acrn-hypervisor/hypervisor/include/lib/spinlock.h

111 lines
3.2 KiB
C

/*
* Copyright (C) 2018 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef SPINLOCK_H
#define SPINLOCK_H
#include <hypervisor.h>
#ifndef ASSEMBLER
#include <types.h>
/** The architecture dependent spinlock type. */
typedef struct _spinlock {
uint32_t head;
uint32_t tail;
} spinlock_t;
/* Function prototypes */
int spinlock_init(spinlock_t *lock);
int spinlock_obtain(spinlock_t *lock);
static inline int spinlock_release(spinlock_t *lock)
{
/* Increment tail of queue */
asm volatile (" lock incl %[tail]\n"
:
: [tail] "m" (lock->tail)
: "cc", "memory");
return 0;
}
#else /* ASSEMBLER */
/** The offset of the head element. */
#define SYNC_SPINLOCK_HEAD_OFFSET 0
/** The offset of the tail element. */
#define SYNC_SPINLOCK_TAIL_OFFSET 4
.macro spinlock_obtain lock
movl $1, % eax
lea \lock, % ebx
lock xaddl % eax, SYNC_SPINLOCK_HEAD_OFFSET(%ebx)
cmpl % eax, SYNC_SPINLOCK_TAIL_OFFSET(%ebx)
jz 1f
2 :
pause
cmpl % eax, SYNC_SPINLOCK_TAIL_OFFSET(%ebx)
jnz 2b
1 :
.endm
#define spinlock_obtain(x) spinlock_obtain lock = (x)
.macro spinlock_release lock
lea \lock, % ebx
lock incl SYNC_SPINLOCK_TAIL_OFFSET(%ebx)
.endm
#define spinlock_release(x) spinlock_release lock = (x)
#endif /* ASSEMBLER */
#define spinlock_rflags unsigned long cpu_int_value
#define spinlock_irq_obtain(l) (CPU_IRQ_DISABLE(), spinlock_obtain((l)))
#define spinlock_irqsave_obtain(l) \
do { \
CPU_INT_ALL_DISABLE(); \
spinlock_obtain((l)); \
} while (0)
#define spinlock_irq_release(l) (spinlock_release((l)), CPU_IRQ_ENABLE())
#define spinlock_irqrestore_release(l) \
do { \
spinlock_release((l)); \
CPU_INT_ALL_RESTORE(); \
} while (0)
#endif /* SPINLOCK_H */