x86: use core id bits for apicid_to_node initialization

We shoud use core id bits instead of max cores, in case later with AMD
downcores Quad core Opteron.

[ tglx: arch/x86 adaptation ]

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 10 insertions, 7 deletions

diff --git a/arch/x86/mm/k8topology_64.c b/arch/x86/mm/k8topology_64.c
index a96006f7ae0c..3695c9e8b9b6 100644
--- a/arch/x86/mm/k8topology_64.c
+++ b/arch/x86/mm/k8topology_64.c
@@ -44,12 +44,14 @@ int __init k8_scan_nodes(unsigned long start, unsigned long end)
 { 
         unsigned long prevbase;
         struct bootnode nodes[8];
-        int nodeid, i, j, nb;
+        int nodeid, i, nb;
         unsigned char nodeids[8];
         int found = 0;
         u32 reg;
         unsigned numnodes;
-        unsigned num_cores;
+        unsigned cores;
+        unsigned bits;
+        int j;
 
         if (!early_pci_allowed())
                 return -1;
@@ -60,9 +62,6 @@ int __init k8_scan_nodes(unsigned long start, unsigned long end)
 
         printk(KERN_INFO "Scanning NUMA topology in Northbridge %d\n", nb); 
 
-        num_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
-        printk(KERN_INFO "CPU has %d num_cores\n", num_cores);
-
         reg = read_pci_config(0, nb, 0, 0x60); 
         numnodes = ((reg >> 4) & 0xF) + 1;
         if (numnodes <= 1)
@@ -168,11 +167,15 @@ int __init k8_scan_nodes(unsigned long start, unsigned long end)
         } 
         printk(KERN_INFO "Using node hash shift of %d\n", memnode_shift); 
 
+        /* use the coreid bits from early_identify_cpu */
+        bits = boot_cpu_data.x86_coreid_bits;
+        cores = (1<<bits);
+
         for (i = 0; i < 8; i++) {
                 if (nodes[i].start != nodes[i].end) { 
                         nodeid = nodeids[i];
-                        for (j = 0; j < num_cores; j++)
-                                apicid_to_node[(nodeid * num_cores) + j] = i;
+                        for (j = 0; j < cores; j++)
+                                apicid_to_node[(nodeid << bits) + j] = i;
                         setup_node_bootmem(i, nodes[i].start, nodes[i].end); 
                 } 
         }