[PATCH 1/2] arm64: capabilities: Allow flexibility in scope
From: suzuki.poulose@arm.com (Suzuki K Poulose)
Date: 2018-02-08 12:13:05
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
So far we have restricted the scopes for the capabilities
as follows :
1) Errata workaround check are run all CPUs (i.e, always
SCOPE_LOCAL_CPU)
2) Arm64 features are run only once after the sanitised
feature registers are available using the SCOPE_SYSTEM.
This prevents detecting cpu features that can be detected
on one or more CPUs with SCOPE_LOCAL_CPU (e.g KPTI). Similarly
for errata workaround with SCOPE_SYSTEM.
This patch makes sure that we allow flexibility of having
any scope for a capability. So, we now run through both
arm64_features and arm64_errata in two phases for detection:
a) with SCOPE_LOCAL_CPU filter on each boot time enabled
CPUs.
b) with SCOPE_SYSTEM filter only once after all boot time
enabled CPUs are active.
Cc: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/kernel/cpufeature.c | 33 ++++++++++++++++++++++++---------
1 file changed, 24 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 61d4c3cfb1cc..e1a56fa889a5 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -505,6 +505,7 @@ static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new) extern const struct arm64_cpu_capabilities arm64_errata[]; static void update_cpu_errata_workarounds(void); +static void update_cpu_local_features(void); void __init init_cpu_features(struct cpuinfo_arm64 *info) {
@@ -554,6 +555,7 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) * initialised the cpu feature infrastructure. */ update_cpu_errata_workarounds(); + update_cpu_local_features(); } static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
@@ -1387,13 +1389,15 @@ static void verify_local_cpu_errata_workarounds(void) static void update_cpu_errata_workarounds(void) { update_cpu_capabilities(arm64_errata, - ARM64_CPUCAP_SCOPE_ALL, + ARM64_CPUCAP_SCOPE_LOCAL_CPU, "enabling workaround for"); } -static void __init enable_errata_workarounds(void) +static void update_cpu_local_features(void) { - enable_cpu_capabilities(arm64_errata, ARM64_CPUCAP_SCOPE_ALL); + update_cpu_capabilities(arm64_features, + ARM64_CPUCAP_SCOPE_LOCAL_CPU, + "detected feature:"); } /*
@@ -1430,23 +1434,34 @@ void check_local_cpu_capabilities(void) /* * If we haven't finalised the system capabilities, this CPU gets - * a chance to update the errata work arounds. + * a chance to update the errata work arounds and local CPU features. * Otherwise, this CPU should verify that it has all the system * advertised capabilities. */ - if (!sys_caps_initialised) + if (!sys_caps_initialised) { update_cpu_errata_workarounds(); - else + update_cpu_local_features(); + } else { verify_local_cpu_capabilities(); + } } static void __init setup_feature_capabilities(void) { update_cpu_capabilities(arm64_features, - ARM64_CPUCAP_SCOPE_ALL, "detected feature:"); + ARM64_CPUCAP_SCOPE_SYSTEM, + "detected feature:"); enable_cpu_capabilities(arm64_features, ARM64_CPUCAP_SCOPE_ALL); } +static void __init setup_errata_workarounds(void) +{ + update_cpu_capabilities(arm64_errata, + ARM64_CPUCAP_SCOPE_SYSTEM, + "enabling workaround for"); + enable_cpu_capabilities(arm64_errata, ARM64_CPUCAP_SCOPE_ALL); +} + DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready); EXPORT_SYMBOL(arm64_const_caps_ready);
@@ -1468,9 +1483,9 @@ void __init setup_cpu_features(void) u32 cwg; int cls; - /* Set the CPU feature capabilies */ + /* Finalise the CPU capabilities */ setup_feature_capabilities(); - enable_errata_workarounds(); + setup_errata_workarounds(); mark_const_caps_ready(); setup_elf_hwcaps(arm64_elf_hwcaps);
--
2.14.3