/*
* x86 SMP booting functions
*
* (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
* (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
*
* 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 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
* 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. */
#include <linux/module.h>
#include <linux/config.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <linux/smp_lock.h>
#include <linux/irq.h>
#include <linux/bootmem.h>
#ifdef CONFIG_KDB
#include <linux/kdb.h>
#endif /* CONFIG_KDB */
#include <linux/delay.h>
#include <linux/mc146818rtc.h>
#include <asm/tlbflush.h>
#include <asm/desc.h>
#include <asm/arch_hooks.h>
#include <mach_apic.h>
#include <mach_wakecpu.h>
#include <smpboot_hooks.h>
/* Set if we find a B stepping CPU */
static int __initdata smp_b_stepping;
/* Number of siblings per CPU package */
int smp_num_siblings = 1;
int phys_proc_id[NR_CPUS]; /* Package ID of each logical CPU */
/* bitmap of online cpus */
cpumask_t cpu_online_map;
static cpumask_t cpu_callin_map;
cpumask_t cpu_callout_map;
static cpumask_t smp_commenced_mask;
/* Per CPU bogomips and other parameters */
struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
/* Set when the idlers are all forked */
int smp_threads_ready;
/*
* Trampoline 80x86 program as an array.
*/
extern unsigned char trampoline_data [];
extern unsigned char trampoline_end [];
static unsigned char *trampoline_base;
static int trampoline_exec;
/*
* Currently trivial. Write the real->protected mode
* bootstrap into the page concerned. The caller
* has made sure it's suitably aligned.
*/
static unsigned long __init setup_trampoline(void)
{
memcpy(trampoline_base, trampoline_data, trampoline_end - trampoline_data);
return virt_to_phys(trampoline_base);
}
/*
* We are called very early to get the low memory for the
* SMP bootup trampoline page.
*/
void __init smp_alloc_memory(void)
{
trampoline_base = (void *) alloc_bootmem_low_pages(PAGE_SIZE);
/*
* Has to be in very low memory so we can execute
* real-mode AP code.
*/
if (__pa(trampoline_base) >= 0x9F000)
BUG();
/*
* Make the SMP trampoline executable:
*/
trampoline_exec = set_kernel_exec((unsigned long)trampoline_base, 1);
}
/*
* The bootstrap kernel entry code has set these up. Save them for
* a given CPU
*/
static void __init smp_store_cpu_info(int id)
{
struct cpuinfo_x86 *c = cpu_data + id;
*c = boot_cpu_data;
if (id!=0)
identify_cpu(c);
/*
* Mask B, Pentium, but not Pentium MMX
*/
if (c->x86_vendor == X86_VENDOR_INTEL &&
c->x86 == 5 &&
c->x86_mask >= 1 && c->x86_mask <= 4 &&
c->x86_model <= 3)
/*
* Remember we have B step Pentia with bugs
*/
smp_b_stepping = 1;
/*
* Certain Athlons might work (for various values of 'work') in SMP
* but they are not certified as MP capable.
*/
if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) {
/* Athlon 660/661 is valid. */
if ((c->x86_model==6) && ((c->x86_mask==0) || (c->x86_mask==1)))
goto valid_k7;
/* Duron 670 is valid */
if ((c->x86_model==7) && (c->x86_mask==0))
goto valid_k7;
/*
* Athlon 662, Duron 671, and Athlon >model 7 have capability bit.
* It's worth noting that the A5 stepping (662) of some Athlon XP's
* have the MP bit set.
* See http://www.heise.de/newsticker/data/jow-18.10.01-000 for more.
*/
if (((c->x86_model==6) && (c->x86_mask>=2)) ||
((c->x86_model==7) && (c->x86_mask>=1)) ||
(c->x86_model> 7))
if (cpu_has_mp)
goto valid_k7;
/* If we get here, it's not a certified SMP capable AMD system. */
tainted |= TAINT_UNSAFE_SMP;
}
valid_k7:
;
}
/*
* TSC synchronization.
*
* We first check whether all CPUs have their TSC's synchronized,
* then we print a warning if not, and always resync.
