220 lines
4.1 KiB
ArmAsm
220 lines
4.1 KiB
ArmAsm
/*
|
|
* i386 semaphore implementation.
|
|
*
|
|
* (C) Copyright 1999 Linus Torvalds
|
|
*
|
|
* Portions Copyright 1999 Red Hat, Inc.
|
|
*
|
|
* 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.
|
|
*
|
|
* rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@kvack.org>
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/rwlock.h>
|
|
#include <asm/alternative-asm.i>
|
|
#include <asm/frame.i>
|
|
#include <asm/dwarf2.h>
|
|
|
|
/*
|
|
* The semaphore operations have a special calling sequence that
|
|
* allow us to do a simpler in-line version of them. These routines
|
|
* need to convert that sequence back into the C sequence when
|
|
* there is contention on the semaphore.
|
|
*
|
|
* %eax contains the semaphore pointer on entry. Save the C-clobbered
|
|
* registers (%eax, %edx and %ecx) except %eax whish is either a return
|
|
* value or just clobbered..
|
|
*/
|
|
.section .sched.text
|
|
ENTRY(__down_failed)
|
|
CFI_STARTPROC
|
|
FRAME
|
|
pushl %edx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET edx,0
|
|
pushl %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx,0
|
|
call __down
|
|
popl %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
CFI_RESTORE ecx
|
|
popl %edx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
CFI_RESTORE edx
|
|
ENDFRAME
|
|
ret
|
|
CFI_ENDPROC
|
|
END(__down_failed)
|
|
|
|
ENTRY(__down_failed_interruptible)
|
|
CFI_STARTPROC
|
|
FRAME
|
|
pushl %edx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET edx,0
|
|
pushl %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx,0
|
|
call __down_interruptible
|
|
popl %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
CFI_RESTORE ecx
|
|
popl %edx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
CFI_RESTORE edx
|
|
ENDFRAME
|
|
ret
|
|
CFI_ENDPROC
|
|
END(__down_failed_interruptible)
|
|
|
|
ENTRY(__down_failed_trylock)
|
|
CFI_STARTPROC
|
|
FRAME
|
|
pushl %edx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET edx,0
|
|
pushl %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx,0
|
|
call __down_trylock
|
|
popl %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
CFI_RESTORE ecx
|
|
popl %edx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
CFI_RESTORE edx
|
|
ENDFRAME
|
|
ret
|
|
CFI_ENDPROC
|
|
END(__down_failed_trylock)
|
|
|
|
ENTRY(__up_wakeup)
|
|
CFI_STARTPROC
|
|
FRAME
|
|
pushl %edx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET edx,0
|
|
pushl %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx,0
|
|
call __up
|
|
popl %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
CFI_RESTORE ecx
|
|
popl %edx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
CFI_RESTORE edx
|
|
ENDFRAME
|
|
ret
|
|
CFI_ENDPROC
|
|
END(__up_wakeup)
|
|
|
|
/*
|
|
* rw spinlock fallbacks
|
|
*/
|
|
#ifdef CONFIG_SMP
|
|
ENTRY(__write_lock_failed)
|
|
CFI_STARTPROC simple
|
|
FRAME
|
|
2: LOCK_PREFIX
|
|
addl $ RW_LOCK_BIAS,(%eax)
|
|
1: rep; nop
|
|
cmpl $ RW_LOCK_BIAS,(%eax)
|
|
jne 1b
|
|
LOCK_PREFIX
|
|
subl $ RW_LOCK_BIAS,(%eax)
|
|
jnz 2b
|
|
ENDFRAME
|
|
ret
|
|
CFI_ENDPROC
|
|
END(__write_lock_failed)
|
|
|
|
ENTRY(__read_lock_failed)
|
|
CFI_STARTPROC
|
|
FRAME
|
|
2: LOCK_PREFIX
|
|
incl (%eax)
|
|
1: rep; nop
|
|
cmpl $1,(%eax)
|
|
js 1b
|
|
LOCK_PREFIX
|
|
decl (%eax)
|
|
js 2b
|
|
ENDFRAME
|
|
ret
|
|
CFI_ENDPROC
|
|
END(__read_lock_failed)
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM
|
|
|
|
/* Fix up special calling conventions */
|
|
ENTRY(call_rwsem_down_read_failed)
|
|
CFI_STARTPROC
|
|
push %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx,0
|
|
push %edx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET edx,0
|
|
call rwsem_down_read_failed
|
|
pop %edx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
pop %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
ret
|
|
CFI_ENDPROC
|
|
END(call_rwsem_down_read_failed)
|
|
|
|
ENTRY(call_rwsem_down_write_failed)
|
|
CFI_STARTPROC
|
|
push %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx,0
|
|
calll rwsem_down_write_failed
|
|
pop %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
ret
|
|
CFI_ENDPROC
|
|
END(call_rwsem_down_write_failed)
|
|
|
|
ENTRY(call_rwsem_wake)
|
|
CFI_STARTPROC
|
|
decw %dx /* do nothing if still outstanding active readers */
|
|
jnz 1f
|
|
push %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx,0
|
|
call rwsem_wake
|
|
pop %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
1: ret
|
|
CFI_ENDPROC
|
|
END(call_rwsem_wake)
|
|
|
|
/* Fix up special calling conventions */
|
|
ENTRY(call_rwsem_downgrade_wake)
|
|
CFI_STARTPROC
|
|
push %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx,0
|
|
push %edx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET edx,0
|
|
call rwsem_downgrade_wake
|
|
pop %edx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
pop %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
ret
|
|
CFI_ENDPROC
|
|
END(call_rwsem_downgrade_wake)
|
|
|
|
#endif
|