[PATCH v5] ARM: Factor out cpuid implementor and part number

Christoffer Dall c.dall at virtualopensystems.com
Fri Nov 30 14:59:15 EST 2012


Decoding the implementor and part number of the CPU id in the CPU ID
register is needed by KVM, so we factor it out to share the code.

Cc: Russell King <linux at arm.linux.org.uk>
Cc: Will Deacon <will.deacon at arm.com>
Signed-off-by: Christoffer Dall <c.dall at virtualopensystems.com>
---
Changes since v4:
 - Properly decode XScale cpu architecture versions
Changes since v3:
 - Only call read_cpuid_part_number once and squash warning
Changes since v2:
 - Take implementor as argument to read_cpuid_part_number
Changes since v1:
 - Accidentally pointed to an old file, this one has more consistent
   naming of the cpu implementor and part number defines.

 arch/arm/include/asm/cputype.h   |   33 +++++++++++++++++++++++++++++++++
 arch/arm/kernel/perf_event_cpu.c |   34 ++++++++++++++++------------------
 2 files changed, 49 insertions(+), 18 deletions(-)

diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index cb47d28..aeb2507 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -51,6 +51,24 @@ extern unsigned int processor_id;
 #define read_cpuid_ext(reg) 0
 #endif
 
+#define ARM_CPU_IMP_ARM			0x41
+#define ARM_CPU_IMP_INTEL		0x69
+
+#define ARM_CPU_PART_ARM1136		0xB360
+#define ARM_CPU_PART_ARM1156		0xB560
+#define ARM_CPU_PART_ARM1176		0xB760
+#define ARM_CPU_PART_ARM11MPCORE	0xB020
+#define ARM_CPU_PART_CORTEX_A8		0xC080
+#define ARM_CPU_PART_CORTEX_A9 		0xC090
+#define ARM_CPU_PART_CORTEX_A5 		0xC050
+#define ARM_CPU_PART_CORTEX_A15		0xC0F0
+#define ARM_CPU_PART_CORTEX_A7		0xC070
+
+#define ARM_CPU_XSCALE_ARCH_MASK	0xe000
+#define ARM_CPU_XSCALE_ARCH_V1		0x2000
+#define ARM_CPU_XSCALE_ARCH_V2		0x4000
+#define ARM_CPU_XSCALE_ARCH_V3		0x6000
+
 /*
  * The CPU ID never changes at run time, so we might as well tell the
  * compiler that it's constant.  Use this function to read the CPU ID
@@ -61,6 +79,21 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void)
 	return read_cpuid(CPUID_ID);
 }
 
+static inline unsigned int __attribute_const__ read_cpuid_implementor(void)
+{
+	return (read_cpuid_id() & 0xFF000000) >> 24;
+}
+
+static inline unsigned int __attribute_const__ read_cpuid_part_number()
+{
+	return (read_cpuid_id() & 0xFFF0);
+}
+
+static inline unsigned int __attribute_const__ xscale_cpu_arch_version(void)
+{
+	return read_cpuid_part_number() &ARM_CPU_XSCALE_ARCH_MASK;
+}
+
 static inline unsigned int __attribute_const__ read_cpuid_cachetype(void)
 {
 	return read_cpuid(CPUID_CACHETYPE);
diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c
index 9a4f630..5c59e19 100644
--- a/arch/arm/kernel/perf_event_cpu.c
+++ b/arch/arm/kernel/perf_event_cpu.c
@@ -201,48 +201,46 @@ static struct platform_device_id __devinitdata cpu_pmu_plat_device_ids[] = {
 static int __devinit probe_current_pmu(struct arm_pmu *pmu)
 {
 	int cpu = get_cpu();
-	unsigned long cpuid = read_cpuid_id();
-	unsigned long implementor = (cpuid & 0xFF000000) >> 24;
-	unsigned long part_number = (cpuid & 0xFFF0);
+	unsigned long implementor = read_cpuid_implementor();
+	unsigned long part_number = read_cpuid_part_number();
 	int ret = -ENODEV;
 
 	pr_info("probing PMU on CPU %d\n", cpu);
 
 	/* ARM Ltd CPUs. */
-	if (0x41 == implementor) {
+	if (implementor == ARM_CPU_IMP_ARM) {
 		switch (part_number) {
-		case 0xB360:	/* ARM1136 */
-		case 0xB560:	/* ARM1156 */
-		case 0xB760:	/* ARM1176 */
+		case ARM_CPU_PART_ARM1136:
+		case ARM_CPU_PART_ARM1156:
+		case ARM_CPU_PART_ARM1176:
 			ret = armv6pmu_init(pmu);
 			break;
-		case 0xB020:	/* ARM11mpcore */
+		case ARM_CPU_PART_ARM11MPCORE:
 			ret = armv6mpcore_pmu_init(pmu);
 			break;
-		case 0xC080:	/* Cortex-A8 */
+		case ARM_CPU_PART_CORTEX_A8:
 			ret = armv7_a8_pmu_init(pmu);
 			break;
-		case 0xC090:	/* Cortex-A9 */
+		case ARM_CPU_PART_CORTEX_A9:
 			ret = armv7_a9_pmu_init(pmu);
 			break;
-		case 0xC050:	/* Cortex-A5 */
+		case ARM_CPU_PART_CORTEX_A5:
 			ret = armv7_a5_pmu_init(pmu);
 			break;
-		case 0xC0F0:	/* Cortex-A15 */
+		case ARM_CPU_PART_CORTEX_A15:
 			ret = armv7_a15_pmu_init(pmu);
 			break;
-		case 0xC070:	/* Cortex-A7 */
+		case ARM_CPU_PART_CORTEX_A7:
 			ret = armv7_a7_pmu_init(pmu);
 			break;
 		}
 	/* Intel CPUs [xscale]. */
-	} else if (0x69 == implementor) {
-		part_number = (cpuid >> 13) & 0x7;
-		switch (part_number) {
-		case 1:
+	} else if (implementor == ARM_CPU_IMP_INTEL) {
+		switch (xscale_cpu_arch_version()) {
+		case ARM_CPU_XSCALE_ARCH_V1:
 			ret = xscale1pmu_init(pmu);
 			break;
-		case 2:
+		case ARM_CPU_XSCALE_ARCH_V2:
 			ret = xscale2pmu_init(pmu);
 			break;
 		}
-- 
1.7.9.5




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