Eric Lee / smarc-fsl-linux-kernel

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kernel/time/timeconst.bc 2.75 KB
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70730bca1   H. Peter Anvin   kernel: Replace t... 
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  scale=0
  
  define gcd(a,b) {
  	auto t;
  	while (b) {
  		t = b;
  		b = a % b;
  		a = t;
  	}
  	return a;
  }
  
  /* Division by reciprocal multiplication. */
  define fmul(b,n,d) {
         return (2^b*n+d-1)/d;
  }
  
  /* Adjustment factor when a ceiling value is used.  Use as:
     (imul * n) + (fmulxx * n + fadjxx) >> xx) */
  define fadj(b,n,d) {
  	auto v;
  	d = d/gcd(n,d);
  	v = 2^b*(d-1)/d;
  	return v;
  }
  
  /* Compute the appropriate mul/adj values as well as a shift count,
     which brings the mul value into the range 2^b-1 <= x < 2^b.  Such
     a shift value will be correct in the signed integer range and off
     by at most one in the upper half of the unsigned range. */
  define fmuls(b,n,d) {
  	auto s, m;
  	for (s = 0; 1; s++) {
  		m = fmul(s,n,d);
  		if (m >= 2^(b-1))
  			return s;
  	}
  	return 0;
  }
  
  define timeconst(hz) {
03f136a20   Jason A. Donenfeld   timeconst: Update... 
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  	print "/* Automatically generated by kernel/time/timeconst.bc */
  "
70730bca1   H. Peter Anvin   kernel: Replace t... 
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  	print "/* Time conversion constants for HZ == ", hz, " */
  "
  	print "
  "
  
  	print "#ifndef KERNEL_TIMECONST_H
  "
  	print "#define KERNEL_TIMECONST_H
  
  "
  
  	print "#include <linux/param.h>
  "
  	print "#include <linux/types.h>
  
  "
  
  	print "#if HZ != ", hz, "
  "
0a227985d   Nicholas Mc Guire   time: Move timeco... 
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  	print "#error \qinclude/generated/timeconst.h has the wrong HZ value!\q
  "
70730bca1   H. Peter Anvin   kernel: Replace t... 
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  	print "#endif
  
  "
  
  	if (hz < 2) {
  		print "#error Totally bogus HZ value!
  "
  	} else {
  		s=fmuls(32,1000,hz)
  		obase=16
  		print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), ")
  "
  		print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), ")
  "
  		obase=10
  		print "#define HZ_TO_MSEC_SHR32\t", s, "
  "
  
  		s=fmuls(32,hz,1000)
  		obase=16
  		print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), ")
  "
  		print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), ")
  "
  		obase=10
  		print "#define MSEC_TO_HZ_SHR32\t", s, "
  "
  
  		obase=10
  		cd=gcd(hz,1000)
  		print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "
  "
  		print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "
  "
  		print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "
  "
  		print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "
  "
  		print "
  "
  
  		s=fmuls(32,1000000,hz)
  		obase=16
  		print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), ")
  "
  		print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), ")
  "
  		obase=10
  		print "#define HZ_TO_USEC_SHR32\t", s, "
  "
  
  		s=fmuls(32,hz,1000000)
  		obase=16
  		print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), ")
  "
  		print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), ")
  "
  		obase=10
  		print "#define USEC_TO_HZ_SHR32\t", s, "
  "
  
  		obase=10
  		cd=gcd(hz,1000000)
  		print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "
  "
  		print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "
  "
  		print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "
  "
  		print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "
  "
  		print "
  "
  
  		print "#endif /* KERNEL_TIMECONST_H */
  "
  	}
  	halt
  }
0a227985d   Nicholas Mc Guire   time: Move timeco... 
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  hz = read();
70730bca1   H. Peter Anvin   kernel: Replace t... 
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  timeconst(hz)