From: Zeng Heng Date: Fri, 8 May 2026 16:23:40 +0000 (+0100) Subject: arm64: cpufeature: Add support for the MPAM v0.1 architecture version X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=5302bc1493be7e00367bd9aab0cdcb40bf073011;p=thirdparty%2Flinux.git arm64: cpufeature: Add support for the MPAM v0.1 architecture version According to the MPAM spec [1], the supported architecture versions are v1.0, v1.1 and v0.1. MPAM versions v0.1 and v1.1 are functionally identical, but v0.1 additionally supports the FORCE_NS feature. ID_AA64PR | ID_AA64PR | MPAM Extension | Notes F0_EL1. | F1_EL1. | Architecture | MPAM | MPAM_frac | version | --------------------------------------------------------------------------- 0b0000 | 0b0001 | v0.1 | MPAM v0.1 is implemented. | | | MPAM v0.1 is the same as MPAM v1.1 | | | with FORCE_NS which is | | | incompatible with MPAM v1.0. --------------------------------------------------------------------------- 0b0001 | 0b0000 | v1.0 | MPAM v1.0 is implemented. --------------------------------------------------------------------------- 0b0001 | 0b0001 | v1.1 | MPAM v1.1 is implemented. | | | MPAM v1.1 includes all features of | | | MPAM v1.0. | | | It must not include FORCE_NS. FORCE_NS is a feature that operates in EL3 mode. Consequently, the current Linux MPAM driver is also compatible with MPAM v0.1. To support v0.1, the existing driver which only checks ID_AA64PFR0_EL1.MPAM for the major version needs to examine ID_AA64PFR1_EL1.MPAM_frac for the minor version as well. [1] https://developer.arm.com/documentation/ddi0598/db/?lang=en Signed-off-by: Zeng Heng Reviewed-by: James Morse Signed-off-by: James Morse Acked-by: Catalin Marinas Signed-off-by: Will Deacon --- diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 4de51f8d92cba..a57870fa96db5 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -620,6 +620,13 @@ static inline bool id_aa64pfr0_mpam(u64 pfr0) return val > 0; } +static inline bool id_aa64pfr1_mpamfrac(u64 pfr1) +{ + u32 val = cpuid_feature_extract_unsigned_field(pfr1, ID_AA64PFR1_EL1_MPAM_frac_SHIFT); + + return val > 0; +} + static inline bool id_aa64pfr1_mte(u64 pfr1) { u32 val = cpuid_feature_extract_unsigned_field(pfr1, ID_AA64PFR1_EL1_MTE_SHIFT); diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index 587507a9980ec..aa8ec9df80243 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -510,7 +510,9 @@ #endif .macro finalise_el2_state - check_override id_aa64pfr0, ID_AA64PFR0_EL1_MPAM_SHIFT, .Linit_mpam_\@, .Lskip_mpam_\@, x1, x2 + check_override id_aa64pfr0, ID_AA64PFR0_EL1_MPAM_SHIFT, .Linit_mpam_\@, .Lmpam_minor_\@, x1, x2 +.Lmpam_minor_\@: + check_override id_aa64pfr1, ID_AA64PFR1_EL1_MPAM_frac_SHIFT, .Linit_mpam_\@, .Lskip_mpam_\@, x1, x2 .Linit_mpam_\@: mov x0, #MPAM2_EL2_EnMPAMSM_MASK diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 6d53bb15cf7bb..0a1d198b39951 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1164,6 +1164,14 @@ static __init void detect_system_supports_pseudo_nmi(void) static inline void detect_system_supports_pseudo_nmi(void) { } #endif +static bool detect_ftr_has_mpam(void) +{ + u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + u64 pfr1 = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1); + + return id_aa64pfr0_mpam(pfr0) || id_aa64pfr1_mpamfrac(pfr1); +} + void __init init_cpu_features(struct cpuinfo_arm64 *info) { /* Before we start using the tables, make sure it is sorted */ @@ -1211,7 +1219,7 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) cpacr_restore(cpacr); } - if (id_aa64pfr0_mpam(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) { + if (detect_ftr_has_mpam()) { info->reg_mpamidr = read_cpuid(MPAMIDR_EL1); init_cpu_ftr_reg(SYS_MPAMIDR_EL1, info->reg_mpamidr); } @@ -1467,7 +1475,7 @@ void update_cpu_features(int cpu, cpacr_restore(cpacr); } - if (id_aa64pfr0_mpam(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) { + if (detect_ftr_has_mpam()) { info->reg_mpamidr = read_cpuid(MPAMIDR_EL1); taint |= check_update_ftr_reg(SYS_MPAMIDR_EL1, cpu, info->reg_mpamidr, boot->reg_mpamidr); @@ -2486,7 +2494,7 @@ cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap) static bool test_has_mpam(const struct arm64_cpu_capabilities *entry, int scope) { - if (!has_cpuid_feature(entry, scope)) + if (!detect_ftr_has_mpam()) return false; /* Check firmware actually enabled MPAM on this cpu. */ @@ -3093,7 +3101,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .capability = ARM64_MPAM, .matches = test_has_mpam, .cpu_enable = cpu_enable_mpam, - ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, MPAM, 1) }, { .desc = "Memory Partitioning And Monitoring Virtualisation",