*/
static atomic_t tsc_start_flag = ATOMIC_INIT(0);
static atomic_t tsc_count_start = ATOMIC_INIT(0);
static atomic_t tsc_count_stop = ATOMIC_INIT(0);
static unsigned long long tsc_values[NR_CPUS];
#define NR_LOOPS 5
/*
* accurate 64-bit/32-bit division, expanded to 32-bit divisions and 64-bit
* multiplication. Not terribly optimized but we need it at boot time only
* anyway.
*
* result == a / b
* == (a1 + a2*(2^32)) / b
* == a1/b + a2*(2^32/b)
* == a1/b + a2*((2^32-1)/b) + a2/b + (a2*((2^32-1) % b))/b
* ^---- (this multiplication can overflow)
*/
static unsigned long long __init div64 (unsigned long long a, unsigned long b0)
{
unsigned int a1, a2;
unsigned long long res;
a1 = ((unsigned int*)&a)[0];
a2 = ((unsigned int*)&a)[1];
res = a1/b0 +
(unsigned long long)a2 * (unsigned long long)(0xffffffff/b0) +
a2 / b0 +
(a2 * (0xffffffff % b0)) / b0;
return res;
}
static void __init synchronize_tsc_bp (void)
{
int i;
unsigned long long t0;
unsigned long long sum, avg;
long long delta;
unsigned long one_usec;
int buggy = 0;
printk("checking TSC synchronization across %u CPUs: ", num_booting_cpus());
/* convert from kcyc/sec to cyc/usec */
one_usec = cpu_khz / 1000;
atomic_set(&tsc_start_flag, 1);
wmb();
/*
* We loop a few times to get a primed instruction cache,
* then the last pass is more or less synchronized and
* the BP and APs set their cycle counters to zero all at
* once. This reduces the chance of having random offsets
* between the processors, and guarantees that the maximum
* delay between the cycle counters is never bigger than
* the latency of information-passing (cachelines) between
* two CPUs.
*/
for (i = 0; i < NR_LOOPS; i++) {
/*
* all APs synchronize but they loop on '== num_cpus'
*/
while (atomic_read(&tsc_count_start) != num_booting_cpus()-1)
mb();
atomic_set(&tsc_count_stop, 0);
wmb();
/*
* this lets the APs save their current TSC:
*/
atomic_inc(&tsc_count_start);
rdtscll(tsc_values[smp_processor_id()]);
/*
* We clear the TSC in the last loop:
*/
if (i == NR_LOOPS-1)
write_tsc(0, 0);
/*
* Wait for all APs to leave the synchronization point:
*/
while (atomic_read(&tsc_count_stop) != num_booting_cpus()-1)
mb();
atomic_set(&tsc_count_start, 0);
wmb();
atomic_inc(&tsc_count_stop);
}
sum = 0;
for (i = 0; i < NR_CPUS; i++) {
if (cpu_isset(i, cpu_callout_map)) {
t0 = tsc_values[i];
sum += t0;
}
}
avg = div64(sum, num_booting_cpus());
sum = 0;
for (i = 0; i < NR_CPUS; i++) {
if (!cpu_isset(i, cpu_callout_map))
continue;
delta = tsc_values[i] - avg;
if (delta < 0)
delta = -delta;
/*
* We report bigger than 2 microseconds clock differences.
*/
if (delta > 2*one_usec) {
long realdelta;
if (!buggy) {
buggy = 1;
printk("\n");
}
realdelta = div64(delta, one_usec);
if (tsc_values[i] < avg)
realdelta = -realdelta;
printk("BIOS BUG: CPU#%d improperly initialized, has %ld usecs TSC skew! FIXED.\n", i, realdelta);
}
sum += delta;
}
if (!buggy)
printk("passed.\n");
;
}
static void __init synchronize_tsc_ap (void)
{
int i;
/*
* Not every cpu is online at the time
* this gets called, so we first wait for the BP to
* finish SMP initialization:
*/
while (!atomic_read(&tsc_start_flag)) mb();
for (i = 0; i < NR_LOOPS; i++) {
atomic_inc(&tsc_count_start);
while (atomic_read(&tsc_count_start) != num_booting_cpus())
mb();
rdtscll(tsc_values[smp_processor_id()]);
if (i == NR_LOOPS-1)
write_tsc(0, 0);
atomic_inc(&tsc_count_stop);
while (atomic_read(&tsc_count_stop) != num_booting_cpus()) mb();
}
}
#undef NR_LOOPS
extern void calibrate_delay(void);
static atomic_t init_deasserted;
void __init 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.
