https://github.com/torvalds/linux
Tip revision: 36a21d51725af2ce0700c6ebcb6b9594aac658a6 authored by Linus Torvalds on 08 August 2021, 20:49:31 UTC
Linux 5.14-rc5
Linux 5.14-rc5
Tip revision: 36a21d5
apic_flat_64.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2004 James Cleverdon, IBM.
*
* Flat APIC subarch code.
*
* Hacked for x86-64 by James Cleverdon from i386 architecture code by
* Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
* James Cleverdon.
*/
#include <linux/cpumask.h>
#include <linux/export.h>
#include <linux/acpi.h>
#include <asm/jailhouse_para.h>
#include <asm/apic.h>
#include "local.h"
static struct apic apic_physflat;
static struct apic apic_flat;
struct apic *apic __ro_after_init = &apic_flat;
EXPORT_SYMBOL_GPL(apic);
static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
return 1;
}
/*
* 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). So here it goes...
*/
void flat_init_apic_ldr(void)
{
unsigned long val;
unsigned long num, id;
num = smp_processor_id();
id = 1UL << num;
apic_write(APIC_DFR, APIC_DFR_FLAT);
val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
val |= SET_APIC_LOGICAL_ID(id);
apic_write(APIC_LDR, val);
}
static void _flat_send_IPI_mask(unsigned long mask, int vector)
{
unsigned long flags;
local_irq_save(flags);
__default_send_IPI_dest_field(mask, vector, APIC_DEST_LOGICAL);
local_irq_restore(flags);
}
static void flat_send_IPI_mask(const struct cpumask *cpumask, int vector)
{
unsigned long mask = cpumask_bits(cpumask)[0];
_flat_send_IPI_mask(mask, vector);
}
static void
flat_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector)
{
unsigned long mask = cpumask_bits(cpumask)[0];
int cpu = smp_processor_id();
if (cpu < BITS_PER_LONG)
__clear_bit(cpu, &mask);
_flat_send_IPI_mask(mask, vector);
}
static unsigned int flat_get_apic_id(unsigned long x)
{
return (x >> 24) & 0xFF;
}
static u32 set_apic_id(unsigned int id)
{
return (id & 0xFF) << 24;
}
static unsigned int read_xapic_id(void)
{
return flat_get_apic_id(apic_read(APIC_ID));
}
static int flat_apic_id_registered(void)
{
return physid_isset(read_xapic_id(), phys_cpu_present_map);
}
static int flat_phys_pkg_id(int initial_apic_id, int index_msb)
{
return initial_apic_id >> index_msb;
}
static int flat_probe(void)
{
return 1;
}
static struct apic apic_flat __ro_after_init = {
.name = "flat",
.probe = flat_probe,
.acpi_madt_oem_check = flat_acpi_madt_oem_check,
.apic_id_valid = default_apic_id_valid,
.apic_id_registered = flat_apic_id_registered,
.delivery_mode = APIC_DELIVERY_MODE_FIXED,
.dest_mode_logical = true,
.disable_esr = 0,
.check_apicid_used = NULL,
.init_apic_ldr = flat_init_apic_ldr,
.ioapic_phys_id_map = NULL,
.setup_apic_routing = NULL,
.cpu_present_to_apicid = default_cpu_present_to_apicid,
.apicid_to_cpu_present = NULL,
.check_phys_apicid_present = default_check_phys_apicid_present,
.phys_pkg_id = flat_phys_pkg_id,
.get_apic_id = flat_get_apic_id,
.set_apic_id = set_apic_id,
.calc_dest_apicid = apic_flat_calc_apicid,
.send_IPI = default_send_IPI_single,
.send_IPI_mask = flat_send_IPI_mask,
.send_IPI_mask_allbutself = flat_send_IPI_mask_allbutself,
.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,
};
/*
* Physflat mode is used when there are more than 8 CPUs on a system.
* We cannot use logical delivery in this case because the mask
* overflows, so use physical mode.
*/
static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
#ifdef CONFIG_ACPI
/*
* Quirk: some x86_64 machines can only use physical APIC mode
* regardless of how many processors are present (x86_64 ES7000
* is an example).
*/
if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
printk(KERN_DEBUG "system APIC only can use physical flat");
return 1;
}
if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) {
printk(KERN_DEBUG "IBM Summit detected, will use apic physical");
return 1;
}
#endif
return 0;
}
static void physflat_init_apic_ldr(void)
{
/*
* LDR and DFR are not involved in physflat mode, rather:
* "In physical destination mode, the destination processor is
* specified by its local APIC ID [...]." (Intel SDM, 10.6.2.1)
*/
}
static int physflat_probe(void)
{
if (apic == &apic_physflat || num_possible_cpus() > 8 ||
jailhouse_paravirt())
return 1;
return 0;
}
static struct apic apic_physflat __ro_after_init = {
.name = "physical flat",
.probe = physflat_probe,
.acpi_madt_oem_check = physflat_acpi_madt_oem_check,
.apic_id_valid = default_apic_id_valid,
.apic_id_registered = flat_apic_id_registered,
.delivery_mode = APIC_DELIVERY_MODE_FIXED,
.dest_mode_logical = false,
.disable_esr = 0,
.check_apicid_used = NULL,
.init_apic_ldr = physflat_init_apic_ldr,
.ioapic_phys_id_map = NULL,
.setup_apic_routing = NULL,
.cpu_present_to_apicid = default_cpu_present_to_apicid,
.apicid_to_cpu_present = NULL,
.check_phys_apicid_present = default_check_phys_apicid_present,
.phys_pkg_id = flat_phys_pkg_id,
.get_apic_id = flat_get_apic_id,
.set_apic_id = set_apic_id,
.calc_dest_apicid = apic_default_calc_apicid,
.send_IPI = default_send_IPI_single_phys,
.send_IPI_mask = default_send_IPI_mask_sequence_phys,
.send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_phys,
.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,
};
/*
* We need to check for physflat first, so this order is important.
*/
apic_drivers(apic_physflat, apic_flat);