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* lib: fix stall in __bitmap_parselist()Yury Norov2018-04-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot is catching stalls at __bitmap_parselist() (https://syzkaller.appspot.com/bug?id=ad7e0351fbc90535558514a71cd3edc11681997a). The trigger is unsigned long v = 0; bitmap_parselist("7:,", &v, BITS_PER_LONG); which results in hitting infinite loop at while (a <= b) { off = min(b - a + 1, used_size); bitmap_set(maskp, a, off); a += group_size; } due to used_size == group_size == 0. Link: http://lkml.kernel.org/r/20180404162647.15763-1-ynorov@caviumnetworks.com Fixes: 0a5ce0831d04382a ("lib/bitmap.c: make bitmap_parselist() thread-safe and much faster") Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+6887cbb011c8054e8a3d@syzkaller.appspotmail.com> Cc: Noam Camus <noamca@mellanox.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bitmap: replace bitmap_{from,to}_u32arrayYury Norov2018-02-061-87/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | with bitmap_{from,to}_arr32 over the kernel. Additionally to it: * __check_eq_bitmap() now takes single nbits argument. * __check_eq_u32_array is not used in new test but may be used in future. So I don't remove it here, but annotate as __used. Tested on arm64 and 32-bit BE mips. [arnd@arndb.de: perf: arm_dsu_pmu: convert to bitmap_from_arr32] Link: http://lkml.kernel.org/r/20180201172508.5739-2-ynorov@caviumnetworks.com [ynorov@caviumnetworks.com: fix net/core/ethtool.c] Link: http://lkml.kernel.org/r/20180205071747.4ekxtsbgxkj5b2fz@yury-thinkpad Link: http://lkml.kernel.org/r/20171228150019.27953-2-ynorov@caviumnetworks.com Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: David Decotigny <decot@googlers.com>, Cc: David S. Miller <davem@davemloft.net>, Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bitmap: new bitmap_copy_safe and bitmap_{from,to}_arr32Yury Norov2018-02-061-0/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patchset replaces bitmap_{to,from}_u32array with more simple and standard looking copy-like functions. bitmap_from_u32array() takes 4 arguments (bitmap_to_u32array is similar): - unsigned long *bitmap, which is destination; - unsigned int nbits, the length of destination bitmap, in bits; - const u32 *buf, the source; and - unsigned int nwords, the length of source buffer in ints. In description to the function it is detailed like: * copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining * bits between nword and nbits in @bitmap (if any) are cleared. Having two size arguments looks unneeded and potentially dangerous. It is unneeded because normally user of copy-like function should take care of the size of destination and make it big enough to fit source data. And it is dangerous because function may hide possible error if user doesn't provide big enough bitmap, and data becomes silently dropped. That's why all copy-like functions have 1 argument for size of copying data, and I don't see any reason to make bitmap_from_u32array() different. One exception that comes in mind is strncpy() which also provides size of destination in arguments, but it's strongly argued by the possibility of taking broken strings in source. This is not the case of bitmap_{from,to}_u32array(). There is no many real users of bitmap_{from,to}_u32array(), and they all very clearly provide size of destination matched with the size of source, so additional functionality is not used in fact. Like this: bitmap_from_u32array(to->link_modes.supported, __ETHTOOL_LINK_MODE_MASK_NBITS, link_usettings.link_modes.supported, __ETHTOOL_LINK_MODE_MASK_NU32); Where: #define __ETHTOOL_LINK_MODE_MASK_NU32 \ DIV_ROUND_UP(__ETHTOOL_LINK_MODE_MASK_NBITS, 32) In this patch, bitmap_copy_safe and bitmap_{from,to}_arr32 are introduced. 'Safe' in bitmap_copy_safe() stands for clearing unused bits in bitmap beyond last bit till the end of last word. It is useful for hardening API when bitmap is assumed to be exposed to userspace. bitmap_{from,to}_arr32 functions are replacements for bitmap_{from,to}_u32array. They don't take unneeded nwords argument, and so simpler in implementation and understanding. This patch suggests optimization for 32-bit systems - aliasing bitmap_{from,to}_arr32 to bitmap_copy_safe. Other possible optimization is aliasing 64-bit LE bitmap_{from,to}_arr32 to more generic function(s). But I didn't end up with the function that would be helpful by itself, and can be used to alias 64-bit LE bitmap_{from,to}_arr32, like bitmap_copy_safe() does. So I preferred to leave things as is. The following patch switches kernel to new API and introduces test for it. Discussion is here: https://lkml.org/lkml/2017/11/15/592 [ynorov@caviumnetworks.com: rename bitmap_copy_safe to bitmap_copy_clear_tail] Link: http://lkml.kernel.org/r/20180201172508.5739-3-ynorov@caviumnetworks.com Link: http://lkml.kernel.org/r/20171228150019.27953-1-ynorov@caviumnetworks.com Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: David Decotigny <decot@googlers.com>, Cc: David S. Miller <davem@davemloft.net>, Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* documentation: kernel-api: add more info on bitmap functionsRandy Dunlap2017-10-191-1/+3