*/
wait_for_init_deassert(&init_deasserted);
/*
* (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)) {
printk("huh, phys CPU#%d, CPU#%d already present??\n",
phys_id, cpuid);
BUG();
}
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;
rep_nop();
}
if (!time_before(jiffies, timeout)) {
printk("BUG: CPU%d started up but did not get a callout!\n",
cpuid);
BUG();
}
/*
* 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");
smp_callin_clear_local_apic();
setup_local_APIC();
map_cpu_to_logical_apicid();
local_irq_enable();
/*
* Get our bogomips.
*/
calibrate_delay();
Dprintk("Stack at about %p\n",&cpuid);
/*
* Save our processor parameters
*/
smp_store_cpu_info(cpuid);
disable_APIC_timer();
local_irq_disable();
/*
* Allow the master to continue.
*/
cpu_set(cpuid, cpu_callin_map);
#ifdef CONFIG_KDB
/* Activate any preset global breakpoints on this cpu */
kdb(KDB_REASON_SILENT, 0, 0);
#endif /* CONFIG_KDB */
/*
* Synchronize the TSC with the BP
*/
if (cpu_has_tsc && cpu_khz)
synchronize_tsc_ap();
}
int cpucount;
extern int cpu_idle(void);
/*
* Activate a secondary processor.
*/
int __init start_secondary(void *unused)
{
/*
* 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();
smp_callin();
while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
rep_nop();
setup_secondary_APIC_clock();
if (nmi_watchdog == NMI_IO_APIC) {
disable_8259A_irq(0);
enable_NMI_through_LVT0(NULL);
enable_8259A_irq(0);
}
enable_APIC_timer();
/*
* low-memory mappings have been cleared, flush them from
* the local TLBs too.
*/
local_flush_tlb();
cpu_set(smp_processor_id(), cpu_online_map);
wmb();
return cpu_idle();
}
/*
* Everything has been set up for the secondary
* CPUs - they just need to reload everything
* from the task structure
* This function must not return.
*/
void __init initialize_secondary(void)
{
/*
* We don't actually need to load the full TSS,
* basically just the stack pointer and the eip.
*/
asm volatile(
"movl %0,%%esp\n\t"
"jmp *%1"
:
:"r" (current->thread.esp),"r" (current->thread.eip));
}
extern struct {
void * esp;
unsigned short ss;
} stack_start;
static struct task_struct * __init fork_by_hand(void)
{
struct pt_regs regs;
/*
* don't care about the eip and regs settings since
* we'll never reschedule the forked task.
*/
return copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
}
#ifdef CONFIG_NUMA
/* which logical CPUs are on which nodes */
cpumask_t node_2_cpu_mask[MAX_NUMNODES] =
{ [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE };
/* which node each logical CPU is on */
int cpu_2_node[NR_CPUS] = { [0 ... NR_CPUS-1] = 0 };
EXPORT_SYMBOL(cpu_2_node);
/* set up a mapping between cpu and node. */
static inline void map_cpu_to_node(int cpu, int node)
{
printk("Mapping cpu %d to node %d\n", cpu, node);
cpu_set(cpu, node_2_cpu_mask[node]);
cpu_2_node[cpu] = node;
}
/* undo a mapping between cpu and node. */
static inline void unmap_cpu_to_node(int cpu)
{
int node;
printk("Unmapping cpu %d from all nodes\n", cpu);
for (node = 0; node < MAX_NUMNODES; node ++)
cpu_clear(cpu, node_2_cpu_mask[node]);
cpu_2_node[cpu] = 0;
}
#else /* !CONFIG_NUMA */
#define map_cpu_to_node(cpu, node) ({})
#define unmap_cpu_to_node(cpu) ({})
#endif /* CONFIG_NUMA */
u8 cpu_2_logical_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
void map_cpu_to_logical_apicid(void)
{
int cpu = smp_processor_id();
int apicid = logical_smp_processor_id();
cpu_2_logical_apicid[cpu] = apicid;
map_cpu_to_node(cpu, apicid_to_node(apicid));
}
void unmap_cpu_to_logical_apicid(int cpu)
{
cpu_2_logical_apicid[cpu] = BAD_APICID;
unmap_cpu_to_node(cpu);
}
#if APIC_DEBUG
static inline void __inquire_remote_apic(int apicid)
{
int i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
char *names[] = { "ID", "VERSION", "SPIV" };
int timeout, status;
printk("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.
