forked from Minki/linux
x86: split spinlock implementations out into their own files
ftrace requires certain low-level code, like spinlocks and timestamps, to be compiled without -pg in order to avoid infinite recursion. This patch splits out the core paravirt spinlocks and the Xen spinlocks into separate files which can be compiled without -pg. Also do xen/time.c while we're about it. As a result, we can now use ftrace within a Xen domain. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Jeremy Fitzhardinge
Ingo Molnar
parent
338b9bb3ad
commit
d5de884135
@ -10,7 +10,7 @@ ifdef CONFIG_FTRACE
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# Do not profile debug and lowlevel utilities
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CFLAGS_REMOVE_tsc.o = -pg
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CFLAGS_REMOVE_rtc.o = -pg
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CFLAGS_REMOVE_paravirt.o = -pg
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CFLAGS_REMOVE_paravirt-spinlocks.o = -pg
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endif
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#
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@ -89,7 +89,7 @@ obj-$(CONFIG_DEBUG_NX_TEST) += test_nx.o
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obj-$(CONFIG_VMI) += vmi_32.o vmiclock_32.o
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obj-$(CONFIG_KVM_GUEST) += kvm.o
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obj-$(CONFIG_KVM_CLOCK) += kvmclock.o
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obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o
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obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o paravirt-spinlocks.o
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obj-$(CONFIG_PARAVIRT_CLOCK) += pvclock.o
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obj-$(CONFIG_PCSPKR_PLATFORM) += pcspeaker.o
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31
arch/x86/kernel/paravirt-spinlocks.c
Normal file
31
arch/x86/kernel/paravirt-spinlocks.c
Normal file
@ -0,0 +1,31 @@
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/*
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* Split spinlock implementation out into its own file, so it can be
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* compiled in a FTRACE-compatible way.
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*/
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <asm/paravirt.h>
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struct pv_lock_ops pv_lock_ops = {
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#ifdef CONFIG_SMP
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.spin_is_locked = __ticket_spin_is_locked,
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.spin_is_contended = __ticket_spin_is_contended,
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.spin_lock = __ticket_spin_lock,
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.spin_trylock = __ticket_spin_trylock,
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.spin_unlock = __ticket_spin_unlock,
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#endif
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};
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EXPORT_SYMBOL_GPL(pv_lock_ops);
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void __init paravirt_use_bytelocks(void)
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{
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#ifdef CONFIG_SMP
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pv_lock_ops.spin_is_locked = __byte_spin_is_locked;
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pv_lock_ops.spin_is_contended = __byte_spin_is_contended;
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pv_lock_ops.spin_lock = __byte_spin_lock;
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pv_lock_ops.spin_trylock = __byte_spin_trylock;
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pv_lock_ops.spin_unlock = __byte_spin_unlock;
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#endif
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}
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@ -268,17 +268,6 @@ enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
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return __get_cpu_var(paravirt_lazy_mode);
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}
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void __init paravirt_use_bytelocks(void)
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{
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#ifdef CONFIG_SMP
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pv_lock_ops.spin_is_locked = __byte_spin_is_locked;
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pv_lock_ops.spin_is_contended = __byte_spin_is_contended;
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pv_lock_ops.spin_lock = __byte_spin_lock;
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pv_lock_ops.spin_trylock = __byte_spin_trylock;
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pv_lock_ops.spin_unlock = __byte_spin_unlock;
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#endif
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}
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struct pv_info pv_info = {
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.name = "bare hardware",
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.paravirt_enabled = 0,
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@ -461,18 +450,6 @@ struct pv_mmu_ops pv_mmu_ops = {
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.set_fixmap = native_set_fixmap,
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};
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struct pv_lock_ops pv_lock_ops = {
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#ifdef CONFIG_SMP
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.spin_is_locked = __ticket_spin_is_locked,
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.spin_is_contended = __ticket_spin_is_contended,
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.spin_lock = __ticket_spin_lock,
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.spin_trylock = __ticket_spin_trylock,
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.spin_unlock = __ticket_spin_unlock,
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#endif
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};
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EXPORT_SYMBOL_GPL(pv_lock_ops);
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EXPORT_SYMBOL_GPL(pv_time_ops);
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EXPORT_SYMBOL (pv_cpu_ops);
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EXPORT_SYMBOL (pv_mmu_ops);
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@ -1,4 +1,10 @@
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ifdef CONFIG_FTRACE
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# Do not profile debug and lowlevel utilities
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CFLAGS_REMOVE_spinlock.o = -pg
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CFLAGS_REMOVE_time.o = -pg
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endif
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obj-y := enlighten.o setup.o multicalls.o mmu.o \
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time.o xen-asm_$(BITS).o grant-table.o suspend.o
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obj-$(CONFIG_SMP) += smp.o
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obj-$(CONFIG_SMP) += smp.o spinlock.o
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@ -15,7 +15,6 @@
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* This does not handle HOTPLUG_CPU yet.
