alpha: Replace smp_read_barrier_depends() usage with smp_[r]mb() (bb7cdd38) · Commits · 戴 / test

arch/alpha/include/asm/atomic.h

+8 −8

Original line number	Diff line number	Diff line
		@@ -16,10 +16,10 @@

		/*
		* To ensure dependency ordering is preserved for the _relaxed and
		* _release atomics, an smp_read_barrier_depends() is unconditionally
		* inserted into the _relaxed variants, which are used to build the
		* barriered versions. Avoid redundant back-to-back fences in the
		* _acquire and _fence versions.
		* _release atomics, an smp_mb() is unconditionally inserted into the
		* _relaxed variants, which are used to build the barriered versions.
		* Avoid redundant back-to-back fences in the _acquire and _fence
		* versions.
		*/
		#define __atomic_acquire_fence()
		#define __atomic_post_full_fence()
		@@ -70,7 +70,7 @@ static inline int atomic_##op##_return_relaxed(int i, atomic_t *v) \
		".previous" \
		:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
		:"Ir" (i), "m" (v->counter) : "memory"); \
		smp_read_barrier_depends(); \
		smp_mb(); \
		return result; \
		}

		@@ -88,7 +88,7 @@ static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v) \
		".previous" \
		:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
		:"Ir" (i), "m" (v->counter) : "memory"); \
		smp_read_barrier_depends(); \
		smp_mb(); \
		return result; \
		}

		@@ -123,7 +123,7 @@ static __inline__ s64 atomic64_##op##_return_relaxed(s64 i, atomic64_t * v) \
		".previous" \
		:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
		:"Ir" (i), "m" (v->counter) : "memory"); \
		smp_read_barrier_depends(); \
		smp_mb(); \
		return result; \
		}

		@@ -141,7 +141,7 @@ static __inline__ s64 atomic64_fetch_##op##_relaxed(s64 i, atomic64_t * v) \
		".previous" \
		:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
		:"Ir" (i), "m" (v->counter) : "memory"); \
		smp_read_barrier_depends(); \
		smp_mb(); \
		return result; \
		}

arch/alpha/include/asm/pgtable.h

+5 −5

Original line number	Diff line number	Diff line
		@@ -277,9 +277,9 @@ extern inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) \|= __DIRTY_BITS; retur
		extern inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) \|= __ACCESS_BITS; return pte; }

		/*
		* The smp_read_barrier_depends() in the following functions are required to
		* order the load of *dir (the pointer in the top level page table) with any
		* subsequent load of the returned pmd_t ret (ret is data dependent on dir).
		* The smp_rmb() in the following functions are required to order the load of
		* *dir (the pointer in the top level page table) with any subsequent load of
		* the returned pmd_t ret (ret is data dependent on dir).
		*
		* If this ordering is not enforced, the CPU might load an older value of
		* *ret, which may be uninitialized data. See mm/memory.c:__pte_alloc for
		@@ -293,7 +293,7 @@ extern inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) \|= __ACCESS_BITS; retu
		extern inline pmd_t * pmd_offset(pud_t * dir, unsigned long address)
		{
		pmd_t ret = (pmd_t ) pud_page_vaddr(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PAGE - 1));
		smp_read_barrier_depends(); /* see above */
		smp_rmb(); /* see above */
		return ret;
		}
		#define pmd_offset pmd_offset
		@@ -303,7 +303,7 @@ extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address)
		{
		pte_t ret = (pte_t ) pmd_page_vaddr(*dir)
		+ ((address >> PAGE_SHIFT) & (PTRS_PER_PAGE - 1));
		smp_read_barrier_depends(); /* see above */
		smp_rmb(); /* see above */
		return ret;
		}
		#define pte_offset_kernel pte_offset_kernel

mm/memory.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -437,7 +437,7 @@ int __pte_alloc(struct mm_struct mm, pmd_t pmd)
		* of a chain of data-dependent loads, meaning most CPUs (alpha
		* being the notable exception) will already guarantee loads are
		* seen in-order. See the alpha page table accessors for the
		* smp_read_barrier_depends() barriers in page table walking code.
		* smp_rmb() barriers in page table walking code.
		*/
		smp_wmb(); /* Could be smp_wmb__xxx(before\|after)_spin_lock */

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