x86/smpboot: Switch to hotplug core state synchronization
The new AP state tracking and synchronization mechanism in the CPU hotplug core code allows to remove quite some x86 specific code: 1) The AP alive synchronization based on cpumasks 2) The decision whether an AP can be brought up again Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Tested-by: Helge Deller <deller@gmx.de> # parisc Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck Link: https://lore.kernel.org/r/20230512205256.529657366@linutronix.de
This commit is contained in:
Thomas Gleixner
Peter Zijlstra
Родитель
6f0621238b
Коммит
2711b8e2b7
|
|
@ -274,6 +274,7 @@ config X86
|
|||
select HAVE_UNSTABLE_SCHED_CLOCK
|
||||
select HAVE_USER_RETURN_NOTIFIER
|
||||
select HAVE_GENERIC_VDSO
|
||||
select HOTPLUG_CORE_SYNC_FULL if SMP
|
||||
select HOTPLUG_SMT if SMP
|
||||
select IRQ_FORCED_THREADING
|
||||
select NEED_PER_CPU_EMBED_FIRST_CHUNK
|
||||
|
|
|
|||
|
|
@ -38,6 +38,8 @@ struct smp_ops {
|
|||
void (*crash_stop_other_cpus)(void);
|
||||
void (*smp_send_reschedule)(int cpu);
|
||||
|
||||
void (*cleanup_dead_cpu)(unsigned cpu);
|
||||
void (*poll_sync_state)(void);
|
||||
int (*cpu_up)(unsigned cpu, struct task_struct *tidle);
|
||||
int (*cpu_disable)(void);
|
||||
void (*cpu_die)(unsigned int cpu);
|
||||
|
|
@ -90,7 +92,8 @@ static inline int __cpu_disable(void)
|
|||
|
||||
static inline void __cpu_die(unsigned int cpu)
|
||||
{
|
||||
smp_ops.cpu_die(cpu);
|
||||
if (smp_ops.cpu_die)
|
||||
smp_ops.cpu_die(cpu);
|
||||
}
|
||||
|
||||
static inline void __noreturn play_dead(void)
|
||||
|
|
@ -123,8 +126,6 @@ void native_smp_cpus_done(unsigned int max_cpus);
|
|||
int common_cpu_up(unsigned int cpunum, struct task_struct *tidle);
|
||||
int native_cpu_up(unsigned int cpunum, struct task_struct *tidle);
|
||||
int native_cpu_disable(void);
|
||||
int common_cpu_die(unsigned int cpu);
|
||||
void native_cpu_die(unsigned int cpu);
|
||||
void __noreturn hlt_play_dead(void);
|
||||
void native_play_dead(void);
|
||||
void play_dead_common(void);
|
||||
|
|
|
|||
|
|
@ -269,7 +269,6 @@ struct smp_ops smp_ops = {
|
|||
.smp_send_reschedule = native_smp_send_reschedule,
|
||||
|
||||
.cpu_up = native_cpu_up,
|
||||
.cpu_die = native_cpu_die,
|
||||
.cpu_disable = native_cpu_disable,
|
||||
.play_dead = native_play_dead,
|
||||
|
||||
|
|
|
|||
|
|
@ -57,6 +57,7 @@
|
|||
#include <linux/pgtable.h>
|
||||
#include <linux/overflow.h>
|
||||
#include <linux/stackprotector.h>
|
||||
#include <linux/cpuhotplug.h>
|
||||
|
||||
#include <asm/acpi.h>
|
||||
#include <asm/cacheinfo.h>
|
||||
|
|
@ -101,9 +102,6 @@ EXPORT_PER_CPU_SYMBOL(cpu_die_map);
|
|||
DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
|
||||
EXPORT_PER_CPU_SYMBOL(cpu_info);
|
||||
|
||||
/* All of these masks are initialized in setup_cpu_local_masks() */
|
||||
static cpumask_var_t cpu_initialized_mask;
|
||||
static cpumask_var_t cpu_callout_mask;
|
||||
/* Representing CPUs for which sibling maps can be computed */
|
||||
static cpumask_var_t cpu_sibling_setup_mask;
|
||||
|
||||
|
|
@ -166,10 +164,10 @@ static void ap_starting(void)
|
|||
int cpuid = smp_processor_id();
|
||||
|
||||
/*
|
||||
* If woken up by an INIT in an 82489DX configuration
|
||||
* cpu_callout_mask guarantees the CPU does not reach this point
|
||||
* before an INIT_deassert IPI reaches the local APIC, so it is now
|
||||
* safe to touch the local APIC.
