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googlers / maze / linux / ea02c63d57d7ec099f66ddb2942b4022e865cd5f / . / arch / x86 / kernel / smpboot.c
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/*
* x86 SMP booting functions
*
* (c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk>
* (c) 1998, 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
* Copyright 2001 Andi Kleen, SuSE Labs.
*
* Much of the core SMP work is based on previous work by Thomas Radke, to
* whom a great many thanks are extended.
*
* Thanks to Intel for making available several different Pentium,
* Pentium Pro and Pentium-II/Xeon MP machines.
* Original development of Linux SMP code supported by Caldera.
*
* This code is released under the GNU General Public License version 2 or
* later.
*
* Fixes
* Felix Koop : NR_CPUS used properly
* Jose Renau : Handle single CPU case.
* Alan Cox : By repeated request 8) - Total BogoMIPS report.
* Greg Wright : Fix for kernel stacks panic.
* Erich Boleyn : MP v1.4 and additional changes.
* Matthias Sattler : Changes for 2.1 kernel map.
* Michel Lespinasse : Changes for 2.1 kernel map.
* Michael Chastain : Change trampoline.S to gnu as.
* Alan Cox : Dumb bug: 'B' step PPro's are fine
* Ingo Molnar : Added APIC timers, based on code
* from Jose Renau
* Ingo Molnar : various cleanups and rewrites
* Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug.
* Maciej W. Rozycki : Bits for genuine 82489DX APICs
* Andi Kleen : Changed for SMP boot into long mode.
* Martin J. Bligh : Added support for multi-quad systems
* Dave Jones : Report invalid combinations of Athlon CPUs.
* Rusty Russell : Hacked into shape for new "hotplug" boot process.
* Andi Kleen : Converted to new state machine.
* Ashok Raj : CPU hotplug support
* Glauber Costa : i386 and x86_64 integration
*/
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/percpu.h>
#include <linux/bootmem.h>
#include <linux/err.h>
#include <linux/nmi.h>
#include <linux/tboot.h>
#include <linux/stackprotector.h>
#include <linux/gfp.h>
#include <asm/acpi.h>
#include <asm/desc.h>
#include <asm/nmi.h>
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/trampoline.h>
#include <asm/cpu.h>
#include <asm/numa.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/mtrr.h>
#include <asm/mwait.h>
#include <asm/apic.h>
#include <asm/io_apic.h>
#include <asm/setup.h>
#include <asm/uv/uv.h>
#include <linux/mc146818rtc.h>
#include <asm/smpboot_hooks.h>
#include <asm/i8259.h>
/* State of each CPU */
DEFINE_PER_CPU(int, cpu_state) = { 0 };
/* Store all idle threads, this can be reused instead of creating
* a new thread. Also avoids complicated thread destroy functionality
* for idle threads.
*/
#ifdef CONFIG_HOTPLUG_CPU
/*
* Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
* removed after init for !CONFIG_HOTPLUG_CPU.
*/
static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
#define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
#define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
/*
* We need this for trampoline_base protection from concurrent accesses when
* off- and onlining cores wildly.
*/
static DEFINE_MUTEX(x86_cpu_hotplug_driver_mutex);
void cpu_hotplug_driver_lock(void)
{
mutex_lock(&x86_cpu_hotplug_driver_mutex);
}
void cpu_hotplug_driver_unlock(void)
{
mutex_unlock(&x86_cpu_hotplug_driver_mutex);
}
ssize_t arch_cpu_probe(const char *buf, size_t count) { return -1; }
ssize_t arch_cpu_release(const char *buf, size_t count) { return -1; }
#else
static struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
#define get_idle_for_cpu(x) (idle_thread_array[(x)])
#define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
#endif
/* Number of siblings per CPU package */
int smp_num_siblings = 1;
EXPORT_SYMBOL(smp_num_siblings);
/* Last level cache ID of each logical CPU */
DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
/* representing HT siblings of each logical CPU */
DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
/* representing HT and core siblings of each logical CPU */
DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
EXPORT_PER_CPU_SYMBOL(cpu_core_map);
DEFINE_PER_CPU(cpumask_var_t, cpu_llc_shared_map);
/* Per CPU bogomips and other parameters */
DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
EXPORT_PER_CPU_SYMBOL(cpu_info);
atomic_t init_deasserted;
/*
* Report back to the Boot Processor.