| | | | | | | | | | | | | There are some good comments about bitmap operations in lib/bitmap.c and include/linux/bitmap.h, so format them for document generation and pull them into core-api/kernel-api.rst. I converted the "tables" of functions from using tabs to using spaces so that they are more readable in the source file and in the generated output. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* lib/bitmap.c: make bitmap_parselist() thread-safe and much fasterYury Norov2017-09-081-12/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current implementation of bitmap_parselist() uses a static variable to save local state while setting bits in the bitmap. It is obviously wrong if we assume execution in multiprocessor environment. Fortunately, it's possible to rewrite this portion of code to avoid using the static variable. It is also possible to set bits in the mask per-range with bitmap_set(), not per-bit, as it is implemented now, with set_bit(); which is way faster. The important side effect of this change is that setting bits in this function from now is not per-bit atomic and less memory-ordered. This is because set_bit() guarantees the order of memory accesses, while bitmap_set() does not. I think that it is the advantage of the new approach, because the bitmap_parselist() is intended to initialise bit arrays, and user should protect the whole bitmap during initialisation if needed. So protecting individual bits looks expensive and useless. Also, other range-oriented functions in lib/bitmap.c don't worry much about atomicity. With all that, setting 2k bits in map with the pattern like 0-2047:128/256 becomes ~50 times faster after applying the patch in my testing environment (arm64 hosted on qemu). The second patch of the series adds the test for bitmap_parselist(). It's not intended to cover all tricky cases, just to make sure that I didn't screw up during rework. Link: http://lkml.kernel.org/r/20170807225438.16161-1-ynorov@caviumnetworks.com Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Cc: Noam Camus <noamca@mellanox.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bitmap: optimise bitmap_set and bitmap_clear of a single bitMatthew Wilcox2017-07-101-4/+4
| | | | | | | | | | | | | | | We have eight users calling bitmap_clear for a single bit and seventeen calling bitmap_set for a single bit. Rather than fix all of them to call __clear_bit or __set_bit, turn bitmap_clear and bitmap_set into inline functions and make this special case efficient. Link: http://lkml.kernel.org/r/20170628153221.11322-3-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel-api.rst: fix some complex tags at lib/bitmap.cmchehab@s-opensource.com2017-04-021-11/+17
| | | | | | | | | | | | | Fix the following issues: ./lib/bitmap.c:869: WARNING: Definition list ends without a blank line; unexpected unindent. ./lib/bitmap.c:876: WARNING: Inline emphasis start-string without end-string. ./lib/bitmap.c:508: ERROR: Unexpected indentation. And make sure that a table and a footnote will use the right tags. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* lib/bitmap.c: enhance bitmap syntaxNoam Camus2016-10-111-4/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today there are platforms with many CPUs (up to 4K). Trying to boot only part of the CPUs may result in too long string. For example lets take NPS platform that is part of arch/arc. This platform have SMP system with 256 cores each with 16 HW threads (SMT machine) where HW thread appears as CPU to the kernel. In this example there is total of 4K CPUs. When one tries to boot only part of the HW threads from each core the string representing the map may be long... For example if for sake of performance we decided to boot only first half of HW threads of each core the map will look like: 0-7,16-23,32-39,...,4080-4087 This patch introduce new syntax to accommodate with such use case. I added an optional postfix to a range of CPUs which will choose according to given modulo the desired range of reminders i.e.: <cpus range>:sed_size/group_size For example, above map can be described in new syntax like this: 0-4095:8/16 Note that this patch is backward compatible with current syntax. [akpm@linux-foundation.org: rework documentation] Link: http://lkml.kernel.org/r/1473579629-4283-1-git-send-email-noamca@mellanox.com Signed-off-by: Noam Camus <noamca@mellanox.com> Cc: David Decotigny <decot@googlers.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: David S. Miller <davem@davemloft.net> Cc: Pan Xinhui <xinhui@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/uaccess: Move thread_info::addr_limit to thread_structAndy Lutomirski2016-07-151-1/+1
