x86: use core id bits for apicid_to_node initialization
authorYinghai Lu <yhlu.kernel@gmail.com>
Wed, 30 Jan 2008 12:30:39 +0000 (13:30 +0100)
committerIngo Molnar <mingo@elte.hu>
Wed, 30 Jan 2008 12:30:39 +0000 (13:30 +0100)
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>
arch/x86/mm/k8topology_64.c

index a96006f..3695c9e 100644 (file)
@@ -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); 
                } 
        }