summaryrefslogtreecommitdiffstats
path: root/arch/x86_64/kernel/smp.c
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2007-10-11 11:14:17 +0200
committerThomas Gleixner <tglx@linutronix.de>2007-10-11 11:14:17 +0200
commit1e272fd4a2291ad8cac52752e0753e165cfe819f (patch)
treea87017ed846dc3dd7be8c95c9ef84c1c44d03d33 /arch/x86_64/kernel/smp.c
parent2e53e9012068eab25406d014618eef8993584ff1 (diff)
downloadop-kernel-dev-1e272fd4a2291ad8cac52752e0753e165cfe819f.zip
op-kernel-dev-1e272fd4a2291ad8cac52752e0753e165cfe819f.tar.gz
x86_64: prepare shared kernel/smp.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86_64/kernel/smp.c')
-rw-r--r--arch/x86_64/kernel/smp.c523
1 files changed, 0 insertions, 523 deletions
diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c
deleted file mode 100644
index df4a828..0000000
--- a/arch/x86_64/kernel/smp.c
+++ /dev/null
@@ -1,523 +0,0 @@
-/*
- * Intel SMP support routines.
- *
- * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
- * (c) 1998-99, 2000 Ingo Molnar <mingo@redhat.com>
- * (c) 2002,2003 Andi Kleen, SuSE Labs.
- *
- * This code is released under the GNU General Public License version 2 or
- * later.
- */
-
-#include <linux/init.h>
-
-#include <linux/mm.h>
-#include <linux/delay.h>
-#include <linux/spinlock.h>
-#include <linux/smp.h>
-#include <linux/kernel_stat.h>
-#include <linux/mc146818rtc.h>
-#include <linux/interrupt.h>
-
-#include <asm/mtrr.h>
-#include <asm/pgalloc.h>
-#include <asm/tlbflush.h>
-#include <asm/mach_apic.h>
-#include <asm/mmu_context.h>
-#include <asm/proto.h>
-#include <asm/apicdef.h>
-#include <asm/idle.h>
-
-/*
- * Smarter SMP flushing macros.
- * c/o Linus Torvalds.
- *
- * These mean you can really definitely utterly forget about
- * writing to user space from interrupts. (Its not allowed anyway).
- *
- * Optimizations Manfred Spraul <manfred@colorfullife.com>
- *
- * More scalable flush, from Andi Kleen
- *
- * To avoid global state use 8 different call vectors.
- * Each CPU uses a specific vector to trigger flushes on other
- * CPUs. Depending on the received vector the target CPUs look into
- * the right per cpu variable for the flush data.
- *
- * With more than 8 CPUs they are hashed to the 8 available
- * vectors. The limited global vector space forces us to this right now.
- * In future when interrupts are split into per CPU domains this could be
- * fixed, at the cost of triggering multiple IPIs in some cases.
- */
-
-union smp_flush_state {
- struct {
- cpumask_t flush_cpumask;
- struct mm_struct *flush_mm;
- unsigned long flush_va;
-#define FLUSH_ALL -1ULL
- spinlock_t tlbstate_lock;
- };
- char pad[SMP_CACHE_BYTES];
-} ____cacheline_aligned;
-
-/* State is put into the per CPU data section, but padded
- to a full cache line because other CPUs can access it and we don't
- want false sharing in the per cpu data segment. */
-static DEFINE_PER_CPU(union smp_flush_state, flush_state);
-
-/*
- * We cannot call mmdrop() because we are in interrupt context,
- * instead update mm->cpu_vm_mask.
- */
-static inline void leave_mm(int cpu)
-{
- if (read_pda(mmu_state) == TLBSTATE_OK)
- BUG();
- cpu_clear(cpu, read_pda(active_mm)->cpu_vm_mask);
- load_cr3(swapper_pg_dir);
-}
-
-/*
- *
- * The flush IPI assumes that a thread switch happens in this order:
- * [cpu0: the cpu that switches]
- * 1) switch_mm() either 1a) or 1b)
- * 1a) thread switch to a different mm
- * 1a1) cpu_clear(cpu, old_mm->cpu_vm_mask);
- * Stop ipi delivery for the old mm. This is not synchronized with
- * the other cpus, but smp_invalidate_interrupt ignore flush ipis
- * for the wrong mm, and in the worst case we perform a superfluous
- * tlb flush.
