From: Yicong Yang <yangyicong@hisilicon.com> commit efe72541355d4d40a4f076af453f6533e98e058c upstream. Armv8.9/v9.4 introduces the feature Hardware managed Access Flag for Table descriptors (FEAT_HAFT). The feature is indicated by ID_AA64MMFR1_EL1.HAFDBS == 0b0011 and can be enabled by TCR2_EL1.HAFT so it has a dependency on FEAT_TCR2. Adds the Kconfig for FEAT_HAFT and support detecting and enabling the feature. The feature is enabled in __cpu_setup() before MMU on just like HA. A CPU capability is added to notify the user of the feature. Add definition of P{G,4,U,M}D_TABLE_AF bit and set the AF bit when creating the page table, which will save the hardware from having to update them at runtime. This will be ignored if FEAT_HAFT is not enabled. The AF bit of table descriptors cannot be managed by the software per spec, unlike the HA. So this should be used only if it's supported system wide by system_supports_haft(). Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Link: https://lore.kernel.org/r/20241102104235.62560-4-yangyicong@huawei.com Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> [catalin.marinas@arm.com: added the ID check back to __cpu_setup in case of future CPU errata] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Conflicts: arch/arm64/Kconfig arch/arm64/include/asm/cpufeature.h arch/arm64/kernel/cpufeature.c arch/arm64/mm/mmu.c arch/arm64/tools/cpucaps [Context conflicts] Signed-off-by: JiangShui Yang <yangjiangshui@h-partners.com> Signed-off-by: Qi Xi <xiqi2@huawei.com> --- arch/arm64/Kconfig | 16 ++++++++++++++++ arch/arm64/include/asm/cpufeature.h | 6 ++++++ arch/arm64/include/asm/pgalloc.h | 10 ++++++---- arch/arm64/include/asm/pgtable-hwdef.h | 3 +++ arch/arm64/include/asm/sysreg.h | 1 + arch/arm64/kernel/cpufeature.c | 18 ++++++++++++++++++ arch/arm64/mm/mmu.c | 6 +++--- arch/arm64/mm/proc.S | 7 ++++++- arch/arm64/tools/cpucaps | 1 + 9 files changed, 60 insertions(+), 8 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 6890847c1a13..750ed20347fe 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1945,6 +1945,22 @@ config ARM64_EPAN The feature is detected at runtime, and will remain disabled if the cpu does not implement the feature. + +config ARM64_HAFT + bool "Support for Hardware managed Access Flag for Table Descriptors" + depends on ARM64_HW_AFDBM + default y + help + The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access + Flag for Table descriptors. When enabled an architectural executed + memory access will update the Access Flag in each Table descriptor + which is accessed during the translation table walk and for which + the Access Flag is 0. The Access Flag of the Table descriptor use + the same bit of PTE_AF. + + The feature will only be enabled if all the CPUs in the system + support this feature. If unsure, say Y. + endmenu config ARM64_SVE diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 5df2188f8839..266ebca324ea 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -808,6 +808,12 @@ static inline bool system_supports_tlb_range(void) cpus_have_const_cap(ARM64_HAS_TLB_RANGE); } +static inline bool system_supports_haft(void) +{ + return IS_ENABLED(CONFIG_ARM64_HAFT) && + cpus_have_final_cap(ARM64_HAFT); +} + int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt); bool try_emulate_mrs(struct pt_regs *regs, u32 isn); diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h index 237224484d0f..661964e99b9d 100644 --- a/arch/arm64/include/asm/pgalloc.h +++ b/arch/arm64/include/asm/pgalloc.h @@ -27,7 +27,7 @@ static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot) static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp) { - pudval_t pudval = PUD_TYPE_TABLE; + pudval_t pudval = PUD_TYPE_TABLE | PUD_TABLE_AF; pudval |= (mm == &init_mm) ? PUD_TABLE_UXN : PUD_TABLE_PXN; __pud_populate(pudp, __pa(pmdp), pudval); @@ -48,7 +48,7 @@ static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot) static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp) { - p4dval_t p4dval = P4D_TYPE_TABLE; + p4dval_t p4dval = P4D_TYPE_TABLE | P4D_TABLE_AF; p4dval |= (mm == &init_mm) ? P4D_TABLE_UXN : P4D_TABLE_PXN; __p4d_populate(p4dp, __pa(pudp), p4dval); @@ -77,14 +77,16 @@ static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep) { VM_BUG_ON(mm && mm != &init_mm); - __pmd_populate(pmdp, __pa(ptep), PMD_TYPE_TABLE | PMD_TABLE_UXN); + __pmd_populate(pmdp, __pa(ptep), + PMD_TYPE_TABLE | PMD_TABLE_AF | PMD_TABLE_UXN); } static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep) { VM_BUG_ON(mm == &init_mm); - __pmd_populate(pmdp, page_to_phys(ptep), PMD_TYPE_TABLE | PMD_TABLE_PXN); + __pmd_populate(pmdp, page_to_phys(ptep), + PMD_TYPE_TABLE | PMD_TABLE_AF | PMD_TABLE_PXN); } #endif diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index 66671ff05183..115e0dced25b 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -94,6 +94,7 @@ #define P4D_TYPE_MASK (_AT(p4dval_t, 3) << 0) #define P4D_TYPE_SECT (_AT(p4dval_t, 1) << 0) #define P4D_SECT_RDONLY (_AT(p4dval_t, 1) << 7) /* AP[2] */ +#define P4D_TABLE_AF (_AT(p4dval_t, 1) << 10) /* Ignored if no FEAT_HAFT */ #define P4D_TABLE_PXN (_AT(p4dval_t, 1) << 59) #define P4D_TABLE_UXN (_AT(p4dval_t, 1) << 60) @@ -105,6 +106,7 @@ #define PUD_TYPE_MASK (_AT(pudval_t, 3) << 0) #define PUD_TYPE_SECT (_AT(pudval_t, 1) << 0) #define PUD_SECT_RDONLY (_AT(pudval_t, 1) << 7) /* AP[2] */ +#define PUD_TABLE_AF (_AT(pudval_t, 1) << 10) /* Ignored if no FEAT_HAFT */ #define PUD_TABLE_PXN (_AT(pudval_t, 1) << 59) #define PUD_TABLE_UXN (_AT(pudval_t, 1) << 60) @@ -115,6 +117,7 @@ #define PMD_TYPE_TABLE (_AT(pmdval_t, 3) << 0) #define PMD_TYPE_SECT (_AT(pmdval_t, 1) << 0) #define PMD_TABLE_BIT (_AT(pmdval_t, 1) << 1) +#define PMD_TABLE_AF (_AT(pmdval_t, 1) << 10) /* Ignored if no FEAT_HAFT */ /* * Section diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 6f4c09bd3f7e..995a1286cbc2 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -1093,6 +1093,7 @@ #define ID_AA64MMFR1_EL1_ETS_ETS2 UL(0b0010) #define ID_AA64MMFR1_EL1_ETS_ETS3 UL(0b0011) +#define ID_AA64MMFR1_EL1_HAFDBS_SHIFT 0 #define ID_AA64MMFR1_EL1_HAFDBS_HAFT UL(0b0011) #define ID_AA64MMFR1_EL1_HAFDBS_HDBSS UL(0b0100) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index e48894fb575d..3b7bd58665f3 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2216,6 +2216,24 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_hw_dbm, .cpu_enable = cpu_enable_hw_dbm, }, +#endif +#ifdef CONFIG_ARM64_HAFT + { + .desc = "Hardware managed Access Flag for Table Descriptors", + /* + * Contrary to the page/block access flag, the table access flag + * cannot be emulated in software (no access fault will occur). + * Therefore this should be used only if it's supported system + * wide. + */ + .capability = ARM64_HAFT, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + .sys_reg = SYS_ID_AA64MMFR1_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64MMFR1_EL1_HAFDBS_SHIFT, + .min_field_value = ID_AA64MMFR1_EL1_HAFDBS_HAFT, + }, #endif { .desc = "CRC32 instructions", diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index d357d3960a26..e21eb04cc0d9 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -188,7 +188,7 @@ static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, BUG_ON(pmd_sect(pmd)); if (pmd_none(pmd)) { - pmdval_t pmdval = PMD_TYPE_TABLE | PMD_TABLE_UXN; + pmdval_t pmdval = PMD_TYPE_TABLE | PMD_TABLE_UXN | PMD_TABLE_AF; phys_addr_t pte_phys; if (flags & NO_EXEC_MAPPINGS) @@ -266,7 +266,7 @@ static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr, */ BUG_ON(pud_sect(pud)); if (pud_none(pud)) { - pudval_t pudval = PUD_TYPE_TABLE | PUD_TABLE_UXN; + pudval_t pudval = PUD_TYPE_TABLE | PUD_TABLE_UXN | PUD_TABLE_AF; phys_addr_t pmd_phys; if (flags & NO_EXEC_MAPPINGS) @@ -317,7 +317,7 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end, p4d_t p4d = READ_ONCE(*p4dp); if (p4d_none(p4d)) { - p4dval_t p4dval = P4D_TYPE_TABLE | P4D_TABLE_UXN; + p4dval_t p4dval = P4D_TYPE_TABLE | P4D_TABLE_UXN | P4D_TABLE_AF; phys_addr_t pud_phys; if (flags & NO_EXEC_MAPPINGS) diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 3d3c081e7881..af7c5139b621 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -450,9 +450,14 @@ SYM_FUNC_START(__cpu_setup) * via capabilities. */ mrs x9, ID_AA64MMFR1_EL1 - and x9, x9, ID_AA64MMFR1_EL1_HAFDBS_MASK + ubfx x9, x9, ID_AA64MMFR1_EL1_HAFDBS_SHIFT, #4 cbz x9, 1f orr tcr, tcr, #TCR_HA // hardware Access flag update +#ifdef CONFIG_ARM64_HAFT + cmp x9, ID_AA64MMFR1_EL1_HAFDBS_HAFT + b.lt 1f + orr tcr2, tcr2, TCR2_EL1x_HAFT +#endif /* CONFIG_ARM64_HAFT */ 1: #endif /* CONFIG_ARM64_HW_AFDBM */ msr mair_el1, mair diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 07891af8aa94..c7282a5d4726 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -38,6 +38,7 @@ HAS_SYSREG_GIC_CPUIF HAS_TIDCP1 HAS_TLB_RANGE HAS_VIRT_HOST_EXTN +HAFT HW_DBM KVM_PROTECTED_MODE MISMATCHED_CACHE_TYPE -- 2.33.0