Eric Lee / smarc-fsl-linux-kernel

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arch/x86/lib/cmpxchg8b_emu.S 909 Bytes
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81f7e3824   Eric Lee   Initial Release, ... 
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  /*
   *	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; version 2
   *	of the License.
   *
   */
  
  #include <linux/linkage.h>
  #include <asm/export.h>
  
  .text
  
  /*
   * Inputs:
   * %esi : memory location to compare
   * %eax : low 32 bits of old value
   * %edx : high 32 bits of old value
   * %ebx : low 32 bits of new value
   * %ecx : high 32 bits of new value
   */
  ENTRY(cmpxchg8b_emu)
  
  #
  # Emulate 'cmpxchg8b (%esi)' on UP except we don't
  # set the whole ZF thing (caller will just compare
  # eax:edx with the expected value)
  #
  	pushfl
  	cli
  
  	cmpl  (%esi), %eax
  	jne .Lnot_same
  	cmpl 4(%esi), %edx
  	jne .Lhalf_same
  
  	movl %ebx,  (%esi)
  	movl %ecx, 4(%esi)
  
  	popfl
  	ret
  
  .Lnot_same:
  	movl  (%esi), %eax
  .Lhalf_same:
  	movl 4(%esi), %edx
  
  	popfl
  	ret
  
  ENDPROC(cmpxchg8b_emu)
  EXPORT_SYMBOL(cmpxchg8b_emu)