Function for revised cpuid format
From: Bahadir Balban <hidden>
Date: 2010-05-21 12:14:08
Subsystem:
the rest · Maintainer:
Linus Torvalds
Below is a patch for this. What do you think? From 30ed7d843d61a9663b7fe8d2f8c67ede3d819e50 Mon Sep 17 00:00:00 2001 From: Bahadir Balban <redacted> Date: Fri, 21 May 2010 14:39:56 +0300 Subject: [PATCH] Define revised cpuid function and convert assembler to use that. This patch defines a minor function to read the revised cpuid format and converts an assembler statement to use this function. Signed-off-by: Bahadir Balban <redacted> --- arch/codezero/include/asm/cputype.h | 5 +++++ arch/codezero/kernel/setup.c | 5 ++--- 2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/codezero/include/asm/cputype.h b/arch/codezero/include/asm/cputype.h
index 20ae96c..60071d8 100644
--- a/arch/codezero/include/asm/cputype.h
+++ b/arch/codezero/include/asm/cputype.h@@ -58,6 +58,11 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void) return read_cpuid(CPUID_ID); } +static inline unsigned int __attribute_const__ read_cpuid_revised_id(void) +{ + return read_cpuid_ext(CPUID_EXT_MMFR0); +} + static inline unsigned int __attribute_const__ read_cpuid_cachetype(void) { return read_cpuid(CPUID_CACHETYPE);
diff --git a/arch/codezero/kernel/setup.c b/arch/codezero/kernel/setup.c
index c91c77b..c64b029 100644
--- a/arch/codezero/kernel/setup.c
+++ b/arch/codezero/kernel/setup.c@@ -213,12 +213,11 @@ int 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_revised_id(); + if ((mmfr0 & 0x0000000f) == 0x00000003 || (mmfr0 & 0x000000f0) == 0x00000030) cpu_arch = CPU_ARCH_ARMv7;
--
1.6.3.3
--
Bahadir