* Running on AP.
*/
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.
*/
if (apic->wait_for_init_deassert)
apic->wait_for_init_deassert(&init_deasserted);
/*
* (This works even if the APIC is not enabled.)
*/
phys_id = read_apic_id();
cpuid = smp_processor_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());
/*
* Get our bogomips.
*
* Need to enable IRQs because it can take longer and then
* the NMI watchdog might kill us.
*/
local_irq_enable();
calibrate_delay();
local_irq_disable();
pr_debug("Stack at about %p\n", &cpuid);
/*
* Save our processor parameters
*/
smp_store_cpu_info(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);
}
/*
* Activate a secondary processor.
*/
notrace static void __cpuinit 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();
preempt_disable();
smp_callin();
#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();
/*
* We need to hold call_lock, so there is no inconsistency
* between the time smp_call_function() determines number of
* IPI recipients, and the time when the determination is made
* for which cpus receive the IPI. Holding this
* lock helps us to not include this cpu in a currently in progress
* smp_call_function().
*
* We need to hold vector_lock so there the set of online cpus
* does not change while we are assigning vectors to cpus. Holding
* this lock ensures we don't half assign or remove an irq from a cpu.
*/
ipi_call_lock();
lock_vector_lock();
set_cpu_online(smp_processor_id(), true);
unlock_vector_lock();
ipi_call_unlock();
per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
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_idle();
}
/*
* The bootstrap kernel entry code has set these up. Save them for
* a given CPU
*/
void __cpuinit smp_store_cpu_info(int id)
{
struct cpuinfo_x86 *c = &cpu_data(id);
*c = boot_cpu_data;
c->cpu_index = id;
if (id != 0)
identify_secondary_cpu(c);
}
static void __cpuinit link_thread_siblings(int cpu1, int cpu2)
{
cpumask_set_cpu(cpu1, cpu_sibling_mask(cpu2));
cpumask_set_cpu(cpu2, cpu_sibling_mask(cpu1));
cpumask_set_cpu(cpu1, cpu_core_mask(cpu2));
cpumask_set_cpu(cpu2, cpu_core_mask(cpu1));
cpumask_set_cpu(cpu1, cpu_llc_shared_mask(cpu2));
cpumask_set_cpu(cpu2, cpu_llc_shared_mask(cpu1));
}
void __cpuinit set_cpu_sibling_map(int cpu)
{
int i;
struct cpuinfo_x86 *c = &cpu_data(cpu);
cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
if (smp_num_siblings > 1) {
for_each_cpu(i, cpu_sibling_setup_mask) {
struct cpuinfo_x86 *o = &cpu_data(i);
if (cpu_has(c, X86_FEATURE_TOPOEXT)) {
if (c->phys_proc_id == o->phys_proc_id &&
per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i) &&
c->compute_unit_id == o->compute_unit_id)
link_thread_siblings(cpu, i);
} else if (c->phys_proc_id == o->phys_proc_id &&
c->cpu_core_id == o->cpu_core_id) {
link_thread_siblings(cpu, i);
}
}
} else {
cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
}
cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu));
if (__this_cpu_read(cpu_info.x86_max_cores) == 1) {
cpumask_copy(cpu_core_mask(cpu), cpu_sibling_mask(cpu));
c->booted_cores = 1;
return;
}
for_each_cpu(i, cpu_sibling_setup_mask) {
if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
cpumask_set_cpu(i, cpu_llc_shared_mask(cpu));
cpumask_set_cpu(cpu, cpu_llc_shared_mask(i));
}
if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
cpumask_set_cpu(i, cpu_core_mask(cpu));
cpumask_set_cpu(cpu, cpu_core_mask(i));
/*
* Does this new cpu bringup a new core?
*/
if (cpumask_weight(cpu_sibling_mask(cpu)) == 1) {
/*
* for each core in package, increment
* the booted_cores for this new cpu
*/
if (cpumask_first(cpu_sibling_mask(i)) == i)
c->booted_cores++;
/*
* increment the core count for all
* the other cpus in this package
*/
if (i != cpu)
cpu_data(i).booted_cores++;
} else if (i != cpu && !c->booted_cores)
c->booted_cores = cpu_data(i).booted_cores;
}
}
}
/* maps the cpu to the sched domain representing multi-core */
const struct cpumask *cpu_coregroup_mask(int cpu)
{
struct cpuinfo_x86 *c = &cpu_data(cpu);
/*
* For perf, we return last level cache shared map.
