ecaf45ee5c
- Move them to a pure assembly file. Previously they were in a C file that only consisted of inline assembly. Doing it in pure assembler is much nicer. - Add a frame.i include with FRAME/ENDFRAME macros to easily add frame pointers to assembly functions - Add dwarf2 annotation to them so that the new dwarf2 unwinder doesn't get stuck on them - Random cleanups Includes feedback from Jan Beulich and a UML build fix from Andrew Morton. Cc: jbeulich@novell.com Cc: jdike@addtoit.com Signed-off-by: Andi Kleen <ak@suse.de>
154 lines
2.9 KiB
ArmAsm
154 lines
2.9 KiB
ArmAsm
/*
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* i386 semaphore implementation.
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*
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* (C) Copyright 1999 Linus Torvalds
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*
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* Portions Copyright 1999 Red Hat, Inc.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@kvack.org>
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*/
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#include <linux/config.h>
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#include <linux/linkage.h>
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#include <asm/rwlock.h>
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#include <asm/alternative-asm.i>
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#include <asm/frame.i>
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#include <asm/dwarf2.h>
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/*
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* The semaphore operations have a special calling sequence that
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* allow us to do a simpler in-line version of them. These routines
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* need to convert that sequence back into the C sequence when
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* there is contention on the semaphore.
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*
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* %eax contains the semaphore pointer on entry. Save the C-clobbered
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* registers (%eax, %edx and %ecx) except %eax whish is either a return
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* value or just clobbered..
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*/
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.section .sched.text
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ENTRY(__down_failed)
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CFI_STARTPROC
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FRAME
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pushl %edx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET edx,0
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pushl %ecx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET ecx,0
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call __down
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popl %ecx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE ecx
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popl %edx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE edx
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ENDFRAME
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ret
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CFI_ENDPROC
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END(__down_failed)
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ENTRY(__down_failed_interruptible)
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CFI_STARTPROC
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FRAME
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pushl %edx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET edx,0
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pushl %ecx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET ecx,0
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call __down_interruptible
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popl %ecx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE ecx
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popl %edx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE edx
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ENDFRAME
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ret
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CFI_ENDPROC
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END(__down_failed_interruptible)
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ENTRY(__down_failed_trylock)
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CFI_STARTPROC
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FRAME
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pushl %edx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET edx,0
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pushl %ecx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET ecx,0
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call __down_trylock
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popl %ecx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE ecx
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popl %edx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE edx
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ENDFRAME
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ret
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CFI_ENDPROC
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END(__down_failed_trylock)
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ENTRY(__up_wakeup)
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CFI_STARTPROC
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FRAME
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pushl %edx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET edx,0
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pushl %ecx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET ecx,0
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call __up
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popl %ecx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE ecx
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popl %edx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE edx
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ENDFRAME
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ret
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CFI_ENDPROC
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END(__up_wakeup)
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/*
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* rw spinlock fallbacks
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*/
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#ifdef CONFIG_SMP
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ENTRY(__write_lock_failed)
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CFI_STARTPROC simple
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FRAME
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2: LOCK_PREFIX
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addl $ RW_LOCK_BIAS,(%eax)
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1: rep; nop
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cmpl $ RW_LOCK_BIAS,(%eax)
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jne 1b
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LOCK_PREFIX
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subl $ RW_LOCK_BIAS,(%eax)
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jnz 2b
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ENDFRAME
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ret
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CFI_ENDPROC
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END(__write_lock_failed)
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ENTRY(__read_lock_failed)
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CFI_STARTPROC
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FRAME
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2: LOCK_PREFIX
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incl (%eax)
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1: rep; nop
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cmpl $1,(%eax)
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js 1b
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LOCK_PREFIX
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decl (%eax)
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js 2b
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ENDFRAME
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ret
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CFI_ENDPROC
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END(__read_lock_failed)
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#endif
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