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authorMarc Zyngier <Marc.Zyngier@arm.com>2013-06-21 12:07:27 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-06-24 15:27:35 +0100
commit0d0752bca1f9a91fb646647aa4abbb21156f316c (patch)
treed5cedcc1ba2f3fd4ed4c095c98851ed1ecf4e110 /arch/arm/kernel/smp_tlb.c
parentb8e4a4740fa2b17c0a447b3ab783b3dc10702e27 (diff)
downloadop-kernel-dev-0d0752bca1f9a91fb646647aa4abbb21156f316c.zip
op-kernel-dev-0d0752bca1f9a91fb646647aa4abbb21156f316c.tar.gz
ARM: 7769/1: Cortex-A15: fix erratum 798181 implementation
Looking into the active_asids array is not enough, as we also need to look into the reserved_asids array (they both represent processes that are currently running). Also, not holding the ASID allocator lock is racy, as another CPU could schedule that process and trigger a rollover, making the erratum workaround miss an IPI. Exposing this outside of context.c is a little ugly on the side, so let's define a new entry point that the erratum workaround can call to obtain the cpumask. Cc: <stable@vger.kernel.org> # 3.9 Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/smp_tlb.c')
-rw-r--r--arch/arm/kernel/smp_tlb.c18
1 files changed, 2 insertions, 16 deletions
diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c
index 9a52a07..a98b62d 100644
--- a/arch/arm/kernel/smp_tlb.c
+++ b/arch/arm/kernel/smp_tlb.c
@@ -103,7 +103,7 @@ static void broadcast_tlb_a15_erratum(void)
static void broadcast_tlb_mm_a15_erratum(struct mm_struct *mm)
{
- int cpu, this_cpu;
+ int this_cpu;
cpumask_t mask = { CPU_BITS_NONE };
if (!erratum_a15_798181())
@@ -111,21 +111,7 @@ static void broadcast_tlb_mm_a15_erratum(struct mm_struct *mm)
dummy_flush_tlb_a15_erratum();
this_cpu = get_cpu();
- for_each_online_cpu(cpu) {
- if (cpu == this_cpu)
- continue;
- /*
- * We only need to send an IPI if the other CPUs are running
- * the same ASID as the one being invalidated. There is no
- * need for locking around the active_asids check since the
- * switch_mm() function has at least one dmb() (as required by
- * this workaround) in case a context switch happens on
- * another CPU after the condition below.
- */
- if (atomic64_read(&mm->context.id) ==
- atomic64_read(&per_cpu(active_asids, cpu)))
- cpumask_set_cpu(cpu, &mask);
- }
+ a15_erratum_get_cpumask(this_cpu, mm, &mask);
smp_call_function_many(&mask, ipi_flush_tlb_a15_erratum, NULL, 1);
put_cpu();
}
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