|
||||
* If woken up by an INIT in an 82489DX configuration the alive
|
||||
* synchronization guarantees that the CPU does not reach this
|
||||
* point before an INIT_deassert IPI reaches the local APIC, so it
|
||||
* is now safe to touch the local APIC.
|
||||
*
|
||||
* Set up this CPU, first the APIC, which is probably redundant on
|
||||
* most boards.
|
||||
|
|
@ -213,17 +211,6 @@ static void ap_calibrate_delay(void)
|
|||
cpu_data(smp_processor_id()).loops_per_jiffy = loops_per_jiffy;
|
||||
}
|
||||
|
||||
static void wait_for_master_cpu(int cpu)
|
||||
{
|
||||
/*
|
||||
* Wait for release by control CPU before continuing with AP
|
||||
* initialization.
|
||||
*/
|
||||
WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask));
|
||||
while (!cpumask_test_cpu(cpu, cpu_callout_mask))
|
||||
cpu_relax();
|
||||
}
|
||||
|
||||
/*
|
||||
* Activate a secondary processor.
|
||||
*/
|
||||
|
|
@ -244,11 +231,11 @@ static void notrace start_secondary(void *unused)
|
|||
cpu_init_exception_handling();
|
||||
|
||||
/*
|
||||
* Sync point with wait_cpu_initialized(). Sets AP in
|
||||
* cpu_initialized_mask and then waits for the control CPU
|
||||
* to release it.
|
||||
* Synchronization point with the hotplug core. Sets the
|
||||
* synchronization state to ALIVE and waits for the control CPU to
|
||||
* release this CPU for further bringup.
|
||||
*/
|
||||
wait_for_master_cpu(raw_smp_processor_id());
|
||||
cpuhp_ap_sync_alive();
|
||||
|
||||
cpu_init();
|
||||
rcu_cpu_starting(raw_smp_processor_id());
|
||||
|
|
@ -278,7 +265,6 @@ static void notrace start_secondary(void *unused)
|
|||
set_cpu_online(smp_processor_id(), true);
|
||||
lapic_online();
|
||||
unlock_vector_lock();
|
||||
cpu_set_state_online(smp_processor_id());
|
||||
x86_platform.nmi_init();
|
||||
|
||||
/* enable local interrupts */
|
||||
|
|
@ -729,9 +715,9 @@ static void impress_friends(void)
|
|||
* Allow the user to impress friends.
|
||||
*/
|
||||
pr_debug("Before bogomips\n");
|
||||
for_each_possible_cpu(cpu)
|
||||
if (cpumask_test_cpu(cpu, cpu_callout_mask))
|
||||
bogosum += cpu_data(cpu).loops_per_jiffy;
|
||||
for_each_online_cpu(cpu)
|
||||
bogosum += cpu_data(cpu).loops_per_jiffy;
|
||||
|
||||
pr_info("Total of %d processors activated (%lu.%02lu BogoMIPS)\n",
|
||||
num_online_cpus(),
|
||||
bogosum/(500000/HZ),
|
||||
|
|
@ -1003,6 +989,7 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle)
|
|||
static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
|
||||
{
|
||||
unsigned long start_ip = real_mode_header->trampoline_start;
|
||||
int ret;
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
/* If 64-bit wakeup method exists, use the 64-bit mode trampoline IP */
|
||||
|
|
@ -1043,13 +1030,6 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
|
|||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* AP might wait on cpu_callout_mask in cpu_init() with
|
||||
* cpu_initialized_mask set if previous attempt to online
|
||||
* it timed-out. Clear cpu_initialized_mask so that after
|
||||
* INIT/SIPI it could start with a clean state.