| | | | | | | | | | | | | | | | | | | struct thread_info is a legacy mess. To prepare for its partial removal, move thread_info::addr_limit out. As an added benefit, this way is simpler. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/15bee834d09402b47ac86f2feccdf6529f9bc5b0.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* lib/bitmap.c: conversion routines to/from u32 arrayDavid Decotigny2016-02-191-0/+89
| | | | | | | | | | | | | Aimed at transferring bitmaps to/from user-space in a 32/64-bit agnostic way. Tested: unit tests (next patch) on qemu i386, x86_64, ppc, ppc64 BE and LE, ARM. Signed-off-by: David Decotigny <decot@googlers.com> Reviewed-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* lib/bitmap.c: bitmap_parselist can accept string with whitespaces on head or ↵Pan Xinhui2015-09-101-14/+18
| | | | | | | | | | | | | | | | | | | | tail In __bitmap_parselist we can accept whitespaces on head or tail during every parsing procedure. If input has valid ranges, there is no reason to reject the user. For example, bitmap_parselist(" 1-3, 5, ", &mask, nmaskbits). After separating the string, we get " 1-3", " 5", and " ". It's possible and reasonable to accept such string as long as the parsing result is correct. Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com> Cc: Yury Norov <yury.norov@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: fix a special string handling bug in __bitmap_parselistPan Xinhui2015-09-101-0/+4
| | | | | | | | | | | | | | If string end with '-', for exapmle, bitmap_parselist("1,0-",&mask, nmaskbits), It is not in a valid pattern, so add a check after loop. Return -EINVAL on such condition. Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com> Cc: Yury Norov <yury.norov@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: correct a code style and do some, optimizationPan Xinhui2015-09-101-3/+4
| | | | | | | | | | | | | | We can avoid in-loop incrementation of ndigits. Save current totaldigits to ndigits before loop, and check ndigits against totaldigits after the loop. Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com> Cc: Yury Norov <yury.norov@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bitmap: remove explicit newline handling using scnprintf format stringSudeep Holla2015-06-251-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | bitmap_print_to_pagebuf uses scnprintf to copy the cpumask/list to page buffer. It handles the newline and trailing null character explicitly. It's unnecessary and also partially duplicated as scnprintf already adds trailing null character. The newline can be passed through format string to scnprintf. This patch does that simplification. However theoretically there's one behavior difference: when the buffer is too small, the original code would still output '\n' at the end while the new code(with this patch) would just continue to print the formatted string. Since this function is dealing with only page buffers, it's highly unlikely to hit that corner case. This patch will help in auditing the users of bitmap_print_to_pagebuf to verify that the buffer passed is large enough and get rid of it completely by replacing them with direct scnprintf() [akpm@linux-foundation.org: tweak comment] Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Suggested-by: Pawel Moll <Pawel.Moll@arm.com> Cc: Tejun Heo <tj@kernel.org> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* __bitmap_parselist: fix bug in empty string handlingChris Metcalf2015-06-251-8/+9
| | | | | | | | | | | | | | | | | bitmap_parselist("", &mask, nmaskbits) will erroneously set bit zero in the mask. The same bug is visible in cpumask_parselist() since it is layered on top of the bitmask code, e.g. if you boot with "isolcpus=", you will actually end up with cpu zero isolated. The bug was introduced in commit 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to /proc/irq") when bitmap_parselist() was generalized to support userspace as well as kernelspace. Fixes: 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to /proc/irq") Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: bitmap_[empty,full]: remove code duplicationYury Norov2015-04-171-30/+0
| | | | | | | | | | | | | | | bitmap_empty() has its own implementation. But it's clearly as simple as: find_first_bit(src, nbits) == nbits The same is true for 'bitmap_full'. Signed-off-by: Yury Norov <yury.norov@gmail.com> Cc: George Spelvin <linux@horizon.com> Cc: Alexey Klimov <klimov.linux@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bitmap, cpumask, nodemask: remove dedicated formatting functionsTejun Heo2015-02-131-41/+0
| | | | | | | | | | | | | | | | | Now that all bitmap formatting usages have been converted to '%*pb[l]', the separate formatting functions are unnecessary. The following functions are removed. * bitmap_scn[list]printf() * cpumask_scnprintf(), cpulist_scnprintf() * [__]nodemask_scnprintf(), [__]nodelist_scnprintf() * seq_bitmap[_list](), seq_cpumask[_list](), seq_nodemask[_list]() * seq_buf_bitmask() Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bitmap: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo2015-02-131-2/+2
| | | | | | | | | | | printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/vsprintf: implement bitmap printing through '%*pb[l]'Tejun Heo2015-02-131-59/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bitmap and its derivatives such as cpumask and nodemask currently only provide formatting functions which put the output string into the provided buffer; however, how long this buffer should be isn't defined anywhere and given that some of these bitmaps can be too large to be formatted into an on-stack buffer it users sometimes are unnecessarily forced to come up with creative solutions and compromises for the buffer just to printk these bitmaps. There have been a couple different attempts at making this easier. 1. Way back, PeterZ tried printk '%pb' extension with the precision for bit width - '%.*pb'. This was intuitive and made sense but unfortunately triggered a compile warning about using precision for a pointer. http://lkml.kernel.org/g/1336577562.2527.58.camel@twins 2. I implemented bitmap_pr_cont[_list]() and its wrappers for cpumask and nodemask. This works but PeterZ pointed out that pr_cont's tendency to produce broken lines when multiple CPUs are printing is bothering considering the usages. http://lkml.kernel.org/g/1418226774-30215-3-git-send-email-tj@kernel.org So, this patch is another attempt at teaching printk and friends how to print bitmaps. It's almost identical to what PeterZ tried with precision but it uses the field width for the number of bits instead of precision. The format used is '%*pb[l]', with the optional trailing 'l' specifying list format instead of hex masks. This is a valid format string and doesn't trigger compiler warnings; however, it does make it impossible to specify output field width when printing bitmaps. I think this is an acceptable trade-off given how much easier it makes printing bitmaps and that we don't have any in-kernel user which is using the field width specification. If any future user wants to use field width with a bitmap, it'd have to format the bitmap into a string buffer and then print that buffer with width spec, which isn't different from how it should be done now. This patch implements bitmap[_list]_string() which are called from the vsprintf pointer() formatting function. The implementation is mostly identical to bitmap_scn[list]printf() except that the output is performed in the vsprintf way. These functions handle formatting into too small buffers and sprintf() family of functions report the correct overrun output length. bitmap_scn[list]printf() are now thin wrappers around scnprintf(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Chris Zankel <chris@zankel.net> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Mike Travis <travis@sgi.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: bitmap: remove redundant code from __bitmap_shift_leftRasmus Villemoes2015-02-131-7/+2
| | | | | | | | | | | | | The first of these conditionals is completely redundant: If k == lim-1, we must have off==0, so the second conditional will also trigger and then it wouldn't matter if upper had some high bits set. But the second conditional is in fact also redundant, since it only serves to clear out some high-order "don't care" bits of dst, about which no guarantee is made. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: bitmap: eliminate branch in __bitmap_shift_leftRasmus Villemoes2015-02-131-4/+3
| | | | | | | | | | We can shift the bits from lower and upper into place before assembling dst[k + off]; moving the shift of lower into the branch where we already know that rem is non-zero allows us to remove a conditional. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: bitmap: change bitmap_shift_left to take unsigned parametersRasmus Villemoes2015-02-131-5/+6
| | | | | | | | | | | | | | | | | | | gcc can generate slightly better code for stuff like "nbits % BITS_PER_LONG" when it knows nbits is not negative. Since negative size bitmaps or shift amounts don't make sense, change these parameters of bitmap_shift_right to unsigned. If off >= lim (which requires shift >= nbits), k is initialized with a large positive value, but since I've let k continue to be signed, the loop will never run and dst will be zeroed as expected. Inside the loop, k is guaranteed to be non-negative, so the fact that it is promoted to unsigned in the various expressions it appears in is harmless. Also use "shift" and "nbits" consistently for the parameter names. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: bitmap: yet another simplification in __bitmap_shift_rightRasmus Villemoes2015-02-131-4/+4
| | | | | | | | | | If left is 0, we can just let mask be ~0UL, so that anding with it is a no-op. Conveniently, BITMAP_LAST_WORD_MASK provides precisely what we need, and we can eliminate left. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: bitmap: remove redundant code from __bitmap_shift_rightRasmus Villemoes2015-02-131-2/+0
