1/* SPDX-License-Identifier: GPL-2.0 */
  2
  3scale=0
  4
  5define gcd(a,b) {
  6	auto t;
  7	while (b) {
  8		t = b;
  9		b = a % b;
 10		a = t;
 11	}
 12	return a;
 13}
 14
 15/* Division by reciprocal multiplication. */
 16define fmul(b,n,d) {
 17       return (2^b*n+d-1)/d;
 18}
 19
 20/* Adjustment factor when a ceiling value is used.  Use as:
 21   (imul * n) + (fmulxx * n + fadjxx) >> xx) */
 22define fadj(b,n,d) {
 23	auto v;
 24	d = d/gcd(n,d);
 25	v = 2^b*(d-1)/d;
 26	return v;
 27}
 28
 29/* Compute the appropriate mul/adj values as well as a shift count,
 30   which brings the mul value into the range 2^b-1 <= x < 2^b.  Such
 31   a shift value will be correct in the signed integer range and off
 32   by at most one in the upper half of the unsigned range. */
 33define fmuls(b,n,d) {
 34	auto s, m;
 35	for (s = 0; 1; s++) {
 36		m = fmul(s,n,d);
 37		if (m >= 2^(b-1))
 38			return s;
 39	}
 40	return 0;
 41}
 42
 43define timeconst(hz) {
 44	print "/* Automatically generated by kernel/time/timeconst.bc */\n"
 45	print "/* Time conversion constants for HZ == ", hz, " */\n"
 46	print "\n"
 47
 48	print "#ifndef KERNEL_TIMECONST_H\n"
 49	print "#define KERNEL_TIMECONST_H\n\n"
 50
 51	print "#include <linux/param.h>\n"
 52	print "#include <linux/types.h>\n\n"
 53
 54	print "#if HZ != ", hz, "\n"
 55	print "#error \qinclude/generated/timeconst.h has the wrong HZ value!\q\n"
 56	print "#endif\n\n"
 57
 58	if (hz < 2) {
 59		print "#error Totally bogus HZ value!\n"
 60	} else {
 61		s=fmuls(32,1000,hz)
 62		obase=16
 63		print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), ")\n"
 64		print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), ")\n"
 65		obase=10
 66		print "#define HZ_TO_MSEC_SHR32\t", s, "\n"
 67
 68		s=fmuls(32,hz,1000)
 69		obase=16
 70		print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), ")\n"
 71		print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), ")\n"
 72		obase=10
 73		print "#define MSEC_TO_HZ_SHR32\t", s, "\n"
 74
 75		obase=10
 76		cd=gcd(hz,1000)
 77		print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "\n"
 78		print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "\n"
 79		print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "\n"
 80		print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "\n"
 81		print "\n"
 82
 83		s=fmuls(32,1000000,hz)
 84		obase=16
 85		print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), ")\n"
 86		print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), ")\n"
 87		obase=10
 88		print "#define HZ_TO_USEC_SHR32\t", s, "\n"
 89
 90		s=fmuls(32,hz,1000000)
 91		obase=16
 92		print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), ")\n"
 93		print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), ")\n"
 94		obase=10
 95		print "#define USEC_TO_HZ_SHR32\t", s, "\n"
 96
 97		obase=10
 98		cd=gcd(hz,1000000)
 99		print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "\n"
100		print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "\n"
101		print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "\n"
102		print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "\n"
103
104		cd=gcd(hz,1000000000)
105		print "#define HZ_TO_NSEC_NUM\t\t", 1000000000/cd, "\n"
106		print "#define HZ_TO_NSEC_DEN\t\t", hz/cd, "\n"
107		print "#define NSEC_TO_HZ_NUM\t\t", hz/cd, "\n"
108		print "#define NSEC_TO_HZ_DEN\t\t", 1000000000/cd, "\n"
109		print "\n"
110
111		print "#endif /* KERNEL_TIMECONST_H */\n"
112	}
113	halt
114}
115
116hz = read();
117timeconst(hz)