*/
apic_wait_icr_idle();
apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
apic_write_around(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
#ifdef WAKE_SECONDARY_VIA_NMI
/*
* 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.
*/
static int __init
wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
{
unsigned long send_status = 0, accept_status = 0;
int timeout, maxlvt;
/* Target chip */
apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));
/* Boot on the stack */
/* Kick the second */
apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);
Dprintk("Waiting for send to finish...\n");
timeout = 0;
do {
Dprintk("+");
udelay(100);
send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
/*
* Give the other CPU some time to accept the IPI.
*/
udelay(200);
/*
* Due to the Pentium erratum 3AP.
*/
maxlvt = get_maxlvt();
if (maxlvt > 3) {
apic_read_around(APIC_SPIV);
apic_write(APIC_ESR, 0);
}
accept_status = (apic_read(APIC_ESR) & 0xEF);
Dprintk("NMI sent.\n");
if (send_status)
printk("APIC never delivered???\n");
if (accept_status)
printk("APIC delivery error (%lx).\n", accept_status);
return (send_status | accept_status);
}
#endif /* WAKE_SECONDARY_VIA_NMI */
#ifdef WAKE_SECONDARY_VIA_INIT
static int __init
wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
{
unsigned long send_status = 0, accept_status = 0;
int maxlvt, timeout, num_starts, j;
/*
* Be paranoid about clearing APIC errors.
*/
if (APIC_INTEGRATED(apic_version[phys_apicid])) {
apic_read_around(APIC_SPIV);
apic_write(APIC_ESR, 0);
apic_read(APIC_ESR);
}
Dprintk("Asserting INIT.\n");
/*
* Turn INIT on target chip
*/
apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
/*
* Send IPI
*/
apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
| APIC_DM_INIT);
Dprintk("Waiting for send to finish...\n");
timeout = 0;
do {
Dprintk("+");
udelay(100);
send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
mdelay(10);
Dprintk("Deasserting INIT.\n");
/* Target chip */
apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
/* Send IPI */
apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
Dprintk("Waiting for send to finish...\n");
timeout = 0;
do {
Dprintk("+");
udelay(100);
send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
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;
/*
* 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_read_around(APIC_SPIV);
apic_write(APIC_ESR, 0);
apic_read(APIC_ESR);
Dprintk("After apic_write.\n");
/*
* STARTUP IPI
*/
/* Target chip */
apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
/* Boot on the stack */
/* Kick the second */
apic_write_around(APIC_ICR, APIC_DM_STARTUP
| (start_eip >> 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");
timeout = 0;
do {
Dprintk("+");
udelay(100);
send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
/*
* Give the other CPU some time to accept the IPI.
*/
udelay(200);
/*
* Due to the Pentium erratum 3AP.
*/
if (maxlvt > 3) {
apic_read_around(APIC_SPIV);
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("APIC never delivered???\n");
if (accept_status)
printk("APIC delivery error (%lx).\n", accept_status);
return (send_status | accept_status);
}
#endif /* WAKE_SECONDARY_VIA_INIT */
extern cpumask_t cpu_initialized;
static int __init do_boot_cpu(int 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.
*/
{
struct task_struct *idle;
unsigned long boot_error;
int timeout, cpu;
unsigned long start_eip;
unsigned short nmi_high = 0, nmi_low = 0;
cpu = ++cpucount;
/*
* We can't use kernel_thread since we must avoid to
* reschedule the child.
