The use of set_64bit() in X86_64 only code is pretty pointless, seeing how it's a direct assignment. Remove all this nonsense. Additionally, since x86_64 unconditionally has HAVE_CMPXCHG_DOUBLE, there is no point in even having that fallback. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> --- arch/um/include/asm/pgtable-3level.h | 8 -------- arch/x86/include/asm/cmpxchg_64.h | 5 ----- drivers/iommu/intel/irq_remapping.c | 10 ++-------- 3 files changed, 2 insertions(+), 21 deletions(-) --- a/arch/um/include/asm/pgtable-3level.h +++ b/arch/um/include/asm/pgtable-3level.h @@ -58,11 +58,7 @@ #define pud_populate(mm, pud, pmd) \ set_pud(pud, __pud(_PAGE_TABLE + __pa(pmd))) -#ifdef CONFIG_64BIT -#define set_pud(pudptr, pudval) set_64bit((u64 *) (pudptr), pud_val(pudval)) -#else #define set_pud(pudptr, pudval) (*(pudptr) = (pudval)) -#endif static inline int pgd_newpage(pgd_t pgd) { @@ -71,11 +67,7 @@ static inline int pgd_newpage(pgd_t pgd) static inline void pgd_mkuptodate(pgd_t pgd) { pgd_val(pgd) &= ~_PAGE_NEWPAGE; } -#ifdef CONFIG_64BIT -#define set_pmd(pmdptr, pmdval) set_64bit((u64 *) (pmdptr), pmd_val(pmdval)) -#else #define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval)) -#endif static inline void pud_clear (pud_t *pud) { --- a/arch/x86/include/asm/cmpxchg_64.h +++ b/arch/x86/include/asm/cmpxchg_64.h @@ -2,11 +2,6 @@ #ifndef _ASM_X86_CMPXCHG_64_H #define _ASM_X86_CMPXCHG_64_H -static inline void set_64bit(volatile u64 *ptr, u64 val) -{ - *ptr = val; -} - #define arch_cmpxchg64(ptr, o, n) \ ({ \ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ --- a/drivers/iommu/intel/irq_remapping.c +++ b/drivers/iommu/intel/irq_remapping.c @@ -173,7 +173,6 @@ static int modify_irte(struct irq_2_iomm index = irq_iommu->irte_index + irq_iommu->sub_handle; irte = &iommu->ir_table->base[index]; -#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) if ((irte->pst == 1) || (irte_modified->pst == 1)) { bool ret; @@ -187,11 +186,6 @@ static int modify_irte(struct irq_2_iomm * same as the old value. */ WARN_ON(!ret); - } else -#endif - { - set_64bit(&irte->low, irte_modified->low); - set_64bit(&irte->high, irte_modified->high); } __iommu_flush_cache(iommu, irte, sizeof(*irte)); @@ -249,8 +243,8 @@ static int clear_entries(struct irq_2_io end = start + (1 << irq_iommu->irte_mask); for (entry = start; entry < end; entry++) { - set_64bit(&entry->low, 0); - set_64bit(&entry->high, 0); + WRITE_ONCE(entry->low, 0); + WRITE_ONCE(entry->high, 0); } bitmap_release_region(iommu->ir_table->bitmap, index, irq_iommu->irte_mask);