diff options
| -rw-r--r-- | Documentation/arm64/cpu-feature-registers.rst | 2 | ||||
| -rw-r--r-- | Documentation/arm64/elf_hwcaps.rst | 4 | ||||
| -rw-r--r-- | arch/arm64/Kconfig | 12 | ||||
| -rw-r--r-- | arch/arm64/include/asm/archrandom.h | 67 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cpucaps.h | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/hwcap.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/sysreg.h | 4 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/hwcap.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 14 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpuinfo.c | 1 |
10 files changed, 108 insertions, 1 deletions
diff --git a/Documentation/arm64/cpu-feature-registers.rst b/Documentation/arm64/cpu-feature-registers.rst index b6e44884e3ad..ce320785fb0c 100644 --- a/Documentation/arm64/cpu-feature-registers.rst +++ b/Documentation/arm64/cpu-feature-registers.rst @@ -117,6 +117,8 @@ infrastructure: +------------------------------+---------+---------+ | Name | bits | visible | +------------------------------+---------+---------+ + | RNDR | [63-60] | y | + +------------------------------+---------+---------+ | TS | [55-52] | y | +------------------------------+---------+---------+ | FHM | [51-48] | y | diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst index 7fa3d215ae6a..276a33414b22 100644 --- a/Documentation/arm64/elf_hwcaps.rst +++ b/Documentation/arm64/elf_hwcaps.rst @@ -204,6 +204,10 @@ HWCAP2_FRINT Functionality implied by ID_AA64ISAR1_EL1.FRINTTS == 0b0001. +HWCAP2_RNG + + Functionality implied by ID_AA64ISAR0_EL1.RNDR == 0b0001. + 4. Unused AT_HWCAP bits ----------------------- diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b1b4476ddb83..835f8158220e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1484,6 +1484,18 @@ config ARM64_PTR_AUTH endmenu +menu "ARMv8.5 architectural features" + +config ARCH_RANDOM + bool "Enable support for random number generation" + default y + help + Random number generation (part of the ARMv8.5 Extensions) + provides a high bandwidth, cryptographically secure + hardware random number generator. + +endmenu + config ARM64_SVE bool "ARM Scalable Vector Extension support" default y diff --git a/arch/arm64/include/asm/archrandom.h b/arch/arm64/include/asm/archrandom.h new file mode 100644 index 000000000000..5ea5a1ce5a5f --- /dev/null +++ b/arch/arm64/include/asm/archrandom.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_ARCHRANDOM_H +#define _ASM_ARCHRANDOM_H + +#ifdef CONFIG_ARCH_RANDOM + +#include <linux/random.h> +#include <asm/cpufeature.h> + +static inline bool __arm64_rndr(unsigned long *v) +{ + bool ok; + + /* + * Reads of RNDR set PSTATE.NZCV to 0b0000 on success, + * and set PSTATE.NZCV to 0b0100 otherwise. + */ + asm volatile( + __mrs_s("%0", SYS_RNDR_EL0) "\n" + " cset %w1, ne\n" + : "=r" (*v), "=r" (ok) + : + : "cc"); + + return ok; +} + +static inline bool __must_check arch_get_random_long(unsigned long *v) +{ + return false; +} + +static inline bool __must_check arch_get_random_int(unsigned int *v) +{ + return false; +} + +static inline bool __must_check arch_get_random_seed_long(unsigned long *v) +{ + /* + * Only support the generic interface after we have detected + * the system wide capability, avoiding complexity with the + * cpufeature code and with potential scheduling between CPUs + * with and without the feature. + */ + if (!cpus_have_const_cap(ARM64_HAS_RNG)) + return false; + + return __arm64_rndr(v); +} + + +static inline bool __must_check arch_get_random_seed_int(unsigned int *v) +{ + unsigned long val; + bool ok = arch_get_random_seed_long(&val); + + *v = val; + return ok; +} + +#else + +static inline bool __arm64_rndr(unsigned long *v) { return false; } + +#endif /* CONFIG_ARCH_RANDOM */ +#endif /* _ASM_ARCHRANDOM_H */ diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index b92683871119..515f4fbcbf91 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -56,7 +56,8 @@ #define ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM 46 #define ARM64_WORKAROUND_1542419 47 #define ARM64_WORKAROUND_1319367 48 +#define ARM64_HAS_RNG 49 -#define ARM64_NCAPS 49 +#define ARM64_NCAPS 50 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 3d2f2472a36c..fa186480e805 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -86,6 +86,7 @@ #define KERNEL_HWCAP_SVESM4 __khwcap2_feature(SVESM4) #define KERNEL_HWCAP_FLAGM2 __khwcap2_feature(FLAGM2) #define KERNEL_HWCAP_FRINT __khwcap2_feature(FRINT) +#define KERNEL_HWCAP_RNG __khwcap2_feature(RNG) /* * This yields a mask that user programs can use to figure out what diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 6e919fafb43d..5e718f279469 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -365,6 +365,9 @@ #define SYS_CTR_EL0 sys_reg(3, 3, 0, 0, 1) #define SYS_DCZID_EL0 sys_reg(3, 3, 0, 0, 7) +#define SYS_RNDR_EL0 sys_reg(3, 3, 2, 4, 0) +#define SYS_RNDRRS_EL0 sys_reg(3, 3, 2, 4, 1) + #define SYS_PMCR_EL0 sys_reg(3, 3, 9, 12, 0) #define SYS_PMCNTENSET_EL0 sys_reg(3, 3, 9, 12, 1) #define SYS_PMCNTENCLR_EL0 sys_reg(3, 3, 9, 12, 2) @@ -539,6 +542,7 @@ ENDIAN_SET_EL1 | SCTLR_EL1_UCI | SCTLR_EL1_RES1) /* id_aa64isar0 */ +#define ID_AA64ISAR0_RNDR_SHIFT 60 #define ID_AA64ISAR0_TS_SHIFT 52 #define ID_AA64ISAR0_FHM_SHIFT 48 #define ID_AA64ISAR0_DP_SHIFT 44 diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index a1e72886b30c..f192ac33fc76 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -65,5 +65,6 @@ #define HWCAP2_SVESM4 (1 << 6) #define HWCAP2_FLAGM2 (1 << 7) #define HWCAP2_FRINT (1 << 8) +#define HWCAP2_RNG (1 << 9) #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 04cf64e9f0c9..3b94e8047c9e 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -119,6 +119,7 @@ static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap); * sync with the documentation of the CPU feature register ABI. */ static const struct arm64_ftr_bits ftr_id_aa64isar0[] = { + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RNDR_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0), @@ -1567,6 +1568,18 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .min_field_value = 1, }, #endif +#ifdef CONFIG_ARCH_RANDOM + { + .desc = "Random Number Generator", + .capability = ARM64_HAS_RNG, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + .sys_reg = SYS_ID_AA64ISAR0_EL1, + .field_pos = ID_AA64ISAR0_RNDR_SHIFT, + .sign = FTR_UNSIGNED, + .min_field_value = 1, + }, +#endif {}, }; @@ -1638,6 +1651,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM), HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2), + HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RNDR_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RNG), HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP), HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP), HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 56bba746da1c..3000dd27816f 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -84,6 +84,7 @@ static const char *const hwcap_str[] = { "svesm4", "flagm2", "frint", + "rng", NULL }; 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