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[PATCH] i386/x86-64: Use new official CPUID to get APICID/core split on AMD platforms

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Previously the apicid<->coreid split was computed based on the max
number of cores. Now use a new CPUID AMD defined for that. On most
systems right now it should be 0 and the old method will be used.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andi Kleen 2006-06-26 13:56:10 +02:00 committed by Linus Torvalds
parent 79121ea9f0
commit faee9a5dc9
2 changed files with 21 additions and 13 deletions
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14
arch/i386/kernel/cpu/amd.c
View File

@ -224,15 +224,17 @@ static void __init init_amd(struct cpuinfo_x86 *c)
#ifdef CONFIG_X86_HT
/*
* On a AMD dual core setup the lower bits of the APIC id
* distingush the cores. Assumes number of cores is a power
* of two.
* On a AMD multi core setup the lower bits of the APIC id
* distingush the cores.
*/
if (c->x86_max_cores > 1) {
int cpu = smp_processor_id();
unsigned bits = 0;
while ((1 << bits) < c->x86_max_cores)
bits++;
unsigned bits = (cpuid_ecx(0x80000008) >> 12) & 0xf;
if (bits == 0) {
while ((1 << bits) < c->x86_max_cores)
bits++;
}
cpu_core_id[cpu] = phys_proc_id[cpu] & ((1<<bits)-1);
phys_proc_id[cpu] >>= bits;
printk(KERN_INFO "CPU %d(%d) -> Core %d\n",

20
arch/x86_64/kernel/setup.c
View File

@ -873,10 +873,18 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
int node = 0;
unsigned apicid = hard_smp_processor_id();
#endif
unsigned ecx = cpuid_ecx(0x80000008);
bits = 0;
while ((1 << bits) < c->x86_max_cores)
bits++;
c->x86_max_cores = (ecx & 0xff) + 1;
/* CPU telling us the core id bits shift? */
bits = (ecx >> 12) & 0xF;
/* Otherwise recompute */
if (bits == 0) {
while ((1 << bits) < c->x86_max_cores)
bits++;
}
/* Low order bits define the core id (index of core in socket) */
cpu_core_id[cpu] = phys_proc_id[cpu] & ((1 << bits)-1);
@ -964,11 +972,9 @@ static int __init init_amd(struct cpuinfo_x86 *c)
if (c->x86_power & (1<<8))
set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability);
if (c->extended_cpuid_level >= 0x80000008) {
c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
/* Multi core CPU? */
if (c->extended_cpuid_level >= 0x80000008)
amd_detect_cmp(c);
}
return r;
}