*/
idle = fork_by_hand();
if (IS_ERR(idle))
panic("failed fork for CPU %d", cpu);
wake_up_forked_process(idle);
/*
* We remove it from the pidhash and the runqueue
* once we got the process:
*/
init_idle(idle, cpu);
idle->thread.eip = (unsigned long) start_secondary;
unhash_process(idle);
/* start_eip had better be page-aligned! */
start_eip = setup_trampoline();
/* So we see what's up */
printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip);
/* Stack for startup_32 can be just as for start_secondary onwards */
stack_start.esp = (void *) idle->thread.esp;
irq_ctx_init(cpu);
/*
* This grunge runs the startup process for
* the targeted processor.
*/
atomic_set(&init_deasserted, 0);
Dprintk("Setting warm reset code and vector.\n");
store_NMI_vector(&nmi_high, &nmi_low);
smpboot_setup_warm_reset_vector(start_eip);
/*
* Starting actual IPI sequence...
*/
boot_error = wakeup_secondary_cpu(apicid, start_eip);
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("OK.\n");
printk("CPU%d: ", cpu);
print_cpu_info(&cpu_data[cpu]);
Dprintk("CPU has booted.\n");
} else {
boot_error= 1;
if (*((volatile unsigned char *)trampoline_base)
== 0xA5)
/* trampoline started but...? */
printk("Stuck ??\n");
else
/* trampoline code not run */
printk("Not responding.\n");
inquire_remote_apic(apicid);
}
}
if (boot_error) {
/* Try to put things back the way they were before ... */
unmap_cpu_to_logical_apicid(cpu);
cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */
cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
cpucount--;
}
/* mark "stuck" area as not stuck */
*((volatile unsigned long *)trampoline_base) = 0;
return boot_error;
}
cycles_t cacheflush_time;
unsigned long cache_decay_ticks;
static void smp_tune_scheduling (void)
{
unsigned long cachesize; /* kB */
unsigned long bandwidth = 350; /* MB/s */
/*
* Rough estimation for SMP scheduling, this is the number of
* cycles it takes for a fully memory-limited process to flush
* the SMP-local cache.
*
* (For a P5 this pretty much means we will choose another idle
* CPU almost always at wakeup time (this is due to the small
* L1 cache), on PIIs it's around 50-100 usecs, depending on
* the cache size)
*/
if (!cpu_khz) {
/*
* this basically disables processor-affinity
* scheduling on SMP without a TSC.
*/
cacheflush_time = 0;
return;
} else {
cachesize = boot_cpu_data.x86_cache_size;
if (cachesize == -1) {
cachesize = 16; /* Pentiums, 2x8kB cache */
bandwidth = 100;
}
cacheflush_time = (cpu_khz>>10) * (cachesize<<10) / bandwidth;
}
cache_decay_ticks = (long)cacheflush_time/cpu_khz + 1;
printk("per-CPU timeslice cutoff: %ld.%02ld usecs.\n",
(long)cacheflush_time/(cpu_khz/1000),
((long)cacheflush_time*100/(cpu_khz/1000)) % 100);
printk("task migration cache decay timeout: %ld msecs.\n",
cache_decay_ticks);
}
/*
* Cycle through the processors sending APIC IPIs to boot each.
*/
static int boot_cpu_logical_apicid;
/* Where the IO area was mapped on multiquad, always 0 otherwise */
void *xquad_portio;
cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
static void __init smp_boot_cpus(unsigned int max_cpus)
{
int apicid, cpu, bit, kicked;
unsigned long bogosum = 0;
/*
* Setup boot CPU information
*/
smp_store_cpu_info(0); /* Final full version of the data */
printk("CPU%d: ", 0);
print_cpu_info(&cpu_data[0]);
boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
boot_cpu_logical_apicid = logical_smp_processor_id();
current_thread_info()->cpu = 0;
smp_tune_scheduling();
cpus_clear(cpu_sibling_map[0]);
cpu_set(0, cpu_sibling_map[0]);
/*
* If we couldn't find an SMP configuration at boot time,
* get out of here now!
