpu);

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index a018f5cae899ae796840cea0492897970083fd79..8ee7b44450eb9b15ca168af14b5e3dd062d13281 100644 (file)
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -442,46 +442,6 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
        return sum;
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
-void migrate_irqs(void)
-{
-       struct irq_desc *desc;
-       unsigned int irq;
-       static int warned;
-       cpumask_var_t mask;
-       const struct cpumask *map = cpu_online_mask;
-
-       alloc_cpumask_var(&mask, GFP_KERNEL);
-
-       for_each_irq_desc(irq, desc) {
-               struct irq_data *data;
-               struct irq_chip *chip;
-
-               data = irq_desc_get_irq_data(desc);
-               if (irqd_is_per_cpu(data))
-                       continue;
-
-               chip = irq_data_get_irq_chip(data);
-
-               cpumask_and(mask, irq_data_get_affinity_mask(data), map);
-               if (cpumask_any(mask) >= nr_cpu_ids) {
-                       pr_warn("Breaking affinity for irq %i\n", irq);
-                       cpumask_copy(mask, map);
-               }
-               if (chip->irq_set_affinity)
-                       chip->irq_set_affinity(data, mask, true);
-               else if (desc->action && !(warned++))
-                       pr_err("Cannot set affinity for irq %i\n", irq);
-       }
-
-       free_cpumask_var(mask);
-
-       local_irq_enable();
-       mdelay(1);
-       local_irq_disable();
-}
-#endif
-
 static inline void check_stack_overflow(void)
 {
 #ifdef CONFIG_DEBUG_STACKOVERFLOW

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index b12f5f0a408f8cc5a68408dfa2d61f50dabab25a..6e61cdb89194d32ef7f31785cfc2c8703dd59d5b 100644 (file)
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -439,7 +439,14 @@ int generic_cpu_disable(void)
 #ifdef CONFIG_PPC64
        vdso_data->processorCount--;
 #endif
-       migrate_irqs();
+       /* Update affinity of all IRQs previously aimed at this CPU */
+       irq_migrate_all_off_this_cpu();
+
+       /* Give the CPU time to drain in-flight ones */
+       local_irq_enable();
+       mdelay(1);
+       local_irq_disable();
+
        return 0;
 }
 

diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 99b0ae8acb783399b47bbfaf7af1567c5b63d084..9b25cded03e9a6f21d1b9bec311429464437a4ff 100644 (file)
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -373,6 +373,7 @@ config PPC_PERF_CTRS
 
 config SMP
        depends on PPC_BOOK3S || PPC_BOOK3E || FSL_BOOKE || PPC_47x
+       select GENERIC_IRQ_MIGRATION
        bool "Symmetric multi-processing support"
        ---help---
          This enables support for systems with more than one CPU. If you have