* And for power savings, we return cpu_core_map
*/
if ((sched_mc_power_savings || sched_smt_power_savings) &&
!(cpu_has(c, X86_FEATURE_AMD_DCM)))
return cpu_core_mask(cpu);
else
return cpu_llc_shared_mask(cpu);
}
static void impress_friends(void)
{
int cpu;
unsigned long bogosum = 0;
/*
* 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;
printk(KERN_INFO
"Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
num_online_cpus(),
bogosum/(500000/HZ),
(bogosum/(5000/HZ))%100);
pr_debug("Before bogocount - setting activated=1.\n");
}
void __inquire_remote_apic(int apicid)
{
unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
char *names[] = { "ID", "VERSION", "SPIV" };
int timeout;
u32 status;
printk(KERN_INFO "Inquiring remote APIC 0x%x...\n", apicid);
for (i = 0; i < ARRAY_SIZE(regs); i++) {
printk(KERN_INFO "... APIC 0x%x %s: ", apicid, names[i]);
/*
* Wait for idle.
*/
status = safe_apic_wait_icr_idle();
if (status)
printk(KERN_CONT
"a previous APIC delivery may have failed\n");
apic_icr_write(APIC_DM_REMRD | regs[i], apicid);
timeout = 0;
do {
udelay(100);
status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
} while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
switch (status) {
case APIC_ICR_RR_VALID:
status = apic_read(APIC_RRR);
printk(KERN_CONT "%08x\n", status);
break;
default:
printk(KERN_CONT "failed\n");
}
}
}
/*
* Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
* INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
* won't ... remember to clear down the APIC, etc later.
*/
int __cpuinit
wakeup_secondary_cpu_via_nmi(int logical_apicid, unsigned long start_eip)
{
unsigned long send_status, accept_status = 0;
int maxlvt;
/* Target chip */
/* Boot on the stack */
/* Kick the second */
apic_icr_write(APIC_DM_NMI | apic->dest_logical, logical_apicid);
pr_debug("Waiting for send to finish...\n");
send_status = safe_apic_wait_icr_idle();
/*
* Give the other CPU some time to accept the IPI.
*/
udelay(200);
if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
maxlvt = lapic_get_maxlvt();
if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
apic_write(APIC_ESR, 0);
accept_status = (apic_read(APIC_ESR) & 0xEF);
}
pr_debug("NMI sent.\n");
if (send_status)
printk(KERN_ERR "APIC never delivered???\n");
if (accept_status)
printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
return (send_status | accept_status);
}
static int __cpuinit
wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
{
unsigned long send_status, accept_status = 0;
int maxlvt, num_starts, j;
maxlvt = lapic_get_maxlvt();
/*
* Be paranoid about clearing APIC errors.
*/
if (APIC_INTEGRATED(apic_version[phys_apicid])) {
if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
apic_write(APIC_ESR, 0);
apic_read(APIC_ESR);
}
pr_debug("Asserting INIT.\n");
/*
* Turn INIT on target chip
*/
/*
* Send IPI
*/
apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT,
phys_apicid);
pr_debug("Waiting for send to finish...\n");
send_status = safe_apic_wait_icr_idle();
mdelay(10);
pr_debug("Deasserting INIT.\n");
/* Target chip */
/* Send IPI */
apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid);
pr_debug("Waiting for send to finish...\n");
send_status = safe_apic_wait_icr_idle();
mb();
atomic_set(&init_deasserted, 1);
/*
* Should we send STARTUP IPIs ?
*
* Determine this based on the APIC version.
* If we don't have an integrated APIC, don't send the STARTUP IPIs.
*/
if (APIC_INTEGRATED(apic_version[phys_apicid]))
num_starts = 2;
else
num_starts = 0;
/*
* Paravirt / VMI wants a startup IPI hook here to set up the
* target processor state.
*/
startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
stack_start);
/*
* Run STARTUP IPI loop.
