Mercurial > hg > aboriginal
annotate sources/patches/linux-noperl-timeconst.patch @ 1817:92d542aa6ceb draft
Teach system-image.sh to handle its own dependencies, rebuilding kernel and
repackaging cpio/squashfs as appropraite, and _not_ doing so when unneeded.
| author | Rob Landley <rob@landley.net> |
|---|---|
| date | Sun, 22 Nov 2015 14:54:16 -0600 |
| parents | db11c049b66b |
| children |
| rev | line source |
|---|---|
| 1598 | 1 Replace timeconst.bc with the c version I've been using for years (to replace |
| 2 the perl version). Eventually I should add bc to toybox, but for now... | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
3 |
| 1698 | 4 --- linux/kernel/time/timeconst.bc 2013-04-28 19:36:01.000000000 -0500 |
| 1598 | 5 +++ /dev/null 2013-02-23 10:58:11.743993346 -0600 |
| 1813 | 6 @@ -1,109 +0,0 @@ |
| 1598 | 7 -scale=0 |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
8 - |
| 1598 | 9 -define gcd(a,b) { |
| 10 - auto t; | |
| 11 - while (b) { | |
| 12 - t = b; | |
| 13 - b = a % b; | |
| 14 - a = t; | |
| 15 - } | |
| 16 - return a; | |
| 17 -} | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
18 - |
| 1598 | 19 -/* Division by reciprocal multiplication. */ |
| 20 -define fmul(b,n,d) { | |
| 21 - return (2^b*n+d-1)/d; | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
22 -} |
|
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
23 - |
| 1598 | 24 -/* Adjustment factor when a ceiling value is used. Use as: |
| 25 - (imul * n) + (fmulxx * n + fadjxx) >> xx) */ | |
| 26 -define fadj(b,n,d) { | |
| 27 - auto v; | |
| 28 - d = d/gcd(n,d); | |
| 29 - v = 2^b*(d-1)/d; | |
| 30 - return v; | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
31 -} |
|
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
32 - |
| 1598 | 33 -/* Compute the appropriate mul/adj values as well as a shift count, |
| 34 - which brings the mul value into the range 2^b-1 <= x < 2^b. Such | |
| 35 - a shift value will be correct in the signed integer range and off | |
| 36 - by at most one in the upper half of the unsigned range. */ | |
| 37 -define fmuls(b,n,d) { | |
| 38 - auto s, m; | |
| 39 - for (s = 0; 1; s++) { | |
| 40 - m = fmul(s,n,d); | |
| 41 - if (m >= 2^(b-1)) | |
| 42 - return s; | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
43 - } |
|
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
44 - return 0; |
|
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
45 -} |
|
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
46 - |
| 1598 | 47 -define timeconst(hz) { |
| 48 - print "/* Automatically generated by kernel/timeconst.bc */\n" | |
| 49 - print "/* Time conversion constants for HZ == ", hz, " */\n" | |
| 50 - print "\n" | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
51 - |
| 1598 | 52 - print "#ifndef KERNEL_TIMECONST_H\n" |
| 53 - print "#define KERNEL_TIMECONST_H\n\n" | |
| 54 - | |
| 55 - print "#include <linux/param.h>\n" | |
| 56 - print "#include <linux/types.h>\n\n" | |
| 57 - | |
| 58 - print "#if HZ != ", hz, "\n" | |
| 1813 | 59 - print "#error \qinclude/generated/timeconst.h has the wrong HZ value!\q\n" |
| 1598 | 60 - print "#endif\n\n" |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
61 - |
| 1598 | 62 - if (hz < 2) { |
| 63 - print "#error Totally bogus HZ value!\n" | |
| 64 - } else { | |
| 65 - s=fmuls(32,1000,hz) | |
| 66 - obase=16 | |
| 67 - print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), ")\n" | |
| 68 - print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), ")\n" | |
| 69 - obase=10 | |
| 70 - print "#define HZ_TO_MSEC_SHR32\t", s, "\n" | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
71 - |
| 1598 | 72 - s=fmuls(32,hz,1000) |
| 73 - obase=16 | |
| 74 - print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), ")\n" | |
| 75 - print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), ")\n" | |
| 76 - obase=10 | |
| 77 - print "#define MSEC_TO_HZ_SHR32\t", s, "\n" | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
78 - |
| 1598 | 79 - obase=10 |
| 80 - cd=gcd(hz,1000) | |
| 81 - print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "\n" | |
| 82 - print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "\n" | |
| 83 - print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "\n" | |
| 84 - print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "\n" | |
| 85 - print "\n" | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
86 - |
| 1598 | 87 - s=fmuls(32,1000000,hz) |
| 88 - obase=16 | |
| 89 - print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), ")\n" | |
| 90 - print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), ")\n" | |
| 91 - obase=10 | |
| 92 - print "#define HZ_TO_USEC_SHR32\t", s, "\n" | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
93 - |
| 1598 | 94 - s=fmuls(32,hz,1000000) |
| 95 - obase=16 | |
| 96 - print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), ")\n" | |
| 97 - print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), ")\n" | |
| 98 - obase=10 | |
| 99 - print "#define USEC_TO_HZ_SHR32\t", s, "\n" | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
100 - |
| 1598 | 101 - obase=10 |
| 102 - cd=gcd(hz,1000000) | |
| 103 - print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "\n" | |
| 104 - print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "\n" | |
| 105 - print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "\n" | |
| 106 - print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "\n" | |
| 107 - print "\n" | |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
108 - |
| 1598 | 109 - print "#endif /* KERNEL_TIMECONST_H */\n" |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
110 - } |
| 1598 | 111 - halt |
|
1337
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
112 -} |
|
1bc0c01950ca
Switch to the noperl patches for 2.6.38.
