99e0c7ddc1
Change-Id: I116b15c83fcc5d69d3f80a2e6cf0fb085064d9a6 Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr> Reviewed-on: https://review.coreboot.org/c/coreboot/+/44604 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>
68 lines
1.6 KiB
C
68 lines
1.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
|
|
#include <console/console.h>
|
|
#include <cpu/intel/hyperthreading.h>
|
|
#include <device/device.h>
|
|
#include <option.h>
|
|
#include <smp/spinlock.h>
|
|
|
|
#if CONFIG(PARALLEL_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(struct device *cpu)
|
|
{
|
|
unsigned int 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;
|
|
struct device *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);
|
|
}
|
|
}
|