| | | | | | | | | | | | If the condition k==lim-1 is true, we must have off == 0 (otherwise, k could never become that big). But in that case we have upper == 0 and hence dst[k] == (src[k] & mask) >> rem. Since mask consists of a consecutive range of bits starting from the LSB, anding dst[k] with mask is a no-op. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: bitmap: eliminate branch in __bitmap_shift_rightRasmus Villemoes2015-02-131-3/+3
| | | | | | | | | | We can shift the bits from lower and upper into place before assembling dst[k]; moving the shift of upper into the branch where we already know that rem is non-zero allows us to remove a conditional. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: bitmap: change bitmap_shift_right to take unsigned parametersRasmus Villemoes2015-02-131-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've previously changed the nbits parameter of most bitmap_* functions to unsigned; now it is bitmap_shift_{left,right}'s turn. This alone saves some .text, but while at it I found that there were a few other things one could do. The end result of these seven patches is $ scripts/bloat-o-meter /tmp/bitmap.o.{old,new} add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-328 (-328) function old new delta __bitmap_shift_right 384 226 -158 __bitmap_shift_left 306 136 -170 and less importantly also a smaller stack footprint $ stack-o-meter.pl master bitmap file function old new delta lib/bitmap.o __bitmap_shift_right 24 8 -16 lib/bitmap.o __bitmap_shift_left 24 0 -24 For each pair of 0 <= shift <= nbits <= 256 I've tested the end result with a few randomly filled src buffers (including garbage beyond nbits), in each case verifying that the shift {left,right}-most bits of dst are zero and the remaining nbits-shift bits correspond to src, so I'm fairly confident I didn't screw up. That hasn't stopped me from being wrong before, though. This patch (of 7): gcc can generate slightly better code for stuff like "nbits % BITS_PER_LONG" when it knows nbits is not negative. Since negative size bitmaps or shift amounts don't make sense, change these parameters of bitmap_shift_right to unsigned. The expressions involving "lim - 1" are still ok, since if lim is 0 the loop is never executed. Also use "shift" and "nbits" consistently for the parameter names. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: elide bitmap_copy_le on little-endianRasmus Villemoes2015-02-131-0/+2
| | | | | | | | | On little-endian, there's no reason to have an extra, presumably less efficient, way of copying a bitmap. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: change prototype of bitmap_copy_leRasmus Villemoes2015-02-131-5/+4
| | | | | | | | | | | | | | | | | Make the prototype of bitmap_copy_le the same as bitmap_copy's. All other bitmap_* functions take unsigned long* parameters; there's no reason this should be special. The only current user is the static inline uwb_mas_bm_copy_le, which already does the void* laundering, so the end users can pass their u8 or __le32 buffers without a cast. Furthermore, this allows us to simply let bitmap_copy_le be an alias for bitmap_copy on little-endian; see next patch. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: make the bits parameter of bitmap_remap unsignedRasmus Villemoes2015-02-121-8/+8
| | | | | | | | | Also, rename bits to nbits. Both changes for consistency with other bitmap_* functions. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: simplify bitmap_ord_to_posRasmus Villemoes2015-02-121-17/+11
| | | | | | | | | | | | | | Make the return value and the ord and nbits parameters of bitmap_ord_to_pos unsigned. Also, simplify the implementation and as a side effect make the result fully defined, returning nbits for ord >= weight, in analogy with what find_{first,next}_bit does. This is a better sentinel than the former ("unofficial") 0. No current users are affected by this change. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: simplify bitmap_pos_to_ordRasmus Villemoes2015-02-121-16/+6
| | | | | | | | | | | | | | | | | | The ordinal of a set bit is simply the number of set bits before it; counting those doesn't need to be done one bit at a time. While at it, update the parameters to unsigned int. It is not completely unthinkable that gcc would see pos as compile-time constant 0 in one of the uses of bitmap_pos_to_ord. Since the static inline frontend bitmap_weight doesn't handle nbits==0 correctly (it would behave exactly as if nbits==BITS_PER_LONG), use __bitmap_weight. Alternatively, the last line could be spelled bitmap_weight(buf, pos+1)-1, but this is simpler. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: change parameters of bitmap_fold to unsignedRasmus Villemoes2015-02-121-5/+5
| | | | | | | | | | | | Change the sz and nbits parameters of bitmap_fold to unsigned int for consistency with other bitmap_* functions, and to save another few bytes in the generated code. [akpm@linux-foundation.org: fix kerneldoc] Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: update bitmap_onto to unsignedRasmus Villemoes2015-02-121-2/+2
