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 067e710b9a98 ("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>

1 files changed, 1 insertions, 4 deletions

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index e55408e96559..1d60bebea4b8 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -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;