*/
if (!smp_found_config && !acpi_lapic) {
printk(KERN_NOTICE "SMP motherboard not detected.\n");
smpboot_clear_io_apic_irqs();
phys_cpu_present_map = physid_mask_of_physid(0);
if (APIC_init_uniprocessor())
printk(KERN_NOTICE "Local APIC not detected."
" Using dummy APIC emulation.\n");
map_cpu_to_logical_apicid();
return;
}
/*
* Should not be necessary because the MP table should list the boot
* CPU too, but we do it for the sake of robustness anyway.
* Makes no sense to do this check in clustered apic mode, so skip it
*/
if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
boot_cpu_physical_apicid);
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 (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) && !cpu_has_apic) {
printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
boot_cpu_physical_apicid);
printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
smpboot_clear_io_apic_irqs();
phys_cpu_present_map = physid_mask_of_physid(0);
return;
}
verify_local_APIC();
/*
* If SMP should be disabled, then really disable it!
*/
if (!max_cpus) {
smp_found_config = 0;
printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
smpboot_clear_io_apic_irqs();
phys_cpu_present_map = physid_mask_of_physid(0);
return;
}
connect_bsp_APIC();
setup_local_APIC();
map_cpu_to_logical_apicid();
setup_portio_remap();
/*
* Scan the CPU present map and fire up the other CPUs via do_boot_cpu
*
* In clustered apic mode, phys_cpu_present_map is a constructed thus:
* bits 0-3 are quad0, 4-7 are quad1, etc. A perverse twist on the
* clustered apic ID.
*/
Dprintk("CPU present map: %lx\n", physids_coerce(phys_cpu_present_map));
kicked = 1;
for (bit = 0; kicked < NR_CPUS && bit < MAX_APICS; bit++) {
apicid = cpu_present_to_apicid(bit);
/*
* Don't even attempt to start the boot CPU!
*/
if ((apicid == boot_cpu_apicid) || (apicid == BAD_APICID))
continue;
if (!check_apicid_present(bit))
continue;
if (max_cpus <= cpucount+1)
continue;
if (do_boot_cpu(apicid))
printk("CPU #%d not responding - cannot use it.\n",
apicid);
else
++kicked;
}
/*
* Cleanup possible dangling ends...
*/
smpboot_restore_warm_reset_vector();
/*
* Allow the user to impress friends.
*/
Dprintk("Before bogomips.\n");
for (cpu = 0; cpu < NR_CPUS; cpu++)
if (cpu_isset(cpu, cpu_callout_map))
bogosum += cpu_data[cpu].loops_per_jiffy;
printk(KERN_INFO
"Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
cpucount+1,
bogosum/(500000/HZ),
(bogosum/(5000/HZ))%100);
Dprintk("Before bogocount - setting activated=1.\n");
if (smp_b_stepping)
printk(KERN_WARNING "WARNING: SMP operation may be unreliable with B stepping processors.\n");
/*
* Don't taint if we are running SMP kernel on a single non-MP
* approved Athlon
*/
if (tainted & TAINT_UNSAFE_SMP) {
if (cpucount)
printk (KERN_INFO "WARNING: This combination of AMD processors is not suitable for SMP.\n");
else
tainted &= ~TAINT_UNSAFE_SMP;
}
Dprintk("Boot done.\n");
/*
* construct cpu_sibling_map[], so that we can tell sibling CPUs
* efficiently.
