x86: get boot_cpu_id as early for k8_scan_nodes

When acpi=off or there is no SRAT defined, apicid_to_node is got from K8
Northbridge PCI configuration space in k8_scan_nodes() in
arch/x86_64/mm/k8toplogy.c.

The problem is that it assumes bsp apic id is 0 at that point.

For four socket system with Quad core cpus installed, all cpus apic id
is offset by 4, and bsp apic id is 4.

For eight socket system with dual core cpus installed, all cpus apic id
is offset by 2, and bsp apic id is 2.

We need get boot_cpu_id --- bsp apic id, before k8_scan_nodes by called.

So create early_acpi_boot_init and early_get_smp_config for get boot_cpu_id.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index f6eb01d8923..8a475793f73 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -861,6 +861,30 @@ static int __init detect_init_APIC(void)
 	return 0;
 }
 
+void __init early_init_lapic_mapping(void)
+{
+	unsigned long apic_phys;
+
+	/*
+	 * If no local APIC can be found then go out
+	 * : it means there is no mpatable and MADT
+	 */
+	if (!smp_found_config)
+		return;
+
+	apic_phys = mp_lapic_addr;
+
+	set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
+	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
+				 APIC_BASE, apic_phys);
+
+	/*
+	 * Fetch the APIC ID of the BSP in case we have a
+	 * default configuration (or the MP table is broken).
+	 */
+	boot_cpu_id = GET_APIC_ID(apic_read(APIC_ID));
+}
+
 /**
  * init_apic_mappings - initialize APIC mappings
  */