|
||||
*/
|
||||
cpumask_clear_cpu(cpu, cpu_initialized_mask);
|
||||
smp_mb();
|
||||
|
||||
/*
|
||||
|
|
@ -1060,47 +1040,16 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
|
|||
* - Use an INIT boot APIC message
|
||||
*/
|
||||
if (apic->wakeup_secondary_cpu_64)
|
||||
return apic->wakeup_secondary_cpu_64(apicid, start_ip);
|
||||
ret = apic->wakeup_secondary_cpu_64(apicid, start_ip);
|
||||
else if (apic->wakeup_secondary_cpu)
|
||||
return apic->wakeup_secondary_cpu(apicid, start_ip);
|
||||
ret = apic->wakeup_secondary_cpu(apicid, start_ip);
|
||||
else
|
||||
ret = wakeup_secondary_cpu_via_init(apicid, start_ip);
|
||||
|
||||
return wakeup_secondary_cpu_via_init(apicid, start_ip);
|
||||
}
|
||||
|
||||
static int wait_cpu_cpumask(unsigned int cpu, const struct cpumask *mask)
|
||||
{
|
||||
unsigned long timeout;
|
||||
|
||||
/*
|
||||
* Wait up to 10s for the CPU to report in.
|
||||
*/
|
||||
timeout = jiffies + 10*HZ;
|
||||
while (time_before(jiffies, timeout)) {
|
||||
if (cpumask_test_cpu(cpu, mask))
|
||||
return 0;
|
||||
|
||||
schedule();
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
/*
|
||||
* Bringup step two: Wait for the target AP to reach cpu_init_secondary()
|
||||
* and thus wait_for_master_cpu(), then set cpu_callout_mask to allow it
|
||||
* to proceed. The AP will then proceed past setting its 'callin' bit
|
||||
* and end up waiting in check_tsc_sync_target() until we reach
|
||||
* wait_cpu_online() to tend to it.
|
||||
*/
|
||||
static int wait_cpu_initialized(unsigned int cpu)
|
||||
{
|
||||
/*
|
||||
* Wait for first sign of life from AP.
|
||||
*/
|
||||
if (wait_cpu_cpumask(cpu, cpu_initialized_mask))
|
||||
return -1;
|
||||
|
||||
cpumask_set_cpu(cpu, cpu_callout_mask);
|
||||
return 0;
|
||||
/* If the wakeup mechanism failed, cleanup the warm reset vector */
|
||||
if (ret)
|
||||
arch_cpuhp_cleanup_kick_cpu(cpu);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int native_kick_ap(unsigned int cpu, struct task_struct *tidle)
|
||||
|
|
@ -1125,11 +1074,6 @@ static int native_kick_ap(unsigned int cpu, struct task_struct *tidle)
|
|||
*/
|
||||
mtrr_save_state();
|
||||
|
||||
/* x86 CPUs take themselves offline, so delayed offline is OK. */
|
||||
err = cpu_check_up_prepare(cpu);
|
||||
if (err && err != -EBUSY)
|
||||
return err;
|
||||
|
||||
/* the FPU context is blank, nobody can own it */
|
||||
per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL;
|
||||
|
||||
|
|
@ -1146,17 +1090,29 @@ static int native_kick_ap(unsigned int cpu, struct task_struct *tidle)
|
|||
|
||||
int native_cpu_up(unsigned int cpu, struct task_struct *tidle)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = native_kick_ap(cpu, tidle);
|
||||
if (!ret)
|
||||
ret = wait_cpu_initialized(cpu);
|
||||
return native_kick_ap(cpu, tidle);
|
||||
}
|
||||
|
||||
void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu)
|
||||
{
|
||||
/* Cleanup possible dangling ends... */
|
||||
if (x86_platform.legacy.warm_reset)
|
||||
if (smp_ops.cpu_up == native_cpu_up && x86_platform.legacy.warm_reset)
|
||||
smpboot_restore_warm_reset_vector();
|
||||
}
|
||||
|
||||
return ret;
|
||||
void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
|
||||
{
|
||||
if (smp_ops.cleanup_dead_cpu)
|
||||
