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| /* SPDX-License-Identifier: GPL-2.0-only */
| /*
| * Copyright (C) 2013 ARM Ltd.
| * Copyright (C) 2013 Linaro.
| *
| * This code is based on glibc cortex strings work originally authored by Linaro
| * be found @
| *
| * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
| * files/head:/src/aarch64/
| */
|
| #include <linux/linkage.h>
| #include <asm/assembler.h>
| #include <asm/cache.h>
|
| /*
| * Move a buffer from src to test (alignment handled by the hardware).
| * If dest <= src, call memcpy, otherwise copy in reverse order.
| *
| * Parameters:
| * x0 - dest
| * x1 - src
| * x2 - n
| * Returns:
| * x0 - dest
| */
| dstin .req x0
| src .req x1
| count .req x2
| tmp1 .req x3
| tmp1w .req w3
| tmp2 .req x4
| tmp2w .req w4
| tmp3 .req x5
| tmp3w .req w5
| dst .req x6
|
| A_l .req x7
| A_h .req x8
| B_l .req x9
| B_h .req x10
| C_l .req x11
| C_h .req x12
| D_l .req x13
| D_h .req x14
|
| SYM_FUNC_START_ALIAS(__memmove)
| SYM_FUNC_START_WEAK_PI(memmove)
| cmp dstin, src
| b.lo __memcpy
| add tmp1, src, count
| cmp dstin, tmp1
| b.hs __memcpy /* No overlap. */
|
| add dst, dstin, count
| add src, src, count
| cmp count, #16
| b.lo .Ltail15 /*probably non-alignment accesses.*/
|
| ands tmp2, src, #15 /* Bytes to reach alignment. */
| b.eq .LSrcAligned
| sub count, count, tmp2
| /*
| * process the aligned offset length to make the src aligned firstly.
| * those extra instructions' cost is acceptable. It also make the
| * coming accesses are based on aligned address.
| */
| tbz tmp2, #0, 1f
| ldrb tmp1w, [src, #-1]!
| strb tmp1w, [dst, #-1]!
| 1:
| tbz tmp2, #1, 2f
| ldrh tmp1w, [src, #-2]!
| strh tmp1w, [dst, #-2]!
| 2:
| tbz tmp2, #2, 3f
| ldr tmp1w, [src, #-4]!
| str tmp1w, [dst, #-4]!
| 3:
| tbz tmp2, #3, .LSrcAligned
| ldr tmp1, [src, #-8]!
| str tmp1, [dst, #-8]!
|
| .LSrcAligned:
| cmp count, #64
| b.ge .Lcpy_over64
|
| /*
| * Deal with small copies quickly by dropping straight into the
| * exit block.
| */
| .Ltail63:
| /*
| * Copy up to 48 bytes of data. At this point we only need the
| * bottom 6 bits of count to be accurate.
| */
| ands tmp1, count, #0x30
| b.eq .Ltail15
| cmp tmp1w, #0x20
| b.eq 1f
| b.lt 2f
| ldp A_l, A_h, [src, #-16]!
| stp A_l, A_h, [dst, #-16]!
| 1:
| ldp A_l, A_h, [src, #-16]!
| stp A_l, A_h, [dst, #-16]!
| 2:
| ldp A_l, A_h, [src, #-16]!
| stp A_l, A_h, [dst, #-16]!
|
| .Ltail15:
| tbz count, #3, 1f
| ldr tmp1, [src, #-8]!
| str tmp1, [dst, #-8]!
| 1:
| tbz count, #2, 2f
| ldr tmp1w, [src, #-4]!
| str tmp1w, [dst, #-4]!
| 2:
| tbz count, #1, 3f
| ldrh tmp1w, [src, #-2]!
| strh tmp1w, [dst, #-2]!
| 3:
| tbz count, #0, .Lexitfunc
| ldrb tmp1w, [src, #-1]
| strb tmp1w, [dst, #-1]
|
| .Lexitfunc:
| ret
|
| .Lcpy_over64:
| subs count, count, #128
| b.ge .Lcpy_body_large
| /*
| * Less than 128 bytes to copy, so handle 64 bytes here and then jump
| * to the tail.
| */
| ldp A_l, A_h, [src, #-16]
| stp A_l, A_h, [dst, #-16]
| ldp B_l, B_h, [src, #-32]
| ldp C_l, C_h, [src, #-48]
| stp B_l, B_h, [dst, #-32]
| stp C_l, C_h, [dst, #-48]
| ldp D_l, D_h, [src, #-64]!
| stp D_l, D_h, [dst, #-64]!
|
| tst count, #0x3f
| b.ne .Ltail63
| ret
|
| /*
| * Critical loop. Start at a new cache line boundary. Assuming
| * 64 bytes per line this ensures the entire loop is in one line.
| */
| .p2align L1_CACHE_SHIFT
| .Lcpy_body_large:
| /* pre-load 64 bytes data. */
| ldp A_l, A_h, [src, #-16]
| ldp B_l, B_h, [src, #-32]
| ldp C_l, C_h, [src, #-48]
| ldp D_l, D_h, [src, #-64]!
| 1:
| /*
| * interlace the load of next 64 bytes data block with store of the last
| * loaded 64 bytes data.
| */
| stp A_l, A_h, [dst, #-16]
| ldp A_l, A_h, [src, #-16]
| stp B_l, B_h, [dst, #-32]
| ldp B_l, B_h, [src, #-32]
| stp C_l, C_h, [dst, #-48]
| ldp C_l, C_h, [src, #-48]
| stp D_l, D_h, [dst, #-64]!
| ldp D_l, D_h, [src, #-64]!
| subs count, count, #64
| b.ge 1b
| stp A_l, A_h, [dst, #-16]
| stp B_l, B_h, [dst, #-32]
| stp C_l, C_h, [dst, #-48]
| stp D_l, D_h, [dst, #-64]!
|
| tst count, #0x3f
| b.ne .Ltail63
| ret
| SYM_FUNC_END_PI(memmove)
| EXPORT_SYMBOL(memmove)
| SYM_FUNC_END_ALIAS(__memmove)
| EXPORT_SYMBOL(__memmove)
|
|
