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Linux kernel mirror (for testing)
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linux
Merge branch 'for-next/rng' into for-next/core
Add support for the TRNG firmware call introduced by Arm spec DEN0098.
* for-next/rng:
arm64: Add support for SMCCC TRNG entropy source
firmware: smccc: Introduce SMCCC TRNG framework
firmware: smccc: Add SMCCC TRNG function call IDs
+119
-10
+10
arch/arm/include/asm/archrandom.h
+10
arch/arm/include/asm/archrandom.h
+72
-10
arch/arm64/include/asm/archrandom.h
+72
-10
arch/arm64/include/asm/archrandom.h
···
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#ifdef CONFIG_ARCH_RANDOM
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#include <linux/arm-smccc.h>
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#include <linux/bug.h>
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#include <linux/kernel.h>
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#include <asm/cpufeature.h>
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#define ARM_SMCCC_TRNG_MIN_VERSION 0x10000UL
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extern bool smccc_trng_available;
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static inline bool __init smccc_probe_trng(void)
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{
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struct arm_smccc_res res;
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arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_VERSION, &res);
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if ((s32)res.a0 < 0)
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return false;
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return res.a0 >= ARM_SMCCC_TRNG_MIN_VERSION;
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}
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static inline bool __arm64_rndr(unsigned long *v)
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{
···
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static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
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{
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struct arm_smccc_res res;
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/*
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* We prefer the SMCCC call, since its semantics (return actual
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* hardware backed entropy) is closer to the idea behind this
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* function here than what even the RNDRSS register provides
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* (the output of a pseudo RNG freshly seeded by a TRNG).
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*/
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if (smccc_trng_available) {
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arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_RND64, 64, &res);
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if ((int)res.a0 >= 0) {
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*v = res.a3;
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return true;
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}
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}
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/*
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* Only support the generic interface after we have detected
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* the system wide capability, avoiding complexity with the
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* cpufeature code and with potential scheduling between CPUs
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* with and without the feature.
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*/
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-
if (!cpus_have_const_cap(ARM64_HAS_RNG))
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return false;
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if (cpus_have_const_cap(ARM64_HAS_RNG) && __arm64_rndr(v))
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return true;
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return __arm64_rndr(v);
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return false;
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}
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-
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static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
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{
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struct arm_smccc_res res;
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unsigned long val;
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bool ok = arch_get_random_seed_long(&val);
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*v = val;
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return ok;
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if (smccc_trng_available) {
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arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_RND64, 32, &res);
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if ((int)res.a0 >= 0) {
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*v = res.a3 & GENMASK(31, 0);
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return true;
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}
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}
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if (cpus_have_const_cap(ARM64_HAS_RNG)) {
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if (__arm64_rndr(&val)) {
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*v = val;
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return true;
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}
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}
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return false;
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}
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static inline bool __init __early_cpu_has_rndr(void)
···
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{
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WARN_ON(system_state != SYSTEM_BOOTING);
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if (!__early_cpu_has_rndr())
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return false;
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if (smccc_trng_available) {
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struct arm_smccc_res res;
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return __arm64_rndr(v);
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arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_RND64, 64, &res);
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if ((int)res.a0 >= 0) {
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*v = res.a3;
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return true;
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}
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}
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if (__early_cpu_has_rndr() && __arm64_rndr(v))
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return true;
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return false;
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}
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#define arch_get_random_seed_long_early arch_get_random_seed_long_early
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#else /* !CONFIG_ARCH_RANDOM */
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static inline bool __init smccc_probe_trng(void)
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{
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return false;
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}
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#endif /* CONFIG_ARCH_RANDOM */
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#endif /* _ASM_ARCHRANDOM_H */
+6
drivers/firmware/smccc/smccc.c
+6
drivers/firmware/smccc/smccc.c
···
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#define pr_fmt(fmt) "smccc: " fmt
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#include <linux/cache.h>
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#include <linux/init.h>
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#include <linux/arm-smccc.h>
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#include <asm/archrandom.h>
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static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
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static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
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bool __ro_after_init smccc_trng_available = false;
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void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
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{
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smccc_version = version;
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smccc_conduit = conduit;
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smccc_trng_available = smccc_probe_trng();
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}
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enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
+31
include/linux/arm-smccc.h
+31
include/linux/arm-smccc.h
···
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ARM_SMCCC_OWNER_STANDARD_HYP, \
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0x21)
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/* TRNG entropy source calls (defined by ARM DEN0098) */
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#define ARM_SMCCC_TRNG_VERSION \
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ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
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ARM_SMCCC_SMC_32, \
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ARM_SMCCC_OWNER_STANDARD, \
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0x50)
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#define ARM_SMCCC_TRNG_FEATURES \
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ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
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ARM_SMCCC_SMC_32, \
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ARM_SMCCC_OWNER_STANDARD, \
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0x51)
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#define ARM_SMCCC_TRNG_GET_UUID \
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ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
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ARM_SMCCC_SMC_32, \
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ARM_SMCCC_OWNER_STANDARD, \
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0x52)
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#define ARM_SMCCC_TRNG_RND32 \
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ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
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ARM_SMCCC_SMC_32, \
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ARM_SMCCC_OWNER_STANDARD, \
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0x53)
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#define ARM_SMCCC_TRNG_RND64 \
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ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
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ARM_SMCCC_SMC_64, \
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ARM_SMCCC_OWNER_STANDARD, \
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0x53)
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/*
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* Return codes defined in ARM DEN 0070A
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* ARM DEN 0070A is now merged/consolidated into ARM DEN 0028 C