Commit 526299ce authored Mar 17, 2015 by Mason Committed by Russell King Mar 18, 2015

ARM: 8313/1: Use read_cpuid_ext() macro instead of inline asm

Replace inline asm statement in __get_cpu_architecture() with equivalent
macro invocation, i.e. read_cpuid_ext(CPUID_EXT_MMFR0);

As an added bonus, this squashes a potential bug, described by Paul
Walmsley in commit 067e710b ("ARM: 7801/1: prevent gcc 4.5 from
reordering extended CP15 reads above is_smp() test").

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent f2ca09f3

arch/arm/kernel/setup.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -246,12 +246,9 @@ static int __get_cpu_architecture(void)
		if (cpu_arch)
		cpu_arch += CPU_ARCH_ARMv3;
		} else if ((read_cpuid_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));
		unsigned int mmfr0 = read_cpuid_ext(CPUID_EXT_MMFR0);
		if ((mmfr0 & 0x0000000f) >= 0x00000003 \|\|
		(mmfr0 & 0x000000f0) >= 0x00000030)
		cpu_arch = CPU_ARCH_ARMv7;