From: Suzuki K Poulose suzuki.poulose@arm.com
commit c47a1900ad710fd2c97127e2ba19da1df79cf733 upstream.
Right now we run through the work around checks on a CPU from __cpuinfo_store_cpu. There are some problems with that:
1) We initialise the system wide CPU feature registers only after the Boot CPU updates its cpuinfo. Now, if a work around depends on the variance of a CPU ID feature (e.g, check for Cache Line size mismatch), we have no way of performing it cleanly for the boot CPU.
2) It is out of place, invoked from __cpuinfo_store_cpu() in cpuinfo.c. It is not an obvious place for that.
This patch rearranges the CPU specific capability(aka work around) checks.
1) At the moment we use verify_local_cpu_capabilities() to check if a new CPU has all the system advertised features. Use this for the secondary CPUs to perform the work around check. For that we rename verify_local_cpu_capabilities() => check_local_cpu_capabilities() which:
If the system wide capabilities haven't been initialised (i.e, the CPU is activated at the boot), update the system wide detected work arounds.
Otherwise (i.e a CPU hotplugged in later) verify that this CPU conforms to the system wide capabilities.
2) Boot CPU updates the work arounds from smp_prepare_boot_cpu() after we have initialised the system wide CPU feature values.
Cc: Mark Rutland mark.rutland@arm.com Cc: Andre Przywara andre.przywara@arm.com Cc: Will Deacon will.deacon@arm.com Cc: 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 Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- arch/arm64/include/asm/cpufeature.h | 8 +------- arch/arm64/kernel/cpufeature.c | 23 +++++++++++++++-------- arch/arm64/kernel/cpuinfo.c | 2 -- arch/arm64/kernel/smp.c | 8 +++++++- 4 files changed, 23 insertions(+), 18 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 0267bab6ac18..1bc51f8835e5 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -177,13 +177,7 @@ void __init enable_errata_workarounds(void);
void verify_local_cpu_errata(void);
-#ifdef CONFIG_HOTPLUG_CPU -void verify_local_cpu_capabilities(void); -#else -static inline void verify_local_cpu_capabilities(void) -{ -} -#endif +void check_local_cpu_capabilities(void);
u64 read_system_reg(u32 id);
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 7773bea6927e..c74df3ca000e 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -860,18 +860,11 @@ static inline void set_sys_caps_initialised(void) * cannot do anything to fix it up and could cause unexpected failures. So * we park the CPU. */ -void verify_local_cpu_capabilities(void) +static void verify_local_cpu_capabilities(void) { int i; const struct arm64_cpu_capabilities *caps;
- /* - * If we haven't computed the system capabilities, there is nothing - * to verify. - */ - if (!sys_caps_initialised) - return; - verify_local_cpu_errata();
caps = arm64_features; @@ -902,6 +895,20 @@ void verify_local_cpu_capabilities(void) } }
+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. + * Otherwise, this CPU should verify that it has all the system + * advertised capabilities. + */ + if (!sys_caps_initialised) + check_local_cpu_errata(); + else + verify_local_cpu_capabilities(); +} + #else /* !CONFIG_HOTPLUG_CPU */
static inline void set_sys_caps_initialised(void) diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 0166cfbc866c..13e659fda04a 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -239,8 +239,6 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info) info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
cpuinfo_detect_icache_policy(info); - - check_local_cpu_errata(); }
void cpuinfo_store_cpu(void) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 752b53daac23..7a9eff0d1ebe 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -161,7 +161,7 @@ asmlinkage notrace void secondary_start_kernel(void) * this CPU ticks all of those. If it doesn't, the CPU will * fail to come online. */ - verify_local_cpu_capabilities(); + check_local_cpu_capabilities();
if (cpu_ops[cpu]->cpu_postboot) cpu_ops[cpu]->cpu_postboot(); @@ -360,6 +360,12 @@ void __init smp_prepare_boot_cpu(void) { set_my_cpu_offset(per_cpu_offset(smp_processor_id())); cpuinfo_store_boot_cpu(); + /* + * Run the errata work around checks on the boot CPU, once we have + * initialised the cpu feature infrastructure from + * cpuinfo_store_boot_cpu() above. + */ + check_local_cpu_errata(); }
static u64 __init of_get_cpu_mpidr(struct device_node *dn)