/*
* x86 SMP booting functions
*
* (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
* (c) 1998, 1999, 2000 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
*
* Fixes
* Felix Koop : NR_CPUS used properly
* Jose Renau : Handle single CPU case.
* Alan Cox : By repeated request 8) - Total BogoMIP 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.
* Rusty Russell : Hacked into shape for new "hotplug" boot process.
* Andi Kleen : Converted to new state machine.
* Various cleanups.
* Probably mostly hotplug CPU ready now.
* Ashok Raj : CPU hotplug support
*/
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/kernel_stat.h>
#include <linux/bootmem.h>
#include <linux/thread_info.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/mc146818rtc.h>
#include <linux/smp.h>
#include <linux/kdebug.h>
#include <asm/mtrr.h>
#include <asm/pgalloc.h>
#include <asm/desc.h>
#include <asm/tlbflush.h>
#include <asm/proto.h>
#include <asm/nmi.h>
#include <asm/irq.h>
#include <asm/hw_irq.h>
#include <asm/numa.h>
/* Number of siblings per CPU package */
int smp_num_siblings = 1;
EXPORT_SYMBOL(smp_num_siblings);
/* Last level cache ID of each logical CPU */
u8 cpu_llc_id[NR_CPUS] __cpuinitdata = {[0 ... NR_CPUS-1] = BAD_APICID};
/* Bitmask of currently online CPUs */
cpumask_t cpu_online_map __read_mostly;
EXPORT_SYMBOL(cpu_online_map);
/*
* Private maps to synchronize booting between AP and BP.
* Probably not needed anymore, but it makes for easier debugging. -AK
*/
cpumask_t cpu_callin_map;
cpumask_t cpu_callout_map;
EXPORT_SYMBOL(cpu_callout_map);
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
/* Per CPU bogomips and other parameters */
struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
EXPORT_SYMBOL(cpu_data);
/* Set when the idlers are all forked */
int smp_threads_ready;
/* representing HT siblings of each logical CPU */
DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
/* representing HT and core siblings of each logical CPU */
DEFINE_PER_CPU(cpumask_t, cpu_core_map);
EXPORT_PER_CPU_SYMBOL(cpu_core_map);
/*
* Trampoline 80x86 program as an array.
*/
extern unsigned char trampoline_data[];
extern unsigned char trampoline_end[];
/* 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.
*/
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))
/*
* Currently trivial. Write the real->protected mode
* bootstrap into the page concerned. The caller
* has made sure it's suitably aligned.
*/
static unsigned long __cpuinit setup_trampoline(void)
{
void *tramp = __va(SMP_TRAMPOLINE_BASE);
memcpy(tramp, trampoline_data, trampoline_end - trampoline_data);
return virt_to_phys(tramp);
}
/*
* The bootstrap kernel entry code has set these up. Save them for
* a given CPU
*/
static void __cpuinit smp_store_cpu_info(int id)
{
struct cpuinfo_x86 *c = cpu_data + id;
*c = boot_cpu_data;
identify_cpu(c);
print_cpu_info(c);
}
static atomic_t init_deasserted __cpuinitdata;
/*
* Report back to the Boot Processor.
* Running on AP.
*/
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.
*/
while (!atomic_read(&init_deasserted))
cpu_relax();
/*
* (This works even if the APIC is not enabled.)
*/
phys_id = GET_APIC_ID(apic_read(APIC_ID));
cpuid = smp_processor_id();
if (cpu_isset(cpuid, cpu_callin_map)) {
panic("smp_callin: phys CPU#%d, CPU#%d already present??\n",
phys_id, cpuid);
}
Dprintk("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 (cpu_isset(cpuid, cpu_callout_map))
break;
cpu_relax();
}
if (!time_before(jiffies, timeout)) {
panic("smp_callin: CPU%d started up but did not get a callout!\n",
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)
*/
Dprintk("CALLIN, before setup_local_APIC().\n");
setup_local_APIC();
/*
* 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();
Dprintk("Stack at about %p\n",&cpuid);
/*
* Save our processor parameters
*/
smp_store_cpu_info(cpuid);
/*
* Allow the master to continue.
