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>

1 files changed, 0 insertions, 167 deletions

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index d8faf79a0a1d..baca7f2fbd8a 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -15,7 +15,6 @@
  * This does not handle HOTPLUG_CPU yet.
  */
 #include <linux/sched.h>
-#include <linux/kernel_stat.h>
 #include <linux/err.h>
 #include <linux/smp.h>
 
@@ -36,8 +35,6 @@
 #include "xen-ops.h"
 #include "mmu.h"
 
-static void __cpuinit xen_init_lock_cpu(int cpu);
-
 cpumask_t xen_cpu_initialized_map;
 
 static DEFINE_PER_CPU(int, resched_irq);
@@ -419,170 +416,6 @@ static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
         return IRQ_HANDLED;
 }
 
-struct xen_spinlock {
-        unsigned char lock;             /* 0 -> free; 1 -> locked */
-        unsigned short spinners;        /* count of waiting cpus */
-};
-
-static int xen_spin_is_locked(struct raw_spinlock *lock)
-{
-        struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-
-        return xl->lock != 0;
-}
-
-static int xen_spin_is_contended(struct raw_spinlock *lock)
-{
-        struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-
-        /* Not strictly true; this is only the count of contended
-           lock-takers entering the slow path. */
-        return xl->spinners != 0;
-}
-
-static int xen_spin_trylock(struct raw_spinlock *lock)
-{
-        struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-        u8 old = 1;
-
-        asm("xchgb %b0,%1"
-            : "+q" (old), "+m" (xl->lock) : : "memory");
-
-        return old == 0;
-}
-
-static DEFINE_PER_CPU(int, lock_kicker_irq) = -1;
-static DEFINE_PER_CPU(struct xen_spinlock *, lock_spinners);
-
-static inline void spinning_lock(struct xen_spinlock *xl)
-{
-        __get_cpu_var(lock_spinners) = xl;
-        wmb();                  /* set lock of interest before count */
-        asm(LOCK_PREFIX " incw %0"
-            : "+m" (xl->spinners) : : "memory");
-}
-
-static inline void unspinning_lock(struct xen_spinlock *xl)
-{
-        asm(LOCK_PREFIX " decw %0"
-            : "+m" (xl->spinners) : : "memory");
-        wmb();                  /* decrement count before clearing lock */
-        __get_cpu_var(lock_spinners) = NULL;
-}
-
-static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
-{
-        struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-        int irq = __get_cpu_var(lock_kicker_irq);
-        int ret;
-
-        /* If kicker interrupts not initialized yet, just spin */
-        if (irq == -1)
-                return 0;
-
-        /* announce we're spinning */
-        spinning_lock(xl);
-
-        /* clear pending */
-        xen_clear_irq_pending(irq);
-
-        /* check again make sure it didn't become free while
-           we weren't looking  */
-        ret = xen_spin_trylock(lock);
-        if (ret)
-                goto out;
-
-        /* block until irq becomes pending */
-        xen_poll_irq(irq);
-        kstat_this_cpu.irqs[irq]++;
-
-out:
-        unspinning_lock(xl);
-        return ret;
-}
-
-static void xen_spin_lock(struct raw_spinlock *lock)
-{
-        struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-        int timeout;
-        u8 oldval;
-
-        do {
-                timeout = 1 << 10;
-
-                asm("1: xchgb %1,%0\n"
-                    "   testb %1,%1\n"
-                    "   jz 3f\n"
-                    "2: rep;nop\n"
-                    "   cmpb $0,%0\n"
-                    "   je 1b\n"
-                    "   dec %2\n"
-                    "   jnz 2b\n"
-                    "3:\n"
-                    : "+m" (xl->lock), "=q" (oldval), "+r" (timeout)
-                    : "1" (1)
-                    : "memory");
-
-        } while (unlikely(oldval != 0 && !xen_spin_lock_slow(lock)));
-}
-
-static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl)
-{
-        int cpu;
-
-        for_each_online_cpu(cpu) {
-                /* XXX should mix up next cpu selection */
-                if (per_cpu(lock_spinners, cpu) == xl) {
-                        xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR);
-                        break;
-                }
-        }
-}
-
-static void xen_spin_unlock(struct raw_spinlock *lock)
-{
-        struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-
-        smp_wmb();              /* make sure no writes get moved after unlock */
-        xl->lock = 0;           /* release lock */
-
-        /* make sure unlock happens before kick */
-        barrier();
-
-        if (unlikely(xl->spinners))
-                xen_spin_unlock_slow(xl);
-}
-
-static __cpuinit void xen_init_lock_cpu(int cpu)
-{
-        int irq;
-        const char *name;
-
-        name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
-        irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
-                                     cpu,
-                                     xen_reschedule_interrupt,
-                                     IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
-                                     name,
-                                     NULL);
-
-        if (irq >= 0) {
-                disable_irq(irq); /* make sure it's never delivered */
-                per_cpu(lock_kicker_irq, cpu) = irq;
-        }
-
-        printk("cpu %d spinlock event irq %d\n", cpu, irq);
-}
-
-static void __init xen_init_spinlocks(void)
-{
-        pv_lock_ops.spin_is_locked = xen_spin_is_locked;
-        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;
-}
-
 static const struct smp_ops xen_smp_ops __initdata = {
         .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
         .smp_prepare_cpus = xen_smp_prepare_cpus,