BMC/Intel-BMC/linux.git/arch/powerpc/lib/memcpy_64.S, branch dev

Merge remote-tracking branch 'anton/abiv2' into next

2014-05-05T10:57:12+00:00

This series adds support for building the powerpc 64-bit LE kernel using the new ABI v2. We already supported running ABI v2 userspace programs but this adds support for building the kernel itself using the new ABI.

powerpc: memcpy optimization for 64bit LE

2014-04-30T05:26:18+00:00

Unaligned stores take alignment exceptions on POWER7 running in little-endian. This is a dumb little-endian base memcpy that prevents unaligned stores. Once booted the feature fixup code switches over to the VMX copy loops (which are already endian safe). The question is what we do before that switch over. The base 64bit memcpy takes alignment exceptions on POWER7 so we can't use it as is. Fixing the causes of alignment exception would slow it down, because we'd need to ensure all loads and stores are aligned either through rotate tricks or bytewise loads and stores. Either would be bad for all other 64bit platforms. [ I simplified the loop a bit - Anton ] Signed-off-by: Philippe Bergheaud Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc: Add _GLOBAL_TOC for ABIv2 assembly functions exported to modules

2014-04-23T00:05:32+00:00

If an assembly function that calls back into c code is exported to modules, we need to ensure r2 is setup correctly. There are only two places crazy enough to do it (two of which are my fault). Signed-off-by: Anton Blanchard

powerpc: Fix unsafe accesses to parameter area in ELFv2

2014-04-23T00:05:24+00:00

Some of the assembler files in lib/ make use of the fact that in the ELFv1 ABI, the caller guarantees to provide stack space to save the parameter registers r3 ... r10. This guarantee is no longer present in ELFv2 for functions that have no variable argument list and no more than 8 arguments. Change the affected routines to temporarily store registers in the red zone and/or the top of their own stack frame (in the space provided to save r31 .. r29, which is actually not used in these routines). In opal_query_takeover, simply always allocate a stack frame; the routine is not performance critical. Signed-off-by: Ulrich Weigand Signed-off-by: Anton Blanchard

powerpc: Fix ABIv2 issues with stack offsets in assembly code

2014-04-23T00:05:23+00:00

Fix STK_PARAM and use it instead of hardcoding ABIv1 offsets. Signed-off-by: Anton Blanchard

selftests/powerpc: Import Anton's memcpy / copy_tofrom_user tests

2014-03-07T04:53:12+00:00

Turn Anton's memcpy / copy_tofrom_user test into something that can live in tools/testing/selftests. It requires one turd in arch/powerpc/lib/memcpy_64.S, but it's pretty harmless IMHO. We are sailing very close to the wind with the feature macros. We define them to nothing, which currently means we get a few extra nops and include the unaligned calls. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc: Change mtcrf to use real register names

2012-07-10T09:18:11+00:00

mtocrf define is just a wrapper around the real instructions so we can just use real register names here (ie. lower case). Also remove braces in macro so this is possible. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix usage of register macros getting ready for %r0 change

2012-07-10T09:17:55+00:00

Anything that uses a constructed instruction (ie. from ppc-opcode.h), need to use the new R0 macro, as %r0 is not going to work. Also convert usages of macros where we are just determining an offset (usually for a load/store), like: std r14,STK_REG(r14)(r1) Can't use STK_REG(r14) as %r14 doesn't work in the STK_REG macro since it's just calculating an offset. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt

powerpc: POWER7 optimised memcpy using VMX and enhanced prefetch

2012-07-03T04:14:46+00:00

Implement a POWER7 optimised memcpy using VMX and enhanced prefetch instructions. This is a copy of the POWER7 optimised copy_to_user/copy_from_user loop. Detailed implementation and performance details can be found in commit a66086b8197d (powerpc: POWER7 optimised copy_to_user/copy_from_user using VMX). I noticed memcpy issues when profiling a RAID6 workload: .memcpy .async_memcpy .async_copy_data .__raid_run_ops .handle_stripe .raid5d .md_thread I created a simplified testcase by building a RAID6 array with 4 1GB ramdisks (booting with brd.rd_size=1048576): # mdadm -CR -e 1.2 /dev/md0 --level=6 -n4 /dev/ram[0-3] I then timed how long it took to write to the entire array: # dd if=/dev/zero of=/dev/md0 bs=1M Before: 892 MB/s After: 999 MB/s A 12% improvement. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove CONFIG_POWER4_ONLY

2012-04-30T05:37:26+00:00

Remove CONFIG_POWER4_ONLY, the option is badly named and only does two things: - It wraps the MMU segment table code. With feature fixups there is little downside to compiling this in. - It uses the newer mtocrf instruction in various assembly functions. Instead of making this a compile option just do it at runtime via a feature fixup. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt