From mboxrd@z Thu Jan 1 00:00:00 1970 From: jeremy.linton@arm.com (Jeremy Linton) Date: Wed, 6 Jul 2016 19:34:23 -0500 Subject: [PATCH 06/11] arm: arm64: Add routine to determine cpuid of other cpus In-Reply-To: <20160706163001.GC31910@arm.com> References: <1466529109-21715-1-git-send-email-jeremy.linton@arm.com> <1466529109-21715-7-git-send-email-jeremy.linton@arm.com> <20160706163001.GC31910@arm.com> Message-ID: <577DA38F.1000709@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/06/2016 11:30 AM, Will Deacon wrote: > On Tue, Jun 21, 2016 at 12:11:44PM -0500, Jeremy Linton wrote: >> It is helpful if we can read the cpuid/midr of other CPUs >> in the system independent of arm/arm64. >> >> Signed-off-by: Jeremy Linton >> --- >> arch/arm/include/asm/cputype.h | 6 +++++- >> arch/arm64/include/asm/cputype.h | 4 ++++ >> 2 files changed, 9 insertions(+), 1 deletion(-) >> >> diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h >> index 1ee94c7..e391b67 100644 >> --- a/arch/arm/include/asm/cputype.h >> +++ b/arch/arm/include/asm/cputype.h >> @@ -81,6 +81,8 @@ >> #define ARM_CPU_XSCALE_ARCH_V2 0x4000 >> #define ARM_CPU_XSCALE_ARCH_V3 0x6000 >> >> +#define ARM_PARTNUM(cpuid_id) (cpuid_id & ARM_CPU_PART_MASK) >> + >> extern unsigned int processor_id; >> >> #ifdef CONFIG_CPU_CP15 >> @@ -180,7 +182,7 @@ static inline unsigned int __attribute_const__ read_cpuid_implementor(void) >> */ >> static inline unsigned int __attribute_const__ read_cpuid_part(void) >> { >> - return read_cpuid_id() & ARM_CPU_PART_MASK; >> + return ARM_PARTNUM(read_cpuid_id()); > > I don't understand why you need to make this change. The short answer is that the ARM_PARTNUM stuff is left over from v4 (?) of the patch, where it seemed a good idea to create a macro that was arm/arm64 independent for use in arm_pmu.c. Somewhere along there I reverted the ARM_PARTNUM to MIDR_PARTNUM in the arm_pmu_acpi.c but didn't drop that portion from this patch. Partially because it seems like a good idea. OTOH, your right probably doesn't belong here without the large cleanup which would form their own patch set.