ACPI / processor: Introduce apic_id in struct processor to save parsed APIC id

For cpu hot add, we evaluate _MAT or parse MADT twice to get APIC id,
here is the code logic:
acpi_processor_add()
	acpi_processor_get_info()
		acpi_get_cpuid() will evaluate _MAT or parse MADT;
	acpi_processor_hotadd_init()
		acpi_map_lsapic() will evaluate _MAT again;

This can be done more effectively, this patch introduces apic_id in struct
processor to save parsed APIC id, and then we can use it and remove the
duplicated _MAT evaluation.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 21 insertions, 5 deletions

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index cf34d903f4f..b3171f30b31 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -162,16 +162,23 @@ exit:
 	return apic_id;
 }
 
-int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
+int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
 {
-#ifdef CONFIG_SMP
-	int i;
-#endif
-	int apic_id = -1;
+	int apic_id;
 
 	apic_id = map_mat_entry(handle, type, acpi_id);
 	if (apic_id == -1)
 		apic_id = map_madt_entry(type, acpi_id);
+
+	return apic_id;
+}
+
+int acpi_map_cpuid(int apic_id, u32 acpi_id)
+{
+#ifdef CONFIG_SMP
+	int i;
+#endif
+
 	if (apic_id == -1) {
 		/*
 		 * On UP processor, there is no _MAT or MADT table.
@@ -211,6 +218,15 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 #endif
 	return -1;
 }
+
+int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
+{
+	int apic_id;
+
+	apic_id = acpi_get_apicid(handle, type, acpi_id);
+
+	return acpi_map_cpuid(apic_id, acpi_id);
+}
 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 
 static bool __init processor_physically_present(acpi_handle handle)