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Commit 180005c4 authored by Catalin Marinas's avatar Catalin Marinas Committed by Russell King
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[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: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent c1f438f5

arch/arm/kernel/setup.c

+17 −4
Original line number Diff line number Diff line
@@ -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;

}