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2012-07-03powerpc: 64bit optimised __clear_userAnton Blanchard
I noticed __clear_user high up in a profile of one of my RAID stress tests. The testcase was doing a dd from /dev/zero which ends up calling __clear_user. __clear_user is basically a loop with a single 4 byte store which is horribly slow. We can do much better by aligning the desination and doing 32 bytes of 8 byte stores in a loop. The following testcase was used to verify the patch: http://ozlabs.org/~anton/junkcode/stress_clear_user.c To show the improvement in performance I ran a dd from /dev/zero to /dev/null on a POWER7 box: Before: # dd if=/dev/zero of=/dev/null bs=1M count=10000 10485760000 bytes (10 GB) copied, 3.72379 s, 2.8 GB/s After: # time dd if=/dev/zero of=/dev/null bs=1M count=10000 10485760000 bytes (10 GB) copied, 0.728318 s, 14.4 GB/s Over 5x faster. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-27powerpc: Use the new generic strncpy_from_user() and strnlen_user()Paul Mackerras
This is much the same as for SPARC except that we can do the find_zero() function more efficiently using the count-leading-zeroes instructions. Tested on 32-bit and 64-bit PowerPC. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-21powerpc: Fix string library functionsAndreas Schwab
The powerpc strncmp implementation does not correctly handle a zero length, despite the claim in 0119536cd314ef95553604208c25bc35581f7f0a (Add hand-coded assembly strcmp). Additionally, all the length arguments are size_t, not int, so use PPC_LCMPI and eq instead of cmpwi and le throughout. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-04-07powerpc: Fix handling of strncmp with zero lenJeff Mahoney
Commit 0119536c, which added the assembly version of strncmp to powerpc, mentions that it adds two instructions to the version from boot/string.S to allow it to handle len=0. Unfortunately, it doesn't always return 0 when that is the case. The length is passed in r5, but the return value is passed back in r3. In certain cases, this will happen to work. Otherwise it will pass back the address of the first string as the return value. This patch lifts the len <= 0 handling code from memcpy to handle that case. Reported by: Christian_Sellars@symantec.com Signed-off-by: Jeff Mahoney <jeffm@suse.com> CC: <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-22powerpc: Use PPC_LONG and PPC_LONG_ALIGN in lib/string.SMichael Ellerman
Replace ifdef clutter with the PPC_LONG and PPC_LONG_ALIGN macros for readability. No change to the generated code. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-04-07[POWERPC] Add hand-coded assembly strcmpSteven Rostedt
We have an assembly version of strncmp for the bootwrapper, but not for the kernel, so we end up using the C version in the kernel. This takes the strncmp code from the bootup and copies it to the kernel proper, adding two instructions so it copes correctly with len==0. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2005-10-10powerpc: Use reg.h instead of processor.h when we just want reg namesPaul Mackerras
Now that the register names and bit definitions are all in reg.h, use that instead of processor.h in assembly code in a few places. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26powerpc: Merge enough to start building in arch/powerpc.Paul Mackerras
This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>