- unsigned 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;
+ unsigned bits = (cpuid_ecx(0x80000008) >> 12) & 0xf;
+
+ if (bits == 0) {
+ while ((1 << bits) < c->x86_max_cores)
+ bits++;
+ }
+ c->cpu_core_id = c->phys_proc_id & ((1<<bits)-1);
+ c->phys_proc_id >>= bits;