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[PATCH] x86-64/i386: Intel HT, Multi core detection fixes

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Fields obtained through cpuid vector 0x1(ebx[16:23]) and
vector 0x4(eax[14:25], eax[26:31]) indicate the maximum values and might not
always be the same as what is available and what OS sees.  So make sure
"siblings" and "cpu cores" values in /proc/cpuinfo reflect the values as seen
by OS instead of what cpuid instruction says. This will also fix the buggy BIOS
cases (for example where cpuid on a single core cpu says there are "2" siblings,
even when HT is disabled in the BIOS.
http://bugzilla.kernel.org/show_bug.cgi?id=4359)

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Siddha, Suresh B
2005-11-05 17:25:54 +01:00
committed by Linus Torvalds
parent e90f22edf4
commit 94605eff57
11 changed files with 178 additions and 110 deletions
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12
arch/i386/kernel/cpu/amd.c
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@@ -206,9 +206,9 @@ static void __init init_amd(struct cpuinfo_x86 *c)
display_cacheinfo(c);
if (cpuid_eax(0x80000000) >= 0x80000008) {
c->x86_num_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
if (c->x86_num_cores & (c->x86_num_cores - 1))
c->x86_num_cores = 1;
c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
if (c->x86_max_cores & (c->x86_max_cores - 1))
c->x86_max_cores = 1;
}
#ifdef CONFIG_X86_HT
@@ -217,15 +217,15 @@ static void __init init_amd(struct cpuinfo_x86 *c)
* distingush the cores. Assumes number of cores is a power
* of two.
*/
if (c->x86_num_cores > 1) {
if (c->x86_max_cores > 1) {
int cpu = smp_processor_id();
unsigned bits = 0;
while ((1 << bits) < c->x86_num_cores)
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",
cpu, c->x86_num_cores, cpu_core_id[cpu]);
cpu, c->x86_max_cores, cpu_core_id[cpu]);
}
#endif
}