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| author | Jeremy Linton <jeremy.linton@arm.com> | 2019-04-15 16:21:20 -0500 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2019-04-26 16:26:42 +0100 |
| commit | e5ce5e7267ddcbe13ab9ead2542524e1b7993e5a (patch) | |
| tree | 67994973a829ee4f85f584c4052fa0870e4f10b1 /arch | |
| parent | cbafee55b5a0ec47baac622bce6b4d19afe45576 (diff) | |
| download | linux-e5ce5e7267ddcbe13ab9ead2542524e1b7993e5a.tar.bz2 | |
arm64: Provide a command line to disable spectre_v2 mitigation
There are various reasons, such as benchmarking, to disable spectrev2
mitigation on a machine. Provide a command-line option to do so.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@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>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 9950bb0cbd52..d2b2c69d31bb 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -220,6 +220,14 @@ static void qcom_link_stack_sanitization(void) : "=&r" (tmp)); } +static bool __nospectre_v2; +static int __init parse_nospectre_v2(char *str) +{ + __nospectre_v2 = true; + return 0; +} +early_param("nospectre_v2", parse_nospectre_v2); + static void enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) { @@ -231,6 +239,11 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) if (!entry->matches(entry, SCOPE_LOCAL_CPU)) return; + if (__nospectre_v2) { + pr_info_once("spectrev2 mitigation disabled by command line option\n"); + return; + } + if (psci_ops.smccc_version == SMCCC_VERSION_1_0) return; |