*/
pr_debug("#startup loops: %d.\n", num_starts);
for (j = 1; j <= num_starts; j++) {
pr_debug("Sending STARTUP #%d.\n", j);
if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
apic_write(APIC_ESR, 0);
apic_read(APIC_ESR);
pr_debug("After apic_write.\n");
/*
* STARTUP IPI
*/
/* Target chip */
/* Boot on the stack */
/* Kick the second */
apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12),
phys_apicid);
/*
* Give the other CPU some time to accept the IPI.
*/
udelay(300);
pr_debug("Startup point 1.\n");
pr_debug("Waiting for send to finish...\n");
send_status = safe_apic_wait_icr_idle();
/*
* Give the other CPU some time to accept the IPI.
*/
udelay(200);
if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
apic_write(APIC_ESR, 0);
accept_status = (apic_read(APIC_ESR) & 0xEF);
if (send_status || accept_status)
break;
}
pr_debug("After Startup.\n");
if (send_status)
printk(KERN_ERR "APIC never delivered???\n");
if (accept_status)
printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
return (send_status | accept_status);
}
struct create_idle {
struct work_struct work;
struct task_struct *idle;
struct completion done;
int cpu;
};
static void __cpuinit do_fork_idle(struct work_struct *work)
{
struct create_idle *c_idle =
container_of(work, struct create_idle, work);
c_idle->idle = fork_idle(c_idle->cpu);
complete(&c_idle->done);
}
/* reduce the number of lines printed when booting a large cpu count system */
static void __cpuinit announce_cpu(int cpu, int apicid)
{
static int current_node = -1;
int node = early_cpu_to_node(cpu);
if (system_state == SYSTEM_BOOTING) {
if (node != current_node) {
if (current_node > (-1))
pr_cont(" Ok.\n");
current_node = node;
pr_info("Booting Node %3d, Processors ", node);
}
pr_cont(" #%d%s", cpu, cpu == (nr_cpu_ids - 1) ? " Ok.\n" : "");
return;
} else
pr_info("Booting Node %d Processor %d APIC 0x%x\n",
node, cpu, apicid);
}
/*
* NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
* (ie clustered apic addressing mode), this is a LOGICAL apic ID.
* Returns zero if CPU booted OK, else error code from
* ->wakeup_secondary_cpu.
*/
static int __cpuinit do_boot_cpu(int apicid, int cpu)
{
unsigned long boot_error = 0;
unsigned long start_ip;
int timeout;
struct create_idle c_idle = {
.cpu = cpu,
.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
};
INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
alternatives_smp_switch(1);
c_idle.idle = get_idle_for_cpu(cpu);
/*
* We can't use kernel_thread since we must avoid to
* reschedule the child.
*/
if (c_idle.idle) {
c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *)
(THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
init_idle(c_idle.idle, cpu);
goto do_rest;
}
schedule_work(&c_idle.work);
wait_for_completion(&c_idle.done);
if (IS_ERR(c_idle.idle)) {
printk("failed fork for CPU %d\n", cpu);
destroy_work_on_stack(&c_idle.work);
return PTR_ERR(c_idle.idle);
}
set_idle_for_cpu(cpu, c_idle.idle);
do_rest:
per_cpu(current_task, cpu) = c_idle.idle;
#ifdef CONFIG_X86_32
/* Stack for startup_32 can be just as for start_secondary onwards */
irq_ctx_init(cpu);
#else
clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
initial_gs = per_cpu_offset(cpu);
per_cpu(kernel_stack, cpu) =
(unsigned long)task_stack_page(c_idle.idle) -
KERNEL_STACK_OFFSET + THREAD_SIZE;
#endif
early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
initial_code = (unsigned long)start_secondary;
stack_start = c_idle.idle->thread.sp;
/* start_ip had better be page-aligned! */
start_ip = trampoline_address();
/* So we see what's up */
announce_cpu(cpu, apicid);
/*
* This grunge runs the startup process for
* the targeted processor.
*/
printk(KERN_DEBUG "smpboot cpu %d: start_ip = %lx\n", cpu, start_ip);
atomic_set(&init_deasserted, 0);
if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
pr_debug("Setting warm reset code and vector.\n");
smpboot_setup_warm_reset_vector(start_ip);
/*
* Be paranoid about clearing APIC errors.
