x86/devicetree: Use CPU description from Device Tree

Current x86 Device Tree implementation does not support multiprocessing.
Use new DT bindings to describe the processors.
Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Link: https://lkml.kernel.org/r/c291fb2cef51b730b59916d7745be0eaa4378c6c.1521753738.git.ivan.gorinov@intel.com

arch/x86/kernel/devicetree.c

@@ -131,34 +131,52 @@ static void __init dtb_setup_hpet(void)
 #endif
 }
 
+#ifdef CONFIG_X86_LOCAL_APIC
+
+static void __init dtb_cpu_setup(void)
+{
+	struct device_node *dn;
+	u32 apic_id, version;
+	int ret;
+
+	version = GET_APIC_VERSION(apic_read(APIC_LVR));
+	for_each_node_by_type(dn, "cpu") {
+		ret = of_property_read_u32(dn, "reg", &apic_id);
+		if (ret < 0) {
+			pr_warn("%pOF: missing local APIC ID\n", dn);
+			continue;
+		}
+		generic_processor_info(apic_id, version);
+	}
+}
+
 static void __init dtb_lapic_setup(void)
 {
-#ifdef CONFIG_X86_LOCAL_APIC
 	struct device_node *dn;
 	struct resource r;
+	unsigned long lapic_addr = APIC_DEFAULT_PHYS_BASE;
 	int ret;
 
 	dn = of_find_compatible_node(NULL, NULL, "intel,ce4100-lapic");
-	if (!dn)
-		return;
-
+	if (dn) {
 		ret = of_address_to_resource(dn, 0, &r);
 		if (WARN_ON(ret))
 			return;
+		lapic_addr = r.start;
+	}
 
 	/* Did the boot loader setup the local APIC ? */
 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
-		if (apic_force_enable(r.start))
+		if (apic_force_enable(lapic_addr))
 			return;
 	}
 	smp_found_config = 1;
 	pic_mode = 1;
-	register_lapic_address(r.start);
-	generic_processor_info(boot_cpu_physical_apicid,
-			       GET_APIC_VERSION(apic_read(APIC_LVR)));
-#endif
+	register_lapic_address(lapic_addr);
 }
 
+#endif /* CONFIG_X86_LOCAL_APIC */
+
 #ifdef CONFIG_X86_IO_APIC
 static unsigned int ioapic_id;
 
@@ -259,7 +277,10 @@ static void __init dtb_ioapic_setup(void) {}
 
 static void __init dtb_apic_setup(void)
 {
+#ifdef CONFIG_X86_LOCAL_APIC
 	dtb_lapic_setup();
+	dtb_cpu_setup();
+#endif
 	dtb_ioapic_setup();
 }