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Subject[PATCH] [2/50] x86_64: use core id bits for apicid_to_node initialization
Date

From: "Yinghai Lu" <yhlu.kernel@gmail.com>

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

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

arch/x86_64/mm/k8topology.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

Index: linux/arch/x86_64/mm/k8topology.c
===================================================================
--- linux.orig/arch/x86_64/mm/k8topology.c
+++ linux/arch/x86_64/mm/k8topology.c
@@ -44,12 +44,14 @@ int __init k8_scan_nodes(unsigned long s
{
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 s

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 s
}
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);
}
}
-
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