From 552ae76face5584085845646c5f57e10c1a4ebdc Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sat, 22 Dec 2018 12:00:10 +0000 Subject: [PATCH 1/3] arm64: Detect the ARMv8.4 TTL feature In order to reduce the cost of TLB invalidation, the ARMv8.4 TTL feature allows TLBs to be issued with a level allowing for quicker invalidation. Let's detect the feature for now. Further patches will implement its actual usage. Reviewed-by : Suzuki K Polose Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/include/asm/sysreg.h | 1 + arch/arm64/kernel/cpufeature.c | 11 +++++++++++ 3 files changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index d7b3bb0cb1804..d44ba903d11d6 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -62,7 +62,8 @@ #define ARM64_HAS_GENERIC_AUTH 52 #define ARM64_HAS_32BIT_EL1 53 #define ARM64_BTI 54 +#define ARM64_HAS_ARMv8_4_TTL 55 -#define ARM64_NCAPS 55 +#define ARM64_NCAPS 56 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 463175f80341f..8c209aa172737 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -746,6 +746,7 @@ /* id_aa64mmfr2 */ #define ID_AA64MMFR2_E0PD_SHIFT 60 +#define ID_AA64MMFR2_TTL_SHIFT 48 #define ID_AA64MMFR2_FWB_SHIFT 40 #define ID_AA64MMFR2_AT_SHIFT 32 #define ID_AA64MMFR2_LVA_SHIFT 16 diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 9f63053a63a98..e877f56ff1ab9 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -323,6 +323,7 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = { static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_E0PD_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_TTL_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0), @@ -1882,6 +1883,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_cpuid_feature, .cpu_enable = cpu_has_fwb, }, + { + .desc = "ARMv8.4 Translation Table Level", + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .capability = ARM64_HAS_ARMv8_4_TTL, + .sys_reg = SYS_ID_AA64MMFR2_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64MMFR2_TTL_SHIFT, + .min_field_value = 1, + .matches = has_cpuid_feature, + }, #ifdef CONFIG_ARM64_HW_AFDBM { /* From 6fcfdf6d72898d1c5118d7dd3d3d38690e2f6a64 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 28 Dec 2018 09:11:50 +0000 Subject: [PATCH 2/3] arm64: Document SW reserved PTE/PMD bits in Stage-2 descriptors Advertise bits [58:55] as reserved for SW in the S2 descriptors. Reviewed-by: Andrew Scull Acked-by: Catalin Marinas Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/pgtable-hwdef.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index 9c91a8f93a0e9..de0b603955f48 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -178,10 +178,12 @@ #define PTE_S2_RDONLY (_AT(pteval_t, 1) << 6) /* HAP[2:1] */ #define PTE_S2_RDWR (_AT(pteval_t, 3) << 6) /* HAP[2:1] */ #define PTE_S2_XN (_AT(pteval_t, 2) << 53) /* XN[1:0] */ +#define PTE_S2_SW_RESVD (_AT(pteval_t, 15) << 55) /* Reserved for SW */ #define PMD_S2_RDONLY (_AT(pmdval_t, 1) << 6) /* HAP[2:1] */ #define PMD_S2_RDWR (_AT(pmdval_t, 3) << 6) /* HAP[2:1] */ #define PMD_S2_XN (_AT(pmdval_t, 2) << 53) /* XN[1:0] */ +#define PMD_S2_SW_RESVD (_AT(pmdval_t, 15) << 55) /* Reserved for SW */ #define PUD_S2_RDONLY (_AT(pudval_t, 1) << 6) /* HAP[2:1] */ #define PUD_S2_RDWR (_AT(pudval_t, 3) << 6) /* HAP[2:1] */ From c10bc62ae4d2135c9db40e96a8e994164faee531 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 2 Jan 2019 10:21:29 +0000 Subject: [PATCH 3/3] arm64: Add level-hinted TLB invalidation helper Add a level-hinted TLB invalidation helper that only gets used if ARMv8.4-TTL gets detected. Reviewed-by: Alexandru Elisei Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/stage2_pgtable.h | 9 +++++ arch/arm64/include/asm/tlbflush.h | 45 +++++++++++++++++++++++++ 2 files changed, 54 insertions(+) diff --git a/arch/arm64/include/asm/stage2_pgtable.h b/arch/arm64/include/asm/stage2_pgtable.h index b767904f28b1d..996bf98f0cab4 100644 --- a/arch/arm64/include/asm/stage2_pgtable.h +++ b/arch/arm64/include/asm/stage2_pgtable.h @@ -256,4 +256,13 @@ stage2_pgd_addr_end(struct kvm *kvm, phys_addr_t addr, phys_addr_t end) return (boundary - 1 < end - 1) ? boundary : end; } +/* + * Level values for the ARMv8.4-TTL extension, mapping PUD/PMD/PTE and + * the architectural page-table level. + */ +#define S2_NO_LEVEL_HINT 0 +#define S2_PUD_LEVEL 1 +#define S2_PMD_LEVEL 2 +#define S2_PTE_LEVEL 3 + #endif /* __ARM64_S2_PGTABLE_H_ */ diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h index bc39490647259..3353f26302de7 100644 --- a/arch/arm64/include/asm/tlbflush.h +++ b/arch/arm64/include/asm/tlbflush.h @@ -10,6 +10,7 @@ #ifndef __ASSEMBLY__ +#include #include #include #include @@ -59,6 +60,50 @@ __ta; \ }) +/* + * Level-based TLBI operations. + * + * When ARMv8.4-TTL exists, TLBI operations take an additional hint for + * the level at which the invalidation must take place. If the level is + * wrong, no invalidation may take place. In the case where the level + * cannot be easily determined, a 0 value for the level parameter will + * perform a non-hinted invalidation. + * + * For Stage-2 invalidation, use the level values provided to that effect + * in asm/stage2_pgtable.h. + */ +#define TLBI_TTL_MASK GENMASK_ULL(47, 44) +#define TLBI_TTL_TG_4K 1 +#define TLBI_TTL_TG_16K 2 +#define TLBI_TTL_TG_64K 3 + +#define __tlbi_level(op, addr, level) \ + do { \ + u64 arg = addr; \ + \ + if (cpus_have_const_cap(ARM64_HAS_ARMv8_4_TTL) && \ + level) { \ + u64 ttl = level & 3; \ + \ + switch (PAGE_SIZE) { \ + case SZ_4K: \ + ttl |= TLBI_TTL_TG_4K << 2; \ + break; \ + case SZ_16K: \ + ttl |= TLBI_TTL_TG_16K << 2; \ + break; \ + case SZ_64K: \ + ttl |= TLBI_TTL_TG_64K << 2; \ + break; \ + } \ + \ + arg &= ~TLBI_TTL_MASK; \ + arg |= FIELD_PREP(TLBI_TTL_MASK, ttl); \ + } \ + \ + __tlbi(op, arg); \ + } while(0) + /* * TLB Invalidation * ================