[ARM] 4585/1: Correctly identify the CPU architecture version (180005c4) · Commits · 戴 / test

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 <catalin.marinas@arm.com> Signed-off-by:

Russell King <rmk+kernel@arm.linux.org.uk>

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;
		}

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