- * 1a2) set cpu mmu_state to TLBSTATE_OK
- * Now the smp_invalidate_interrupt won't call leave_mm if cpu0
- * was in lazy tlb mode.
- * 1a3) update cpu active_mm
- * Now cpu0 accepts tlb flushes for the new mm.
- * 1a4) cpu_set(cpu, new_mm->cpu_vm_mask);
- * Now the other cpus will send tlb flush ipis.
- * 1a4) change cr3.
- * 1b) thread switch without mm change
- * cpu active_mm is correct, cpu0 already handles
- * flush ipis.
- * 1b1) set cpu mmu_state to TLBSTATE_OK
- * 1b2) test_and_set the cpu bit in cpu_vm_mask.
- * Atomically set the bit [other cpus will start sending flush ipis],
- * and test the bit.
- * 1b3) if the bit was 0: leave_mm was called, flush the tlb.
- * 2) switch %%esp, ie current
- *
- * The interrupt must handle 2 special cases:
- * - cr3 is changed before %%esp, ie. it cannot use current->{active_,}mm.
- * - the cpu performs speculative tlb reads, i.e. even if the cpu only
- * runs in kernel space, the cpu could load tlb entries for user space
- * pages.
- *
- * The good news is that cpu mmu_state is local to each cpu, no
- * write/read ordering problems.
- */
-
-/*
- * TLB flush IPI:
- *
- * 1) Flush the tlb entries if the cpu uses the mm that's being flushed.
- * 2) Leave the mm if we are in the lazy tlb mode.
- *
- * Interrupts are disabled.
- */
-
-asmlinkage void smp_invalidate_interrupt(struct pt_regs *regs)
-{
- int cpu;
- int sender;
- union smp_flush_state *f;
-
- cpu = smp_processor_id();
- /*
- * orig_rax contains the negated interrupt vector.
- * Use that to determine where the sender put the data.
- */
- sender = ~regs->orig_rax - INVALIDATE_TLB_VECTOR_START;
- f = &per_cpu(flush_state, sender);
-
- if (!cpu_isset(cpu, f->flush_cpumask))
- goto out;
- /*
- * This was a BUG() but until someone can quote me the
- * line from the intel manual that guarantees an IPI to
- * multiple CPUs is retried _only_ on the erroring CPUs
- * its staying as a return
- *
- * BUG();
- */
-
- if (f->flush_mm == read_pda(active_mm)) {
- if (read_pda(mmu_state) == TLBSTATE_OK) {
- if (f->flush_va == FLUSH_ALL)
- local_flush_tlb();
- else
- __flush_tlb_one(f->flush_va);
- } else
- leave_mm(cpu);
- }
-out:
- ack_APIC_irq();
- cpu_clear(cpu, f->flush_cpumask);
-}
-
-static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
- unsigned long va)
-{
- int sender;
- union smp_flush_state *f;
-
- /* Caller has disabled preemption */
- sender = smp_processor_id() % NUM_INVALIDATE_TLB_VECTORS;
- f = &per_cpu(flush_state, sender);
-
- /* Could avoid this lock when
- num_online_cpus() <= NUM_INVALIDATE_TLB_VECTORS, but it is
- probably not worth checking this for a cache-hot lock. */
- spin_lock(&f->tlbstate_lock);
-
- f->flush_mm = mm;
- f->flush_va = va;
- cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask);
-
- /*
- * We have to send the IPI only to
- * CPUs affected.
