diff options
| author | Steve Capper <steve.capper@linaro.org> | 2014-03-21 10:55:36 +0000 |
|---|---|---|
| committer | Steve Capper <steve.capper@linaro.org> | 2014-09-01 11:58:27 +0100 |
| commit | d3dae122b108edf27fcd8d05fcac928ad274a278 (patch) | |
| tree | c7802e2235e8f30de5e20bedbefe43b5258b0bcc | |
| parent | 0e169dc51e89ef1ca2ce9e49441d68764d385bbe (diff) | |
| download | linux-d3dae122b108edf27fcd8d05fcac928ad274a278.tar.gz | |
arm64: mm: Enable RCU fast_gupfast_gup/for_kevin
Activate the RCU fast_gup for ARM64. We also need to force THP splits
to broadcast an IPI s.t. we block in the fast_gup page walker. As THP
splits are comparatively rare, this should not lead to a noticeable
performance degradation.
Some pre-requisite functions pud_write and pud_page are also added.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
[steve.capper@linaro.org: rebased against 3.15-rc8]
| -rw-r--r-- | arch/arm64/Kconfig | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 22 | ||||
| -rw-r--r-- | arch/arm64/mm/flush.c | 15 |
3 files changed, 39 insertions, 1 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 24203903d93..9db5ee36994 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -95,6 +95,9 @@ config GENERIC_CALIBRATE_DELAY config ZONE_DMA def_bool y +config HAVE_GENERIC_RCU_GUP + def_bool y + config ARCH_DMA_ADDR_T_64BIT def_bool y diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 7b1c67a0b48..f67a6b17127 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -227,6 +227,16 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, #define __HAVE_ARCH_PTE_SPECIAL +static inline pte_t pud_pte(pud_t pud) +{ + return __pte(pud_val(pud)); +} + +static inline pmd_t pud_pmd(pud_t pud) +{ + return __pmd(pud_val(pud)); +} + static inline pte_t pmd_pte(pmd_t pmd) { return __pte(pmd_val(pmd)); @@ -244,7 +254,13 @@ static inline pmd_t pte_pmd(pte_t pte) #ifdef CONFIG_TRANSPARENT_HUGEPAGE #define pmd_trans_huge(pmd) (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT)) #define pmd_trans_splitting(pmd) pte_special(pmd_pte(pmd)) -#endif +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH +struct vm_area_struct; +void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp); +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #define pmd_young(pmd) pte_young(pmd_pte(pmd)) #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) @@ -265,6 +281,8 @@ static inline pmd_t pte_pmd(pte_t pte) #define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot) #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) +#define pud_write(pud) pte_write(pud_pte(pud)) +#define pud_pfn(pud) (((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT) #define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd)) @@ -354,6 +372,8 @@ static inline pmd_t *pud_page_vaddr(pud_t pud) /* Find an entry in the second-level page table.. */ #ifndef CONFIG_ARM64_64K_PAGES +#define pud_page(pud) pmd_page(pud_pmd(pud)) + #define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) { diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index e4193e3adc7..bed31308d36 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -103,3 +103,18 @@ EXPORT_SYMBOL(flush_dcache_page); */ EXPORT_SYMBOL(flush_cache_all); EXPORT_SYMBOL(flush_icache_range); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp) +{ + pmd_t pmd = pmd_mksplitting(*pmdp); + VM_BUG_ON(address & ~PMD_MASK); + set_pmd_at(vma->vm_mm, address, pmdp, pmd); + + /* dummy IPI to serialise against fast_gup */ + kick_all_cpus_sync(); +} +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |