From: Anton Blanchard <anton@samba.org>
Date: Mon, 14 Oct 2013 10:03:58 +0000 (+1100)
Subject: powerpc: Add VMX optimised xor for RAID5
X-Git-Tag: omap-for-v3.13/fixes-for-merge-window-take2~19^2~22
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef1313deafb7baa6d3382044e962d5ad5e8c8dd6;p=pandora-kernel.git

powerpc: Add VMX optimised xor for RAID5

Add a VMX optimised xor, used primarily for RAID5. On a POWER7 blade
this is a decent win:

   32regs    : 17932.800 MB/sec
   altivec   : 19724.800 MB/sec

The bigger gain is when the same test is run in SMT4 mode, as it
would if there was a lot of work going on:

   8regs     :  8377.600 MB/sec
   altivec   : 15801.600 MB/sec

I tested this against an array created without the patch, and also
verified it worked as expected on a little endian kernel.

[ Fix !CONFIG_ALTIVEC build -- BenH ]

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

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