arm64: Enable ARCH_HAS_NONLEAF_PMD_YOUNG

With the support of FEAT_HAFT, the NONLEAF_PMD_YOUNG can be enabled
on arm64 since the hardware is capable of updating the AF flag for
PMD table descriptor. Since the AF bit of the table descriptor
shares the same bit position in block descriptors, we only need
to implement arch_has_hw_nonleaf_pmd_young() and select related
configs. The related pmd_young test/update operations keeps the
same with and already implemented for transparent page support.

Currently ARCH_HAS_NONLEAF_PMD_YOUNG is used to improve the
efficiency of lru-gen aging.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20241102104235.62560-5-yangyicong@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b90f92f89d540ed8fb7cf6a3112dc99beacdfaf9..d2ca7b6c6f8594eab683a69fed67ab48560cc0a2 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -38,6 +38,7 @@ config ARM64
        select ARCH_HAS_MEM_ENCRYPT
        select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
        select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+       select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
        select ARCH_HAS_PTE_DEVMAP
        select ARCH_HAS_PTE_SPECIAL
        select ARCH_HAS_HW_PTE_YOUNG

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index c329ea061dc988a05d50931e24bd9b4389028f61..5182feabd943f61a3019f0899b7dce5160586e83 100644 (file)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1259,7 +1259,7 @@ static inline int __ptep_clear_flush_young(struct vm_area_struct *vma,
        return young;
 }
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
                                            unsigned long address,
@@ -1267,7 +1267,7 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 {
        return __ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
 }
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */
 
 static inline pte_t __ptep_get_and_clear(struct mm_struct *mm,
                                       unsigned long address, pte_t *ptep)
@@ -1502,6 +1502,10 @@ static inline void update_mmu_cache_range(struct vm_fault *vmf,
  */
 #define arch_has_hw_pte_young          cpu_has_hw_af
 
+#ifdef CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
+#define arch_has_hw_nonleaf_pmd_young  system_supports_haft
+#endif
+
 /*
  * Experimentally, it's cheap to set the access flag in hardware and we
  * benefit from prefaulting mappings as 'old' to start with.