linux/arch/x86/xen/spinlock.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Split spinlock implementation out into its own file, so it can be
 * compiled in a FTRACE-compatible way.
 */
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/atomic.h>

#include <asm/paravirt.h>
#include <asm/qspinlock.h>

#include <xen/events.h>

#include "xen-ops.h"

static DEFINE_PER_CPU(int, lock_kicker_irq) = …;
static DEFINE_PER_CPU(char *, irq_name);
static DEFINE_PER_CPU(atomic_t, xen_qlock_wait_nest);

static void xen_qlock_kick(int cpu)
{ … }

/*
 * Halt the current CPU & release it back to the host
 */
static void xen_qlock_wait(u8 *byte, u8 val)
{ … }

static irqreturn_t dummy_handler(int irq, void *dev_id)
{ … }

void xen_init_lock_cpu(int cpu)
{ … }

void xen_uninit_lock_cpu(int cpu)
{ … }

PV_CALLEE_SAVE_REGS_THUNK(…);

/*
 * Our init of PV spinlocks is split in two init functions due to us
 * using paravirt patching and jump labels patching and having to do
 * all of this before SMP code is invoked.
 *
 * The paravirt patching needs to be done _before_ the alternative asm code
 * is started, otherwise we would not patch the core kernel code.
 */
void __init xen_init_spinlocks(void)
{ … }