*/
if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
apic_write(APIC_ESR, 0);
apic_read(APIC_ESR);
}
}
/*
* Kick the secondary CPU. Use the method in the APIC driver
* if it's defined - or use an INIT boot APIC message otherwise:
*/
if (apic->wakeup_secondary_cpu)
boot_error = apic->wakeup_secondary_cpu(apicid, start_ip);
else
boot_error = wakeup_secondary_cpu_via_init(apicid, start_ip);
if (!boot_error) {
/*
* allow APs to start initializing.
*/
pr_debug("Before Callout %d.\n", cpu);
cpumask_set_cpu(cpu, cpu_callout_mask);
pr_debug("After Callout %d.\n", cpu);
/*
* Wait 5s total for a response
*/
for (timeout = 0; timeout < 50000; timeout++) {
if (cpumask_test_cpu(cpu, cpu_callin_mask))
break; /* It has booted */
udelay(100);
/*
* Allow other tasks to run while we wait for the
* AP to come online. This also gives a chance
* for the MTRR work(triggered by the AP coming online)
* to be completed in the stop machine context.
*/
schedule();
}
if (cpumask_test_cpu(cpu, cpu_callin_mask))
pr_debug("CPU%d: has booted.\n", cpu);
else {
boot_error = 1;
if (*(volatile u32 *)TRAMPOLINE_SYM(trampoline_status)
== 0xA5A5A5A5)
/* trampoline started but...? */
pr_err("CPU%d: Stuck ??\n", cpu);
else
/* trampoline code not run */
pr_err("CPU%d: Not responding.\n", cpu);
if (apic->inquire_remote_apic)
apic->inquire_remote_apic(apicid);
}
}
if (boot_error) {
/* Try to put things back the way they were before ... */
numa_remove_cpu(cpu); /* was set by numa_add_cpu */
/* was set by do_boot_cpu() */
cpumask_clear_cpu(cpu, cpu_callout_mask);
/* was set by cpu_init() */
cpumask_clear_cpu(cpu, cpu_initialized_mask);
set_cpu_present(cpu, false);
per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
}
/* mark "stuck" area as not stuck */
*(volatile u32 *)TRAMPOLINE_SYM(trampoline_status) = 0;
if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
/*
* Cleanup possible dangling ends...
*/
smpboot_restore_warm_reset_vector();
}
destroy_work_on_stack(&c_idle.work);
return boot_error;
}
int __cpuinit native_cpu_up(unsigned int cpu)
{
int apicid = apic->cpu_present_to_apicid(cpu);
unsigned long flags;
int err;
WARN_ON(irqs_disabled());
pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);
if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
!physid_isset(apicid, phys_cpu_present_map)) {
printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
return -EINVAL;
}
/*
* Already booted CPU?
*/
if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
pr_debug("do_boot_cpu %d Already started\n", cpu);
return -ENOSYS;
}
/*
* Save current MTRR state in case it was changed since early boot
* (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
*/
mtrr_save_state();
per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
err = do_boot_cpu(apicid, cpu);
if (err) {
pr_debug("do_boot_cpu failed %d\n", err);
return -EIO;
}
/*
* Check TSC synchronization with the AP (keep irqs disabled
* while doing so):
*/
local_irq_save(flags);
check_tsc_sync_source(cpu);
local_irq_restore(flags);
while (!cpu_online(cpu)) {
cpu_relax();
touch_nmi_watchdog();
}
return 0;
}
/**
* arch_disable_smp_support() - disables SMP support for x86 at runtime
*/
void arch_disable_smp_support(void)
{
disable_ioapic_support();
}
/*
* Fall back to non SMP mode after errors.
*
* RED-PEN audit/test this more. I bet there is more state messed up here.
*/
static __init void disable_smp(void)
{
init_cpu_present(cpumask_of(0));
init_cpu_possible(cpumask_of(0));
smpboot_clear_io_apic_irqs();
if (smp_found_config)
physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
else
physid_set_mask_of_physid(0, &phys_cpu_present_map);
cpumask_set_cpu(0, cpu_sibling_mask(0));
cpumask_set_cpu(0, cpu_core_mask(0));
}
/*
* Various sanity checks.