| | | | | | | | | | Change the nbits parameter of bitmap_onto to unsigned int for consistency with other bitmap_* functions. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'driver-core-3.19-rc1' of ↵Linus Torvalds2014-12-141-0/+29
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core update from Greg KH: "Here's the set of driver core patches for 3.19-rc1. They are dominated by the removal of the .owner field in platform drivers. They touch a lot of files, but they are "simple" changes, just removing a line in a structure. Other than that, a few minor driver core and debugfs changes. There are some ath9k patches coming in through this tree that have been acked by the wireless maintainers as they relied on the debugfs changes. Everything has been in linux-next for a while" * tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits) Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries" fs: debugfs: add forward declaration for struct device type firmware class: Deletion of an unnecessary check before the function call "vunmap" firmware loader: fix hung task warning dump devcoredump: provide a one-way disable function device: Add dev_<level>_once variants ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries ath: use seq_file api for ath9k debugfs files debugfs: add helper function to create device related seq_file drivers/base: cacheinfo: remove noisy error boot message Revert "core: platform: add warning if driver has no owner" drivers: base: support cpu cache information interface to userspace via sysfs drivers: base: add cpu_device_create to support per-cpu devices topology: replace custom attribute macros with standard DEVICE_ATTR* cpumask: factor out show_cpumap into separate helper function driver core: Fix unbalanced device reference in drivers_probe driver core: fix race with userland in device_add() sysfs/kernfs: make read requests on pre-alloc files use the buffer. sysfs/kernfs: allow attributes to request write buffer be pre-allocated. fs: sysfs: return EGBIG on write if offset is larger than file size ...
| * cpumask: factor out show_cpumap into separate helper functionSudeep Holla2014-11-071-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many sysfs *_show function use cpu{list,mask}_scnprintf to copy cpumap to the buffer aligned to PAGE_SIZE, append '\n' and '\0' to return null terminated buffer with newline. This patch creates a new helper function cpumap_print_to_pagebuf in cpumask.h using newly added bitmap_print_to_pagebuf and consolidates most of those sysfs functions using the new helper function. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: x86@kernel.org Cc: linux-acpi@vger.kernel.org Cc: linux-pci@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | lib: bitmap: add alignment offset for bitmap_find_next_zero_area()Michal Nazarewicz2014-12-131-11/+13
|/ | | | | | | | | | | | | | | | | | | Add a bitmap_find_next_zero_area_off() function which works like bitmap_find_next_zero_area() function except it allows an offset to be specified when alignment is checked. This lets caller request a bit such that its number plus the offset is aligned according to the mask. [gregory.0xf0@gmail.com: Retrieved from https://patchwork.linuxtv.org/patch/6254/ and updated documentation] Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/bitmap.c: fix undefined shift in __bitmap_shift_{left|right}()Jan Kara2014-10-291-2/+6
| | | | | | | | | | | | | | | If __bitmap_shift_left() or __bitmap_shift_right() are asked to shift by a multiple of BITS_PER_LONG, they will try to shift a long value by BITS_PER_LONG bits which is undefined. Change the functions to avoid the undefined shift. Coverity id: 1192175 Coverity id: 1192174 Signed-off-by: Jan Kara <jack@suse.cz> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2014-10-071-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull "trivial tree" updates from Jiri Kosina: "Usual pile from trivial tree everyone is so eagerly waiting for" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) Remove MN10300_PROC_MN2WS0038 mei: fix comments treewide: Fix typos in Kconfig kprobes: update jprobe_example.c for do_fork() change Documentation: change "&" to "and" in Documentation/applying-patches.txt Documentation: remove obsolete pcmcia-cs from Changes Documentation: update links in Changes Documentation: Docbook: Fix generated DocBook/kernel-api.xml score: Remove GENERIC_HAS_IOMAP gpio: fix 'CONFIG_GPIO_IRQCHIP' comments tty: doc: Fix grammar in serial/tty dma-debug: modify check_for_stack output treewide: fix errors in printk genirq: fix reference in devm_request_threaded_irq comment treewide: fix synchronize_rcu() in comments checkstack.pl: port to AArch64 doc: queue-sysfs: minor fixes init/do_mounts: better syntax description MIPS: fix comment spelling powerpc/simpleboot: fix comment ...
