v4.19.13 snapshot.
diff --git a/kernel/time/timeconst.bc b/kernel/time/timeconst.bc
new file mode 100644
index 0000000..f83bbb8
--- /dev/null
+++ b/kernel/time/timeconst.bc
@@ -0,0 +1,115 @@
+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) {
+ print "/* Automatically generated by kernel/time/timeconst.bc */\n"
+ print "/* Time conversion constants for HZ == ", hz, " */\n"
+ print "\n"
+
+ print "#ifndef KERNEL_TIMECONST_H\n"
+ print "#define KERNEL_TIMECONST_H\n\n"
+
+ print "#include <linux/param.h>\n"
+ print "#include <linux/types.h>\n\n"
+
+ print "#if HZ != ", hz, "\n"
+ print "#error \qinclude/generated/timeconst.h has the wrong HZ value!\q\n"
+ print "#endif\n\n"
+
+ if (hz < 2) {
+ print "#error Totally bogus HZ value!\n"
+ } else {
+ s=fmuls(32,1000,hz)
+ obase=16
+ print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), ")\n"
+ print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), ")\n"
+ obase=10
+ print "#define HZ_TO_MSEC_SHR32\t", s, "\n"
+
+ s=fmuls(32,hz,1000)
+ obase=16
+ print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), ")\n"
+ print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), ")\n"
+ obase=10
+ print "#define MSEC_TO_HZ_SHR32\t", s, "\n"
+
+ obase=10
+ cd=gcd(hz,1000)
+ print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "\n"
+ print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "\n"
+ print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "\n"
+ print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "\n"
+ print "\n"
+
+ s=fmuls(32,1000000,hz)
+ obase=16
+ print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), ")\n"
+ print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), ")\n"
+ obase=10
+ print "#define HZ_TO_USEC_SHR32\t", s, "\n"
+
+ s=fmuls(32,hz,1000000)
+ obase=16
+ print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), ")\n"
+ print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), ")\n"
+ obase=10
+ print "#define USEC_TO_HZ_SHR32\t", s, "\n"
+
+ obase=10
+ cd=gcd(hz,1000000)
+ print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "\n"
+ print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "\n"
+ print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "\n"
+ print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "\n"
+
+ cd=gcd(hz,1000000000)
+ print "#define HZ_TO_NSEC_NUM\t\t", 1000000000/cd, "\n"
+ print "#define HZ_TO_NSEC_DEN\t\t", hz/cd, "\n"
+ print "#define NSEC_TO_HZ_NUM\t\t", hz/cd, "\n"
+ print "#define NSEC_TO_HZ_DEN\t\t", 1000000000/cd, "\n"
+ print "\n"
+
+ print "#endif /* KERNEL_TIMECONST_H */\n"
+ }
+ halt
+}
+
+hz = read();
+timeconst(hz)