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*/
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#include <linux/sched.h>
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#include <linux/kernel_stat.h>
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#include <linux/err.h>
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#include <linux/smp.h>
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@ -36,8 +35,6 @@
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#include "xen-ops.h"
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#include "mmu.h"
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static void __cpuinit xen_init_lock_cpu(int cpu);
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cpumask_t xen_cpu_initialized_map;
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static DEFINE_PER_CPU(int, resched_irq);
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@ -419,170 +416,6 @@ static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
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return IRQ_HANDLED;
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}
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struct xen_spinlock {
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unsigned char lock; /* 0 -> free; 1 -> locked */
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unsigned short spinners; /* count of waiting cpus */
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};
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static int xen_spin_is_locked(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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return xl->lock != 0;
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}
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static int xen_spin_is_contended(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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/* Not strictly true; this is only the count of contended
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lock-takers entering the slow path. */
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return xl->spinners != 0;
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}
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static int xen_spin_trylock(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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u8 old = 1;
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asm("xchgb %b0,%1"
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: "+q" (old), "+m" (xl->lock) : : "memory");
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return old == 0;
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}
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static DEFINE_PER_CPU(int, lock_kicker_irq) = -1;
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static DEFINE_PER_CPU(struct xen_spinlock *, lock_spinners);
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static inline void spinning_lock(struct xen_spinlock *xl)
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{
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__get_cpu_var(lock_spinners) = xl;
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wmb(); /* set lock of interest before count */
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asm(LOCK_PREFIX " incw %0"
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: "+m" (xl->spinners) : : "memory");
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}
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static inline void unspinning_lock(struct xen_spinlock *xl)
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{
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asm(LOCK_PREFIX " decw %0"
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: "+m" (xl->spinners) : : "memory");
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wmb(); /* decrement count before clearing lock */
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__get_cpu_var(lock_spinners) = NULL;
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}
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static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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int irq = __get_cpu_var(lock_kicker_irq);
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int ret;
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/* If kicker interrupts not initialized yet, just spin */
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if (irq == -1)
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return 0;
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/* announce we're spinning */
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spinning_lock(xl);
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/* clear pending */
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xen_clear_irq_pending(irq);
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/* check again make sure it didn't become free while
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we weren't looking */
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ret = xen_spin_trylock(lock);
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if (ret)
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goto out;
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/* block until irq becomes pending */
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xen_poll_irq(irq);
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kstat_this_cpu.irqs[irq]++;
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out:
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unspinning_lock(xl);
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return ret;
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}
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static void xen_spin_lock(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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int timeout;
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u8 oldval;
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do {
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timeout = 1 << 10;
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asm("1: xchgb %1,%0\n"
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" testb %1,%1\n"
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" jz 3f\n"
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"2: rep;nop\n"
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" cmpb $0,%0\n"
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" je 1b\n"
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" dec %2\n"
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" jnz 2b\n"
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"3:\n"
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: "+m" (xl->lock), "=q" (oldval), "+r" (timeout)
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: "1" (1)
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: "memory");
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} while (unlikely(oldval != 0 && !xen_spin_lock_slow(lock)));
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}
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static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl)
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{
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int cpu;
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for_each_online_cpu(cpu) {
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/* XXX should mix up next cpu selection */
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if (per_cpu(lock_spinners, cpu) == xl) {
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xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR);
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break;
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}
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}
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}
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static void xen_spin_unlock(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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smp_wmb(); /* make sure no writes get moved after unlock */
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xl->lock = 0; /* release lock */
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/* make sure unlock happens before kick */
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barrier();
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if (unlikely(xl->spinners))
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xen_spin_unlock_slow(xl);
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}
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static __cpuinit void xen_init_lock_cpu(int cpu)
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{
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int irq;
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const char *name;
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name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
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irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
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cpu,
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xen_reschedule_interrupt,
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IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
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name,
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NULL);
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if (irq >= 0) {
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disable_irq(irq); /* make sure it's never delivered */
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per_cpu(lock_kicker_irq, cpu) = irq;
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}
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printk("cpu %d spinlock event irq %d\n", cpu, irq);
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}
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static void __init xen_init_spinlocks(void)
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{
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pv_lock_ops.spin_is_locked = xen_spin_is_locked;
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pv_lock_ops.spin_is_contended = xen_spin_is_contended;
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pv_lock_ops.spin_lock = xen_spin_lock;
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pv_lock_ops.spin_trylock = xen_spin_trylock;
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pv_lock_ops.spin_unlock = xen_spin_unlock;
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}
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static const struct smp_ops xen_smp_ops __initdata = {
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.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
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.smp_prepare_cpus = xen_smp_prepare_cpus,
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183
arch/x86/xen/spinlock.c
Normal file
183
arch/x86/xen/spinlock.c
Normal file
@ -0,0 +1,183 @@
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/*
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* Split spinlock implementation out into its own file, so it can be
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* compiled in a FTRACE-compatible way.