*/
for (cpu = 0; cpu < NR_CPUS; cpu++)
cpus_clear(cpu_sibling_map[cpu]);
for (cpu = 0; cpu < NR_CPUS; cpu++) {
int siblings = 0;
int i;
if (!cpu_isset(cpu, cpu_callout_map))
continue;
if (smp_num_siblings > 1) {
for (i = 0; i < NR_CPUS; i++) {
if (!cpu_isset(i, cpu_callout_map))
continue;
if (phys_proc_id[cpu] == phys_proc_id[i]) {
siblings++;
cpu_set(i, cpu_sibling_map[cpu]);
}
}
} else {
siblings++;
cpu_set(cpu, cpu_sibling_map[cpu]);
}
if (siblings != smp_num_siblings)
printk(KERN_WARNING "WARNING: %d siblings found for CPU%d, should be %d\n", siblings, cpu, smp_num_siblings);
}
if (nmi_watchdog == NMI_LOCAL_APIC)
check_nmi_watchdog();
smpboot_setup_io_apic();
setup_boot_APIC_clock();
/*
* Synchronize the TSC with the AP
*/
if (cpu_has_tsc && cpucount && cpu_khz)
synchronize_tsc_bp();
}
#ifdef CONFIG_SCHED_SMT
#ifdef CONFIG_NUMA
static struct sched_group sched_group_cpus[NR_CPUS];
static struct sched_group sched_group_phys[NR_CPUS];
static struct sched_group sched_group_nodes[MAX_NUMNODES];
static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
static DEFINE_PER_CPU(struct sched_domain, phys_domains);
static DEFINE_PER_CPU(struct sched_domain, node_domains);
__init void arch_init_sched_domains(void)
{
int i;
struct sched_group *first = NULL, *last = NULL;
/* Set up domains */
for_each_cpu(i) {
struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
struct sched_domain *phys_domain = &per_cpu(phys_domains, i);
struct sched_domain *node_domain = &per_cpu(node_domains, i);
int node = cpu_to_node(i);
cpumask_t nodemask = node_to_cpumask(node);
*cpu_domain = SD_SIBLING_INIT;
cpu_domain->span = cpu_sibling_map[i];
cpu_domain->parent = phys_domain;
cpu_domain->groups = &sched_group_cpus[i];
*phys_domain = SD_CPU_INIT;
phys_domain->span = nodemask;
phys_domain->parent = node_domain;
phys_domain->groups = &sched_group_phys[first_cpu(cpu_domain->span)];
*node_domain = SD_NODE_INIT;
node_domain->span = cpu_possible_map;
node_domain->groups = &sched_group_nodes[cpu_to_node(i)];
}
/* Set up CPU (sibling) groups */
for_each_cpu(i) {
struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
int j;
first = last = NULL;
if (i != first_cpu(cpu_domain->span))
continue;
for_each_cpu_mask(j, cpu_domain->span) {
struct sched_group *cpu = &sched_group_cpus[j];
cpu->cpumask = CPU_MASK_NONE;
cpu_set(j, cpu->cpumask);
cpu->cpu_power = SCHED_LOAD_SCALE;
if (!first)
first = cpu;
if (last)
last->next = cpu;
last = cpu;
}
last->next = first;
}
for (i = 0; i < MAX_NUMNODES; i++) {
int j;
cpumask_t nodemask;
struct sched_group *node = &sched_group_nodes[i];
cpumask_t node_cpumask = node_to_cpumask(i);
cpus_and(nodemask, node_cpumask, cpu_possible_map);
if (cpus_empty(nodemask))
continue;
first = last = NULL;
/* Set up physical groups */
for_each_cpu_mask(j, nodemask) {
struct sched_domain *cpu_domain = &per_cpu(cpu_domains, j);
struct sched_group *cpu = &sched_group_phys[j];
if (j != first_cpu(cpu_domain->span))
continue;
cpu->cpumask = cpu_domain->span;
/*
* Make each extra sibling increase power by 10% of
* the basic CPU. This is very arbitrary.