| * Documentation: Docbook: Fix generated DocBook/kernel-api.xmlMasanari Iida2014-09-091-2/+2
| | | | | | | | | | | | | | | | | | | | This patch fix spelling typo found in DocBook/kernel-api.xml. It is because the file is generated from the source comments, I have to fix the comments in source codes. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | lib: bitmap: add missing mask in bitmap_andnotRasmus Villemoes2014-08-061-2/+5
| | | | | | | | | | | | | | | | | | | | Apparently, bitmap_andnot is supposed to return whether the new bitmap is empty. But it didn't take potential garbage bits in the last word into account. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: add missing mask in bitmap_andRasmus Villemoes2014-08-061-2/+5
| | | | | | | | | | | | | | | | | | | | Apparently, bitmap_and is supposed to return whether the new bitmap is empty. But it didn't take potential garbage bits in the last word into account. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: micro-optimize bitmap_allocate_regionRasmus Villemoes2014-08-061-2/+1
| | | | | | | | | | | | | | | | | | __reg_op(..., REG_OP_ALLOC) always returns 0, so we might as well use that and save an instruction. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: change parameter of bitmap_*_region to unsignedRasmus Villemoes2014-08-061-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | Changing the pos parameter of __reg_op to unsigned allows the compiler to generate slightly smaller and simpler code. Also update its callers bitmap_*_region to receive and pass unsigned int. The return types of bitmap_find_free_region and bitmap_allocate_region are still int to allow a negative error code to be returned. An int is certainly capable of representing any realistic return value. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: fix typo in kerneldoc for bitmap_pos_to_ordRasmus Villemoes2014-08-061-1/+1
| | | | | | | | | | | | | | | | | | A few lines above, it was stated that positions for non-set bits are mapped to -1, which is obviously also what the code does. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: simplify bitmap_parselistRasmus Villemoes2014-08-061-7/+2
| | | | | | | | | | | | | | | | | | | | | | We want len to be the index of the first '\n', or the length of the string if there is no newline. This is a good example of the usefulness of strchrnul(). Use that instead, thus eliminating a branch and a call to strlen(). Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: make the start index of bitmap_clear unsignedRasmus Villemoes2014-08-061-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | The compiler can generate slightly smaller and simpler code when it knows that "start" is non-negative. Also, use the names "start" and "len" for the two parameters for consistency with bitmap_set. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: make the start index of bitmap_set unsignedRasmus Villemoes2014-08-061-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | The compiler can generate slightly smaller and simpler code when it knows that "start" is non-negative. Also, use the names "start" and "len" for the two parameters in both header file and implementation, instead of the previous mix. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: make nbits parameter of bitmap_weight unsignedRasmus Villemoes2014-08-061-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. I didn't change the return type, since that might change the semantics of some expression containing a call to bitmap_weight(). Certainly an int is capable of holding the result. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: make nbits parameter of bitmap_subset unsignedRasmus Villemoes2014-08-061-2/+2
| | | | | | | | | | | | | | | | | | | | The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: bitmap: make nbits parameter of bitmap_intersects unsignedRasmus Villemoes2014-08-061-2/+2
| | | | | | | | | | | | | | | | | | | | The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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