Avoid open-coded atomic_dec on mm->context.active_cpus and use the
function made for it. Add CONFIG_DEBUG_VM underflow checking on the
counter.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/include/asm/book3s/64/mmu.h | 2 +-
arch/powerpc/include/asm/mmu_context.h | 1 +
arch/powerpc/mm/book3s64/radix_tlb.c | 2 +-
3 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h
b/arch/powerpc/include/asm/book3s/64/mmu.h
index 570a4960cf17..5cf0e9c953b3 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -261,7 +261,7 @@ static inline void radix_init_pseries(void) { }
#define arch_clear_mm_cpumask_cpu(cpu, mm) \
do { \
if (cpumask_test_cpu(cpu, mm_cpumask(mm))) { \
- atomic_dec(&(mm)->context.active_cpus); \
+ dec_mm_active_cpus(mm); \
cpumask_clear_cpu(cpu, mm_cpumask(mm)); \
} \
} while (0)
diff --git a/arch/powerpc/include/asm/mmu_context.h
b/arch/powerpc/include/asm/mmu_context.h
index 57f5017111f4..37bffa0f7918 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -127,6 +127,7 @@ static inline void inc_mm_active_cpus(struct mm_struct *mm)
static inline void dec_mm_active_cpus(struct mm_struct *mm)
{
+ VM_WARN_ON_ONCE(atomic_read(&mm->context.active_cpus) <= 0);
atomic_dec(&mm->context.active_cpus);
}
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c
b/arch/powerpc/mm/book3s64/radix_tlb.c
index 90953cf9f648..8160c1630c3d 100644
--- a/arch/powerpc/mm/book3s64/radix_tlb.c
+++ b/arch/powerpc/mm/book3s64/radix_tlb.c
@@ -808,7 +808,7 @@ void exit_lazy_flush_tlb(struct mm_struct *mm, bool
always_flush)
* that's what the caller expects.
*/
if (cpumask_test_cpu(cpu, mm_cpumask(mm))) {
- atomic_dec(&mm->context.active_cpus);
+ dec_mm_active_cpus(mm);
cpumask_clear_cpu(cpu, mm_cpumask(mm));
always_flush = true;
}
--
2.40.1
