diff options
| author | Andi Kleen | 2005-04-17 00:25:15 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2005-04-17 00:25:15 +0200 |
| commit | 3dd9d514846cdca1dcef2e4fce666d85e199e844 (patch) | |
| tree | 28e60a8b733db213e88b0aee8ef3861a93a6fa48 /arch/i386/kernel/cpu/intel.c | |
| parent | [PATCH] x86_64: Remove duplicated syscall entry. (diff) | |
| download | kernel-qcow2-linux-3dd9d514846cdca1dcef2e4fce666d85e199e844.tar.gz kernel-qcow2-linux-3dd9d514846cdca1dcef2e4fce666d85e199e844.tar.xz kernel-qcow2-linux-3dd9d514846cdca1dcef2e4fce666d85e199e844.zip | |
[PATCH] x86_64: add support for Intel dual-core detection and displaying
Appended patch adds the support for Intel dual-core detection and displaying
the core related information in /proc/cpuinfo.
It adds two new fields "core id" and "cpu cores" to x86 /proc/cpuinfo and the
"core id" field for x86_64("cpu cores" field is already present in x86_64).
Number of processor cores in a die is detected using cpuid(4) and this is
documented in IA-32 Intel Architecture Software Developer's Manual (vol 2a)
(http://developer.intel.com/design/pentium4/manuals/index_new.htm#sdm_vol2a)
This patch also adds cpu_core_map similar to cpu_sibling_map.
Slightly hacked by AK.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/kernel/cpu/intel.c')
| -rw-r--r-- | arch/i386/kernel/cpu/intel.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/intel.c b/arch/i386/kernel/cpu/intel.c index b8d847b850dc..121aa2176e69 100644 --- a/arch/i386/kernel/cpu/intel.c +++ b/arch/i386/kernel/cpu/intel.c @@ -77,6 +77,27 @@ static void __init Intel_errata_workarounds(struct cpuinfo_x86 *c) } +/* + * find out the number of processor cores on the die + */ +static int __init num_cpu_cores(struct cpuinfo_x86 *c) +{ + unsigned int eax; + + if (c->cpuid_level < 4) + return 1; + + __asm__("cpuid" + : "=a" (eax) + : "0" (4), "c" (0) + : "bx", "dx"); + + if (eax & 0x1f) + return ((eax >> 26) + 1); + else + return 1; +} + static void __init init_intel(struct cpuinfo_x86 *c) { unsigned int l2 = 0; @@ -139,6 +160,8 @@ static void __init init_intel(struct cpuinfo_x86 *c) if ( p ) strcpy(c->x86_model_id, p); + c->x86_num_cores = num_cpu_cores(c); + detect_ht(c); /* Work around errata */ |