Rob Landley <rob@landley.net>
parents:
diff
changeset
|
113 - |
| 1813 | 114 -hz = read(); |
| 1598 | 115 -timeconst(hz) |
| 1813 | 116 diff --git a/Kbuild b/Kbuild |
| 117 index f55cefd..e412515 100644 | |
| 118 --- a/Kbuild | |
| 119 +++ b/Kbuild | |
| 120 @@ -53,16 +53,18 @@ $(obj)/$(bounds-file): kernel/bounds.s FORCE | |
| 121 timeconst-file := include/generated/timeconst.h | |
| 122 | |
| 123 targets += $(timeconst-file) | |
| 124 +hostprogs-y += mktimeconst | |
| 125 +mktimeconst-objs = kernel/time/mktimeconst.o | |
| 1598 | 126 |
| 1813 | 127 quiet_cmd_gentimeconst = GEN $@ |
| 128 define cmd_gentimeconst | |
| 129 - (echo $(CONFIG_HZ) | bc -q $< ) > $@ | |
| 130 + $(obj)/mktimeconst $(CONFIG_HZ) $@ | |
| 131 endef | |
| 132 define filechk_gentimeconst | |
| 133 - (echo $(CONFIG_HZ) | bc -q $< ) | |
| 134 + $(obj)/mktimeconst $(CONFIG_HZ) - | |
| 135 endef | |
| 136 | |
| 137 -$(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE | |
| 138 +$(obj)/$(timeconst-file): $(obj)/mktimeconst FORCE | |
| 139 $(call filechk,gentimeconst) | |
| 1598 | 140 |
| 1813 | 141 ##### |
| 142 --- /dev/null | |
| 143 +++ b/kernel/time/mktimeconst.c | |
| 144 @@ -0,0 +1,110 @@ | |
| 145 + /* Copyright 2010-2013 Rob Landley <rob@landley.net> */ | |
| 146 + | |
| 147 + #include <inttypes.h> | |
| 148 + #include <stdio.h> | |
| 149 + #include <stdlib.h> | |
| 150 + #include <string.h> | |
| 151 + | |
| 152 + int main(int argc, char *argv[]) | |
| 153 + { | |
| 154 + uint64_t hz, periods[] = {1000, 1000000}; | |
| 155 + char *names[] = {"MSEC", "USEC"}; | |
| 156 + FILE *file; | |
| 157 + int i, j; | |
| 158 + | |
| 159 + if (argc != 3 || (hz = atol(argv[1])) < 1 | |
| 160 + || !(file = !strcmp(argv[2], "-") ? stdout : fopen(argv[2], "w"))) | |
| 161 + { | |
| 162 + fprintf(stderr, "Usage: mktimeconst HZ FILENAME\n\n"); | |
| 163 + fprintf(stderr, "Generate a header file with constants to convert between\n"); | |
| 164 + fprintf(stderr, "decimal HZ timer ticks and milisecond or microsecond delays,\n"); | |
| 165 + fprintf(stderr, "using reciprocal multiplication to avoid 64 bit division.\n"); | |
| 166 + exit(1); | |
| 167 + } | |
| 168 + | |
| 169 + fprintf(file, | |
| 170 + "/* Automatically generated by kernel/mktimeconst */\n" | |
| 171 + "/* Conversion constants for HZ == %"PRIu64" */\n\n" | |
| 172 + "#ifndef __KERNEL_TIMECONST_H\n" | |
| 173 + "#define __KERNEL_TIMECONST_H\n\n" | |
| 174 + "#include <linux/param.h>\n" | |
| 175 + "#include <linux/types.h>\n\n" | |
| 176 + "#if HZ != %"PRIu64"\n" | |
| 177 + "#error \"include/generated/timeconst.h has the wrong HZ value!\"\n" | |
| 178 + "#endif\n\n", hz, hz); | |
| 179 + | |
