+++ /dev/null
-/* include/arch-x86_64/rwlock.h
- *
- * Helpers used by both rw spinlocks and rw semaphores.
- *
- * Based in part on code from semaphore.h and
- * spinlock.h Copyright 1996 Linus Torvalds.
- *
- * Copyright 1999 Red Hat, Inc.
- * Copyright 2001,2002 SuSE labs
- *
- * Written by Benjamin LaHaise.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-#ifndef _ARCH_X86_64_RWLOCK_H
-#define _ARCH_X86_64_RWLOCK_H
-
-#include <lwk/stringify.h>
-
-#define RW_LOCK_BIAS 0x01000000
-#define RW_LOCK_BIAS_STR "0x01000000"
-
-#define __build_read_lock_ptr(rw, helper) \
- asm volatile("lock ; subl $1,(%0)\n\t" \
- "js 2f\n" \
- "1:\n" \
- LOCK_SECTION_START("") \
- "2:\tcall " helper "\n\t" \
- "jmp 1b\n" \
- LOCK_SECTION_END \
- ::"a" (rw) : "memory")
-
-#define __build_read_lock_const(rw, helper) \
- asm volatile("lock ; subl $1,%0\n\t" \
- "js 2f\n" \
- "1:\n" \
- LOCK_SECTION_START("") \
- "2:\tpushq %%rax\n\t" \
- "leaq %0,%%rax\n\t" \
- "call " helper "\n\t" \
- "popq %%rax\n\t" \
- "jmp 1b\n" \
- LOCK_SECTION_END \
- :"=m" (*((volatile int *)rw))::"memory")
-
-#define __build_read_lock(rw, helper) do { \
- if (__builtin_constant_p(rw)) \
- __build_read_lock_const(rw, helper); \
- else \
- __build_read_lock_ptr(rw, helper); \
- } while (0)
-
-#define __build_write_lock_ptr(rw, helper) \
- asm volatile("lock ; subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
- "jnz 2f\n" \
- "1:\n" \
- LOCK_SECTION_START("") \
- "2:\tcall " helper "\n\t" \
- "jmp 1b\n" \
- LOCK_SECTION_END \
- ::"a" (rw) : "memory")
-
-#define __build_write_lock_const(rw, helper) \
- asm volatile("lock ; subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
- "jnz 2f\n" \
- "1:\n" \
- LOCK_SECTION_START("") \
- "2:\tpushq %%rax\n\t" \
- "leaq %0,%%rax\n\t" \
- "call " helper "\n\t" \
- "popq %%rax\n\t" \
- "jmp 1b\n" \
- LOCK_SECTION_END \
- :"=m" (*((volatile long *)rw))::"memory")
-
-#define __build_write_lock(rw, helper) do { \
- if (__builtin_constant_p(rw)) \
- __build_write_lock_const(rw, helper); \
- else \
- __build_write_lock_ptr(rw, helper); \
- } while (0)
-
-#endif