From: Cong Wang <[email protected]> The tranditional smp_processor_id() is a software-defined CPU ID which is only unique within the same kernel. With Multikernel architecture, we run multiple Linux kernels on different CPU's, hence the host kernel needs a globally unique CPU ID to manage the CPU's. The physical CPU ID is perfect for this case.
This API will be used to globally distinguish CPU's among different multikernels. Signed-off-by: Cong Wang <[email protected]> --- arch/x86/include/asm/smp.h | 6 ++++++ arch/x86/kernel/smp.c | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 1a59fd0de759..378be65ceafa 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -40,6 +40,7 @@ struct smp_ops { void (*send_call_func_ipi)(const struct cpumask *mask); void (*send_call_func_single_ipi)(int cpu); + int (*cpu_physical_id)(int cpu); }; /* Globals due to paravirt */ @@ -100,6 +101,11 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask) smp_ops.send_call_func_ipi(mask); } +static inline int arch_cpu_physical_id(int cpu) +{ + return smp_ops.cpu_physical_id(cpu); +} + void cpu_disable_common(void); void native_smp_prepare_boot_cpu(void); void smp_prepare_cpus_common(void); diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index 59658fcd9037..e2eba09da7fc 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -288,6 +288,11 @@ static int __init nonmi_ipi_setup(char *str) __setup("nonmi_ipi", nonmi_ipi_setup); +static int native_cpu_physical_id(int cpu) +{ + return cpu_physical_id(cpu); +} + struct smp_ops smp_ops = { .smp_prepare_boot_cpu = native_smp_prepare_boot_cpu, .smp_prepare_cpus = native_smp_prepare_cpus, @@ -305,6 +310,7 @@ struct smp_ops smp_ops = { .send_call_func_ipi = native_send_call_func_ipi, .send_call_func_single_ipi = native_send_call_func_single_ipi, + .cpu_physical_id = native_cpu_physical_id, }; EXPORT_SYMBOL_GPL(smp_ops); -- 2.34.1