| 180 + /* Repeat for MSEC and USEC */ | |
| 181 + | |
| 182 + for (i = 0; i < 2; i++) { | |
| 183 + uint64_t gcd, period; | |
| 184 + | |
| 185 + /* Find greatest common denominator using Euclid's algorithm. */ | |
| 186 + | |
| 187 + gcd = hz; | |
| 188 + period = periods[i]; | |
| 189 + while (period) { | |
| 190 + uint64_t temp = gcd % period; | |
| 191 + gcd = period; | |
| 192 + period = temp; | |
| 193 + } | |
| 194 + | |
| 195 + /* Output both directions (HZ_TO_PERIOD and PERIOD_TO_HZ) */ | |
| 196 + | |
| 197 + for (j = 0; j < 2; j++) { | |
| 198 + char name[16]; | |
| 199 + uint64_t from = j ? periods[i] : hz; | |
| 200 + uint64_t to = j ? hz : periods[i]; | |
| 201 + uint64_t mul32 = 0, adj32 = 0, shift = 0; | |
| 202 + | |
| 203 + sprintf(name, j ? "%s_TO_HZ" : "HZ_TO_%s", names[i]); | |
| 204 + | |
| 205 + /* Figure out what shift value gives 32 significant | |
| 206 + bits of MUL32 data. (Worst case to=1 from=1000000 | |
| 207 + uses 52 bits, to<<shift won't overflow 64 bit math.) | |
| 208 + */ | |
| 209 + | |
| 210 + for (;;) { | |
| 211 + mul32 = ((to << shift) + from - 1) / from; | |
| 212 + if (mul32 >= (1UL<<31)) | |
| 213 + break; | |
| 214 + shift++; | |
| 215 + } | |
| 216 + | |
| 217 + /* ADJ32 is is just (((FROM/GCD)-1)<<SHIFT)/(FROM/GCD) | |
| 218 + but this can overflow 64 bit math (examples, HZ=24 | |
| 219 + or HZ=122). Worst case scenario uses 32+20+20=72 | |
| 220 + bits. Workaround: split off bottom 32 bits and | |
| 221 + reassemble after calculation (32+64=96 bits). */ | |
| 222 + | |
| 223 + adj32 = from / gcd; | |
| 224 + | |
| 225 + if (shift > 32) { | |
| 226 + uint64_t upper, lower; | |
| 227 + | |
| 228 + upper = (adj32 - 1) << (shift - 32); | |
| 229 + lower = (upper % adj32) << 32; | |
| 230 + adj32 = ((upper/adj32) << 32) + (lower/adj32); | |
| 231 + } else | |
| 232 + adj32 = ((adj32 - 1) << shift) / adj32; | |
| 233 + | |
| 234 + /* Emit the constants into the header file. */ | |
| 235 + | |
| 236 + fprintf(file, "#define %s_MUL32\tU64_C(0x%"PRIx64")\n", | |
| 237 + name, mul32); | |
| 238 + fprintf(file, "#define %s_ADJ32\tU64_C(0x%"PRIx64")\n", | |
| 239 + name, adj32); | |
| 240 + fprintf(file, "#define %s_SHR32\t%"PRIu64"\n", | |
| 241 + name, shift); | |
| 242 + fprintf(file, "#define %s_NUM\t\tU64_C(%"PRIu64")\n", | |
| 243 + name, to/gcd); | |
| 244 + fprintf(file, "#define %s_DEN\t\tU64_C(%"PRIu64")\n\n", | |
| 245 + name, from/gcd); | |
| 246 + } | |
| 247 + } | |
| 248 + fprintf(file, "#endif /* __KERNEL_TIMECONST_H */\n"); | |
| 249 + | |
| 250 + /* Notice if the disk fills up. */ | |
| 251 + | |
| 252 + fflush(file); | |
| 253 + return ferror(file); | |
| 254 + } |