--- /dev/null
+Replace timeconst.bc with the c version I've been using for years (to replace
+the perl version). Eventually I should add bc to toybox, but for now...
+
+--- /dev/null
++++ linux/kernel/time/mktimeconst.c
+@@ -0,0 +1,110 @@
++/* Copyright 2010 Parallels Inc, licensed under GPLv2 */
++/* Copyright 2010-2013 Rob Landley <rob@landley.net> */
++
++#include <inttypes.h>
++#include <stdio.h>
++#include <stdlib.h>
++
++int main(int argc, char *argv[])
++{
++ uint64_t hz, periods[] = {1000, 1000000};
++ char *names[] = {"MSEC", "USEC"};
++ FILE *file;
++ int i, j;
++
++ if (argc != 3 || (hz = atol(argv[1])) < 1
++ || !(file = fopen(argv[2], "w")))
++ {
++ fprintf(stderr, "Usage: mktimeconst HZ FILENAME\n\n");
++ fprintf(stderr, "Generate a header file with constants to convert between\n");
++ fprintf(stderr, "decimal HZ timer ticks and milisecond or microsecond delays,\n");
++ fprintf(stderr, "using reciprocal multiplication to avoid 64 bit division.\n");
++ exit(1);
++ }
++
++ fprintf(file,
++ "/* Automatically generated by kernel/mktimeconst */\n"
++ "/* Conversion constants for HZ == %"PRIu64" */\n\n"
++ "#ifndef __KERNEL_TIMECONST_H\n"
++ "#define __KERNEL_TIMECONST_H\n\n"
++ "#include <linux/param.h>\n"
++ "#include <linux/types.h>\n\n"
++ "#if HZ != %"PRIu64"\n"
++ "#error \"kernel/timeconst.h has the wrong HZ value!\"\n"
++ "#endif\n\n", hz, hz);
++
++ /* Repeat for MSEC and USEC */
++
++ for (i = 0; i < 2; i++) {
++ uint64_t gcd, period;
++
++ /* Find greatest common denominator using Euclid's algorithm. */
++
++ gcd = hz;
++ period = periods[i];
++ while (period) {
++ uint64_t temp = gcd % period;
++ gcd = period;
++ period = temp;
++ }
++
++ /* Output both directions (HZ_TO_PERIOD and PERIOD_TO_HZ) */
++
++ for (j = 0; j < 2; j++) {
++ char name[16];
++ uint64_t from = j ? periods[i] : hz;
++ uint64_t to = j ? hz : periods[i];
++ uint64_t mul32 = 0, adj32 = 0, shift = 0;
++
++ sprintf(name, j ? "%s_TO_HZ" : "HZ_TO_%s", names[i]);
++
++ /* Figure out what shift value gives 32 significant
++ bits of MUL32 data. (Worst case to=1 from=1000000
++ uses 52 bits, to<<shift won't overflow 64 bit math.)
++ */
++
++ for (;;) {
++ mul32 = ((to << shift) + from - 1) / from;
++ if (mul32 >= (1UL<<31))
++ break;
++ shift++;
++ }
++
++ /* ADJ32 is is just (((FROM/GCD)-1)<<SHIFT)/(FROM/GCD)
++ but this can overflow 64 bit math (examples, HZ=24
++ or HZ=122). Worst case scenario uses 32+20+20=72
++ bits. Workaround: split off bottom 32 bits and
++ reassemble after calculation (32+64=96 bits). */
++
++ adj32 = from / gcd;
++
++ if (shift > 32) {
++ uint64_t upper, lower;
++
++ upper = (adj32 - 1) << (shift - 32);
++ lower = (upper % adj32) << 32;
++ adj32 = ((upper/adj32) << 32) + (lower/adj32);
++ } else
++ adj32 = ((adj32 - 1) << shift) / adj32;
++
++ /* Emit the constants into the header file. */
++
++ fprintf(file, "#define %s_MUL32\tU64_C(0x%"PRIx64")\n",
++ name, mul32);
++ fprintf(file, "#define %s_ADJ32\tU64_C(0x%"PRIx64")\n",
++ name, adj32);
++ fprintf(file, "#define %s_SHR32\t%"PRIu64"\n",
++ name, shift);
++ fprintf(file, "#define %s_NUM\t\tU64_C(%"PRIu64")\n",
++ name, to/gcd);
++ fprintf(file, "#define %s_DEN\t\tU64_C(%"PRIu64")\n\n",
++ name, from/gcd);
++ }
++ }
++ fprintf(file, "#endif /* __KERNEL_TIMECONST_H */\n");
++
++ /* Notice if the disk fills up. */
++
++ fflush(stdout);
++ return ferror(stdout);
++}
+--- linux/kernel/time/timeconst.bc 2013-04-28 19:36:01.000000000 -0500
++++ /dev/null 2013-02-23 10:58:11.743993346 -0600
+@@ -1,108 +0,0 @@
+-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)
+--- linux/kernel/time/Makefile
++++ linux/kernel/time/Makefile
+@@ -125,17 +125,11 @@
+
+ $(obj)/time.o: $(obj)/timeconst.h
+
+-quiet_cmd_hzfile = HZFILE $@
+- cmd_hzfile = echo "hz=$(CONFIG_HZ)" > $@
+-
+-targets += hz.bc
+-$(obj)/hz.bc: $(objtree)/include/config/hz.h FORCE
+- $(call if_changed,hzfile)
+-
+-quiet_cmd_bc = BC $@
+- cmd_bc = bc -q $(filter-out FORCE,$^) > $@
++hostprogs-y += mktimeconst
++quiet_cmd_mktimeconst = TIMEC $@
++ cmd_mktimeconst = $(obj)/mktimeconst $(CONFIG_HZ) $@ || ( rm -f $@ && exit 1 )
+
+ targets += timeconst.h
+-$(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE
+- $(call if_changed,bc)
++$(obj)/timeconst.h: $(obj)/mktimeconst FORCE
++ $(call if_changed,mktimeconst)
+
projects / hvlinux.git / blobdiff