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*/
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#include <linux/kernel_stat.h>
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#include <linux/spinlock.h>
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#include <asm/paravirt.h>
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#include <xen/interface/xen.h>
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#include <xen/events.h>
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#include "xen-ops.h"
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struct xen_spinlock {
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unsigned char lock; /* 0 -> free; 1 -> locked */
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unsigned short spinners; /* count of waiting cpus */
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};
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static int xen_spin_is_locked(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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return xl->lock != 0;
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}
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static int xen_spin_is_contended(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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/* Not strictly true; this is only the count of contended
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lock-takers entering the slow path. */
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return xl->spinners != 0;
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}
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static int xen_spin_trylock(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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u8 old = 1;
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asm("xchgb %b0,%1"
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: "+q" (old), "+m" (xl->lock) : : "memory");
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return old == 0;
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}
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static DEFINE_PER_CPU(int, lock_kicker_irq) = -1;
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static DEFINE_PER_CPU(struct xen_spinlock *, lock_spinners);
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static inline void spinning_lock(struct xen_spinlock *xl)
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{
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__get_cpu_var(lock_spinners) = xl;
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wmb(); /* set lock of interest before count */
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asm(LOCK_PREFIX " incw %0"
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: "+m" (xl->spinners) : : "memory");
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}
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static inline void unspinning_lock(struct xen_spinlock *xl)
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{
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asm(LOCK_PREFIX " decw %0"
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: "+m" (xl->spinners) : : "memory");
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wmb(); /* decrement count before clearing lock */
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__get_cpu_var(lock_spinners) = NULL;
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}
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static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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int irq = __get_cpu_var(lock_kicker_irq);
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int ret;
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/* If kicker interrupts not initialized yet, just spin */
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if (irq == -1)
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return 0;
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/* announce we're spinning */
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spinning_lock(xl);
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/* clear pending */
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xen_clear_irq_pending(irq);
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/* check again make sure it didn't become free while
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we weren't looking */
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ret = xen_spin_trylock(lock);
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if (ret)
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goto out;
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/* block until irq becomes pending */
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xen_poll_irq(irq);
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kstat_this_cpu.irqs[irq]++;
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out:
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unspinning_lock(xl);
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return ret;
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}
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static void xen_spin_lock(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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int timeout;
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u8 oldval;
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do {
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timeout = 1 << 10;
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asm("1: xchgb %1,%0\n"
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" testb %1,%1\n"
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" jz 3f\n"
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"2: rep;nop\n"
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" cmpb $0,%0\n"
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" je 1b\n"
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" dec %2\n"
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" jnz 2b\n"
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"3:\n"
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: "+m" (xl->lock), "=q" (oldval), "+r" (timeout)
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: "1" (1)
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: "memory");
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} while (unlikely(oldval != 0 && !xen_spin_lock_slow(lock)));
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}
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static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl)
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{
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int cpu;
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for_each_online_cpu(cpu) {
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/* XXX should mix up next cpu selection */
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if (per_cpu(lock_spinners, cpu) == xl) {
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xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR);
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break;
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}
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}
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}
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static void xen_spin_unlock(struct raw_spinlock *lock)
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{
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struct xen_spinlock *xl = (struct xen_spinlock *)lock;
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smp_wmb(); /* make sure no writes get moved after unlock */
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xl->lock = 0; /* release lock */
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/* make sure unlock happens before kick */
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barrier();
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if (unlikely(xl->spinners))
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xen_spin_unlock_slow(xl);
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}
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static irqreturn_t dummy_handler(int irq, void *dev_id)
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{
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BUG();
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return IRQ_HANDLED;
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}
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void __cpuinit xen_init_lock_cpu(int cpu)
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{
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int irq;
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const char *name;
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name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
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irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
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cpu,
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dummy_handler,
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IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
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name,
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NULL);
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if (irq >= 0) {
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disable_irq(irq); /* make sure it's never delivered */
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per_cpu(lock_kicker_irq, cpu) = irq;
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}
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printk("cpu %d spinlock event irq %d\n", cpu, irq);
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}
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void __init xen_init_spinlocks(void)
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{
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pv_lock_ops.spin_is_locked = xen_spin_is_locked;
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pv_lock_ops.spin_is_contended = xen_spin_is_contended;
|
||||
pv_lock_ops.spin_lock = xen_spin_lock;
|
||||
pv_lock_ops.spin_trylock = xen_spin_trylock;
|
||||
pv_lock_ops.spin_unlock = xen_spin_unlock;
|
||||
}
|
||||
@ -50,6 +50,9 @@ void __init xen_setup_vcpu_info_placement(void);
|
||||
#ifdef CONFIG_SMP
|
||||
void xen_smp_init(void);
|
||||
|
||||
void __init xen_init_spinlocks(void);
|
||||
__cpuinit void xen_init_lock_cpu(int cpu);
|
||||
|
||||
extern cpumask_t xen_cpu_initialized_map;
|
||||
#else
|
||||
static inline void xen_smp_init(void) {}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user