From: Chunyan Zhang Date: Thu, 13 Nov 2025 07:28:04 +0000 (+0800) Subject: riscv: mm: add soft-dirty page tracking support X-Git-Tag: v6.19-rc1~112^2~30 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2a3ebad4db63e86a9443d6bff4a5977320dc09f6;p=thirdparty%2Flinux.git riscv: mm: add soft-dirty page tracking support The Svrsw60t59b extension allows to free the PTE reserved bits 60 and 59 for software, this patch uses bit 59 for soft-dirty. To add swap PTE soft-dirty tracking, we borrow bit 3 which is available for swap PTEs on RISC-V systems. Link: https://lkml.kernel.org/r/20251113072806.795029-5-zhangchunyan@iscas.ac.cn Signed-off-by: Chunyan Zhang Reviewed-by: Deepak Gupta Cc: Albert Ou Cc: Alexandre Ghiti Cc: Alexandre Ghiti Cc: Al Viro Cc: Andrew Jones Cc: Arnd Bergmann Cc: Axel Rasmussen Cc: Christian Brauner Cc: Conor Dooley Cc: Conor Dooley Cc: David Hildenbrand Cc: Jan Kara Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Xu Cc: Rob Herring Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Yuanchu Xie Signed-off-by: Andrew Morton --- diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 829d95d173cfb..e5f070485bbe1 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -142,6 +142,7 @@ config RISCV select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET select HAVE_ARCH_SECCOMP_FILTER + select HAVE_ARCH_SOFT_DIRTY if 64BIT && MMU && RISCV_ISA_SVRSW60T59B select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h index 179bd4afece46..f3bac2bbc1577 100644 --- a/arch/riscv/include/asm/pgtable-bits.h +++ b/arch/riscv/include/asm/pgtable-bits.h @@ -19,6 +19,25 @@ #define _PAGE_SOFT (3 << 8) /* Reserved for software */ #define _PAGE_SPECIAL (1 << 8) /* RSW: 0x1 */ + +#ifdef CONFIG_MEM_SOFT_DIRTY + +/* ext_svrsw60t59b: bit 59 for soft-dirty tracking */ +#define _PAGE_SOFT_DIRTY \ + ((riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B)) ? \ + (1UL << 59) : 0) +/* + * Bit 3 is always zero for swap entry computation, so we + * can borrow it for swap page soft-dirty tracking. + */ +#define _PAGE_SWP_SOFT_DIRTY \ + ((riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B)) ? \ + _PAGE_EXEC : 0) +#else +#define _PAGE_SOFT_DIRTY 0 +#define _PAGE_SWP_SOFT_DIRTY 0 +#endif /* CONFIG_MEM_SOFT_DIRTY */ + #define _PAGE_TABLE _PAGE_PRESENT /* diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 5a08eb5fe99fc..049ba0e64f941 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -428,7 +428,7 @@ static inline pte_t pte_mkwrite_novma(pte_t pte) static inline pte_t pte_mkdirty(pte_t pte) { - return __pte(pte_val(pte) | _PAGE_DIRTY); + return __pte(pte_val(pte) | _PAGE_DIRTY | _PAGE_SOFT_DIRTY); } static inline pte_t pte_mkclean(pte_t pte) @@ -456,6 +456,42 @@ static inline pte_t pte_mkhuge(pte_t pte) return pte; } +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY +#define pgtable_supports_soft_dirty() \ + (IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) && \ + riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B)) + +static inline bool pte_soft_dirty(pte_t pte) +{ + return !!(pte_val(pte) & _PAGE_SOFT_DIRTY); +} + +static inline pte_t pte_mksoft_dirty(pte_t pte) +{ + return __pte(pte_val(pte) | _PAGE_SOFT_DIRTY); +} + +static inline pte_t pte_clear_soft_dirty(pte_t pte) +{ + return __pte(pte_val(pte) & ~(_PAGE_SOFT_DIRTY)); +} + +static inline bool pte_swp_soft_dirty(pte_t pte) +{ + return !!(pte_val(pte) & _PAGE_SWP_SOFT_DIRTY); +} + +static inline pte_t pte_swp_mksoft_dirty(pte_t pte) +{ + return __pte(pte_val(pte) | _PAGE_SWP_SOFT_DIRTY); +} + +static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) +{ + return __pte(pte_val(pte) & ~(_PAGE_SWP_SOFT_DIRTY)); +} +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ + #ifdef CONFIG_RISCV_ISA_SVNAPOT #define pte_leaf_size(pte) (pte_napot(pte) ? \ napot_cont_size(napot_cont_order(pte)) :\ @@ -805,6 +841,40 @@ static inline pud_t pud_mkspecial(pud_t pud) } #endif +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY +static inline bool pmd_soft_dirty(pmd_t pmd) +{ + return pte_soft_dirty(pmd_pte(pmd)); +} + +static inline pmd_t pmd_mksoft_dirty(pmd_t pmd) +{ + return pte_pmd(pte_mksoft_dirty(pmd_pte(pmd))); +} + +static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd) +{ + return pte_pmd(pte_clear_soft_dirty(pmd_pte(pmd))); +} + +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +static inline bool pmd_swp_soft_dirty(pmd_t pmd) +{ + return pte_swp_soft_dirty(pmd_pte(pmd)); +} + +static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) +{ + return pte_pmd(pte_swp_mksoft_dirty(pmd_pte(pmd))); +} + +static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) +{ + return pte_pmd(pte_swp_clear_soft_dirty(pmd_pte(pmd))); +} +#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ + static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd) { @@ -1003,7 +1073,8 @@ static inline pud_t pud_modify(pud_t pud, pgprot_t newprot) * * Format of swap PTE: * bit 0: _PAGE_PRESENT (zero) - * bit 1 to 3: _PAGE_LEAF (zero) + * bit 1 to 2: (zero) + * bit 3: _PAGE_SWP_SOFT_DIRTY * bit 5: _PAGE_PROT_NONE (zero) * bit 6: exclusive marker * bits 7 to 11: swap type