From 180005c4efb76a81fd0abcef4c2412d238eea20c Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 25 Sep 2007 16:49:45 +0100 Subject: [PATCH] [ARM] 4585/1: Correctly identify the CPU architecture version The cpu_architecture() function in arch/arm/kernel/setup.c only works with cores produced by ARM Ltd. The more generic approach is to read the ID_MMFR0 register and check for the VMSA or PMSA version supported. With this patch, the ARM11MPCore would be reported as ARMv7 since its MMU is compatible with ARMv7. Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/kernel/setup.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 4de432ec903..efac7df72d6 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -304,10 +304,23 @@ int cpu_architecture(void) cpu_arch = (processor_id >> 16) & 7; if (cpu_arch) cpu_arch += CPU_ARCH_ARMv3; - } else { - /* the revised CPUID */ - cpu_arch = ((processor_id >> 12) & 0xf) - 0xb + CPU_ARCH_ARMv6; - } + } else if ((processor_id & 0x000f0000) == 0x000f0000) { + unsigned int mmfr0; + + /* Revised CPUID format. Read the Memory Model Feature + * Register 0 and check for VMSAv7 or PMSAv7 */ + asm("mrc p15, 0, %0, c0, c1, 4" + : "=r" (mmfr0)); + if ((mmfr0 & 0x0000000f) == 0x00000003 || + (mmfr0 & 0x000000f0) == 0x00000030) + cpu_arch = CPU_ARCH_ARMv7; + else if ((mmfr0 & 0x0000000f) == 0x00000002 || + (mmfr0 & 0x000000f0) == 0x00000020) + cpu_arch = CPU_ARCH_ARMv6; + else + cpu_arch = CPU_ARCH_UNKNOWN; + } else + cpu_arch = CPU_ARCH_UNKNOWN; return cpu_arch; } -- 2.41.0