From: Jeremy Linton jeremy.linton@arm.com
[ Upstream commit d42281b6e49510f078ace15a8ea10f71e6262581 ]
Ensure we are always able to detect whether or not the CPU is affected by SSB, so that we can later advertise this to userspace.
Signed-off-by: Jeremy Linton jeremy.linton@arm.com Reviewed-by: Andre Przywara andre.przywara@arm.com Reviewed-by: Catalin Marinas catalin.marinas@arm.com Tested-by: Stefan Wahren stefan.wahren@i2se.com [will: Use IS_ENABLED instead of #ifdef] Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/include/asm/cpufeature.h | 4 ---- arch/arm64/kernel/cpu_errata.c | 9 +++++---- 2 files changed, 5 insertions(+), 8 deletions(-)
--- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -493,11 +493,7 @@ static inline int arm64_get_ssbd_state(v #endif }
-#ifdef CONFIG_ARM64_SSBD void arm64_set_ssbd_mitigation(bool state); -#else -static inline void arm64_set_ssbd_mitigation(bool state) {} -#endif
#endif /* __ASSEMBLY__ */
--- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -231,7 +231,6 @@ enable_smccc_arch_workaround_1(const str } #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */
-#ifdef CONFIG_ARM64_SSBD DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
int ssbd_state __read_mostly = ARM64_SSBD_KERNEL; @@ -304,6 +303,11 @@ void __init arm64_enable_wa2_handling(st
void arm64_set_ssbd_mitigation(bool state) { + if (!IS_ENABLED(CONFIG_ARM64_SSBD)) { + pr_info_once("SSBD disabled by kernel configuration\n"); + return; + } + if (this_cpu_has_cap(ARM64_SSBS)) { if (state) asm volatile(SET_PSTATE_SSBS(0)); @@ -423,7 +427,6 @@ out_printmsg:
return required; } -#endif /* CONFIG_ARM64_SSBD */
#define CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max) \ .matches = is_affected_midr_range, \ @@ -627,14 +630,12 @@ const struct arm64_cpu_capabilities arm6 .cpu_enable = enable_smccc_arch_workaround_1, }, #endif -#ifdef CONFIG_ARM64_SSBD { .desc = "Speculative Store Bypass Disable", .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, .capability = ARM64_SSBD, .matches = has_ssbd_mitigation, }, -#endif { } };