- */
- send_IPI_mask(cpumask, INVALIDATE_TLB_VECTOR_START + sender);
-
- while (!cpus_empty(f->flush_cpumask))
- cpu_relax();
-
- f->flush_mm = NULL;
- f->flush_va = 0;
- spin_unlock(&f->tlbstate_lock);
-}
-
-int __cpuinit init_smp_flush(void)
-{
- int i;
- for_each_cpu_mask(i, cpu_possible_map) {
- spin_lock_init(&per_cpu(flush_state, i).tlbstate_lock);
- }
- return 0;
-}
-
-core_initcall(init_smp_flush);
-
-void flush_tlb_current_task(void)
-{
- struct mm_struct *mm = current->mm;
- cpumask_t cpu_mask;
-
- preempt_disable();
- cpu_mask = mm->cpu_vm_mask;
- cpu_clear(smp_processor_id(), cpu_mask);
-
- local_flush_tlb();
- if (!cpus_empty(cpu_mask))
- flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
- preempt_enable();
-}
-EXPORT_SYMBOL(flush_tlb_current_task);
-
-void flush_tlb_mm (struct mm_struct * mm)
-{
- cpumask_t cpu_mask;
-
- preempt_disable();
- cpu_mask = mm->cpu_vm_mask;
- cpu_clear(smp_processor_id(), cpu_mask);
-
- if (current->active_mm == mm) {
- if (current->mm)
- local_flush_tlb();
- else
- leave_mm(smp_processor_id());
- }
- if (!cpus_empty(cpu_mask))
- flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
-
- preempt_enable();
-}
-EXPORT_SYMBOL(flush_tlb_mm);
-
-void flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
-{
- struct mm_struct *mm = vma->vm_mm;
- cpumask_t cpu_mask;
-
- preempt_disable();
- cpu_mask = mm->cpu_vm_mask;
- cpu_clear(smp_processor_id(), cpu_mask);
-
- if (current->active_mm == mm) {
- if(current->mm)
- __flush_tlb_one(va);
- else
- leave_mm(smp_processor_id());
- }
-
- if (!cpus_empty(cpu_mask))
- flush_tlb_others(cpu_mask, mm, va);
-
- preempt_enable();
-}
-EXPORT_SYMBOL(flush_tlb_page);
-
-static void do_flush_tlb_all(void* info)
-{
- unsigned long cpu = smp_processor_id();
-
- __flush_tlb_all();
- if (read_pda(mmu_state) == TLBSTATE_LAZY)
- leave_mm(cpu);
-}
-
-void flush_tlb_all(void)
-{
- on_each_cpu(do_flush_tlb_all, NULL, 1, 1);
-}
-
-/*
- * this function sends a 'reschedule' IPI to another CPU.
- * it goes straight through and wastes no time serializing
- * anything. Worst case is that we lose a reschedule ...
- */
-
-void smp_send_reschedule(int cpu)
-{
- send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR);
-}
-
-/*
- * Structure and data for smp_call_function(). This is designed to minimise
- * static memory requirements. It also looks cleaner.
- */
-static DEFINE_SPINLOCK(call_lock);
-
-struct call_data_struct {
- void (*func) (void *info);
- void *info;
- atomic_t started;
- atomic_t finished;
- int wait;
-};
-
-static struct call_data_struct * call_data;
-
-void lock_ipi_call_lock(void)
-{
- spin_lock_irq(&call_lock);
-}
-
-void unlock_ipi_call_lock(void)
-{
- spin_unlock_irq(&call_lock);
-}
-
-/*
- * this function sends a 'generic call function' IPI to one other CPU
- * in the system.
- *
- * cpu is a standard Linux logical CPU number.
- */
-static void
-__smp_call_function_single(int cpu, void (*func) (void *info), void *info,
- int nonatomic, int wait)
-{
- struct call_data_struct data;
- int cpus = 1;
-
- data.func = func;
- data.info = info;
- atomic_set(&data.started, 0);
- data.wait = wait;
- if (wait)
- atomic_set(&data.finished, 0);
-
- call_data = &data;
- wmb();
- /* Send a message to all other CPUs and wait for them to respond */
- send_IPI_mask(cpumask_of_cpu(cpu), CALL_FUNCTION_VECTOR);
-
- /* Wait for response */
- while (atomic_read(&data.started) != cpus)
- cpu_relax();
-
- if (!wait)
- return;
-
- while (atomic_read(&data.finished) != cpus)
- cpu_relax();
-}
-
-/*
- * smp_call_function_single - Run a function on a specific CPU
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @nonatomic: Currently unused.