*/
cpu_set(cpuid, cpu_callin_map);
}
/* maps the cpu to the sched domain representing multi-core */
cpumask_t cpu_coregroup_map(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)
return per_cpu(cpu_core_map, cpu);
else
return c->llc_shared_map;
}
/* representing cpus for which sibling maps can be computed */
static cpumask_t cpu_sibling_setup_map;
static inline void set_cpu_sibling_map(int cpu)
{
int i;
struct cpuinfo_x86 *c = cpu_data;
cpu_set(cpu, cpu_sibling_setup_map);
if (smp_num_siblings > 1) {
for_each_cpu_mask(i, cpu_sibling_setup_map) {
if (c[cpu].phys_proc_id == c[i].phys_proc_id &&
c[cpu].cpu_core_id == c[i].cpu_core_id) {
cpu_set(i, per_cpu(cpu_sibling_map, cpu));
cpu_set(cpu, per_cpu(cpu_sibling_map, i));
cpu_set(i, per_cpu(cpu_core_map, cpu));
cpu_set(cpu, per_cpu(cpu_core_map, i));
cpu_set(i, c[cpu].llc_shared_map);
cpu_set(cpu, c[i].llc_shared_map);
}
}
} else {
cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
}
cpu_set(cpu, c[cpu].llc_shared_map);
if (current_cpu_data.x86_max_cores == 1) {
per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
c[cpu].booted_cores = 1;
return;
}
for_each_cpu_mask(i, cpu_sibling_setup_map) {
if (cpu_llc_id[cpu] != BAD_APICID &&
cpu_llc_id[cpu] == cpu_llc_id[i]) {
cpu_set(i, c[cpu].llc_shared_map);
cpu_set(cpu, c[i].llc_shared_map);
}
if (c[cpu].phys_proc_id == c[i].phys_proc_id) {
cpu_set(i, per_cpu(cpu_core_map, cpu));
cpu_set(cpu, per_cpu(cpu_core_map, i));
/*
* Does this new cpu bringup a new core?
*/
if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) {
/*
* for each core in package, increment
* the booted_cores for this new cpu
*/
if (first_cpu(per_cpu(cpu_sibling_map, i)) == i)
c[cpu].booted_cores++;
/*
* increment the core count for all
* the other cpus in this package
*/
if (i != cpu)
c[i].booted_cores++;
} else if (i != cpu && !c[cpu].booted_cores)
c[cpu].booted_cores = c[i].booted_cores;
}
}
}
/*
* Setup code on secondary processor (after comming out of the trampoline)
*/
void __cpuinit start_secondary(void)
{
/*
* Dont put anything before smp_callin(), 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();
/* otherwise gcc will move up the smp_processor_id before the cpu_init */
barrier();
/*
* Check TSC sync first:
*/
check_tsc_sync_target();
if (nmi_watchdog == NMI_IO_APIC) {
disable_8259A_irq(0);
enable_NMI_through_LVT0(NULL);
enable_8259A_irq(0);
}
/*
* The sibling maps must be set before turing the online map on for
* this cpu
*/
set_cpu_sibling_map(smp_processor_id());
/*
* We need to hold call_lock, so there is no inconsistency
* between the time smp_call_function() determines number of
* IPI receipients, and the time when the determination is made
* for which cpus receive the IPI in genapic_flat.c. Holding this
* lock helps us to not include this cpu in a currently in progress
* smp_call_function().
*/
lock_ipi_call_lock();
spin_lock(&vector_lock);
/* Setup the per cpu irq handling data structures */
__setup_vector_irq(smp_processor_id());
/*
* Allow the master to continue.
*/
cpu_set(smp_processor_id(), cpu_online_map);
per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
spin_unlock(&vector_lock);
unlock_ipi_call_lock();
setup_secondary_APIC_clock();
cpu_idle();
}
extern volatile unsigned long init_rsp;
extern void (*initial_code)(void);
#ifdef APIC_DEBUG
static 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;
unsigned int status;
printk(KERN_INFO "Inquiring remote APIC #%d...\n", apicid);
for (i = 0; i < sizeof(regs) / sizeof(*regs); i++) {
printk("... APIC #%d %s: ", apicid, names[i]);
/*
* Wait for idle.
*/
status = safe_apic_wait_icr_idle();
if (status)
printk("a previous APIC delivery may have failed\n");
apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
apic_write(APIC_ICR, APIC_DM_REMRD | regs[i]);
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("%08x\n", status);
break;
default:
printk("failed\n");
}
}
}
#endif
/*
* Kick the secondary to wake up.
