diff options
Diffstat (limited to 'arch/arm/include')
-rw-r--r-- | arch/arm/include/asm/system_info.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/arm/include/asm/system_info.h b/arch/arm/include/asm/system_info.h index 56ebb11a2b..50769ec3bc 100644 --- a/arch/arm/include/asm/system_info.h +++ b/arch/arm/include/asm/system_info.h @@ -110,8 +110,51 @@ #ifndef __ASSEMBLY__ #ifdef ARM_MULTIARCH +/* + * Early version to get the ARM cpu architecture. Only needed during + * early startup when the C environment is not yet fully initialized. + * Normally you should use cpu_architecture() instead. + */ +static inline int arm_early_get_cpu_architecture(void) +{ + int cpu_arch; + + if ((read_cpuid_id() & 0x0008f000) == 0) { + cpu_arch = CPU_ARCH_UNKNOWN; + } else if ((read_cpuid_id() & 0x0008f000) == 0x00007000) { + cpu_arch = (read_cpuid_id() & (1 << 23)) ? CPU_ARCH_ARMv4T : CPU_ARCH_ARMv3; + } else if ((read_cpuid_id() & 0x00080000) == 0x00000000) { + cpu_arch = (read_cpuid_id() >> 16) & 7; + 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)); + 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; +} + extern int __pure cpu_architecture(void); #else +static inline int __pure arm_early_get_cpu_architecture(void) +{ + return ARM_ARCH; +} + static inline int __pure cpu_architecture(void) { return ARM_ARCH; |