Messages in this thread Patch in this message | | | From | Jeremy Linton <> | Subject | [PATCH] arm64: cpufeature: Display the set of cores with a feature | Date | Thu, 12 Oct 2023 20:30:16 -0500 |
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The AMU feature can be enabled on a subset of the cores in a system. Because of that, it prints a message for each core as it is detected. This becomes tedious when there are hundreds of cores. Instead, for CPU features which can be enabled on a subset of the present cores, lets wait until update_cpu_capabilities() and print the subset of cores the feature was enabled on.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> --- arch/arm64/include/asm/cpufeature.h | 2 ++ arch/arm64/kernel/cpufeature.c | 16 +++++++++++++--- 2 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 5bba39376055..19b4d001d845 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -23,6 +23,7 @@ #include <linux/bug.h> #include <linux/jump_label.h> #include <linux/kernel.h> +#include <linux/cpumask.h> /* * CPU feature register tracking @@ -380,6 +381,7 @@ struct arm64_cpu_capabilities { * method is robust against being called multiple times. */ const struct arm64_cpu_capabilities *match_list; + const struct cpumask *cpus; }; static inline int cpucap_default_scope(const struct arm64_cpu_capabilities *cap) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 444a73c2e638..18711e35924c 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1944,8 +1944,6 @@ int get_cpu_with_amu_feat(void) static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap) { if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) { - pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n", - smp_processor_id()); cpumask_set_cpu(smp_processor_id(), &amu_cpus); /* 0 reference values signal broken/disabled counters */ @@ -2411,10 +2409,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = { * message to be shown until at least one CPU is detected to * support the feature. */ + .desc = "Activity Monitors Unit (AMU)", .capability = ARM64_HAS_AMU_EXTN, .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, .matches = has_amu, .cpu_enable = cpu_amu_enable, + .cpus = &amu_cpus, ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, AMU, IMP) }, #endif /* CONFIG_ARM64_AMU_EXTN */ @@ -2981,7 +2981,7 @@ static void update_cpu_capabilities(u16 scope_mask) !caps->matches(caps, cpucap_default_scope(caps))) continue; - if (caps->desc) + if (caps->desc && !caps->cpus) pr_info("detected: %s\n", caps->desc); __set_bit(caps->capability, system_cpucaps); @@ -3330,6 +3330,7 @@ unsigned long cpu_get_elf_hwcap2(void) static void __init setup_system_capabilities(void) { + int i; /* * We have finalised the system-wide safe feature * registers, finalise the capabilities that depend @@ -3338,6 +3339,15 @@ static void __init setup_system_capabilities(void) */ update_cpu_capabilities(SCOPE_SYSTEM); enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU); + + for (i = 0; i < ARM64_NCAPS; i++) { + const struct arm64_cpu_capabilities *caps = cpucap_ptrs[i]; + + if (caps && caps->cpus && caps->desc && + cpumask_any(caps->cpus) < nr_cpu_ids) + pr_info("detected: %s on CPU%*pbl\n", + caps->desc, cpumask_pr_args(caps->cpus)); + } } void __init setup_cpu_features(void) -- 2.41.0
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