*/
static int __init smp_sanity_check(unsigned max_cpus)
{
preempt_disable();
#if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32)
if (def_to_bigsmp && nr_cpu_ids > 8) {
unsigned int cpu;
unsigned nr;
printk(KERN_WARNING
"More than 8 CPUs detected - skipping them.\n"
"Use CONFIG_X86_BIGSMP.\n");
nr = 0;
for_each_present_cpu(cpu) {
if (nr >= 8)
set_cpu_present(cpu, false);
nr++;
}
nr = 0;
for_each_possible_cpu(cpu) {
if (nr >= 8)
set_cpu_possible(cpu, false);
nr++;
}
nr_cpu_ids = 8;
}
#endif
if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
printk(KERN_WARNING
"weird, boot CPU (#%d) not listed by the BIOS.\n",
hard_smp_processor_id());
physid_set(hard_smp_processor_id(), phys_cpu_present_map);
}
/*
* If we couldn't find an SMP configuration at boot time,
* get out of here now!
*/
if (!smp_found_config && !acpi_lapic) {
preempt_enable();
printk(KERN_NOTICE "SMP motherboard not detected.\n");
disable_smp();
if (APIC_init_uniprocessor())
printk(KERN_NOTICE "Local APIC not detected."
" Using dummy APIC emulation.\n");
return -1;
}
/*
* Should not be necessary because the MP table should list the boot
* CPU too, but we do it for the sake of robustness anyway.
*/
if (!apic->check_phys_apicid_present(boot_cpu_physical_apicid)) {
printk(KERN_NOTICE
"weird, boot CPU (#%d) not listed by the BIOS.\n",
boot_cpu_physical_apicid);
physid_set(hard_smp_processor_id(), phys_cpu_present_map);
}
preempt_enable();
/*
* If we couldn't find a local APIC, then get out of here now!
*/
if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
!cpu_has_apic) {
if (!disable_apic) {
pr_err("BIOS bug, local APIC #%d not detected!...\n",
boot_cpu_physical_apicid);
pr_err("... forcing use of dummy APIC emulation."
"(tell your hw vendor)\n");
}
smpboot_clear_io_apic();
disable_ioapic_support();
return -1;
}
verify_local_APIC();
/*
* If SMP should be disabled, then really disable it!
*/
if (!max_cpus) {
printk(KERN_INFO "SMP mode deactivated.\n");
smpboot_clear_io_apic();
connect_bsp_APIC();
setup_local_APIC();
bsp_end_local_APIC_setup();
return -1;
}
return 0;
}
static void __init smp_cpu_index_default(void)
{
int i;
struct cpuinfo_x86 *c;
for_each_possible_cpu(i) {
c = &cpu_data(i);
/* mark all to hotplug */
c->cpu_index = nr_cpu_ids;
}
}
/*
* Prepare for SMP bootup. The MP table or ACPI has been read
* earlier. Just do some sanity checking here and enable APIC mode.
*/
void __init native_smp_prepare_cpus(unsigned int max_cpus)
{
unsigned int i;
preempt_disable();
smp_cpu_index_default();
/*
* Setup boot CPU information
*/
smp_store_cpu_info(0); /* Final full version of the data */
cpumask_copy(cpu_callin_mask, cpumask_of(0));
mb();
current_thread_info()->cpu = 0; /* needed? */
for_each_possible_cpu(i) {
zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
}
set_cpu_sibling_map(0);
if (smp_sanity_check(max_cpus) < 0) {
printk(KERN_INFO "SMP disabled\n");
disable_smp();
goto out;
}
default_setup_apic_routing();
preempt_disable();
if (read_apic_id() != boot_cpu_physical_apicid) {
panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
read_apic_id(), boot_cpu_physical_apicid);
/* Or can we switch back to PIC here? */
}
preempt_enable();
connect_bsp_APIC();
/*
* Switch from PIC to APIC mode.
*/
setup_local_APIC();
/*
* Enable IO APIC before setting up error vector
*/
if (!skip_ioapic_setup && nr_ioapics)
enable_IO_APIC();
bsp_end_local_APIC_setup();
if (apic->setup_portio_remap)
apic->setup_portio_remap();
smpboot_setup_io_apic();
/*
* Set up local APIC timer on boot CPU.