*/
static int __cpuinit wakeup_secondary_via_INIT(int phys_apicid, unsigned int start_rip)
{
unsigned long send_status, accept_status = 0;
int maxlvt, num_starts, j;
Dprintk("Asserting INIT.\n");
/*
* Turn INIT on target chip
*/
apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
/*
* Send IPI
*/
apic_write(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
| APIC_DM_INIT);
Dprintk("Waiting for send to finish...\n");
send_status = safe_apic_wait_icr_idle();
mdelay(10);
Dprintk("Deasserting INIT.\n");
/* Target chip */
apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
/* Send IPI */
apic_write(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
Dprintk("Waiting for send to finish...\n");
send_status = safe_apic_wait_icr_idle();
mb();
atomic_set(&init_deasserted, 1);
num_starts = 2;
/*
* Run STARTUP IPI loop.
*/
Dprintk("#startup loops: %d.\n", num_starts);
maxlvt = get_maxlvt();
for (j = 1; j <= num_starts; j++) {
Dprintk("Sending STARTUP #%d.\n",j);
apic_write(APIC_ESR, 0);
apic_read(APIC_ESR);
Dprintk("After apic_write.\n");
/*
* STARTUP IPI
*/
/* Target chip */
apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
/* Boot on the stack */
/* Kick the second */
apic_write(APIC_ICR, APIC_DM_STARTUP | (start_rip >> 12));
/*
* Give the other CPU some time to accept the IPI.
*/
udelay(300);
Dprintk("Startup point 1.\n");
Dprintk("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);
/*
* Due to the Pentium erratum 3AP.
*/
if (maxlvt > 3) {
apic_write(APIC_ESR, 0);
}
accept_status = (apic_read(APIC_ESR) & 0xEF);
if (send_status || accept_status)
break;
}
Dprintk("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;
};
void 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);
}
/*
* Boot one CPU.
*/
static int __cpuinit do_boot_cpu(int cpu, int apicid)
{
unsigned long boot_error;
int timeout;
unsigned long start_rip;
struct create_idle c_idle = {
.work = __WORK_INITIALIZER(c_idle.work, do_fork_idle),
.cpu = cpu,
.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
};
/* allocate memory for gdts of secondary cpus. Hotplug is considered */
if (!cpu_gdt_descr[cpu].address &&
!(cpu_gdt_descr[cpu].address = get_zeroed_page(GFP_KERNEL))) {
printk(KERN_ERR "Failed to allocate GDT for CPU %d\n", cpu);
return -1;
}
/* Allocate node local memory for AP pdas */
if (cpu_pda(cpu) == &boot_cpu_pda[cpu]) {
struct x8664_pda *newpda, *pda;
int node = cpu_to_node(cpu);
pda = cpu_pda(cpu);
newpda = kmalloc_node(sizeof (struct x8664_pda), GFP_ATOMIC,
node);
if (newpda) {
memcpy(newpda, pda, sizeof (struct x8664_pda));
cpu_pda(cpu) = newpda;
} else
printk(KERN_ERR
"Could not allocate node local PDA for CPU %d on node %d\n",
cpu, node);
}
alternatives_smp_switch(1);
c_idle.idle = get_idle_for_cpu(cpu);
if (c_idle.idle) {
c_idle.idle->thread.rsp = (unsigned long) (((struct pt_regs *)
(THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
init_idle(c_idle.idle, cpu);
goto do_rest;
}
/*
* During cold boot process, keventd thread is not spun up yet.
* When we do cpu hot-add, we create idle threads on the fly, we should
* not acquire any attributes from the calling context. Hence the clean
* way to create kernel_threads() is to do that from keventd().
* We do the current_is_keventd() due to the fact that ACPI notifier
* was also queuing to keventd() and when the caller is already running
* in context of keventd(), we would end up with locking up the keventd
* thread.
*/
if (!keventd_up() || current_is_keventd())
c_idle.work.func(&c_idle.work);
else {
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);
return PTR_ERR(c_idle.idle);
}
set_idle_for_cpu(cpu, c_idle.idle);
do_rest:
cpu_pda(cpu)->pcurrent = c_idle.idle;
start_rip = setup_trampoline();
init_rsp = c_idle.idle->thread.rsp;
per_cpu(init_tss,cpu).rsp0 = init_rsp;
initial_code = start_secondary;
clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
printk(KERN_INFO "Booting processor %d/%d APIC 0x%x\n", cpu,
cpus_weight(cpu_present_map),
apicid);
/*
* This grunge runs the startup process for
* the targeted processor.
*/
atomic_set(&init_deasserted, 0);
Dprintk("Setting warm reset code and vector.\n");
CMOS_WRITE(0xa, 0xf);
local_flush_tlb();
Dprintk("1.\n");
*((volatile unsigned short *) phys_to_virt(0x469)) = start_rip >> 4;
Dprintk("2.\n");
*((volatile unsigned short *) phys_to_virt(0x467)) = start_rip & 0xf;
Dprintk("3.\n");
/*
* Be paranoid about clearing APIC errors.
