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kernel_samsung_sm7125/arch/x86/kernel/smpboot_64.c

1109 lines
27 KiB

/*
* 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 */
DEFINE_PER_CPU(u16, cpu_llc_id) = 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;
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
/* Per CPU bogomips and other parameters */
DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
EXPORT_PER_CPU_SYMBOL(cpu_info);
/* 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 const unsigned char trampoline_data[];
extern const 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.
*/
#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))
#else
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
/*
* 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;
c->cpu_index = id;
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();
end_local_APIC_setup();
/*
* 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);
cpu_set(cpu, cpu_sibling_setup_map);
if (smp_num_siblings > 1) {
for_each_cpu_mask(i, cpu_sibling_setup_map) {
if (c->phys_proc_id == cpu_data(i).phys_proc_id &&
c->cpu_core_id == cpu_data(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->llc_shared_map);
cpu_set(cpu, cpu_data(i).llc_shared_map);
}
}
} else {
cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
}
cpu_set(cpu, c->llc_shared_map);
if (current_cpu_data.x86_max_cores == 1) {
per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
c->booted_cores = 1;
return;
}
for_each_cpu_mask(i, cpu_sibling_setup_map) {
if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
cpu_set(i, c->llc_shared_map);
cpu_set(cpu, cpu_data(i).llc_shared_map);
}
if (c->phys_proc_id == cpu_data(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->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;
}
}
}
/*
* 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();
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 recipients, 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_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;
u32 status;
printk(KERN_INFO "Inquiring remote APIC #%d...\n", apicid);
for (i = 0; i < ARRAY_SIZE(regs); i++) {
printk(KERN_INFO "... APIC #%d %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_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(KERN_CONT "%08x\n", status);
break;
default:
printk(KERN_CONT "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 = lapic_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;
};
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);
}
/*
* 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.sp = (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.sp;
load_sp0(&per_cpu(init_tss, cpu), &c_idle.idle->thread);
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, (unsigned long *)&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);
per_cpu(x86_cpu_to_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;
}
static void __init smp_cpu_index_default(void)
{
int i;
struct cpuinfo_x86 *c;
for_each_cpu_mask(i, cpu_possible_map) {
c = &cpu_data(i);
/* mark all to hotplug */
c->cpu_index = NR_CPUS;
}
}
/*
* 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();
smp_cpu_index_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();
/*
* Enable IO APIC before setting up error vector
*/
if (!skip_ioapic_setup && nr_ioapics)
enable_IO_APIC();
end_local_APIC_setup();
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_clock();
}
/*
* Early setup to make printk work.
*/
void __init smp_prepare_boot_cpu(void)
{
int me = smp_processor_id();
/* already set me in cpu_online_map in boot_cpu_init() */
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;
}
[PATCH] x86: Save the MTRRs of the BSP before booting an AP Applied fix by Andew Morton: http://lkml.org/lkml/2007/4/8/88 - Fix `make headers_check'. AMD and Intel x86 CPU manuals state that it is the responsibility of system software to initialize and maintain MTRR consistency across all processors in Multi-Processing Environments. Quote from page 188 of the AMD64 System Programming manual (Volume 2): 7.6.5 MTRRs in Multi-Processing Environments "In multi-processing environments, the MTRRs located in all processors must characterize memory in the same way. Generally, this means that identical values are written to the MTRRs used by the processors." (short omission here) "Failure to do so may result in coherency violations or loss of atomicity. Processor implementations do not check the MTRR settings in other processors to ensure consistency. It is the responsibility of system software to initialize and maintain MTRR consistency across all processors." Current Linux MTRR code already implements the above in the case that the BIOS does not properly initialize MTRRs on the secondary processors, but the case where the fixed-range MTRRs of the boot processor are changed after Linux started to boot, before the initialsation of a secondary processor, is not handled yet. In this case, secondary processors are currently initialized by Linux with MTRRs which the boot processor had very early, when mtrr_bp_init() did run, but not with the MTRRs which the boot processor uses at the time when that secondary processors is actually booted, causing differing MTRR contents on the secondary processors. Such situation happens on Acer Ferrari 1000 and 5000 notebooks where the BIOS enables and sets AMD-specific IORR bits in the fixed-range MTRRs of the boot processor when it transitions the system into ACPI mode. The SMI handler of the BIOS does this in SMM, entered while Linux ACPI code runs acpi_enable(). Other occasions where the SMI handler of the BIOS may change bits in the MTRRs could occur as well. To initialize newly booted secodary processors with the fixed-range MTRRs which the boot processor uses at that time, this patch saves the fixed-range MTRRs of the boot processor before new secondary processors are started. When the secondary processors run their Linux initialisation code, their fixed-range MTRRs will be updated with the saved fixed-range MTRRs. If CONFIG_MTRR is not set, we define mtrr_save_state as an empty statement because there is nothing to do. Possible TODOs: *) CPU-hotplugging outside of SMP suspend/resume is not yet tested with this patch. *) If, even in this case, an AP never runs i386/do_boot_cpu or x86_64/cpu_up, then the calls to mtrr_save_state() could be replaced by calls to mtrr_save_fixed_ranges(NULL) and mtrr_save_state() would not be needed. That would need either verification of the CPU-hotplug code or at least a test on a >2 CPU machine. *) The MTRRs of other running processors are not yet checked at this time but it might be interesting to syncronize the MTTRs of all processors before booting. That would be an incremental patch, but of rather low priority since there is no machine known so far which would require this. AK: moved prototypes on x86-64 around to fix warnings Signed-off-by: Bernhard Kaindl <bk@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Dave Jones <davej@codemonkey.org.uk>
18 years ago
/*
* 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(cpu);
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)
cpu_data(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->phys_proc_id = 0;
c->cpu_core_id = 0;
cpu_clear(cpu, cpu_sibling_setup_map);
}
static void __ref 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, (unsigned long *)&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 */