*/
printk(KERN_INFO "CPU%d: ", 0);
print_cpu_info(&cpu_data(0));
x86_init.timers.setup_percpu_clockev();
if (is_uv_system())
uv_system_init();
set_mtrr_aps_delayed_init();
out:
preempt_enable();
}
void arch_disable_nonboot_cpus_begin(void)
{
/*
* Avoid the smp alternatives switch during the disable_nonboot_cpus().
* In the suspend path, we will be back in the SMP mode shortly anyways.
*/
skip_smp_alternatives = true;
}
void arch_disable_nonboot_cpus_end(void)
{
skip_smp_alternatives = false;
}
void arch_enable_nonboot_cpus_begin(void)
{
set_mtrr_aps_delayed_init();
}
void arch_enable_nonboot_cpus_end(void)
{
mtrr_aps_init();
}
/*
* Early setup to make printk work.
*/
void __init native_smp_prepare_boot_cpu(void)
{
int me = smp_processor_id();
switch_to_new_gdt(me);
/* already set me in cpu_online_mask in boot_cpu_init() */
cpumask_set_cpu(me, cpu_callout_mask);
per_cpu(cpu_state, me) = CPU_ONLINE;
}
void __init native_smp_cpus_done(unsigned int max_cpus)
{
pr_debug("Boot done.\n");
impress_friends();
#ifdef CONFIG_X86_IO_APIC
setup_ioapic_dest();
#endif
mtrr_aps_init();
}
static int __initdata setup_possible_cpus = -1;
static int __init _setup_possible_cpus(char *str)
{
get_option(&str, &setup_possible_cpus);
return 0;
}
early_param("possible_cpus", _setup_possible_cpus);
/*
* cpu_possible_mask should be static, it cannot change as cpu's
* are onlined, or offlined. The reason is per-cpu data-structures
* are allocated by some modules at init time, and dont expect to
* do this dynamically on cpu arrival/departure.
* cpu_present_mask on the other hand can change dynamically.
* In case when cpu_hotplug is not compiled, then we resort to current
* behaviour, which is cpu_possible == cpu_present.
* - Ashok Raj
*
* Three ways to find out the number of additional hotplug CPUs:
* - If the BIOS specified disabled CPUs in ACPI/mptables use that.
* - The user can overwrite it with possible_cpus=NUM
* - Otherwise don't reserve additional CPUs.
* We do this because additional CPUs waste a lot of memory.
* -AK
*/
__init void prefill_possible_map(void)
{
int i, possible;
/* no processor from mptable or madt */
if (!num_processors)
num_processors = 1;
i = setup_max_cpus ?: 1;
if (setup_possible_cpus == -1) {
possible = num_processors;
#ifdef CONFIG_HOTPLUG_CPU
if (setup_max_cpus)
possible += disabled_cpus;
#else
if (possible > i)
possible = i;
#endif
} else
possible = setup_possible_cpus;
total_cpus = max_t(int, possible, num_processors + disabled_cpus);
/* nr_cpu_ids could be reduced via nr_cpus= */
if (possible > nr_cpu_ids) {
printk(KERN_WARNING
"%d Processors exceeds NR_CPUS limit of %d\n",
possible, nr_cpu_ids);
possible = nr_cpu_ids;
}
#ifdef CONFIG_HOTPLUG_CPU
if (!setup_max_cpus)
#endif
if (possible > i) {
printk(KERN_WARNING
"%d Processors exceeds max_cpus limit of %u\n",
possible, setup_max_cpus);
possible = i;
}
printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
possible, max_t(int, possible - num_processors, 0));
for (i = 0; i < possible; i++)
set_cpu_possible(i, true);
for (; i < NR_CPUS; i++)
set_cpu_possible(i, false);
nr_cpu_ids = possible;
}
#ifdef CONFIG_HOTPLUG_CPU
static void remove_siblinginfo(int cpu)
{
int sibling;
struct cpuinfo_x86 *c = &cpu_data(cpu);
for_each_cpu(sibling, cpu_core_mask(cpu)) {
cpumask_clear_cpu(cpu, cpu_core_mask(sibling));
/*/
* last thread sibling in this cpu core going down
*/
if (cpumask_weight(cpu_sibling_mask(cpu)) == 1)
cpu_data(sibling).booted_cores--;
}
for_each_cpu(sibling, cpu_sibling_mask(cpu))
cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling));
cpumask_clear(cpu_sibling_mask(cpu));
cpumask_clear(cpu_core_mask(cpu));
c->phys_proc_id = 0;
c->cpu_core_id = 0;
cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
}
static void __ref remove_cpu_from_maps(int cpu)
{
set_cpu_online(cpu, false);
cpumask_clear_cpu(cpu, cpu_callout_mask);
cpumask_clear_cpu(cpu, cpu_callin_mask);
/* was set by cpu_init() */
cpumask_clear_cpu(cpu, cpu_initialized_mask);
numa_remove_cpu(cpu);
}
void cpu_disable_common(void)
{
int cpu = smp_processor_id();
remove_siblinginfo(cpu);
/* It's now safe to remove this processor from the online map */
lock_vector_lock();
remove_cpu_from_maps(cpu);
unlock_vector_lock();
fixup_irqs();
}
int native_cpu_disable(void)
{
int cpu = smp_processor_id();
/*
* Perhaps use cpufreq to drop frequency, but that could go
* into generic code.
