/*
* Activate a secondary processor.
*/
static void notrace start_secondary(void *unused)
{
/*
* Don't put *anything* before cpu_init(), SMP booting is too
* fragile that we want to limit the things done here to the
* most necessary things.
*/
cpu_init();
x86_cpuinit.early_percpu_clock_init();
preempt_disable();
smp_callin();
enable_start_cpu0 = 0;
#ifdef CONFIG_X86_32
/* switch away from the initial page table */
load_cr3(swapper_pg_dir);
__flush_tlb_all();
#endif
/* otherwise gcc will move up smp_processor_id before the cpu_init */
barrier();
/*
* Check TSC synchronization with the BP:
*/
check_tsc_sync_target();
/*
* Lock vector_lock and initialize the vectors on this cpu
* before setting the cpu online. We must set it online with
* vector_lock held to prevent a concurrent setup/teardown
* from seeing a half valid vector space.
*/
lock_vector_lock();
setup_vector_irq(smp_processor_id());
set_cpu_online(smp_processor_id(), true);
unlock_vector_lock();
cpu_set_state_online(smp_processor_id());
x86_platform.nmi_init();
/* enable local interrupts */
local_irq_enable();
/* to prevent fake stack check failure in clock setup */
boot_init_stack_canary();
x86_cpuinit.setup_percpu_clockev();
wmb();
cpu_startup_entry(CPUHP_ONLINE);
}
/*
* Report back to the Boot Processor during boot time or to the caller processor
* during CPU online.
*/
static void __cpuinit smp_callin(void)
{
int cpuid, phys_id;
unsigned long timeout;
/*
* If waken up by an INIT in an 82489DX configuration
* we may get here before an INIT-deassert IPI reaches
* our local APIC. We have to wait for the IPI or we'll
* lock up on an APIC access.
*
* Since CPU0 is not wakened up by INIT, it doesn't wait for the IPI.
*/
cpuid = smp_processor_id();
if (apic->wait_for_init_deassert && cpuid != 0)
apic->wait_for_init_deassert(&init_deasserted);
/*
* (This works even if the APIC is not enabled.)
*/
phys_id = read_apic_id();
if (cpumask_test_cpu(cpuid, cpu_callin_mask)) {
panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
phys_id, cpuid);
}
pr_debug("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
/*
* STARTUP IPIs are fragile beasts as they might sometimes
* trigger some glue motherboard logic. Complete APIC bus
* silence for 1 second, this overestimates the time the
* boot CPU is spending to send the up to 2 STARTUP IPIs
* by a factor of two. This should be enough.
*/
/*
* Waiting 2s total for startup (udelay is not yet working)
*/
timeout = jiffies + 2*HZ;
while (time_before(jiffies, timeout)) {
/*
* Has the boot CPU finished it's STARTUP sequence?
*/
if (cpumask_test_cpu(cpuid, cpu_callout_mask))
break;
cpu_relax();
}
if (!time_before(jiffies, timeout)) {
panic("%s: CPU%d started up but did not get a callout!\n",
__func__, cpuid);
}
/*
* the boot CPU has finished the init stage and is spinning
* on callin_map until we finish. We are free to set up this
* CPU, first the APIC. (this is probably redundant on most
* boards)
*/
pr_debug("CALLIN, before setup_local_APIC()\n");
if (apic->smp_callin_clear_local_apic)
apic->smp_callin_clear_local_apic();
setup_local_APIC();
end_local_APIC_setup();
/*
* Need to setup vector mappings before we enable interrupts.
*/
setup_vector_irq(smp_processor_id());
/*
* Save our processor parameters. Note: this information
* is needed for clock calibration.
*/
smp_store_cpu_info(cpuid);
/*
* Get our bogomips.
* Update loops_per_jiffy in cpu_data. Previous call to
* smp_store_cpu_info() stored a value that is close but not as
* accurate as the value just calculated.
*/
calibrate_delay();
cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy;
pr_debug("Stack at about %p\n", &cpuid);
/*
* This must be done before setting cpu_online_mask
* or calling notify_cpu_starting.
*/
set_cpu_sibling_map(raw_smp_processor_id());
wmb();
notify_cpu_starting(cpuid);
/*
* Allow the master to continue.
*/
cpumask_set_cpu(cpuid, cpu_callin_mask);
}
/*
* Report back to the Boot Processor during boot time or to the caller processor
* during CPU online.
*/
static void smp_callin(void)
{
int cpuid, phys_id;
/*
* If waken up by an INIT in an 82489DX configuration
* we may get here before an INIT-deassert IPI reaches
* our local APIC. We have to wait for the IPI or we'll
* lock up on an APIC access.
*
* Since CPU0 is not wakened up by INIT, it doesn't wait for the IPI.
*/
cpuid = smp_processor_id();
if (apic->wait_for_init_deassert && cpuid)
while (!atomic_read(&init_deasserted))
cpu_relax();
/*
* (This works even if the APIC is not enabled.)
*/
phys_id = read_apic_id();
/*
* the boot CPU has finished the init stage and is spinning
* on callin_map until we finish. We are free to set up this
* CPU, first the APIC. (this is probably redundant on most
* boards)
*/
pr_debug("CALLIN, before setup_local_APIC()\n");
if (apic->smp_callin_clear_local_apic)
apic->smp_callin_clear_local_apic();
setup_local_APIC();
end_local_APIC_setup();
/*
* Need to setup vector mappings before we enable interrupts.
*/
setup_vector_irq(smp_processor_id());
/*
* Save our processor parameters. Note: this information
* is needed for clock calibration.
*/
smp_store_cpu_info(cpuid);
/*
* Get our bogomips.
* Update loops_per_jiffy in cpu_data. Previous call to
* smp_store_cpu_info() stored a value that is close but not as
* accurate as the value just calculated.
*/
calibrate_delay();
cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy;
pr_debug("Stack at about %p\n", &cpuid);
/*
* This must be done before setting cpu_online_mask
* or calling notify_cpu_starting.
*/
set_cpu_sibling_map(raw_smp_processor_id());
wmb();
notify_cpu_starting(cpuid);
/*
* Allow the master to continue.
*/
cpumask_set_cpu(cpuid, cpu_callin_mask);
}