[lfs-patches] r3035 - trunk/linux

igor at higgs.linuxfromscratch.org igor at higgs.linuxfromscratch.org
Fri Oct 10 01:49:15 PDT 2014


Author: igor
Date: Fri Oct 10 01:49:15 2014
New Revision: 3035

Log:
rediff linux nobc_timeconst patch

Added:
   trunk/linux/linux-3.17-nobc_timeconst-1.patch

Added: trunk/linux/linux-3.17-nobc_timeconst-1.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ trunk/linux/linux-3.17-nobc_timeconst-1.patch	Fri Oct 10 01:49:15 2014	(r3035)
@@ -0,0 +1,146 @@
+Submitted By:            Igor Živković
+Date:                    2014-07-26
+Initial Package Version: 3.15.6
+Upstream Status:         Unknown
+Origin:                  sabotage
+Description:             Replaces timeconst.bc with the C version thus removing
+                         dependency on bc.
+
+--- linux-3.17.orig/kernel/time/Makefile
++++ linux-3.17/kernel/time/Makefile
+@@ -17,17 +17,11 @@
+ 
+ $(obj)/time.o: $(obj)/timeconst.h
+ 
+-quiet_cmd_hzfile = HZFILE  $@
+-      cmd_hzfile = echo "hz=$(CONFIG_HZ)" > $@
++hostprogs-y    += mktimeconst
++quiet_cmd_mktimeconst = TIMEC   $@
++	cmd_mktimeconst = $(obj)/mktimeconst $(CONFIG_HZ) $@ || ( rm -f $@ && exit 1 )
+ 
+-targets += hz.bc
+-$(obj)/hz.bc: $(objtree)/include/config/hz.h FORCE
+-	$(call if_changed,hzfile)
+-
+-quiet_cmd_bc  = BC      $@
+-      cmd_bc  = bc -q $(filter-out FORCE,$^) > $@
+-
+ targets += timeconst.h
+-$(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE
+-	$(call if_changed,bc)
++$(obj)/timeconst.h: $(obj)/mktimeconst FORCE
++	$(call if_changed,mktimeconst)
+ 
+--- /dev/null
++++ linux-3.17/kernel/time/mktimeconst.c
+@@ -0,0 +1,110 @@
++/* Copyright 2010 Parallels Inc, licensed under GPLv2 */
++/* Copyright 2010-2013 Rob Landley <rob at 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);
++}


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