[PATCH] x86_64: to use lapic ids instead of initial apic ids

phys_proc_id[] on AMD boxes is right now populated with the initial
apic id, obtained by the cpuid instruction.  But, the initial apic id
need not be the local apic id on clustered APIC systems (see comment at
x86_64/kernel/genapic_cluster.c, line 110).  On vSMPowered with AMD
CPUs the cpu_to_node will turn out to be incorrect (as apicid_to_node[] is
indexed by the initial apic id rather than the local apic id).
On vSMPowered boxes with Intel CPUs this is working correctly as
phys_proc_id[] is initialized correctly in detect_ht().

This fixes AMD boot path according to specification, to use the correct
routines for local apic id and socket ids.  We use
hard_smp_processor_id() to read the local apic id, and phys_pkg_id() to
determine socket id for phys_proc_id[]

Patch tested on Tyan multicore boxes as well as vSMPowered boxes.

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index ad3b7fc24a05..49f285871df5 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -846,7 +846,7 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
         unsigned bits;
 #ifdef CONFIG_NUMA
         int node = 0;
-        unsigned apicid = phys_proc_id[cpu];
+        unsigned apicid = hard_smp_processor_id();
 #endif
 
         bits = 0;
@@ -856,7 +856,7 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
         /* Low order bits define the core id (index of core in socket) */
         cpu_core_id[cpu] = phys_proc_id[cpu] & ((1 << bits)-1);
         /* Convert the APIC ID into the socket ID */
-        phys_proc_id[cpu] >>= bits;
+        phys_proc_id[cpu] = phys_pkg_id(bits);
 
 #ifdef CONFIG_NUMA
         node = phys_proc_id[cpu];