Messages in this thread Patch in this message | | | From | Al Stone <> | Subject | [PATCH 1/3] arm64: cpuinfo: add MPIDR value to /proc/cpuinfo | Date | Tue, 26 Sep 2017 16:23:22 -0600 |
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When displaying cpuinfo on an arm64 system, include the MPIDR register value which can be used to understand the CPU topology on a platform. This can serve as a cross-check to the information provided in sysfs, and has been useful in understanding CPU and NUMA allocation issues.
Signed-off-by: Al Stone <ahs3@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> --- arch/arm64/include/asm/cpu.h | 1 + arch/arm64/kernel/cpuinfo.c | 8 ++++++++ 2 files changed, 9 insertions(+)
diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h index 889226b4c6e1..ac40894df247 100644 --- a/arch/arm64/include/asm/cpu.h +++ b/arch/arm64/include/asm/cpu.h @@ -32,6 +32,7 @@ struct cpuinfo_arm64 { u32 reg_midr; u32 reg_revidr; + u64 reg_id_aa64mpidr; u64 reg_id_aa64dfr0; u64 reg_id_aa64dfr1; u64 reg_id_aa64isar0; diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 4a6f875ac854..e505007138eb 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -120,6 +120,7 @@ static int c_show(struct seq_file *m, void *v) for_each_online_cpu(i) { struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i); u32 midr = cpuinfo->reg_midr; + u64 mpidr = cpuinfo->reg_id_aa64mpidr; /* * glibc reads /proc/cpuinfo to determine the number of @@ -159,6 +160,12 @@ static int c_show(struct seq_file *m, void *v) } seq_puts(m, "\n"); + seq_printf(m, "CPU MPIDR\t: 0x%016llx ", mpidr); + seq_printf(m, "(Aff3 %d Aff2 %d Aff1 %d Aff0 %d)\n", + (u8) MPIDR_AFFINITY_LEVEL(mpidr, 3), + (u8) MPIDR_AFFINITY_LEVEL(mpidr, 2), + (u8) MPIDR_AFFINITY_LEVEL(mpidr, 1), + (u8) MPIDR_AFFINITY_LEVEL(mpidr, 0)); seq_printf(m, "CPU implementer\t: 0x%02x\n", MIDR_IMPLEMENTOR(midr)); seq_printf(m, "CPU architecture: 8\n"); @@ -372,6 +379,7 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info) info->reg_midr = read_cpuid_id(); info->reg_revidr = read_cpuid(REVIDR_EL1); + info->reg_id_aa64mpidr = read_cpuid_mpidr(); info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1); info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1); info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1); -- 2.13.5
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