kernel/linux.git/arch/arc/lib/memcpy-archs.S, branch linux-7.0.y

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

ARCv2: lib: memcpy: fix doing prefetchw outside of buffer

2019-02-21T19:03:16+00:00

ARCv2 optimized memcpy uses PREFETCHW instruction for prefetching the next cache line but doesn't ensure that the line is not past the end of the buffer. PRETECHW changes the line ownership and marks it dirty, which can cause data corruption if this area is used for DMA IO. Fix the issue by avoiding the PREFETCHW. This leads to performance degradation but it is OK as we'll introduce new memcpy implementation optimized for unaligned memory access using. We also cut off all PREFETCH instructions at they are quite useless here: * we call PREFETCH right before LOAD instruction call. * we copy 16 or 32 bytes of data (depending on CONFIG_ARC_HAS_LL64) in a main logical loop. so we call PREFETCH 4 times (or 2 times) for each L1 cache line (in case of 64B L1 cache Line which is default case). Obviously this is not optimal. Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta

ARC: dw2 unwind: enable cfi pseudo ops in string lib

2016-09-30T21:48:22+00:00

This uses a new set of annoations viz. ENTRY_CFI/END_CFI to enabel cfi ops generation. Note that we didn't change the normal ENTRY/EXIT as we don't actually want unwind info in the trap/exception/interrutp handlers which use these, as unwinder then gets confused (it keeps recursing vs. stopping). Semantically these are leaf routines and unwinding should stop when it hits those routines. Before ------ 28.52% 1.19% 9929 hackbench libuClibc-1.0.17.so [.] __write_nocancel | ---__write_nocancel |--8.95%--EV_Trap | --8.25%--sys_write | |--3.93%--sock_write_iter ... |--2.62%--memset <==== [LEAF entry as no unwind info] ^^^^^^ After ----- 29.46% 1.24% 13622 hackbench libuClibc-1.0.17.so [.] __write_nocancel | ---__write_nocancel |--9.31%--EV_Trap | --8.62%--sys_write | |--4.17%--sock_write_iter ... |--6.19%--sys_write | --6.19%--sock_write_iter | unix_stream_sendmsg | |--1.62%--sock_alloc_send_pskb | |--0.89%--sock_def_readable | |--0.88%--_raw_spin_unlock_irqrestore | |--0.69%--memset | | ^^^^^^ <==== [now in proper callframe] | | | --0.52%--skb_copy_datagram_from_iter Signed-off-by: Vineet Gupta

ARCv2: lib: memcpy: use local symbols

2015-11-03T12:03:00+00:00

Otherwise perf profiles don't charge tme to memcpy Signed-off-by: Vineet Gupta

ARCv2: lib: memcpy: Missing PREFETCHW

2015-07-20T14:27:35+00:00

Signed-off-by: Vineet Gupta

ARCv2: optimised string/mem lib routines

2015-06-22T08:36:56+00:00

Signed-off-by: Vineet Gupta