Commit Graph

5 Commits

Author SHA1 Message Date
Cihangir Akturk
36f671be1d Documentation/unaligned-memory-access.txt: fix incorrect comparison operator
In the actual implementation ether_addr_equal function tests for equality to 0
when returning. It seems in commit 0d74c4 it is somehow overlooked to change
this operator to reflect the actual function.

Signed-off-by: Cihangir Akturk <cakturk@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-12-27 13:08:42 -07:00
Joe Perches
0d74c42f78 ether_addr_equal: Optimize implementation, remove unused compare_ether_addr
Add a new check for CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to reduce
the number of or's used in the ether_addr_equal comparison to very
slightly improve function performance.

Simplify the ether_addr_equal_64bits implementation.
Integrate and remove the zap_last_2bytes helper as it's now
used only once.

Remove the now unused compare_ether_addr function.

Update the unaligned-memory-access documentation to remove the
compare_ether_addr description and show how unaligned accesses
could occur with ether_addr_equal.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-06 16:37:43 -05:00
Johannes Berg
58340a07c1 introduce HAVE_EFFICIENT_UNALIGNED_ACCESS Kconfig symbol
In many cases, especially in networking, it can be beneficial to know at
compile time whether the architecture can do unaligned accesses efficiently.
This patch introduces a new Kconfig symbol

	HAVE_EFFICIENT_UNALIGNED_ACCESS

for that purpose and adds it to the powerpc and x86 architectures.  Also add
some documentation about alignment and networking, and especially one intended
use of this symbol.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Ingo Molnar <mingo@elte.hu> [x86 architecture part]
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:27 -07:00
Dmitri Vorobiev
e8d49f3a6f Fix typos in Documentation/unaligned-memory-access.txt
This patch deletes a couple of superfluous word occurrences in the
document Documentation/unaligned-memory-access.txt.

Thanks to Sebastien Dugue for the remark about English usage.

Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-02 15:28:19 -07:00
Daniel Drake
d156042f9f Documentation about unaligned memory access
Here's a document I wrote after figuring out what unaligned memory access
is all about.  I've tried to cover the information I was looking for when
trying to learn about this, without producing a hopelessly detailed/complex
spew.  I hope it is useful to others.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Cc: Rob Landley <rob@landley.net>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jan Engelhardt <jengelh@computergmbh.de>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Kyle Moffett <mrmacman_g4@mac.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:07 -08:00