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kernel/linux-imx6_3.14.28/arch/arm64/lib/bitops.S 1.63 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * Based on arch/arm/lib/bitops.h
   *
   * Copyright (C) 2013 ARM Ltd.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  #include <linux/linkage.h>
  #include <asm/assembler.h>
  
  /*
   * x0: bits 5:0  bit offset
   *     bits 31:6 word offset
   * x1: address
   */
  	.macro	bitop, name, instr
  ENTRY(	
  ame	)
  	and	w3, w0, #63		// Get bit offset
  	eor	w0, w0, w3		// Clear low bits
  	mov	x2, #1
  	add	x1, x1, x0, lsr #3	// Get word offset
  	lsl	x3, x2, x3		// Create mask
  1:	ldxr	x2, [x1]
  	\instr	x2, x2, x3
  	stxr	w0, x2, [x1]
  	cbnz	w0, 1b
  	ret
  ENDPROC(
  ame	)
  	.endm
  
  	.macro	testop, name, instr
  ENTRY(	
  ame	)
  	and	w3, w0, #63		// Get bit offset
  	eor	w0, w0, w3		// Clear low bits
  	mov	x2, #1
  	add	x1, x1, x0, lsr #3	// Get word offset
  	lsl	x4, x2, x3		// Create mask
  1:	ldxr	x2, [x1]
  	lsr	x0, x2, x3		// Save old value of bit
  	\instr	x2, x2, x4		// toggle bit
  	stlxr	w5, x2, [x1]
  	cbnz	w5, 1b
  	dmb	ish
  	and	x0, x0, #1
  3:	ret
  ENDPROC(
  ame	)
  	.endm
  
  /*
   * Atomic bit operations.
   */
  	bitop	change_bit, eor
  	bitop	clear_bit, bic
  	bitop	set_bit, orr
  
  	testop	test_and_change_bit, eor
  	testop	test_and_clear_bit, bic
  	testop	test_and_set_bit, orr