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/*
* Save registers before calling assembly functions. This avoids
* disturbance of register allocation in some inline assembly constructs.
* Copyright 2001,2002 by Andi Kleen, SuSE Labs.
* Subject to the GNU public license, v.2. No warranty of any kind.
* $Id: thunk.S,v 1.2 2002/03/13 20:06:58 ak Exp $
*/
#include <linux/config.h>
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/calling.h>
#include <asm/rwlock.h>
/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
.macro thunk name,func
.globl \name
\name:
CFI_STARTPROC
SAVE_ARGS
call \func
jmp restore
CFI_ENDPROC
.endm
/* rdi: arg1 ... normal C conventions. rax is passed from C. */
.macro thunk_retrax name,func
.globl \name
\name:
CFI_STARTPROC
SAVE_ARGS
call \func
jmp restore_norax
CFI_ENDPROC
.endm
.section .sched.text
#ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM
thunk rwsem_down_read_failed_thunk,rwsem_down_read_failed
thunk rwsem_down_write_failed_thunk,rwsem_down_write_failed
thunk rwsem_wake_thunk,rwsem_wake
thunk rwsem_downgrade_thunk,rwsem_downgrade_wake
#endif
thunk __down_failed,__down
thunk_retrax __down_failed_interruptible,__down_interruptible
thunk_retrax __down_failed_trylock,__down_trylock
thunk __up_wakeup,__up
/* SAVE_ARGS below is used only for the .cfi directives it contains. */
CFI_STARTPROC
SAVE_ARGS
restore:
RESTORE_ARGS
ret
CFI_ENDPROC
CFI_STARTPROC
SAVE_ARGS
restore_norax:
RESTORE_ARGS 1
ret
CFI_ENDPROC
#ifdef CONFIG_SMP
/* Support for read/write spinlocks. */
.text
/* rax: pointer to rwlock_t */
ENTRY(__write_lock_failed)
lock
addl $RW_LOCK_BIAS,(%rax)
1: rep
nop
cmpl $RW_LOCK_BIAS,(%rax)
jne 1b
lock
subl $RW_LOCK_BIAS,(%rax)
jnz __write_lock_failed
ret
/* rax: pointer to rwlock_t */
ENTRY(__read_lock_failed)
lock
incl (%rax)
1: rep
nop
cmpl $1,(%rax)
js 1b
lock
decl (%rax)
js __read_lock_failed
ret
#endif
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