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 ++++++ kernel/multikernel.c | 9 +++++---- 3 files changed, 17 insertions(+), 4 deletions(-) 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 3ee515e32383..face9f80e05c 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -289,6 +289,11 @@ 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, @@ -306,6 +311,7 @@ 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); diff --git a/kernel/multikernel.c b/kernel/multikernel.c index 74e2f84b7914..7f6f90485876 100644 --- a/kernel/multikernel.c +++ b/kernel/multikernel.c @@ -150,7 +150,7 @@ int multikernel_send_ipi_data(int cpu, void *data, size_t data_size, unsigned lo /* Set header information */ target->data_size = data_size; - target->sender_cpu = smp_processor_id(); + target->sender_cpu = arch_cpu_physical_id(smp_processor_id()); target->type = type; /* Copy the actual data into the buffer */ @@ -175,6 +175,7 @@ static void multikernel_interrupt_handler(void) struct mk_ipi_data *data; struct mk_ipi_handler *handler; int current_cpu = smp_processor_id(); + int current_physical_id = arch_cpu_physical_id(current_cpu); /* Ensure shared memory is initialized */ if (!mk_shared_mem) { @@ -183,10 +184,10 @@ static void multikernel_interrupt_handler(void) } /* Get this CPU's data area from shared memory */ - data = &mk_shared_mem->cpu_data[current_cpu]; + data = &mk_shared_mem->cpu_data[current_physical_id]; - pr_debug("Multikernel IPI received on CPU %d from CPU %d, type=%u\n", - current_cpu, data->sender_cpu, data->type); + pr_info("Multikernel IPI received on CPU %d (physical id %d) from CPU %d type=%u\n", + current_cpu, current_physical_id, data->sender_cpu, data->type); raw_spin_lock(&mk_handlers_lock); for (handler = mk_handlers; handler; handler = handler->next) { -- 2.34.1
