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arm64: Verify CPU errata work arounds on hotplugged CPU

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CPU Errata work arounds are detected and applied to the
kernel code at boot time and the data is then freed up.
If a new hotplugged CPU requires a work around which
was not applied at boot time, there is nothing we can
do but simply fail the booting.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Suzuki K Poulose 2016-04-22 12:25:34 +01:00 committed by Will Deacon
parent 25fc11aead
commit 6a6efbb45b
3 changed files with 22 additions and 0 deletions
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1
arch/arm64/include/asm/cpufeature.h
View File

@ -193,6 +193,7 @@ void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
const char *info);
void check_local_cpu_errata(void);
void verify_local_cpu_errata(void);
void verify_local_cpu_capabilities(void);
u64 read_system_reg(u32 id);

20
arch/arm64/kernel/cpu_errata.c
View File

@ -103,6 +103,26 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
}
};
/*
* The CPU Errata work arounds are detected and applied at boot time
* and the related information is freed soon after. If the new CPU requires
* an errata not detected at boot, fail this CPU.
*/
void verify_local_cpu_errata(void)
{
const struct arm64_cpu_capabilities *caps = arm64_errata;
for (; caps->matches; caps++)
if (!cpus_have_cap(caps->capability) &&
caps->matches(caps, SCOPE_LOCAL_CPU)) {
pr_crit("CPU%d: Requires work around for %s, not detected"
" at boot time\n",
smp_processor_id(),
caps->desc ? : "an erratum");
cpu_die_early();
}
}
void check_local_cpu_errata(void)
{
update_cpu_capabilities(arm64_errata, "enabling workaround for");

1
arch/arm64/kernel/cpufeature.c
View File

@ -998,6 +998,7 @@ void verify_local_cpu_capabilities(void)
if (!sys_caps_initialised)
return;
verify_local_cpu_errata();
verify_local_cpu_features(arm64_features);
verify_local_elf_hwcaps(arm64_elf_hwcaps);
if (system_supports_32bit_el0())