From 94a7734d0967e89fac5be1fd5115f5194e4a4017 Mon Sep 17 00:00:00 2001 From: Yong-Xuan Wang Date: Fri, 26 Jul 2024 16:49:26 +0800 Subject: [PATCH] RISC-V: Add Svade and Svadu Extensions Support Svade and Svadu extensions represent two schemes for managing the PTE A/D bits. When the PTE A/D bits need to be set, Svade extension intdicates that a related page fault will be raised. In contrast, the Svadu extension supports hardware updating of PTE A/D bits. Since the Svade extension is mandatory and the Svadu extension is optional in RVA23 profile, by default the M-mode firmware will enable the Svadu extension in the menvcfg CSR when only Svadu is present in DT. This patch detects Svade and Svadu extensions from DT and adds arch_has_hw_pte_young() to enable optimization in MGLRU and __wp_page_copy_user() when we have the PTE A/D bits hardware updating support. Co-developed-by: Jinyu Tang Signed-off-by: Jinyu Tang Signed-off-by: Yong-Xuan Wang Reviewed-by: Andrew Jones Reviewed-by: Alexandre Ghiti Acked-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20240726084931.28924-2-yongxuan.wang@sifive.com Signed-off-by: Anup Patel --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/csr.h | 1 + arch/riscv/include/asm/hwcap.h | 2 ++ arch/riscv/include/asm/pgtable.h | 13 ++++++++++++- arch/riscv/kernel/cpufeature.c | 12 ++++++++++++ 5 files changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 62545946ecf43..2e499918e15ea 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -32,6 +32,7 @@ config RISCV select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_GIGANTIC_PAGE + select ARCH_HAS_HW_PTE_YOUNG select ARCH_HAS_KCOV select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU select ARCH_HAS_MEMBARRIER_CALLBACKS diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h index 25966995da04e..524cd4131c713 100644 --- a/arch/riscv/include/asm/csr.h +++ b/arch/riscv/include/asm/csr.h @@ -195,6 +195,7 @@ /* xENVCFG flags */ #define ENVCFG_STCE (_AC(1, ULL) << 63) #define ENVCFG_PBMTE (_AC(1, ULL) << 62) +#define ENVCFG_ADUE (_AC(1, ULL) << 61) #define ENVCFG_CBZE (_AC(1, UL) << 7) #define ENVCFG_CBCFE (_AC(1, UL) << 6) #define ENVCFG_CBIE_SHIFT 4 diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 46d9de54179ed..7f72789ba3d5d 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -93,6 +93,8 @@ #define RISCV_ISA_EXT_ZCMOP 84 #define RISCV_ISA_EXT_ZAWRS 85 #define RISCV_ISA_EXT_SVVPTC 86 +#define RISCV_ISA_EXT_SVADE 87 +#define RISCV_ISA_EXT_SVADU 88 #define RISCV_ISA_EXT_XLINUXENVCFG 127 diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index e79f15293492d..02aa7ee6def8b 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -113,6 +113,7 @@ #include #include #include +#include #define __page_val_to_pfn(_val) (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT) @@ -284,7 +285,6 @@ static inline pte_t pud_pte(pud_t pud) } #ifdef CONFIG_RISCV_ISA_SVNAPOT -#include static __always_inline bool has_svnapot(void) { @@ -655,6 +655,17 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot) return __pgprot(prot); } +/* + * Both Svade and Svadu control the hardware behavior when the PTE A/D bits need to be set. By + * default the M-mode firmware enables the hardware updating scheme when only Svadu is present in + * DT. + */ +#define arch_has_hw_pte_young arch_has_hw_pte_young +static inline bool arch_has_hw_pte_young(void) +{ + return riscv_has_extension_unlikely(RISCV_ISA_EXT_SVADU); +} + /* * THP functions */ diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 3a8eeaa9310c3..06ca264d48101 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -132,6 +132,16 @@ static int riscv_ext_zcf_validate(const struct riscv_isa_ext_data *data, return -EPROBE_DEFER; } +static int riscv_ext_svadu_validate(const struct riscv_isa_ext_data *data, + const unsigned long *isa_bitmap) +{ + /* SVADE has already been detected, use SVADE only */ + if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_SVADE)) + return -EOPNOTSUPP; + + return 0; +} + static const unsigned int riscv_zk_bundled_exts[] = { RISCV_ISA_EXT_ZBKB, RISCV_ISA_EXT_ZBKC, @@ -378,6 +388,8 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = { __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA), __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF), __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC), + __RISCV_ISA_EXT_DATA(svade, RISCV_ISA_EXT_SVADE), + __RISCV_ISA_EXT_DATA_VALIDATE(svadu, RISCV_ISA_EXT_SVADU, riscv_ext_svadu_validate), __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL), __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT), __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),