Merge branch 'akpm' (patches from Andrew)

Merge third patchbomb from Andrew Morton:

 - various misc things

 - a couple of lib/ optimisations

 - provide DIV_ROUND_CLOSEST_ULL()

 - checkpatch updates

 - rtc tree

 - befs, nilfs2, hfs, hfsplus, fatfs, adfs, affs, bfs

 - ptrace fixes

 - fork() fixes

 - seccomp cleanups

 - more mmap_sem hold time reductions from Davidlohr

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (138 commits)
  proc: show locks in /proc/pid/fdinfo/X
  docs: add missing and new /proc/PID/status file entries, fix typos
  drivers/rtc/rtc-at91rm9200.c: make IO endian agnostic
  Documentation/spi/spidev_test.c: fix warning
  drivers/rtc/rtc-s5m.c: allow usage on device type different than main MFD type
  .gitignore: ignore *.tar
  MAINTAINERS: add Mediatek SoC mailing list
  tomoyo: reduce mmap_sem hold for mm->exe_file
  powerpc/oprofile: reduce mmap_sem hold for exe_file
  oprofile: reduce mmap_sem hold for mm->exe_file
  mips: ip32: add platform data hooks to use DS1685 driver
  lib/Kconfig: fix up HAVE_ARCH_BITREVERSE help text
  x86: switch to using asm-generic for seccomp.h
  sparc: switch to using asm-generic for seccomp.h
  powerpc: switch to using asm-generic for seccomp.h
  parisc: switch to using asm-generic for seccomp.h
  mips: switch to using asm-generic for seccomp.h
  microblaze: use asm-generic for seccomp.h
  arm: use asm-generic for seccomp.h
  seccomp: allow COMPAT sigreturn overrides
  ...

1 files changed, 14 insertions, 22 deletions

diff --git a/lib/find_last_bit.c b/lib/find_last_bit.c
index 91ca09fbf6f9..3e3be40c6a6e 100644
--- a/lib/find_last_bit.c
+++ b/lib/find_last_bit.c
@@ -4,6 +4,9 @@
  * Written by Rusty Russell <rusty@rustcorp.com.au>
  * (Inspired by David Howell's find_next_bit implementation)
  *
+ * Rewritten by Yury Norov <yury.norov@gmail.com> to decrease
+ * size and improve performance, 2015.
+ *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
@@ -11,37 +14,26 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/bitmap.h>
 #include <linux/export.h>
-#include <asm/types.h>
-#include <asm/byteorder.h>
+#include <linux/kernel.h>
 
 #ifndef find_last_bit
 
 unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
 {
-        unsigned long words;
-        unsigned long tmp;
-
-        /* Start at final word. */
-        words = size / BITS_PER_LONG;
+        if (size) {
+                unsigned long val = BITMAP_LAST_WORD_MASK(size);
+                unsigned long idx = (size-1) / BITS_PER_LONG;
 
-        /* Partial final word? */
-        if (size & (BITS_PER_LONG-1)) {
-                tmp = (addr[words] & (~0UL >> (BITS_PER_LONG
-                                         - (size & (BITS_PER_LONG-1)))));
-                if (tmp)
-                        goto found;
-        }
+                do {
+                        val &= addr[idx];
+                        if (val)
+                                return idx * BITS_PER_LONG + __fls(val);
 
-        while (words) {
-                tmp = addr[--words];
-                if (tmp) {
-found:
-                        return words * BITS_PER_LONG + __fls(tmp);
-                }
+                        val = ~0ul;
+                } while (idx--);
         }
-
-        /* Not found */
         return size;
 }
 EXPORT_SYMBOL(find_last_bit);