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 --- arch/arm64/include/asm/cpufeature.h | 4 ---- arch/arm64/kernel/cpu_errata.c | 9 +++++---- 2 files changed, 5 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 510f687d269a..dda6e5056810 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -525,11 +525,7 @@ static inline int arm64_get_ssbd_state(void) #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__ */
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 3758ba538a43..10571a378f4c 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -239,7 +239,6 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) } #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; @@ -312,6 +311,11 @@ void __init arm64_enable_wa2_handling(struct alt_instr *alt,
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)); @@ -431,7 +435,6 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
return required; } -#endif /* CONFIG_ARM64_SSBD */
#ifdef CONFIG_ARM64_ERRATUM_1463225 DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa); @@ -710,14 +713,12 @@ const struct arm64_cpu_capabilities arm64_errata[] = { ERRATA_MIDR_RANGE_LIST(arm64_harden_el2_vectors), }, #endif -#ifdef CONFIG_ARM64_SSBD { .desc = "Speculative Store Bypass Disable", .capability = ARM64_SSBD, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, .matches = has_ssbd_mitigation, }, -#endif #ifdef CONFIG_ARM64_ERRATUM_1463225 { .desc = "ARM erratum 1463225",