user/sven/linux.git/include/linux/bitmap.h, branch v5.15.6

cpumask: introduce cpumap_print_list/bitmask_to_buf to support large bitmask and list

2021-08-13T08:27:49Z

The existing cpumap_print_to_pagebuf() is used by cpu topology and other drivers to export hexadecimal bitmask and decimal list to userspace by sysfs ABI. Right now, those drivers are using a normal attribute for this kind of ABIs. A normal attribute typically has show entry as below: static ssize_t example_dev_show(struct device *dev, struct device_attribute *attr, char *buf) { ... return cpumap_print_to_pagebuf(true, buf, &pmu_mmdc->cpu); } show entry of attribute has no offset and count parameters and this means the file is limited to one page only. cpumap_print_to_pagebuf() API works terribly well for this kind of normal attribute with buf parameter and without offset, count: static inline ssize_t cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) { return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask), nr_cpu_ids); } The problem is once we have many cpus, we have a chance to make bitmask or list more than one page. Especially for list, it could be as complex as 0,3,5,7,9,...... We have no simple way to know it exact size. It turns out bin_attribute is a way to break this limit. bin_attribute has show entry as below: static ssize_t example_bin_attribute_show(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t offset, size_t count) { ... } With the new offset and count parameters, this makes sysfs ABI be able to support file size more than one page. For example, offset could be >= 4096. This patch introduces cpumap_print_bitmask/list_to_buf() and their bitmap infrastructure bitmap_print_bitmask/list_to_buf() so that those drivers can move to bin_attribute to support large bitmask and list. At the same time, we have to pass those corresponding parameters such as offset, count from bin_attribute to this new API. Cc: Andrew Morton Cc: Andy Shevchenko Cc: Randy Dunlap Cc: Stefano Brivio Cc: Alexander Gordeev Cc: "Ma, Jianpeng" Cc: Yury Norov Cc: Valentin Schneider Cc: Peter Zijlstra Cc: Daniel Bristot de Oliveira Reviewed-by: Jonathan Cameron Signed-off-by: Tian Tao Signed-off-by: Barry Song Link: https://lore.kernel.org/r/20210806110251.560-2-song.bao.hua@hisilicon.com Signed-off-by: Greg Kroah-Hartman

Merge branch 'akpm' (patches from Andrew)

2021-05-07T07:34:51Z

Merge yet more updates from Andrew Morton: "This is everything else from -mm for this merge window. 90 patches. Subsystems affected by this patch series: mm (cleanups and slub), alpha, procfs, sysctl, misc, core-kernel, bitmap, lib, compat, checkpatch, epoll, isofs, nilfs2, hpfs, exit, fork, kexec, gcov, panic, delayacct, gdb, resource, selftests, async, initramfs, ipc, drivers/char, and spelling" * emailed patches from Andrew Morton : (90 commits) mm: fix typos in comments mm: fix typos in comments treewide: remove editor modelines and cruft ipc/sem.c: spelling fix fs: fat: fix spelling typo of values kernel/sys.c: fix typo kernel/up.c: fix typo kernel/user_namespace.c: fix typos kernel/umh.c: fix some spelling mistakes include/linux/pgtable.h: few spelling fixes mm/slab.c: fix spelling mistake "disired" -> "desired" scripts/spelling.txt: add "overflw" scripts/spelling.txt: Add "diabled" typo scripts/spelling.txt: add "overlfow" arm: print alloc free paths for address in registers mm/vmalloc: remove vwrite() mm: remove xlate_dev_kmem_ptr() drivers/char: remove /dev/kmem for good mm: fix some typos and code style problems ipc/sem.c: mundane typo fixes ...

lib: extend the scope of small_const_nbits() macro

2021-05-07T02:24:11Z

find_bit would also benefit from small_const_nbits() optimizations. The detailed comment is provided by Rasmus Villemoes. Link: https://lkml.kernel.org/r/20210401003153.97325-6-yury.norov@gmail.com Suggested-by: Rasmus Villemoes Signed-off-by: Yury Norov Acked-by: Rasmus Villemoes Acked-by: Andy Shevchenko Cc: Alexey Klimov Cc: Arnd Bergmann Cc: David Sterba Cc: Dennis Zhou Cc: Geert Uytterhoeven Cc: Jianpeng Ma Cc: Joe Perches Cc: John Paul Adrian Glaubitz Cc: Josh Poimboeuf Cc: Rich Felker Cc: Stefano Brivio Cc: Wei Yang Cc: Wolfram Sang Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel.h: drop inclusion in bitmap.h

2021-05-07T02:24:11Z

The bitmap.h header is used in a lot of code around the kernel. Besides that it includes kernel.h which sometimes makes a loop. The problem here is many unneeded loops that make header hell dependencies. For example, how may you move bitmap_zalloc() from C-file to the header? Currently it's impossible. And bitmap.h here is only the tip of an iceberg. kerne.h is a dump of everything that even has nothing in common at all. We may still have it, but in my new code I prefer to include only the headers that I want to use, without the bulk of unneeded kernel code. Break the loop by introducing align.h, including it in kernel.h and bitmap.h followed by replacing kernel.h with limits.h. Link: https://lkml.kernel.org/r/20210326170347.37441-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Acked-by: Yury Norov Cc: Rasmus Villemoes Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib: bitmap: provide devm_bitmap_alloc() and devm_bitmap_zalloc()

2021-05-05T14:07:39Z

Provide managed variants of bitmap_alloc() and bitmap_zalloc(). Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko

lib: bitmap: order includes alphabetically

2021-05-05T14:07:39Z

For better readability and maintenance: order the includes in bitmap source files alphabetically. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko

lib: bitmap: remove the 'extern' keyword from function declarations

2021-05-05T14:07:39Z

The 'extern' keyword doesn't have any benefits for functions in header files. Remove it. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko

bitmap: remove unused function declaration

2020-12-16T06:46:16Z

Link: https://lkml.kernel.org/r/BN7PR11MB26097166B6B46387D8A1ABA4FDE30@BN7PR11MB2609.namprd11.prod.outlook.com Fixes: 2afe27c718b6 ("lib/bitmap.c: bitmap_[empty,full]: remove code duplication") Signed-off-by: Jianpeng Ma Acked-by: Yury Norov Reviewed-by: Andy Shevchenko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

include/linux/bitmap.h: convert bitmap_empty() / bitmap_full() to return boolean

2020-12-16T06:46:15Z

There is no need to return int type out of boolean expression. Link: https://lkml.kernel.org/r/20201027180936.20806-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Cc: Yury Norov Cc: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

include/bitmap.h: add new functions to documentation

2020-03-05T21:23:25Z

I found these functions only by chance although I was looking exactly for something like them. So, add them to the list of functions to make them more visible. Fixes: e837dfde15a4 ("bitmap: genericize percpu bitmap region iterators") Signed-off-by: Wolfram Sang Signed-off-by: Dennis Zhou