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>

drivers/acpi/acpi_processor.c

@@ -270,7 +270,9 @@ static int acpi_processor_get_info(struct acpi_device *device)
 		device_declaration = 1;
 		pr->acpi_id = value;
 	}
-	cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
+	pr->apic_id = acpi_get_apicid(pr->handle, device_declaration,
+					pr->acpi_id);
+	cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id);
 
 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
 	if (!cpu0_initialized && (cpu_index == -1) &&

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)

include/acpi/processor.h

@@ -199,6 +199,7 @@ struct acpi_processor_flags {
 struct acpi_processor {
 	acpi_handle handle;
 	u32 acpi_id;
+	u32 apic_id;
 	u32 id;
 	u32 pblk;
 	int performance_platform_limit;
@@ -314,6 +315,8 @@ static inline int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
 
 /* in processor_core.c */
 void acpi_processor_set_pdc(acpi_handle handle);
+int acpi_get_apicid(acpi_handle, int type, u32 acpi_id);
+int acpi_map_cpuid(int apic_id, u32 acpi_id);
 int acpi_get_cpuid(acpi_handle, int type, u32 acpi_id);
 
 /* in processor_throttling.c */