smp_ops.cleanup_dead_cpu(cpu);
|
||||
|
||||
if (system_state == SYSTEM_RUNNING)
|
||||
pr_info("CPU %u is now offline\n", cpu);
|
||||
}
|
||||
|
||||
void arch_cpuhp_sync_state_poll(void)
|
||||
{
|
||||
if (smp_ops.poll_sync_state)
|
||||
smp_ops.poll_sync_state();
|
||||
}
|
||||
|
||||
/**
|
||||
|
|
@ -1348,9 +1304,6 @@ void __init native_smp_prepare_boot_cpu(void)
|
|||
if (!IS_ENABLED(CONFIG_SMP))
|
||||
switch_gdt_and_percpu_base(me);
|
||||
|
||||
/* already set me in cpu_online_mask in boot_cpu_init() */
|
||||
cpumask_set_cpu(me, cpu_callout_mask);
|
||||
cpu_set_state_online(me);
|
||||
native_pv_lock_init();
|
||||
}
|
||||
|
||||
|
|
@ -1477,8 +1430,6 @@ __init void prefill_possible_map(void)
|
|||
/* correctly size the local cpu masks */
|
||||
void __init setup_cpu_local_masks(void)
|
||||
{
|
||||
alloc_bootmem_cpumask_var(&cpu_initialized_mask);
|
||||
alloc_bootmem_cpumask_var(&cpu_callout_mask);
|
||||
alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
|
||||
}
|
||||
|
||||
|
|
@ -1540,9 +1491,6 @@ static void remove_siblinginfo(int cpu)
|
|||
static void remove_cpu_from_maps(int cpu)
|
||||
{
|
||||
set_cpu_online(cpu, false);
|
||||
cpumask_clear_cpu(cpu, cpu_callout_mask);
|
||||
/* was set by cpu_init() */
|
||||
cpumask_clear_cpu(cpu, cpu_initialized_mask);
|
||||
numa_remove_cpu(cpu);
|
||||
}
|
||||
|
||||
|
|
@ -1593,36 +1541,11 @@ int native_cpu_disable(void)
|
|||
return 0;
|
||||
}
|
||||
|
||||
int common_cpu_die(unsigned int cpu)
|
||||
{
|
||||
int ret = 0;
|
||||
|
||||
/* We don't do anything here: idle task is faking death itself. */
|
||||
|
||||
/* They ack this in play_dead() by setting CPU_DEAD */
|
||||
if (cpu_wait_death(cpu, 5)) {
|
||||
if (system_state == SYSTEM_RUNNING)
|
||||
pr_info("CPU %u is now offline\n", cpu);
|
||||
} else {
|
||||
pr_err("CPU %u didn't die...\n", cpu);
|
||||
ret = -1;
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
void native_cpu_die(unsigned int cpu)
|
||||
{
|
||||
common_cpu_die(cpu);
|
||||
}
|
||||
|
||||
void play_dead_common(void)
|
||||
{
|
||||
idle_task_exit();
|
||||
|
||||
/* Ack it */
|
||||
(void)cpu_report_death();
|
||||
|
||||
cpuhp_ap_report_dead();
|
||||
/*
|
||||
* With physical CPU hotplug, we should halt the cpu
|
||||
*/
|
||||
|
|
@ -1724,12 +1647,6 @@ int native_cpu_disable(void)
|
|||
return -ENOSYS;
|
||||
}
|
||||
|
||||
void native_cpu_die(unsigned int cpu)
|
||||
{
|
||||
/* We said "no" in __cpu_disable */
|
||||
BUG();
|
||||
}
|
||||
|
||||
void native_play_dead(void)
|
||||
{
|
||||
BUG();
|
||||
|
|
|
|||
|
|
@ -55,18 +55,16 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
|
|||
}
|
||||
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
static void xen_hvm_cpu_die(unsigned int cpu)
|
||||
static void xen_hvm_cleanup_dead_cpu(unsigned int cpu)
|
||||
{
|
||||
if (common_cpu_die(cpu) == 0) {
|
||||
if (xen_have_vector_callback) {
|
||||
xen_smp_intr_free(cpu);
|
||||
xen_uninit_lock_cpu(cpu);
|
||||
xen_teardown_timer(cpu);
|
||||
}
|
||||
if (xen_have_vector_callback) {
|
||||
xen_smp_intr_free(cpu);
|
||||
xen_uninit_lock_cpu(cpu);
|
||||
xen_teardown_timer(cpu);
|
||||
}
|
||||
}
|
||||
#else
|
||||
static void xen_hvm_cpu_die(unsigned int cpu)
|
||||
static void xen_hvm_cleanup_dead_cpu(unsigned int cpu)
