probe_32.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Default generic APIC driver. This handles up to 8 CPUs.
*
* Copyright 2003 Andi Kleen, SuSE Labs.
*
* Generic x86 APIC driver probe layer.
*/
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/smp.h>
#include <asm/apic.h>
#include <asm/acpi.h>
#include "local.h"
static int default_x86_32_early_logical_apicid(int cpu)
{
return 1 << cpu;
}
static void setup_apic_flat_routing(void)
{
#ifdef CONFIG_X86_IO_APIC
printk(KERN_INFO
"Enabling APIC mode: Flat. Using %d I/O APICs\n",
nr_ioapics);
#endif
}
static int default_apic_id_registered(void)
{
return physid_isset(read_apic_id(), phys_cpu_present_map);
}
/*
* Set up the logical destination ID. Intel recommends to set DFR, LDR and
* TPR before enabling an APIC. See e.g. "AP-388 82489DX User's Manual"
* (Intel document number 292116).
*/
static void default_init_apic_ldr(void)
{
unsigned long val;
apic_write(APIC_DFR, APIC_DFR_VALUE);
val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
apic_write(APIC_LDR, val);
}
static int default_phys_pkg_id(int cpuid_apic, int index_msb)
{
return cpuid_apic >> index_msb;
}
/* should be called last. */
static int probe_default(void)
{
return 1;
}
static struct apic apic_default __ro_after_init = {
.name = "default",
.probe = probe_default,
.acpi_madt_oem_check = NULL,
.apic_id_valid = default_apic_id_valid,
.apic_id_registered = default_apic_id_registered,
.irq_delivery_mode = dest_Fixed,
/* logical delivery broadcast to all CPUs: */
.irq_dest_mode = 1,
.disable_esr = 0,
.dest_logical = APIC_DEST_LOGICAL,
.check_apicid_used = default_check_apicid_used,
.init_apic_ldr = default_init_apic_ldr,
.ioapic_phys_id_map = default_ioapic_phys_id_map,
.setup_apic_routing = setup_apic_flat_routing,
.cpu_present_to_apicid = default_cpu_present_to_apicid,
.apicid_to_cpu_present = physid_set_mask_of_physid,
.check_phys_apicid_present = default_check_phys_apicid_present,
.phys_pkg_id = default_phys_pkg_id,
.get_apic_id = default_get_apic_id,
.set_apic_id = NULL,
.calc_dest_apicid = apic_flat_calc_apicid,
.send_IPI = default_send_IPI_single,
.send_IPI_mask = default_send_IPI_mask_logical,
.send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_logical,
.send_IPI_allbutself = default_send_IPI_allbutself,
.send_IPI_all = default_send_IPI_all,
.send_IPI_self = default_send_IPI_self,
.inquire_remote_apic = default_inquire_remote_apic,
.read = native_apic_mem_read,
.write = native_apic_mem_write,
.eoi_write = native_apic_mem_write,
.icr_read = native_apic_icr_read,
.icr_write = native_apic_icr_write,
.wait_icr_idle = native_apic_wait_icr_idle,
.safe_wait_icr_idle = native_safe_apic_wait_icr_idle,
.x86_32_early_logical_apicid = default_x86_32_early_logical_apicid,
};
apic_driver(apic_default);
struct apic *apic __ro_after_init = &apic_default;
EXPORT_SYMBOL_GPL(apic);
static int cmdline_apic __initdata;
static int __init parse_apic(char *arg)
{
struct apic **drv;
if (!arg)
return -EINVAL;
for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
if (!strcmp((*drv)->name, arg)) {
apic = *drv;
cmdline_apic = 1;
return 0;
}
}
/* Parsed again by __setup for debug/verbose */
return 0;
}
early_param("apic", parse_apic);
void __init default_setup_apic_routing(void)
{
int version = boot_cpu_apic_version;
if (num_possible_cpus() > 8) {
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_INTEL:
if (!APIC_XAPIC(version)) {
def_to_bigsmp = 0;
break;
}
/* P4 and above */
/* fall through */
case X86_VENDOR_HYGON:
case X86_VENDOR_AMD:
def_to_bigsmp = 1;
}
}
#ifdef CONFIG_X86_BIGSMP
/*
* This is used to switch to bigsmp mode when
* - There is no apic= option specified by the user
* - generic_apic_probe() has chosen apic_default as the sub_arch
* - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
*/
if (!cmdline_apic && apic == &apic_default)
generic_bigsmp_probe();
#endif
if (apic->setup_apic_routing)
apic->setup_apic_routing();
if (x86_platform.apic_post_init)
x86_platform.apic_post_init();
}
void __init generic_apic_probe(void)
{
if (!cmdline_apic) {
struct apic **drv;
for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
if ((*drv)->probe()) {
apic = *drv;
break;
}
}
/* Not visible without early console */
if (drv == __apicdrivers_end)
panic("Didn't find an APIC driver");
}
printk(KERN_INFO "Using APIC driver %s\n", apic->name);
}
/* This function can switch the APIC even after the initial ->probe() */
int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
struct apic **drv;
for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
if (!(*drv)->acpi_madt_oem_check)
continue;
if (!(*drv)->acpi_madt_oem_check(oem_id, oem_table_id))
continue;
if (!cmdline_apic) {
apic = *drv;
printk(KERN_INFO "Switched to APIC driver `%s'.\n",
apic->name);
}
return 1;
}
return 0;
}