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path: root/include/asm-xtensa/param.h
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2008-05-14asm-{alpha,h8300,um,v850,xtensa}/param.h: unbreak HZ for userspaceMike Frysinger
I noticed this because alpha was broken due to the recent commit commit bdc807871d58285737d50dc6163d0feb72cb0dc2 ("avoid overflows in kernel/time.c"). Most arches do something like this in their asm/param.h: #ifdef __KERNEL__ # define HZ CONFIG_HZ #else # define HZ 100 #endif A few arches though (namely alpha/h8300/um/v850/xtensa) either do no set HZ at all for !__KERNEL__, or they set it wrongly. This should bring all arches in line by setting up HZ for userspace. Without this currently perl 5.10 doesn't build on alpha: perl.c: In function 'perl_construct': perl.c:388: error: 'CONFIG_HZ' undeclared (first use in this function) -> http://buildd.debian.org/fetch.cgi?pkg=perl;ver=5.10.0-10;arch=alpha;stamp=1210252894 Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Jeff Dike <jdike@addtoit.com> Cc: Chris Zankel <chris@zankel.net> Cc: maximilian attems <max@stro.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ HZ on alpha is 1024 for historical reasons. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08avoid overflows in kernel/time.cH. Peter Anvin
When the conversion factor between jiffies and milli- or microseconds is not a single multiply or divide, as for the case of HZ == 300, we currently do a multiply followed by a divide. The intervening result, however, is subject to overflows, especially since the fraction is not simplified (for HZ == 300, we multiply by 300 and divide by 1000). This is exposed to the user when passing a large timeout to poll(), for example. This patch replaces the multiply-divide with a reciprocal multiplication on 32-bit platforms. When the input is an unsigned long, there is no portable way to do this on 64-bit platforms there is no portable way to do this since it requires a 128-bit intermediate result (which gcc does support on 64-bit platforms but may generate libgcc calls, e.g. on 64-bit s390), but since the output is a 32-bit integer in the cases affected, just simplify the multiply-divide (*3/10 instead of *300/1000). The reciprocal multiply used can have off-by-one errors in the upper half of the valid output range. This could be avoided at the expense of having to deal with a potential 65-bit intermediate result. Since the intent is to avoid overflow problems and most of the other time conversions are only semiexact, the off-by-one errors were considered an acceptable tradeoff. At Ralf Baechle's suggestion, this version uses a Perl script to compute the necessary constants. We already have dependencies on Perl for kernel compiles. This does, however, require the Perl module Math::BigInt, which is included in the standard Perl distribution starting with version 5.8.0. In order to support older versions of Perl, include a table of canned constants in the script itself, and structure the script so that Math::BigInt isn't required if pulling values from said table. Running the script requires that the HZ value is available from the Makefile. Thus, this patch also adds the Kconfig variable CONFIG_HZ to the architectures which didn't already have it (alpha, cris, frv, h8300, m32r, m68k, m68knommu, sparc, v850, and xtensa.) It does *not* touch the sh or sh64 architectures, since Paul Mundt has dealt with those separately in the sh tree. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Ralf Baechle <ralf@linux-mips.org>, Cc: Sam Ravnborg <sam@ravnborg.org>, Cc: Paul Mundt <lethal@linux-sh.org>, Cc: Richard Henderson <rth@twiddle.net>, Cc: Michael Starvik <starvik@axis.com>, Cc: David Howells <dhowells@redhat.com>, Cc: Yoshinori Sato <ysato@users.sourceforge.jp>, Cc: Hirokazu Takata <takata@linux-m32r.org>, Cc: Geert Uytterhoeven <geert@linux-m68k.org>, Cc: Roman Zippel <zippel@linux-m68k.org>, Cc: William L. Irwin <sparclinux@vger.kernel.org>, Cc: Chris Zankel <chris@zankel.net>, Cc: H. Peter Anvin <hpa@zytor.com>, Cc: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-31[XTENSA] clean-up header filesChris Zankel
The header files in the asm-xtensa directory are not clean and 'make headers_check' fails. This is a first patch to fix most of the header files. It removes unnecessary include statements and adds some that are required for building the kernel. The linker script required some updates or the linking stage would fail. Signed-off-by: Chris Zankel <chris@zankel.net>
2006-12-10[PATCH] xtensa: remove extra header filesChris Zankel
The Xtensa port contained many header files that were never needed. This rather lengthy patch removes all those files. Unfortunately, there were many dependencies that needed to be updated, so this patch touches quite a few source files. Signed-off-by: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6Chris Zankel
The attached patches provides part 6 of an architecture implementation for the Tensilica Xtensa CPU series. Signed-off-by: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>