*/
apic_write(APIC_ESR, 0);
apic_read(APIC_ESR);
/*
* Status is now clean
*/
boot_error = 0;
/*
* Starting actual IPI sequence...
*/
boot_error = wakeup_secondary_via_INIT(apicid, start_rip);
if (!boot_error) {
/*
* allow APs to start initializing.
*/
Dprintk("Before Callout %d.\n", cpu);
cpu_set(cpu, cpu_callout_map);
Dprintk("After Callout %d.\n", cpu);
/*
* Wait 5s total for a response
*/
for (timeout = 0; timeout < 50000; timeout++) {
if (cpu_isset(cpu, cpu_callin_map))
break; /* It has booted */
udelay(100);
}
if (cpu_isset(cpu, cpu_callin_map)) {
/* number CPUs logically, starting from 1 (BSP is 0) */
Dprintk("CPU has booted.\n");
} else {
boot_error = 1;
if (*((volatile unsigned char *)phys_to_virt(SMP_TRAMPOLINE_BASE))
== 0xA5)
/* trampoline started but...? */
printk("Stuck ??\n");
else
/* trampoline code not run */
printk("Not responding.\n");
#ifdef APIC_DEBUG
inquire_remote_apic(apicid);
#endif
}
}
if (boot_error) {
cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */
clear_bit(cpu, &cpu_initialized); /* was set by cpu_init() */
clear_node_cpumask(cpu); /* was set by numa_add_cpu */
cpu_clear(cpu, cpu_present_map);
cpu_clear(cpu, cpu_possible_map);
x86_cpu_to_apicid[cpu] = BAD_APICID;
x86_cpu_to_log_apicid[cpu] = BAD_APICID;
return -EIO;
}
return 0;
}
cycles_t cacheflush_time;
unsigned long cache_decay_ticks;
/*
* Cleanup possible dangling ends...
*/
static __cpuinit void smp_cleanup_boot(void)
{
/*
* Paranoid: Set warm reset code and vector here back
* to default values.
*/
CMOS_WRITE(0, 0xf);
/*
* Reset trampoline flag
*/
*((volatile int *) phys_to_virt(0x467)) = 0;
}
/*
* 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)
{
cpu_present_map = cpumask_of_cpu(0);
cpu_possible_map = cpumask_of_cpu(0);
if (smp_found_config)
phys_cpu_present_map = physid_mask_of_physid(boot_cpu_id);
else
phys_cpu_present_map = physid_mask_of_physid(0);
cpu_set(0, per_cpu(cpu_sibling_map, 0));
cpu_set(0, per_cpu(cpu_core_map, 0));
}
#ifdef CONFIG_HOTPLUG_CPU
int additional_cpus __initdata = -1;
/*
* cpu_possible_map 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_map 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 additional_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;
int possible;
if (additional_cpus == -1) {
if (disabled_cpus > 0)
additional_cpus = disabled_cpus;
else
additional_cpus = 0;
}
possible = num_processors + additional_cpus;
if (possible > NR_CPUS)
possible = NR_CPUS;
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++)
cpu_set(i, cpu_possible_map);
}
#endif
/*
* Various sanity checks.
*/
static int __init smp_sanity_check(unsigned max_cpus)
{
if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
printk("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) {
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 (!physid_isset(boot_cpu_id, phys_cpu_present_map)) {
printk(KERN_NOTICE "weird, boot CPU (#%d) not listed by the BIOS.\n",
boot_cpu_id);
physid_set(hard_smp_processor_id(), phys_cpu_present_map);
}
/*
* If we couldn't find a local APIC, then get out of here now!
*/
if (!cpu_has_apic) {
printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
boot_cpu_id);
printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
nr_ioapics = 0;
return -1;
}
/*
* If SMP should be disabled, then really disable it!
*/
if (!max_cpus) {
printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
nr_ioapics = 0;
return -1;
}
return 0;
}
/*
* 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 smp_prepare_cpus(unsigned int max_cpus)
{
nmi_watchdog_default();
current_cpu_data = boot_cpu_data;
current_thread_info()->cpu = 0; /* needed? */
set_cpu_sibling_map(0);
if (smp_sanity_check(max_cpus) < 0) {
printk(KERN_INFO "SMP disabled\n");
disable_smp();
return;
}
/*
* Switch from PIC to APIC mode.
