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author | Harvey Harrison <harvey.harrison@gmail.com> | 2008-04-29 01:03:27 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 08:06:27 -0700 |
commit | 064106a91be5e76cb42c1ddf5d3871e3a1bd2a23 (patch) | |
tree | 7bb3931857c933343abf9a55d663e8a9b8af13ae /include/asm-ia64 | |
parent | dddfbaf8f86894415abb8256b55da68dab966ebe (diff) | |
download | linux-stable-064106a91be5e76cb42c1ddf5d3871e3a1bd2a23.tar.gz linux-stable-064106a91be5e76cb42c1ddf5d3871e3a1bd2a23.tar.bz2 linux-stable-064106a91be5e76cb42c1ddf5d3871e3a1bd2a23.zip |
kernel: add common infrastructure for unaligned access
Create a linux/unaligned directory similar in spirit to the linux/byteorder
folder to hold generic implementations collected from various arches.
Currently there are five implementations:
1) packed_struct.h: C-struct based, from asm-generic/unaligned.h
2) le_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
3) be_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
4) memmove.h: taken from multiple implementations in tree
5) access_ok.h: taken from x86 and others, unaligned access is ok.
All of the new implementations checks for sizes not equal to 1,2,4,8
and will fail to link.
API additions:
get_unaligned_{le16|le32|le64|be16|be32|be64}(p) which is meant to replace
code of the form:
le16_to_cpu(get_unaligned((__le16 *)p));
put_unaligned_{le16|le32|le64|be16|be32|be64}(val, pointer) which is meant to
replace code of the form:
put_unaligned(cpu_to_le16(val), (__le16 *)p);
The headers that arches should include from their asm/unaligned.h:
access_ok.h : Wrappers of the byteswapping functions in asm/byteorder
Choose a particular implementation for little-endian access:
le_byteshift.h
le_memmove.h (arch must be LE)
le_struct.h (arch must be LE)
Choose a particular implementation for big-endian access:
be_byteshift.h
be_memmove.h (arch must be BE)
be_struct.h (arch must be BE)
After including as needed from the above, include unaligned/generic.h and
define your arch's get/put_unaligned as (for LE):
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-ia64')
0 files changed, 0 insertions, 0 deletions