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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-14 13:39:34 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-14 13:39:34 -0700 |
commit | d25282d1c9b9bc4cda7f9d3c0205108e99aa7a9d (patch) | |
tree | f414482d768b015a609924293b779b4ad0b8f764 /include/asm-generic/bitops/count_zeros.h | |
parent | b6eea87fc6850d3531a64a27d2323a4498cd4e43 (diff) | |
parent | dbadc17683e6c673a69b236c0f041b931cc55c42 (diff) | |
download | op-kernel-dev-d25282d1c9b9bc4cda7f9d3c0205108e99aa7a9d.zip op-kernel-dev-d25282d1c9b9bc4cda7f9d3c0205108e99aa7a9d.tar.gz |
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/count_zeros.h')
-rw-r--r-- | include/asm-generic/bitops/count_zeros.h | 57 |
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 0000000..97520d2 --- /dev/null +++ b/include/asm-generic/bitops/count_zeros.h @@ -0,0 +1,57 @@ +/* Count leading and trailing zeros functions + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#ifndef _ASM_GENERIC_BITOPS_COUNT_ZEROS_H_ +#define _ASM_GENERIC_BITOPS_COUNT_ZEROS_H_ + +#include <asm/bitops.h> + +/** + * count_leading_zeros - Count the number of zeros from the MSB back + * @x: The value + * + * Count the number of leading zeros from the MSB going towards the LSB in @x. + * + * If the MSB of @x is set, the result is 0. + * If only the LSB of @x is set, then the result is BITS_PER_LONG-1. + * If @x is 0 then the result is COUNT_LEADING_ZEROS_0. + */ +static inline int count_leading_zeros(unsigned long x) +{ + if (sizeof(x) == 4) + return BITS_PER_LONG - fls(x); + else + return BITS_PER_LONG - fls64(x); +} + +#define COUNT_LEADING_ZEROS_0 BITS_PER_LONG + +/** + * count_trailing_zeros - Count the number of zeros from the LSB forwards + * @x: The value + * + * Count the number of trailing zeros from the LSB going towards the MSB in @x. + * + * If the LSB of @x is set, the result is 0. + * If only the MSB of @x is set, then the result is BITS_PER_LONG-1. + * If @x is 0 then the result is COUNT_TRAILING_ZEROS_0. + */ +static inline int count_trailing_zeros(unsigned long x) +{ +#define COUNT_TRAILING_ZEROS_0 (-1) + + if (sizeof(x) == 4) + return ffs(x); + else + return (x != 0) ? __ffs(x) : COUNT_TRAILING_ZEROS_0; +} + +#endif /* _ASM_GENERIC_BITOPS_COUNT_ZEROS_H_ */ |