From a978e13965a40ac07163643cc3fa0ddb0d354198 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 5 Apr 2017 17:54:49 +1000 Subject: [PATCH] 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 Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/smp.h | 1 - arch/powerpc/kernel/irq.c | 40 -------------------------- arch/powerpc/kernel/smp.c | 9 +++++- arch/powerpc/platforms/Kconfig.cputype | 1 + 4 files changed, 9 insertions(+), 42 deletions(-) diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index 2f8e36f91acd..63fa780b71a0 100644 --- 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 a018f5cae899..8ee7b44450eb 100644 --- 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 b12f5f0a408f..6e61cdb89194 100644 --- 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 99b0ae8acb78..9b25cded03e9 100644 --- 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 -- 2.20.1