From: Andre Przywara andre.przywara@arm.com
mainline inclusion from mainline-v5.12-rc1 commit a37e31fc97ef category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4QOJF CVE: NA
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The ARM DEN0098 document describe an SMCCC based firmware service to deliver hardware generated random numbers. Its existence is advertised according to the SMCCC v1.1 specification.
Add a (dummy) call to probe functions implemented in each architecture (ARM and arm64), to determine the existence of this interface. For now this return false, but this will be overwritten by each architecture's support patch.
Signed-off-by: Andre Przywara andre.przywara@arm.com Reviewed-by: Linus Walleij linus.walleij@linaro.org Reviewed-by: Sudeep Holla sudeep.holla@arm.com Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- arch/arm/include/asm/archrandom.h | 10 ++++++++++ arch/arm64/include/asm/archrandom.h | 12 ++++++++++++ drivers/firmware/smccc/smccc.c | 6 ++++++ 3 files changed, 28 insertions(+) create mode 100644 arch/arm/include/asm/archrandom.h
diff --git a/arch/arm/include/asm/archrandom.h b/arch/arm/include/asm/archrandom.h new file mode 100644 index 000000000000..a8e84ca5c2ee --- /dev/null +++ b/arch/arm/include/asm/archrandom.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_ARCHRANDOM_H +#define _ASM_ARCHRANDOM_H + +static inline bool __init smccc_probe_trng(void) +{ + return false; +} + +#endif /* _ASM_ARCHRANDOM_H */ diff --git a/arch/arm64/include/asm/archrandom.h b/arch/arm64/include/asm/archrandom.h index ffb1a40d5475..abe07c21da8e 100644 --- a/arch/arm64/include/asm/archrandom.h +++ b/arch/arm64/include/asm/archrandom.h @@ -8,6 +8,11 @@ #include <linux/kernel.h> #include <asm/cpufeature.h>
+static inline bool __init smccc_probe_trng(void) +{ + return false; +} + static inline bool __arm64_rndr(unsigned long *v) { bool ok; @@ -79,5 +84,12 @@ arch_get_random_seed_long_early(unsigned long *v) } #define arch_get_random_seed_long_early arch_get_random_seed_long_early
+#else /* !CONFIG_ARCH_RANDOM */ + +static inline bool __init smccc_probe_trng(void) +{ + return false; +} + #endif /* CONFIG_ARCH_RANDOM */ #endif /* _ASM_ARCHRANDOM_H */ diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c index 00c88b809c0c..d52bfc5ed5e4 100644 --- a/drivers/firmware/smccc/smccc.c +++ b/drivers/firmware/smccc/smccc.c @@ -5,16 +5,22 @@
#define pr_fmt(fmt) "smccc: " fmt
+#include <linux/cache.h> #include <linux/init.h> #include <linux/arm-smccc.h> +#include <asm/archrandom.h>
static u32 smccc_version = ARM_SMCCC_VERSION_1_0; static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
+bool __ro_after_init smccc_trng_available = false; + void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit) { smccc_version = version; smccc_conduit = conduit; + + smccc_trng_available = smccc_probe_trng(); }
enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)