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| author | Eugeniy Paltsev <eugeniy.paltsev@synopsys.com> | 2019-01-30 17:32:43 +0100 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2019-02-25 17:52:16 +0100 |
| commit | 4d1e7918aae59ef504f5170a4f0c7ae82339fcb2 (patch) | |
| tree | 358a3cf4544a01622172ecbd2d85f933b9de9995 /arch/arc/lib/memcpy-archs-unaligned.S | |
| parent | ARC: [plat-hsdk]: Enable AXI DW DMAC support (diff) | |
| download | linux-4d1e7918aae59ef504f5170a4f0c7ae82339fcb2.tar.xz linux-4d1e7918aae59ef504f5170a4f0c7ae82339fcb2.zip | |
ARCv2: lib: introduce memcpy optimized for unaligned access
Optimise code to use efficient unaligned memory access which is
available on ARCv2. This allows us to really simplify memcpy code
and speed up the code one and a half times (in case of unaligned
source or destination).
Don't wire it up yet !
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/lib/memcpy-archs-unaligned.S')
| -rw-r--r-- | arch/arc/lib/memcpy-archs-unaligned.S | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/arch/arc/lib/memcpy-archs-unaligned.S b/arch/arc/lib/memcpy-archs-unaligned.S new file mode 100644 index 000000000000..28993a73fdde --- /dev/null +++ b/arch/arc/lib/memcpy-archs-unaligned.S @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * ARCv2 memcpy implementation optimized for unaligned memory access using. + * + * Copyright (C) 2019 Synopsys + * Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> + */ + +#include <linux/linkage.h> + +#ifdef CONFIG_ARC_HAS_LL64 +# define LOADX(DST,RX) ldd.ab DST, [RX, 8] +# define STOREX(SRC,RX) std.ab SRC, [RX, 8] +# define ZOLSHFT 5 +# define ZOLAND 0x1F +#else +# define LOADX(DST,RX) ld.ab DST, [RX, 4] +# define STOREX(SRC,RX) st.ab SRC, [RX, 4] +# define ZOLSHFT 4 +# define ZOLAND 0xF +#endif + +ENTRY_CFI(memcpy) + mov r3, r0 ; don;t clobber ret val + + lsr.f lp_count, r2, ZOLSHFT + lpnz @.Lcopy32_64bytes + ;; LOOP START + LOADX (r6, r1) + LOADX (r8, r1) + LOADX (r10, r1) + LOADX (r4, r1) + STOREX (r6, r3) + STOREX (r8, r3) + STOREX (r10, r3) + STOREX (r4, r3) +.Lcopy32_64bytes: + + and.f lp_count, r2, ZOLAND ;Last remaining 31 bytes + lpnz @.Lcopyremainingbytes + ;; LOOP START + ldb.ab r5, [r1, 1] + stb.ab r5, [r3, 1] +.Lcopyremainingbytes: + + j [blink] +END_CFI(memcpy) |