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 \n" print "#include \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" print "\n" print "#endif /* KERNEL_TIMECONST_H */\n" } halt } hz = read(); timeconst(hz) ange'>range
path: root/kernel/time/tick-internal.h
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 10:56:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 10:56:56 -0800
commit2c5d9555d6d937966d79d4c6529a5f7b9206e405 (patch)
tree4f3d220ea3aeaadcae0796c5456e0ef9a908071d /kernel/time/tick-internal.h
parent53cd1ad1a68fd10f677445e04ed63aa9ce39b36b (diff)
parent2ad5d52d42810bed95100a3d912679d8864421ec (diff)
Merge branch 'parisc-4.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull two parisc fixes from Helge Deller: "One fix to avoid usage of BITS_PER_LONG in user-space exported swab.h header which breaks compiling qemu, and one trivial fix for printk continuation in the parisc parport driver" * 'parisc-4.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Don't use BITS_PER_LONG in userspace-exported swab.h header parisc, parport_gsc: Fixes for printk continuation lines
Diffstat (limited to 'kernel/time/tick-internal.h')