diff options
| author | Andi Kleen <ak@suse.de> | 2006-06-26 13:56:10 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-26 10:48:14 -0700 |
| commit | faee9a5dc9d8399cc3b1b8e18b6d7ff7b17f1af1 (patch) | |
| tree | e909f4ca48bd3d61b06e3b77f4c380301cd7b857 | |
| parent | 79121ea9f098934850347eeed3857ffd836810c3 (diff) | |
| download | linux-faee9a5dc9d8399cc3b1b8e18b6d7ff7b17f1af1.tar.gz | |
[PATCH] i386/x86-64: Use new official CPUID to get APICID/core split on AMD platforms
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>
| -rw-r--r-- | arch/i386/kernel/cpu/amd.c | 14 | ||||
| -rw-r--r-- | arch/x86_64/kernel/setup.c | 20 |
2 files changed, 21 insertions, 13 deletions
diff --git a/arch/i386/kernel/cpu/amd.c b/arch/i386/kernel/cpu/amd.c index 786d1a57048b9..b9c93d9789e71 100644 --- a/arch/i386/kernel/cpu/amd.c +++ b/arch/i386/kernel/cpu/amd.c @@ -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", diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c index fb850b52b4da7..1cb3e21c571ac 100644 --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -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; } |