Kyösti Mälkki (kyosti.malkki@gmail.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/1172 -gerrit commit 850fd7a8379c49ec961dda12c8119f405c0d3cec Author: Kyösti Mälkki <kyosti.malkki@gmail.com> Date: Wed Jul 4 12:02:58 2012 +0300 Intel CPUs: Fix counting of CPU cores Detection for a hyper-threading CPU was not compatible with multicore CPUs. When using CPUID eax==4, also need to set ecx=0. CAR init tested on real hardware with hyper-threading model_f25 and under qemu 0.15.1 with multicore CPU. Change-Id: I28ac8790f94652e4ba8ff88fe7812c812f967608 Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com> --- src/cpu/intel/car/cache_as_ram_ht.inc | 34 ++++++++++++++++++++----- src/cpu/intel/hyperthreading/intel_sibling.c | 7 ++++- 2 files changed, 32 insertions(+), 9 deletions(-) diff --git a/src/cpu/intel/car/cache_as_ram_ht.inc b/src/cpu/intel/car/cache_as_ram_ht.inc index 65da516..2a8d854 100644 --- a/src/cpu/intel/car/cache_as_ram_ht.inc +++ b/src/cpu/intel/car/cache_as_ram_ht.inc @@ -127,16 +127,36 @@ bsp_init: post_code(0x24) - /* For a hyper-threading processor, cache must not be disabled - * on an AP on the same physical package with the BSP. - */ - movl $01, %eax + movl $1, %eax cpuid btl $28, %edx jnc sipi_complete bswapl %ebx - cmpb $01, %bh - jbe sipi_complete + movzx %bh, %edi + cmpb $1, %bh + jbe sipi_complete /* only one LAPIC ID in package */ + + movl $0, %eax + cpuid + movb $1, %bl + cmpl $4, %eax + jb cores_counted + movl $4, %eax + movl $0, %ecx + cpuid + shr $26, %eax + movb %al, %bl + inc %bl + +cores_counted: + movl %edi, %eax + divb %bl + cmpb $1, %al + jbe sipi_complete /* only LAPIC ID of a core */ + + /* For a hyper-threading processor, cache must not be disabled + * on an AP on the same physical package with the BSP. + */ hyper_threading_cpu: @@ -202,7 +222,7 @@ ap_init: ap_halt: cli 1: hlt - jnz 1b + jmp 1b diff --git a/src/cpu/intel/hyperthreading/intel_sibling.c b/src/cpu/intel/hyperthreading/intel_sibling.c index b9a9ae7..f30ea45 100644 --- a/src/cpu/intel/hyperthreading/intel_sibling.c +++ b/src/cpu/intel/hyperthreading/intel_sibling.c @@ -28,8 +28,11 @@ int intel_ht_sibling(void) apic_ids = 1; core_ids = 1; - if (cpuid_eax(0) >= 4) - core_ids += (cpuid_eax(4) >> 26) & 0x3f; + if (cpuid_eax(0) >= 4) { + struct cpuid_result result; + result = cpuid_ext(4, 0); + core_ids += (result.eax >> 26) & 0x3f; + } threads = (apic_ids / core_ids); return !!(lapicid() & (threads-1));