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authorSuzuki K Poulose <suzuki.poulose@arm.com>2016-09-09 16:07:10 +0300
committerWill Deacon <will.deacon@arm.com>2016-09-09 17:03:28 +0300
commitc47a1900ad710fd2c97127e2ba19da1df79cf733 (patch)
tree280ee1f75639c56aca3f82abd3065f94b740c68f /arch/arm64
parent89ba26458b72422e0a1d85eb729a15220b204458 (diff)
downloadlinux-c47a1900ad710fd2c97127e2ba19da1df79cf733.tar.xz
arm64: Rearrange CPU errata workaround checks
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>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/cpufeature.h4
-rw-r--r--arch/arm64/kernel/cpufeature.c30
-rw-r--r--arch/arm64/kernel/cpuinfo.c2
-rw-r--r--arch/arm64/kernel/smp.c8
4 files changed, 29 insertions, 15 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index ddea66642ce1..6806b86ab791 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -202,11 +202,11 @@ void __init setup_cpu_features(void);
void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
const char *info);
void enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps);
+void check_local_cpu_capabilities(void);
+
void update_cpu_errata_workarounds(void);
void __init enable_errata_workarounds(void);
-
void verify_local_cpu_errata_workarounds(void);
-void verify_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 c74b8215991f..d577f263cc4a 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1009,23 +1009,33 @@ verify_local_cpu_features(const struct arm64_cpu_capabilities *caps)
* 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)
{
+ verify_local_cpu_errata_workarounds();
+ verify_local_cpu_features(arm64_features);
+ verify_local_elf_hwcaps(arm64_elf_hwcaps);
+ if (system_supports_32bit_el0())
+ verify_local_elf_hwcaps(compat_elf_hwcaps);
+}
+void check_local_cpu_capabilities(void)
+{
+ /*
+ * All secondary CPUs should conform to the early CPU features
+ * in use by the kernel based on boot CPU.
+ */
check_early_cpu_features();
/*
- * If we haven't computed the system capabilities, there is nothing
- * to verify.
+ * 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)
- return;
-
- verify_local_cpu_errata_workarounds();
- verify_local_cpu_features(arm64_features);
- verify_local_elf_hwcaps(arm64_elf_hwcaps);
- if (system_supports_32bit_el0())
- verify_local_elf_hwcaps(compat_elf_hwcaps);
+ update_cpu_errata_workarounds();
+ else
+ verify_local_cpu_capabilities();
}
static void __init setup_feature_capabilities(void)
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 4fa7b73e27e4..b3d5b3e8fbcb 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -363,8 +363,6 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
}
cpuinfo_detect_icache_policy(info);
-
- update_cpu_errata_workarounds();
}
void cpuinfo_store_cpu(void)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 8b048e6ec34a..a8e64095cd69 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -239,7 +239,7 @@ asmlinkage 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();
@@ -444,6 +444,12 @@ void __init smp_prepare_boot_cpu(void)
jump_label_init();
cpuinfo_store_boot_cpu();
save_boot_cpu_run_el();
+ /*
+ * Run the errata work around checks on the boot CPU, once we have
+ * initialised the cpu feature infrastructure from
+ * cpuinfo_store_boot_cpu() above.
+ */
+ update_cpu_errata_workarounds();
}
static u64 __init of_get_cpu_mpidr(struct device_node *dn)