*/
setup_local_APIC();
if (GET_APIC_ID(apic_read(APIC_ID)) != boot_cpu_id) {
panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
GET_APIC_ID(apic_read(APIC_ID)), boot_cpu_id);
/* Or can we switch back to PIC here? */
}
/*
* Now start the IO-APICs
*/
if (!skip_ioapic_setup && nr_ioapics)
setup_IO_APIC();
else
nr_ioapics = 0;
/*
* Set up local APIC timer on boot CPU.
*/
setup_boot_APIC_clock();
}
/*
* Early setup to make printk work.
*/
void __init smp_prepare_boot_cpu(void)
{
int me = smp_processor_id();
cpu_set(me, cpu_online_map);
cpu_set(me, cpu_callout_map);
per_cpu(cpu_state, me) = CPU_ONLINE;
}
/*
* Entry point to boot a CPU.
*/
int __cpuinit __cpu_up(unsigned int cpu)
{
int apicid = cpu_present_to_apicid(cpu);
unsigned long flags;
int err;
WARN_ON(irqs_disabled());
Dprintk("++++++++++++++++++++=_---CPU UP %u\n", cpu);
if (apicid == BAD_APICID || apicid == boot_cpu_id ||
!physid_isset(apicid, phys_cpu_present_map)) {
printk("__cpu_up: bad cpu %d\n", cpu);
return -EINVAL;
}
/*
* Already booted CPU?
*/
if (cpu_isset(cpu, cpu_callin_map)) {
Dprintk("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;
/* Boot it! */
err = do_boot_cpu(cpu, apicid);
if (err < 0) {
Dprintk("do_boot_cpu failed %d\n", err);
return err;
}
/* Unleash the CPU! */
Dprintk("waiting for cpu %d\n", cpu);
/*
* Make sure and check TSC sync:
*/
local_irq_save(flags);
check_tsc_sync_source(cpu);
local_irq_restore(flags);
while (!cpu_isset(cpu, cpu_online_map))
cpu_relax();
err = 0;
return err;
}
/*
* Finish the SMP boot.
*/
void __init smp_cpus_done(unsigned int max_cpus)
{
smp_cleanup_boot();
setup_ioapic_dest();
check_nmi_watchdog();
}
#ifdef CONFIG_HOTPLUG_CPU
static void remove_siblinginfo(int cpu)
{
int sibling;
struct cpuinfo_x86 *c = cpu_data;
for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) {
cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
/*
* last thread sibling in this cpu core going down
*/
if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1)
c[sibling].booted_cores--;
}
for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu))
cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling));
cpus_clear(per_cpu(cpu_sibling_map, cpu));
cpus_clear(per_cpu(cpu_core_map, cpu));
c[cpu].phys_proc_id = 0;
c[cpu].cpu_core_id = 0;
cpu_clear(cpu, cpu_sibling_setup_map);
}
void remove_cpu_from_maps(void)
{
int cpu = smp_processor_id();
cpu_clear(cpu, cpu_callout_map);
cpu_clear(cpu, cpu_callin_map);
clear_bit(cpu, &cpu_initialized); /* was set by cpu_init() */
clear_node_cpumask(cpu);
}
int __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;
if (nmi_watchdog == NMI_LOCAL_APIC)
stop_apic_nmi_watchdog(NULL);
clear_local_APIC();
/*
* HACK:
* Allow any queued timer interrupts to get serviced
* This is only a temporary solution until we cleanup
* fixup_irqs as we do for IA64.
*/
local_irq_enable();
mdelay(1);
local_irq_disable();
remove_siblinginfo(cpu);
spin_lock(&vector_lock);
/* It's now safe to remove this processor from the online map */
cpu_clear(cpu, cpu_online_map);
spin_unlock(&vector_lock);
remove_cpu_from_maps();
fixup_irqs(cpu_online_map);
return 0;
}
void __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) {
printk ("CPU %d is now offline\n", cpu);
if (1 == num_online_cpus())
alternatives_smp_switch(0);
return;
}
msleep(100);
}
printk(KERN_ERR "CPU %u didn't die...\n", cpu);
}
static __init int setup_additional_cpus(char *s)
{
return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL;
}
early_param("additional_cpus", setup_additional_cpus);
#else /* ... !CONFIG_HOTPLUG_CPU */
int __cpu_disable(void)
{
return -ENOSYS;
}
void __cpu_die(unsigned int cpu)
{
/* We said "no" in __cpu_disable */
BUG();
}
#endif /* CONFIG_HOTPLUG_CPU */
