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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 1.1.1.1 2004-04-15 01:36:27 phoenix Exp $
         */

        #include <linux/config.h>
        #include <linux/linkage.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:  
        SAVE_ARGS
        call \func
        jmp  restore
        .endm

        /* rdi: arg1 ... normal C conventions. rax is passed from C. */         
        .macro thunk_retrax name,func
        .globl \name
\name:  
        SAVE_ARGS
        call \func
        jmp  restore_norax
        .endm
        

#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
#endif  
        thunk do_softirq_thunk,do_softirq
        
        thunk __down_failed,__down
        thunk_retrax __down_failed_interruptible,__down_interruptible
        thunk_retrax __down_failed_trylock,__down_trylock
        thunk __up_wakeup,__up
        
restore:
        RESTORE_ARGS
        ret     
        
restore_norax:  
        RESTORE_ARGS 1
        ret

#ifdef CONFIG_SMP
/* Support for read/write spinlocks. */
        
/* 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