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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-14 16:39:34 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-14 16:39:34 -0400
commitd25282d1c9b9bc4cda7f9d3c0205108e99aa7a9d (patch)
treef414482d768b015a609924293b779b4ad0b8f764 /include/asm-generic/bitops
parentb6eea87fc6850d3531a64a27d2323a4498cd4e43 (diff)
parentdbadc17683e6c673a69b236c0f041b931cc55c42 (diff)
Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module signing support from Rusty Russell: "module signing is the highlight, but it's an all-over David Howells frenzy..." Hmm "Magrathea: Glacier signing key". Somebody has been reading too much HHGTTG. * 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (37 commits) X.509: Fix indefinite length element skip error handling X.509: Convert some printk calls to pr_devel asymmetric keys: fix printk format warning MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checking MODSIGN: Make mrproper should remove generated files. MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certs MODSIGN: Use the same digest for the autogen key sig as for the module sig MODSIGN: Sign modules during the build process MODSIGN: Provide a script for generating a key ID from an X.509 cert MODSIGN: Implement module signature checking MODSIGN: Provide module signing public keys to the kernel MODSIGN: Automatically generate module signing keys if missing MODSIGN: Provide Kconfig options MODSIGN: Provide gitignore and make clean rules for extra files MODSIGN: Add FIPS policy module: signature checking hook X.509: Add a crypto key parser for binary (DER) X.509 certificates MPILIB: Provide a function to read raw data into an MPI X.509: Add an ASN.1 decoder X.509: Add simple ASN.1 grammar compiler ...
Diffstat (limited to 'include/asm-generic/bitops')
-rw-r--r--include/asm-generic/bitops/count_zeros.h57
1 files changed, 57 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/count_zeros.h b/include/asm-generic/bitops/count_zeros.h
new file mode 100644
index 000000000000..97520d21fe62
--- /dev/null
+++ b/include/asm-generic/bitops/count_zeros.h
@@ -0,0 +1,57 @@
1/* Count leading and trailing zeros functions
2 *
3 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12#ifndef _ASM_GENERIC_BITOPS_COUNT_ZEROS_H_
13#define _ASM_GENERIC_BITOPS_COUNT_ZEROS_H_
14
15#include <asm/bitops.h>
16
17/**
18 * count_leading_zeros - Count the number of zeros from the MSB back
19 * @x: The value
20 *
21 * Count the number of leading zeros from the MSB going towards the LSB in @x.
22 *
23 * If the MSB of @x is set, the result is 0.
24 * If only the LSB of @x is set, then the result is BITS_PER_LONG-1.
25 * If @x is 0 then the result is COUNT_LEADING_ZEROS_0.
26 */
27static inline int count_leading_zeros(unsigned long x)
28{
29 if (sizeof(x) == 4)
30 return BITS_PER_LONG - fls(x);
31 else
32 return BITS_PER_LONG - fls64(x);
33}
34
35#define COUNT_LEADING_ZEROS_0 BITS_PER_LONG
36
37/**
38 * count_trailing_zeros - Count the number of zeros from the LSB forwards
39 * @x: The value
40 *
41 * Count the number of trailing zeros from the LSB going towards the MSB in @x.
42 *
43 * If the LSB of @x is set, the result is 0.
44 * If only the MSB of @x is set, then the result is BITS_PER_LONG-1.
45 * If @x is 0 then the result is COUNT_TRAILING_ZEROS_0.
46 */
47static inline int count_trailing_zeros(unsigned long x)
48{
49#define COUNT_TRAILING_ZEROS_0 (-1)
50
51 if (sizeof(x) == 4)
52 return ffs(x);
53 else
54 return (x != 0) ? __ffs(x) : COUNT_TRAILING_ZEROS_0;
55}
56
57#endif /* _ASM_GENERIC_BITOPS_COUNT_ZEROS_H_ */