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author | Thomas Gleixner <tglx@linutronix.de> | 2014-06-22 10:06:40 (GMT) |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2014-06-23 09:22:35 (GMT) |
commit | 5cee964597260237dd2cabb3ec22bba0da24b25d (patch) | |
tree | f548efb4181a4cffb026adf43178e65330533e87 /kernel/time/timeconst.bc | |
parent | 58394271c610e9c65dd0165a1c1f6dec75dc5f3e (diff) | |
download | linux-5cee964597260237dd2cabb3ec22bba0da24b25d.tar.xz |
time/timers: Move all time(r) related files into kernel/time
Except for Kconfig.HZ. That needs a separate treatment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time/timeconst.bc')
-rw-r--r-- | kernel/time/timeconst.bc | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/kernel/time/timeconst.bc b/kernel/time/timeconst.bc new file mode 100644 index 0000000..511bdf2 --- /dev/null +++ b/kernel/time/timeconst.bc @@ -0,0 +1,108 @@ +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/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 \qkernel/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" + print "\n" + + print "#endif /* KERNEL_TIMECONST_H */\n" + } + halt +} + +timeconst(hz) |