|
||||
{
|
||||
BUG();
|
||||
}
|
||||
|
|
@ -77,7 +75,7 @@ void __init xen_hvm_smp_init(void)
|
|||
smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu;
|
||||
smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
|
||||
smp_ops.smp_cpus_done = xen_smp_cpus_done;
|
||||
smp_ops.cpu_die = xen_hvm_cpu_die;
|
||||
smp_ops.cleanup_dead_cpu = xen_hvm_cleanup_dead_cpu;
|
||||
|
||||
if (!xen_have_vector_callback) {
|
||||
#ifdef CONFIG_PARAVIRT_SPINLOCKS
|
||||
|
|
|
|||
|
|
@ -62,6 +62,7 @@ static void cpu_bringup(void)
|
|||
int cpu;
|
||||
|
||||
cr4_init();
|
||||
cpuhp_ap_sync_alive();
|
||||
cpu_init();
|
||||
touch_softlockup_watchdog();
|
||||
|
||||
|
|
@ -83,7 +84,7 @@ static void cpu_bringup(void)
|
|||
|
||||
set_cpu_online(cpu, true);
|
||||
|
||||
cpu_set_state_online(cpu); /* Implies full memory barrier. */
|
||||
smp_mb();
|
||||
|
||||
/* We can take interrupts now: we're officially "up". */
|
||||
local_irq_enable();
|
||||
|
|
@ -323,14 +324,6 @@ static int xen_pv_cpu_up(unsigned int cpu, struct task_struct *idle)
|
|||
|
||||
xen_setup_runstate_info(cpu);
|
||||
|
||||
/*
|
||||
* PV VCPUs are always successfully taken down (see 'while' loop
|
||||
* in xen_cpu_die()), so -EBUSY is an error.
|
||||
*/
|
||||
rc = cpu_check_up_prepare(cpu);
|
||||
if (rc)
|
||||
return rc;
|
||||
|
||||
/* make sure interrupts start blocked */
|
||||
per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
|
||||
|
||||
|
|
@ -349,6 +342,11 @@ static int xen_pv_cpu_up(unsigned int cpu, struct task_struct *idle)
|
|||
return 0;
|
||||
}
|
||||
|
||||
static void xen_pv_poll_sync_state(void)
|
||||
{
|
||||
HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
static int xen_pv_cpu_disable(void)
|
||||
{
|
||||
|
|
@ -364,18 +362,18 @@ static int xen_pv_cpu_disable(void)
|
|||
|
||||
static void xen_pv_cpu_die(unsigned int cpu)
|
||||
{
|
||||
while (HYPERVISOR_vcpu_op(VCPUOP_is_up,
|
||||
xen_vcpu_nr(cpu), NULL)) {
|
||||
while (HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu), NULL)) {
|
||||
__set_current_state(TASK_UNINTERRUPTIBLE);
|
||||
schedule_timeout(HZ/10);
|
||||
}
|
||||
}
|
||||
|
||||
if (common_cpu_die(cpu) == 0) {
|
||||
xen_smp_intr_free(cpu);
|
||||
xen_uninit_lock_cpu(cpu);
|
||||
xen_teardown_timer(cpu);
|
||||
xen_pmu_finish(cpu);
|
||||
}
|
||||
static void xen_pv_cleanup_dead_cpu(unsigned int cpu)
|
||||
{
|
||||
xen_smp_intr_free(cpu);
|
||||
xen_uninit_lock_cpu(cpu);
|
||||
xen_teardown_timer(cpu);
|
||||
xen_pmu_finish(cpu);
|
||||
}
|
||||
|
||||
static void __noreturn xen_pv_play_dead(void) /* used only with HOTPLUG_CPU */
|
||||
|
|
@ -397,6 +395,11 @@ static void xen_pv_cpu_die(unsigned int cpu)
|
|||
BUG();
|
||||
}
|
||||
|
||||
static void xen_pv_cleanup_dead_cpu(unsigned int cpu)
|
||||
{
|
||||
BUG();
|
||||
}
|
||||
|
||||
static void __noreturn xen_pv_play_dead(void)
|
||||
{
|
||||
BUG();
|
||||
|
|
@ -437,6 +440,8 @@ static const struct smp_ops xen_smp_ops __initconst = {
|
|||
|
||||
.cpu_up = xen_pv_cpu_up,
|
||||
.cpu_die = xen_pv_cpu_die,
|
||||
.cleanup_dead_cpu = xen_pv_cleanup_dead_cpu,
|
||||
.poll_sync_state = xen_pv_poll_sync_state,
|
||||
.cpu_disable = xen_pv_cpu_disable,
|
||||
.play_dead = xen_pv_play_dead,
|
||||
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче