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#include <console/console.h>
#include <cpu/cpu.h>
#include <cpu/x86/lapic.h>
#include <cpu/intel/hyperthreading.h>
#include <device/device.h>
#include <pc80/mc146818rtc.h>
#include <smp/spinlock.h>
#include <assert.h>
#if !CONFIG_SERIAL_CPU_INIT
#error Intel hyper-threading requires serialized cpu init
#endif
static int first_time = 1;
static int disable_siblings = !CONFIG_LOGICAL_CPUS;
void intel_sibling_init(device_t cpu)
{
unsigned i, siblings;
struct cpuid_result result;
/* On the bootstrap processor see if I want sibling cpus enabled */
if (first_time) {
first_time = 0;
get_option(&disable_siblings, "hyper_threading");
}
result = cpuid(1);
/* Is hyperthreading supported */
if (!(result.edx & (1 << 28))) {
return;
}
/* See how many sibling cpus we have */
siblings = (result.ebx >> 16) & 0xff;
if (siblings < 1) {
siblings = 1;
}
printk(BIOS_DEBUG, "CPU: %u %d siblings\n",
cpu->path.apic.apic_id,
siblings);
/* See if I am a sibling cpu */
if (cpu->path.apic.apic_id & (siblings -1)) {
if (disable_siblings) {
cpu->enabled = 0;
}
return;
}
/* I am the primary cpu start up my siblings */
for(i = 1; i < siblings; i++) {
struct device_path cpu_path;
device_t new;
/* Build the cpu device path */
cpu_path.type = DEVICE_PATH_APIC;
cpu_path.apic.apic_id = cpu->path.apic.apic_id + i;
/* Allocate new cpu device structure iff sibling CPU
* was not in static device tree.
*/
new = alloc_find_dev(cpu->bus, &cpu_path);
if (!new) {
continue;
}
printk(BIOS_DEBUG, "CPU: %u has sibling %u\n",
cpu->path.apic.apic_id,
new->path.apic.apic_id);
}
}
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