diff options
Diffstat (limited to 'arch/arm64/include/asm/archrandom.h')
| -rw-r--r-- | arch/arm64/include/asm/archrandom.h | 48 |
1 files changed, 10 insertions, 38 deletions
diff --git a/arch/arm64/include/asm/archrandom.h b/arch/arm64/include/asm/archrandom.h index 109e2a4454be..2f5f3da34782 100644 --- a/arch/arm64/include/asm/archrandom.h +++ b/arch/arm64/include/asm/archrandom.h @@ -5,6 +5,7 @@ #include <linux/arm-smccc.h> #include <linux/bug.h> #include <linux/kernel.h> +#include <linux/irqflags.h> #include <asm/cpufeature.h> #define ARM_SMCCC_TRNG_MIN_VERSION 0x10000UL @@ -58,6 +59,13 @@ static inline bool __arm64_rndrrs(unsigned long *v) return ok; } +static __always_inline bool __cpu_has_rng(void) +{ + if (unlikely(!system_capabilities_finalized() && !preemptible())) + return this_cpu_has_cap(ARM64_HAS_RNG); + return cpus_have_const_cap(ARM64_HAS_RNG); +} + static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs) { /* @@ -66,7 +74,7 @@ static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t * cpufeature code and with potential scheduling between CPUs * with and without the feature. */ - if (max_longs && cpus_have_const_cap(ARM64_HAS_RNG) && __arm64_rndr(v)) + if (max_longs && __cpu_has_rng() && __arm64_rndr(v)) return 1; return 0; } @@ -108,7 +116,7 @@ static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, s * reseeded after each invocation. This is not a 100% fit but good * enough to implement this API if no other entropy source exists. */ - if (cpus_have_const_cap(ARM64_HAS_RNG) && __arm64_rndrrs(v)) + if (__cpu_has_rng() && __arm64_rndrrs(v)) return 1; return 0; @@ -121,40 +129,4 @@ static inline bool __init __early_cpu_has_rndr(void) return (ftr >> ID_AA64ISAR0_EL1_RNDR_SHIFT) & 0xf; } -static inline size_t __init __must_check -arch_get_random_seed_longs_early(unsigned long *v, size_t max_longs) -{ - WARN_ON(system_state != SYSTEM_BOOTING); - - if (!max_longs) - return 0; - - if (smccc_trng_available) { - struct arm_smccc_res res; - - max_longs = min_t(size_t, 3, max_longs); - arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_RND64, max_longs * 64, &res); - if ((int)res.a0 >= 0) { - switch (max_longs) { - case 3: - *v++ = res.a1; - fallthrough; - case 2: - *v++ = res.a2; - fallthrough; - case 1: - *v++ = res.a3; - break; - } - return max_longs; - } - } - - if (__early_cpu_has_rndr() && __arm64_rndr(v)) - return 1; - - return 0; -} -#define arch_get_random_seed_longs_early arch_get_random_seed_longs_early - #endif /* _ASM_ARCHRANDOM_H */ |