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kernel/linux-imx6_3.14.28/arch/m32r/lib/delay.c 2.92 KB
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  /*
   * linux/arch/m32r/lib/delay.c
   *
   * Copyright (c) 2002  Hitoshi Yamamoto, Hirokazu Takata
   * Copyright (c) 2004  Hirokazu Takata
   */
  
  #include <linux/param.h>
  #include <linux/module.h>
  #ifdef CONFIG_SMP
  #include <linux/sched.h>
  #include <asm/current.h>
  #include <asm/smp.h>
  #endif  /* CONFIG_SMP */
  #include <asm/processor.h>
  
  void __delay(unsigned long loops)
  {
  #ifdef CONFIG_ISA_DUAL_ISSUE
  	__asm__ __volatile__ (
  		"beqz	%0, 2f			
  \t"
  		"addi	%0, #-1			
  \t"
  
  		" .fillinsn			
  \t"
  		"1:				
  \t"
  		"cmpz	%0  ||  addi  %0, #-1	
  \t"
  		"bc	2f  ||  cmpz  %0	
  \t"
  		"bc	2f  ||  addi  %0, #-1	
  \t"
  		"cmpz	%0  ||  addi  %0, #-1	
  \t"
  		"bc	2f  ||  cmpz  %0	
  \t"
  		"bnc	1b  ||  addi  %0, #-1	
  \t"
  		" .fillinsn			
  \t"
  		"2:				
  \t"
  		: "+r" (loops)
  		: "r" (0)
  		: "cbit"
  	);
  #else
  	__asm__ __volatile__ (
  		"beqz	%0, 2f			
  \t"
  		" .fillinsn			
  \t"
  		"1:				
  \t"
  		"addi	%0, #-1			
  \t"
  		"blez	%0, 2f			
  \t"
  		"addi	%0, #-1			
  \t"
  		"blez	%0, 2f			
  \t"
  		"addi	%0, #-1			
  \t"
  		"blez	%0, 2f			
  \t"
  		"addi	%0, #-1			
  \t"
  		"bgtz	%0, 1b			
  \t"
  		" .fillinsn			
  \t"
  		"2:				
  \t"
  		: "+r" (loops)
  		: "r" (0)
  	);
  #endif
  }
  
  void __const_udelay(unsigned long xloops)
  {
  #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
  	/*
  	 * loops [1] = (xloops >> 32) [sec] * loops_per_jiffy [1/jiffy]
  	 *            * HZ [jiffy/sec]
  	 *          = (xloops >> 32) [sec] * (loops_per_jiffy * HZ) [1/sec]
  	 *          = (((xloops * loops_per_jiffy) >> 32) * HZ) [1]
  	 *
  	 * NOTE:
  	 *   - '[]' depicts variable's dimension in the above equation.
  	 *   - "rac" instruction rounds the accumulator in word size.
  	 */
  	__asm__ __volatile__ (
  		"srli	%0, #1				
  \t"
  		"mulwhi	%0, %1	; a0			
  \t"
  		"mulwu1	%0, %1	; a1			
  \t"
  		"sadd		; a0 += (a1 >> 16)	
  \t"
  		"rac	a0, a0, #1			
  \t"
  		"mvfacmi %0, a0				
  \t"
  		: "+r" (xloops)
  		: "r" (current_cpu_data.loops_per_jiffy)
  		: "a0", "a1"
  	);
  #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
  	/*
  	 * u64 ull;
  	 * ull = (u64)xloops * (u64)current_cpu_data.loops_per_jiffy;
  	 * xloops = (ull >> 32);
  	 */
  	__asm__ __volatile__ (
  		"and3	r4, %0, #0xffff		
  \t"
  		"and3	r5, %1, #0xffff		
  \t"
  		"mul	r4, r5			
  \t"
  		"srl3	r6, %0, #16		
  \t"
  		"srli	r4, #16			
  \t"
  		"mul	r5, r6			
  \t"
  		"add	r4, r5			
  \t"
  		"and3	r5, %0, #0xffff		
  \t"
  		"srl3	r6, %1, #16		
  \t"
  		"mul	r5, r6			
  \t"
  		"add	r4, r5			
  \t"
  		"srl3	r5, %0, #16		
  \t"
  		"srli	r4, #16			
  \t"
  		"mul	r5, r6			
  \t"
  		"add	r4, r5			
  \t"
  		"mv	%0, r4			
  \t"
  		: "+r" (xloops)
  		: "r" (current_cpu_data.loops_per_jiffy)
  		: "r4", "r5", "r6"
  	);
  #else
  #error unknown isa configuration
  #endif
  	__delay(xloops * HZ);
  }
  
  void __udelay(unsigned long usecs)
  {
  	__const_udelay(usecs * 0x000010c7);  /* 2**32 / 1000000 (rounded up) */
  }
  
  void __ndelay(unsigned long nsecs)
  {
  	__const_udelay(nsecs * 0x00005);  /* 2**32 / 1000000000 (rounded up) */
  }
  
  EXPORT_SYMBOL(__delay);
  EXPORT_SYMBOL(__const_udelay);
  EXPORT_SYMBOL(__udelay);
  EXPORT_SYMBOL(__ndelay);