*/
cpu->cpu_power = SCHED_LOAD_SCALE + SCHED_LOAD_SCALE*(cpus_weight(cpu->cpumask)-1) / 10;
node->cpu_power += cpu->cpu_power;
if (!first)
first = cpu;
if (last)
last->next = cpu;
last = cpu;
}
last->next = first;
}
/* Set up nodes */
first = last = NULL;
for (i = 0; i < MAX_NUMNODES; i++) {
struct sched_group *cpu = &sched_group_nodes[i];
cpumask_t nodemask;
cpumask_t node_cpumask = node_to_cpumask(i);
cpus_and(nodemask, node_cpumask, cpu_possible_map);
if (cpus_empty(nodemask))
continue;
cpu->cpumask = nodemask;
/* ->cpu_power already setup */
if (!first)
first = cpu;
if (last)
last->next = cpu;
last = cpu;
}
last->next = first;
mb();
for_each_cpu(i) {
struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
cpu_attach_domain(cpu_domain, i);
}
}
#else /* !CONFIG_NUMA */
static struct sched_group sched_group_cpus[NR_CPUS];
static struct sched_group sched_group_phys[NR_CPUS];
static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
static DEFINE_PER_CPU(struct sched_domain, phys_domains);
__init void arch_init_sched_domains(void)
{
int i;
struct sched_group *first = NULL, *last = NULL;
/* Set up domains */
for_each_cpu(i) {
struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
struct sched_domain *phys_domain = &per_cpu(phys_domains, i);
*cpu_domain = SD_SIBLING_INIT;
cpu_domain->span = cpu_sibling_map[i];
cpu_domain->parent = phys_domain;
cpu_domain->groups = &sched_group_cpus[i];
*phys_domain = SD_CPU_INIT;
phys_domain->span = cpu_possible_map;
phys_domain->groups = &sched_group_phys[first_cpu(cpu_domain->span)];
}
/* Set up CPU (sibling) groups */
for_each_cpu(i) {
struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
int j;
first = last = NULL;
if (i != first_cpu(cpu_domain->span))
continue;
for_each_cpu_mask(j, cpu_domain->span) {
struct sched_group *cpu = &sched_group_cpus[j];
cpus_clear(cpu->cpumask);
cpu_set(j, cpu->cpumask);
cpu->cpu_power = SCHED_LOAD_SCALE;
if (!first)
first = cpu;
if (last)
last->next = cpu;
last = cpu;
}
last->next = first;
}
first = last = NULL;
/* Set up physical groups */
for_each_cpu(i) {
struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
struct sched_group *cpu = &sched_group_phys[i];
if (i != first_cpu(cpu_domain->span))
continue;
cpu->cpumask = cpu_domain->span;
/* See SMT+NUMA setup for comment */
cpu->cpu_power = SCHED_LOAD_SCALE + SCHED_LOAD_SCALE*(cpus_weight(cpu->cpumask)-1) / 10;
if (!first)
first = cpu;
if (last)
last->next = cpu;
last = cpu;
}
last->next = first;
mb();
for_each_cpu(i) {
struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
cpu_attach_domain(cpu_domain, i);
}
}
#endif /* CONFIG_NUMA */
#endif /* CONFIG_SCHED_SMT */
/* These are wrappers to interface to the new boot process. Someone
who understands all this stuff should rewrite it properly. --RR 15/Jul/02 */
void __init smp_prepare_cpus(unsigned int max_cpus)
{
smp_boot_cpus(max_cpus);
}
void __devinit smp_prepare_boot_cpu(void)
{
cpu_set(smp_processor_id(), cpu_online_map);
cpu_set(smp_processor_id(), cpu_callout_map);
}
int __devinit __cpu_up(unsigned int cpu)
{
/* This only works at boot for x86. See "rewrite" above. */
if (cpu_isset(cpu, smp_commenced_mask)) {
local_irq_enable();
return -ENOSYS;
}
/* In case one didn't come up */
if (!cpu_isset(cpu, cpu_callin_map)) {
local_irq_enable();
return -EIO;
}
local_irq_enable();
/* Unleash the CPU! */
cpu_set(cpu, smp_commenced_mask);
while (!cpu_isset(cpu, cpu_online_map))
mb();
return 0;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
#ifdef CONFIG_X86_IO_APIC
setup_ioapic_dest();
#endif
zap_low_mappings();
/*
* Disable executability of the SMP trampoline:
*/
set_kernel_exec((unsigned long)trampoline_base, trampoline_exec);
}
void __init smp_intr_init(void)
{
/*
* IRQ0 must be given a fixed assignment and initialized,
* because it's used before the IO-APIC is set up.
*/
set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
/*
* The reschedule interrupt is a CPU-to-CPU reschedule-helper
* IPI, driven by wakeup.
*/
set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
/* IPI for invalidation */
set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
/* IPI for generic function call */
set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
}
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