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| author | Will Deacon <will.deacon@arm.com> | 2013-06-12 12:25:56 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-06-17 09:27:06 +0100 |
| commit | 621a0147d5c921f4cc33636ccd0602ad5d7cbfbc (patch) | |
| tree | 59bbba6a677dc8fa5fc6375ef1f391bad2dd9ed4 | |
| parent | 2874865c1271cc8e8b663804e5de4bc0c36273e1 (diff) | |
| download | linux-621a0147d5c921f4cc33636ccd0602ad5d7cbfbc.tar.gz linux-621a0147d5c921f4cc33636ccd0602ad5d7cbfbc.tar.bz2 linux-621a0147d5c921f4cc33636ccd0602ad5d7cbfbc.zip | |
ARM: 7757/1: mm: don't flush icache in switch_mm with hardware broadcasting
When scheduling an mm on a CPU where it hasn't previously been used, we
flush the icache on that CPU so that any code loaded previously on
a different core can be safely executed.
For cores with hardware broadcasting of cache maintenance operations,
this is clearly unnecessary, since the inner-shareable invalidation in
__sync_icache_dcache will affect all CPUs.
This patch conditionalises the icache flush in switch_mm based on
cache_ops_need_broadcast().
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Albin Tonnerre <albin.tonnerre@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/mmu_context.h | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h index a7b85e0d0cc1..2a45c33ebdc8 100644 --- a/arch/arm/include/asm/mmu_context.h +++ b/arch/arm/include/asm/mmu_context.h @@ -18,6 +18,7 @@ #include <asm/cacheflush.h> #include <asm/cachetype.h> #include <asm/proc-fns.h> +#include <asm/smp_plat.h> #include <asm-generic/mm_hooks.h> void __check_vmalloc_seq(struct mm_struct *mm); @@ -98,12 +99,16 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next, #ifdef CONFIG_MMU unsigned int cpu = smp_processor_id(); -#ifdef CONFIG_SMP - /* check for possible thread migration */ - if (!cpumask_empty(mm_cpumask(next)) && + /* + * __sync_icache_dcache doesn't broadcast the I-cache invalidation, + * so check for possible thread migration and invalidate the I-cache + * if we're new to this CPU. + */ + if (cache_ops_need_broadcast() && + !cpumask_empty(mm_cpumask(next)) && !cpumask_test_cpu(cpu, mm_cpumask(next))) __flush_icache_all(); -#endif + if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next) { check_and_switch_context(next, tsk); if (cache_is_vivt()) |