[PATCH] x86_64: fix cpu_to_node setup for sparse apic_ids

While booting with SMT disabled in bios, when using acpi srat to setup
cpu_to_node[], sparse apic_ids create problems.

Without this patch, intel x86_64 boxes with hyperthreading disabled in the
bios (and which rely on srat for numa setup) endup having incorrect values in
cpu_to_node[] arrays, causing sched domains to be built incorrectly etc.
Signed-off-by: NRavikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: NShai Fultheim <shai@scalex86.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/x86_64/mm/srat.c

@@ -20,6 +20,9 @@
 
 static struct acpi_table_slit *acpi_slit;
 
+/* Internal processor count */
+static unsigned int __initdata num_processors = 0;
+
 static nodemask_t nodes_parsed __initdata;
 static nodemask_t nodes_found __initdata;
 static struct node nodes[MAX_NUMNODES] __initdata;
@@ -101,16 +104,18 @@ acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
 		bad_srat();
 		return;
 	}
-	if (pa->apic_id >= NR_CPUS) {
-		printk(KERN_ERR "SRAT: lapic %u too large.\n",
-		       pa->apic_id);
+	if (num_processors >= NR_CPUS) {
+		printk(KERN_ERR "SRAT: Processor #%d (lapic %u) INVALID. (Max ID: %d).\n",
+			num_processors, pa->apic_id, NR_CPUS);
 		bad_srat();
 		return;
 	}
-	cpu_to_node[pa->apic_id] = node;
+	cpu_to_node[num_processors] = node;
 	acpi_numa = 1;
-	printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> Node %u\n",
-	       pxm, pa->apic_id, node);
+	printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> CPU %u -> Node %u\n",
+	       pxm, pa->apic_id, num_processors, node);
+
+	num_processors++;
 }
 
 /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */