mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-10-31 16:54:21 +00:00
c98aa86df3
The USEC_TO_HZ and HZ_TO_USEC constant sets were mislabelled, with seriously incorrect results. This among other things manifested itself as cpufreq not working when a tickless kernel was configured. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Tested-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
402 lines
9.4 KiB
Perl
402 lines
9.4 KiB
Perl
#!/usr/bin/perl
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# -----------------------------------------------------------------------
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#
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# Copyright 2007 rPath, Inc. - All Rights Reserved
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#
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# This file is part of the Linux kernel, and is made available under
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# the terms of the GNU General Public License version 2 or (at your
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# option) any later version; incorporated herein by reference.
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#
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# -----------------------------------------------------------------------
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#
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#
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# Usage: timeconst.pl HZ > timeconst.h
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#
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# Precomputed values for systems without Math::BigInt
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# Generated by:
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# timeconst.pl --can 24 32 48 64 100 122 128 200 250 256 300 512 1000 1024 1200
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%canned_values = (
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24 => [
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'0xa6aaaaab','0x2aaaaaa',26,
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'0xa6aaaaaaaaaaaaab','0x2aaaaaaaaaaaaaa',58,
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125,3,
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'0xc49ba5e4','0x1fbe76c8b4',37,
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'0xc49ba5e353f7ceda','0x1fbe76c8b439581062',69,
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3,125,
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'0xa2c2aaab','0xaaaa',16,
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'0xa2c2aaaaaaaaaaab','0xaaaaaaaaaaaa',48,
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125000,3,
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'0xc9539b89','0x7fffbce4217d',47,
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'0xc9539b8887229e91','0x7fffbce4217d2849cb25',79,
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3,125000,
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], 32 => [
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'0xfa000000','0x6000000',27,
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'0xfa00000000000000','0x600000000000000',59,
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125,4,
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'0x83126e98','0xfdf3b645a',36,
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'0x83126e978d4fdf3c','0xfdf3b645a1cac0831',68,
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4,125,
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'0xf4240000','0x0',17,
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'0xf424000000000000','0x0',49,
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31250,1,
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'0x8637bd06','0x3fff79c842fa',46,
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'0x8637bd05af6c69b6','0x3fff79c842fa5093964a',78,
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1,31250,
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], 48 => [
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'0xa6aaaaab','0x6aaaaaa',27,
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'0xa6aaaaaaaaaaaaab','0x6aaaaaaaaaaaaaa',59,
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125,6,
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'0xc49ba5e4','0xfdf3b645a',36,
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'0xc49ba5e353f7ceda','0xfdf3b645a1cac0831',68,
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6,125,
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'0xa2c2aaab','0x15555',17,
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'0xa2c2aaaaaaaaaaab','0x1555555555555',49,
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62500,3,
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'0xc9539b89','0x3fffbce4217d',46,
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'0xc9539b8887229e91','0x3fffbce4217d2849cb25',78,
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3,62500,
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], 64 => [
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'0xfa000000','0xe000000',28,
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'0xfa00000000000000','0xe00000000000000',60,
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125,8,
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'0x83126e98','0x7ef9db22d',35,
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'0x83126e978d4fdf3c','0x7ef9db22d0e560418',67,
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8,125,
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'0xf4240000','0x0',18,
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'0xf424000000000000','0x0',50,
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15625,1,
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'0x8637bd06','0x1fff79c842fa',45,
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'0x8637bd05af6c69b6','0x1fff79c842fa5093964a',77,
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1,15625,
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], 100 => [
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'0xa0000000','0x0',28,
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'0xa000000000000000','0x0',60,
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10,1,
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'0xcccccccd','0x733333333',35,
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'0xcccccccccccccccd','0x73333333333333333',67,
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1,10,
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'0x9c400000','0x0',18,
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'0x9c40000000000000','0x0',50,
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10000,1,
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'0xd1b71759','0x1fff2e48e8a7',45,
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'0xd1b71758e219652c','0x1fff2e48e8a71de69ad4',77,
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1,10000,
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], 122 => [
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'0x8325c53f','0xfbcda3a',28,
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'0x8325c53ef368eb05','0xfbcda3ac10c9714',60,
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500,61,
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'0xf9db22d1','0x7fbe76c8b',35,
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'0xf9db22d0e560418a','0x7fbe76c8b43958106',67,
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61,500,
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'0x8012e2a0','0x3ef36',18,
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'0x8012e29f79b47583','0x3ef368eb04325',50,
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500000,61,
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'0xffda4053','0x1ffffbce4217',45,
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'0xffda4052d666a983','0x1ffffbce4217d2849cb2',77,
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61,500000,
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], 128 => [
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'0xfa000000','0x1e000000',29,
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'0xfa00000000000000','0x1e00000000000000',61,
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125,16,
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'0x83126e98','0x3f7ced916',34,
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'0x83126e978d4fdf3c','0x3f7ced916872b020c',66,
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16,125,
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'0xf4240000','0x40000',19,
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'0xf424000000000000','0x4000000000000',51,
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15625,2,
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'0x8637bd06','0xfffbce4217d',44,
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'0x8637bd05af6c69b6','0xfffbce4217d2849cb25',76,
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2,15625,
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], 200 => [
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'0xa0000000','0x0',29,
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'0xa000000000000000','0x0',61,
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5,1,
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'0xcccccccd','0x333333333',34,
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'0xcccccccccccccccd','0x33333333333333333',66,
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1,5,
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'0x9c400000','0x0',19,
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'0x9c40000000000000','0x0',51,
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5000,1,
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'0xd1b71759','0xfff2e48e8a7',44,
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'0xd1b71758e219652c','0xfff2e48e8a71de69ad4',76,
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1,5000,
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], 250 => [
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'0x80000000','0x0',29,
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'0x8000000000000000','0x0',61,
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4,1,
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'0x80000000','0x180000000',33,
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'0x8000000000000000','0x18000000000000000',65,
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1,4,
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'0xfa000000','0x0',20,
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'0xfa00000000000000','0x0',52,
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4000,1,
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'0x83126e98','0x7ff7ced9168',43,
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'0x83126e978d4fdf3c','0x7ff7ced916872b020c4',75,
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1,4000,
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], 256 => [
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'0xfa000000','0x3e000000',30,
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'0xfa00000000000000','0x3e00000000000000',62,
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125,32,
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'0x83126e98','0x1fbe76c8b',33,
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'0x83126e978d4fdf3c','0x1fbe76c8b43958106',65,
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32,125,
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'0xf4240000','0xc0000',20,
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'0xf424000000000000','0xc000000000000',52,
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15625,4,
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'0x8637bd06','0x7ffde7210be',43,
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'0x8637bd05af6c69b6','0x7ffde7210be9424e592',75,
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4,15625,
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], 300 => [
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'0xd5555556','0x2aaaaaaa',30,
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'0xd555555555555556','0x2aaaaaaaaaaaaaaa',62,
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10,3,
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'0x9999999a','0x1cccccccc',33,
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'0x999999999999999a','0x1cccccccccccccccc',65,
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3,10,
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'0xd0555556','0xaaaaa',20,
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'0xd055555555555556','0xaaaaaaaaaaaaa',52,
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10000,3,
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'0x9d495183','0x7ffcb923a29',43,
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'0x9d495182a9930be1','0x7ffcb923a29c779a6b5',75,
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3,10000,
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], 512 => [
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'0xfa000000','0x7e000000',31,
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'0xfa00000000000000','0x7e00000000000000',63,
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125,64,
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'0x83126e98','0xfdf3b645',32,
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'0x83126e978d4fdf3c','0xfdf3b645a1cac083',64,
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64,125,
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'0xf4240000','0x1c0000',21,
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'0xf424000000000000','0x1c000000000000',53,
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15625,8,
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'0x8637bd06','0x3ffef39085f',42,
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'0x8637bd05af6c69b6','0x3ffef39085f4a1272c9',74,
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8,15625,
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], 1000 => [
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'0x80000000','0x0',31,
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'0x8000000000000000','0x0',63,
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1,1,
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'0x80000000','0x0',31,
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'0x8000000000000000','0x0',63,
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1,1,
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'0xfa000000','0x0',22,
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'0xfa00000000000000','0x0',54,
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1000,1,
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'0x83126e98','0x1ff7ced9168',41,
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'0x83126e978d4fdf3c','0x1ff7ced916872b020c4',73,
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1,1000,
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], 1024 => [
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'0xfa000000','0xfe000000',32,
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'0xfa00000000000000','0xfe00000000000000',64,
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125,128,
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'0x83126e98','0x7ef9db22',31,
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'0x83126e978d4fdf3c','0x7ef9db22d0e56041',63,
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128,125,
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'0xf4240000','0x3c0000',22,
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'0xf424000000000000','0x3c000000000000',54,
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15625,16,
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'0x8637bd06','0x1fff79c842f',41,
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'0x8637bd05af6c69b6','0x1fff79c842fa5093964',73,
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16,15625,
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], 1200 => [
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'0xd5555556','0xd5555555',32,
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'0xd555555555555556','0xd555555555555555',64,
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5,6,
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'0x9999999a','0x66666666',31,
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'0x999999999999999a','0x6666666666666666',63,
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6,5,
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'0xd0555556','0x2aaaaa',22,
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'0xd055555555555556','0x2aaaaaaaaaaaaa',54,
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2500,3,
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'0x9d495183','0x1ffcb923a29',41,
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'0x9d495182a9930be1','0x1ffcb923a29c779a6b5',73,
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3,2500,
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]
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);
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$has_bigint = eval 'use Math::BigInt qw(bgcd); 1;';
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sub bint($)
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{
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my($x) = @_;
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return Math::BigInt->new($x);
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}
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#
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# Constants for division by reciprocal multiplication.
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# (bits, numerator, denominator)
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#
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sub fmul($$$)
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{
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my ($b,$n,$d) = @_;
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$n = bint($n);
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$d = bint($d);
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return scalar (($n << $b)+$d-bint(1))/$d;
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}
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sub fadj($$$)
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{
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my($b,$n,$d) = @_;
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$n = bint($n);
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$d = bint($d);
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$d = $d/bgcd($n, $d);
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return scalar (($d-bint(1)) << $b)/$d;
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}
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sub fmuls($$$) {
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my($b,$n,$d) = @_;
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my($s,$m);
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my($thres) = bint(1) << ($b-1);
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$n = bint($n);
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$d = bint($d);
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for ($s = 0; 1; $s++) {
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$m = fmul($s,$n,$d);
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return $s if ($m >= $thres);
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}
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return 0;
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}
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# Provides mul, adj, and shr factors for a specific
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# (bit, time, hz) combination
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sub muladj($$$) {
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my($b, $t, $hz) = @_;
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my $s = fmuls($b, $t, $hz);
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my $m = fmul($s, $t, $hz);
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my $a = fadj($s, $t, $hz);
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return ($m->as_hex(), $a->as_hex(), $s);
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}
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# Provides numerator, denominator values
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sub numden($$) {
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my($n, $d) = @_;
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my $g = bgcd($n, $d);
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return ($n/$g, $d/$g);
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}
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# All values for a specific (time, hz) combo
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sub conversions($$) {
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my ($t, $hz) = @_;
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my @val = ();
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# HZ_TO_xx
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push(@val, muladj(32, $t, $hz));
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push(@val, muladj(64, $t, $hz));
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push(@val, numden($t, $hz));
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# xx_TO_HZ
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push(@val, muladj(32, $hz, $t));
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push(@val, muladj(64, $hz, $t));
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push(@val, numden($hz, $t));
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return @val;
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}
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sub compute_values($) {
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my($hz) = @_;
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my @val = ();
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my $s, $m, $a, $g;
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if (!$has_bigint) {
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die "$0: HZ == $hz not canned and ".
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"Math::BigInt not available\n";
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}
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# MSEC conversions
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push(@val, conversions(1000, $hz));
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# USEC conversions
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push(@val, conversions(1000000, $hz));
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return @val;
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}
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sub output($@)
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{
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my($hz, @val) = @_;
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my $pfx, $bit, $suf, $s, $m, $a;
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print "/* Automatically generated by kernel/timeconst.pl */\n";
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print "/* Conversion constants for HZ == $hz */\n";
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print "\n";
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print "#ifndef KERNEL_TIMECONST_H\n";
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print "#define KERNEL_TIMECONST_H\n";
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print "\n";
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print "#include <linux/param.h>\n";
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print "\n";
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print "#if HZ != $hz\n";
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print "#error \"kernel/timeconst.h has the wrong HZ value!\"\n";
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print "#endif\n";
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print "\n";
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foreach $pfx ('HZ_TO_MSEC','MSEC_TO_HZ',
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'HZ_TO_USEC','USEC_TO_HZ') {
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foreach $bit (32, 64) {
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foreach $suf ('MUL', 'ADJ', 'SHR') {
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printf "#define %-23s %s\n",
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"${pfx}_$suf$bit", shift(@val);
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}
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}
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foreach $suf ('NUM', 'DEN') {
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printf "#define %-23s %s\n",
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"${pfx}_$suf", shift(@val);
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}
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}
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print "\n";
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print "#endif /* KERNEL_TIMECONST_H */\n";
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}
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($hz) = @ARGV;
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# Use this to generate the %canned_values structure
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if ($hz eq '--can') {
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shift(@ARGV);
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@hzlist = sort {$a <=> $b} (@ARGV);
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print "# Precomputed values for systems without Math::BigInt\n";
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print "# Generated by:\n";
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print "# timeconst.pl --can ", join(' ', @hzlist), "\n";
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print "\%canned_values = (\n";
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my $pf = "\t";
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foreach $hz (@hzlist) {
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my @values = compute_values($hz);
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print "$pf$hz => [\n";
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while (scalar(@values)) {
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my $bit;
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foreach $bit (32, 64) {
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my $m = shift(@values);
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my $a = shift(@values);
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my $s = shift(@values);
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print "\t\t\'",$m,"\',\'",$a,"\',",$s,",\n";
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}
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my $n = shift(@values);
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my $d = shift(@values);
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print "\t\t",$n,',',$d,",\n";
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}
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print "\t]";
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$pf = ', ';
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}
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print "\n);\n";
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} else {
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$hz += 0; # Force to number
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if ($hz < 1) {
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die "Usage: $0 HZ\n";
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}
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@val = @{$canned_values{$hz}};
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if (!defined(@val)) {
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@val = compute_values($hz);
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}
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output($hz, @val);
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}
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exit 0;
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