- * @wait: If true, wait until function has completed on other CPUs.
- *
- * Retrurns 0 on success, else a negative status code.
- *
- * Does not return until the remote CPU is nearly ready to execute <func>
- * or is or has executed.
- */
-
-int smp_call_function_single (int cpu, void (*func) (void *info), void *info,
- int nonatomic, int wait)
-{
- /* prevent preemption and reschedule on another processor */
- int me = get_cpu();
-
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
-
- if (cpu == me) {
- local_irq_disable();
- func(info);
- local_irq_enable();
- put_cpu();
- return 0;
- }
-
- spin_lock(&call_lock);
- __smp_call_function_single(cpu, func, info, nonatomic, wait);
- spin_unlock(&call_lock);
- put_cpu();
- return 0;
-}
-EXPORT_SYMBOL(smp_call_function_single);
-
-/*
- * this function sends a 'generic call function' IPI to all other CPUs
- * in the system.
- */
-static void __smp_call_function (void (*func) (void *info), void *info,
- int nonatomic, int wait)
-{
- struct call_data_struct data;
- int cpus = num_online_cpus()-1;
-
- if (!cpus)
- return;
-
- data.func = func;
- data.info = info;
- atomic_set(&data.started, 0);
- data.wait = wait;
- if (wait)
- atomic_set(&data.finished, 0);
-
- call_data = &data;
- wmb();
- /* Send a message to all other CPUs and wait for them to respond */
- send_IPI_allbutself(CALL_FUNCTION_VECTOR);
-
- /* Wait for response */
- while (atomic_read(&data.started) != cpus)
- cpu_relax();
-
- if (!wait)
- return;
-
- while (atomic_read(&data.finished) != cpus)
- cpu_relax();
-}
-
-/*
- * smp_call_function - run a function on all other CPUs.
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @nonatomic: currently unused.
- * @wait: If true, wait (atomically) until function has completed on other
- * CPUs.
- *
- * Returns 0 on success, else a negative status code. Does not return until
- * remote CPUs are nearly ready to execute func or are or have executed.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
- * Actually there are a few legal cases, like panic.
- */
-int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
- int wait)
-{
- spin_lock(&call_lock);
- __smp_call_function(func,info,nonatomic,wait);
- spin_unlock(&call_lock);
- return 0;
-}
-EXPORT_SYMBOL(smp_call_function);
-
-static void stop_this_cpu(void *dummy)
-{
- local_irq_disable();
- /*
- * Remove this CPU:
- */
- cpu_clear(smp_processor_id(), cpu_online_map);
- disable_local_APIC();
- for (;;)
- halt();
-}
-
-void smp_send_stop(void)
-{
- int nolock;
- unsigned long flags;
-
- if (reboot_force)
- return;
-
- /* Don't deadlock on the call lock in panic */
- nolock = !spin_trylock(&call_lock);
- local_irq_save(flags);
- __smp_call_function(stop_this_cpu, NULL, 0, 0);
- if (!nolock)
- spin_unlock(&call_lock);
- disable_local_APIC();
- local_irq_restore(flags);
-}
-
-/*
- * Reschedule call back. Nothing to do,
- * all the work is done automatically when
- * we return from the interrupt.
- */
-asmlinkage void smp_reschedule_interrupt(void)
-{
- ack_APIC_irq();
-}
-
-asmlinkage void smp_call_function_interrupt(void)
-{
- void (*func) (void *info) = call_data->func;
- void *info = call_data->info;
- int wait = call_data->wait;
-
- ack_APIC_irq();
- /*
- * Notify initiating CPU that I've grabbed the data and am
- * about to execute the function
- */
- mb();
- atomic_inc(&call_data->started);
- /*
- * At this point the info structure may be out of scope unless wait==1
- */
- exit_idle();
- irq_enter();
- (*func)(info);
- irq_exit();
- if (wait) {
- mb();
- atomic_inc(&call_data->finished);
- }
-}
-
OpenPOWER on IntegriCloud