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Diffstat (limited to 'src/arch/x86/cpu.c')
| -rw-r--r-- | src/arch/x86/cpu.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/src/arch/x86/cpu.c b/src/arch/x86/cpu.c index 80d4d0da4a..f19b389441 100644 --- a/src/arch/x86/cpu.c +++ b/src/arch/x86/cpu.c @@ -219,6 +219,35 @@ static void set_cpu_ops(struct device *cpu) cpu->ops = driver ? driver->ops : NULL; } +/* Keep track of default apic ids for SMM. */ +static int cpus_default_apic_id[CONFIG_MAX_CPUS]; + +/* + * When CPUID executes with EAX set to 1, additional processor identification + * information is returned to EBX register: + * Default APIC ID: EBX[31-24] - this number is the 8 bit ID that is assigned + * to the local APIC on the processor during power on. + */ +static int initial_lapicid(void) +{ + return cpuid_ebx(1) >> 24; +} + +/* Function to keep track of cpu default apic_id */ +void cpu_add_map_entry(unsigned int index) +{ + cpus_default_apic_id[index] = initial_lapicid(); +} + +/* Returns default APIC id based on logical_cpu number or < 0 on failure. */ +int cpu_get_apic_id(int logical_cpu) +{ + if (logical_cpu >= CONFIG_MAX_CPUS || logical_cpu < 0) + return -1; + + return cpus_default_apic_id[logical_cpu]; +} + void cpu_initialize(unsigned int index) { /* Because we busy wait at the printk spinlock. |