*
* We won't take down the boot processor on i386 due to some
* interrupts only being able to be serviced by the BSP.
* Especially so if we're not using an IOAPIC -zwane
*/
if (cpu == 0)
return -EBUSY;
clear_local_APIC();
cpu_disable_common();
return 0;
}
void native_cpu_die(unsigned int cpu)
{
/* We don't do anything here: idle task is faking death itself. */
unsigned int i;
for (i = 0; i < 10; i++) {
/* They ack this in play_dead by setting CPU_DEAD */
if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
if (system_state == SYSTEM_RUNNING)
pr_info("CPU %u is now offline\n", cpu);
if (1 == num_online_cpus())
alternatives_smp_switch(0);
return;
}
msleep(100);
}
pr_err("CPU %u didn't die...\n", cpu);
}
void play_dead_common(void)
{
idle_task_exit();
reset_lazy_tlbstate();
c1e_remove_cpu(raw_smp_processor_id());
mb();
/* Ack it */
__this_cpu_write(cpu_state, CPU_DEAD);
/*
* With physical CPU hotplug, we should halt the cpu
*/
local_irq_disable();
}
/*
* We need to flush the caches before going to sleep, lest we have
* dirty data in our caches when we come back up.
*/
static inline void mwait_play_dead(void)
{
unsigned int eax, ebx, ecx, edx;
unsigned int highest_cstate = 0;
unsigned int highest_subcstate = 0;
int i;
void *mwait_ptr;
struct cpuinfo_x86 *c = __this_cpu_ptr(&cpu_info);
if (!(cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)))
return;
if (!cpu_has(__this_cpu_ptr(&cpu_info), X86_FEATURE_CLFLSH))
return;
if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF)
return;
eax = CPUID_MWAIT_LEAF;
ecx = 0;
native_cpuid(&eax, &ebx, &ecx, &edx);
/*
* eax will be 0 if EDX enumeration is not valid.
* Initialized below to cstate, sub_cstate value when EDX is valid.
*/
if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) {
eax = 0;
} else {
edx >>= MWAIT_SUBSTATE_SIZE;
for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
if (edx & MWAIT_SUBSTATE_MASK) {
highest_cstate = i;
highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
}
}
eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
(highest_subcstate - 1);
}
/*
* This should be a memory location in a cache line which is
* unlikely to be touched by other processors. The actual
* content is immaterial as it is not actually modified in any way.
*/
mwait_ptr = &current_thread_info()->flags;
wbinvd();
while (1) {
/*
* The CLFLUSH is a workaround for erratum AAI65 for
* the Xeon 7400 series. It's not clear it is actually
* needed, but it should be harmless in either case.
* The WBINVD is insufficient due to the spurious-wakeup
* case where we return around the loop.
*/
clflush(mwait_ptr);
__monitor(mwait_ptr, 0, 0);
mb();
__mwait(eax, 0);
}
}
static inline void hlt_play_dead(void)
{
if (__this_cpu_read(cpu_info.x86) >= 4)
wbinvd();
while (1) {
native_halt();
}
}
void native_play_dead(void)
{
play_dead_common();
tboot_shutdown(TB_SHUTDOWN_WFS);
mwait_play_dead(); /* Only returns on failure */
hlt_play_dead();
}
#else /* ... !CONFIG_HOTPLUG_CPU */
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();
}
#endif