[PATCH v3 1/6] arm64: cpufeature: Allow early detect of specific features

From: Julien Thierry
Date: Mon May 21 2018 - 06:40:55 EST


From: Daniel Thompson <daniel.thompson@xxxxxxxxxx>

Currently it is not possible to detect features of the boot CPU
until the other CPUs have been brought up.

This prevents us from reacting to features of the boot CPU until
fairly late in the boot process. To solve this we allow a subset
of features (that are likely to be common to all clusters) to be
detected based on the boot CPU alone.

Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
[julien.thierry@xxxxxxx: check non-boot cpu missing early features, avoid
duplicates between early features and normal
features]
Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
arch/arm64/kernel/cpufeature.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9d1b06d..e03e897 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1030,7 +1030,7 @@ static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
{
.desc = "GIC system register CPU interface",
.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
- .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
.matches = has_useable_gicv3_cpuif,
.sys_reg = SYS_ID_AA64PFR0_EL1,
.field_pos = ID_AA64PFR0_GIC_SHIFT,
--
1.9.1