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| /* SPDX-License-Identifier: GPL-2.0-only */
| /*
| * linux/arch/arm/lib/csumpartialcopygeneric.S
| *
| * Copyright (C) 1995-2001 Russell King
| */
| #include <asm/assembler.h>
|
| /*
| * unsigned int
| * csum_partial_copy_xxx(const char *src, char *dst, int len, int sum, )
| * r0 = src, r1 = dst, r2 = len, r3 = sum
| * Returns : r0 = checksum
| *
| * Note that 'tst' and 'teq' preserve the carry flag.
| */
|
| src .req r0
| dst .req r1
| len .req r2
| sum .req r3
|
| .Lzero: mov r0, sum
| load_regs
|
| /*
| * Align an unaligned destination pointer. We know that
| * we have >= 8 bytes here, so we don't need to check
| * the length. Note that the source pointer hasn't been
| * aligned yet.
| */
| .Ldst_unaligned:
| tst dst, #1
| beq .Ldst_16bit
|
| load1b ip
| sub len, len, #1
| adcs sum, sum, ip, put_byte_1 @ update checksum
| strb ip, [dst], #1
| tst dst, #2
| reteq lr @ dst is now 32bit aligned
|
| .Ldst_16bit: load2b r8, ip
| sub len, len, #2
| adcs sum, sum, r8, put_byte_0
| strb r8, [dst], #1
| adcs sum, sum, ip, put_byte_1
| strb ip, [dst], #1
| ret lr @ dst is now 32bit aligned
|
| /*
| * Handle 0 to 7 bytes, with any alignment of source and
| * destination pointers. Note that when we get here, C = 0
| */
| .Lless8: teq len, #0 @ check for zero count
| beq .Lzero
|
| /* we must have at least one byte. */
| tst dst, #1 @ dst 16-bit aligned
| beq .Lless8_aligned
|
| /* Align dst */
| load1b ip
| sub len, len, #1
| adcs sum, sum, ip, put_byte_1 @ update checksum
| strb ip, [dst], #1
| tst len, #6
| beq .Lless8_byteonly
|
| 1: load2b r8, ip
| sub len, len, #2
| adcs sum, sum, r8, put_byte_0
| strb r8, [dst], #1
| adcs sum, sum, ip, put_byte_1
| strb ip, [dst], #1
| .Lless8_aligned:
| tst len, #6
| bne 1b
| .Lless8_byteonly:
| tst len, #1
| beq .Ldone
| load1b r8
| adcs sum, sum, r8, put_byte_0 @ update checksum
| strb r8, [dst], #1
| b .Ldone
|
| FN_ENTRY
| save_regs
| mov sum, #-1
|
| cmp len, #8 @ Ensure that we have at least
| blo .Lless8 @ 8 bytes to copy.
|
| adds sum, sum, #0 @ C = 0
| tst dst, #3 @ Test destination alignment
| blne .Ldst_unaligned @ align destination, return here
|
| /*
| * Ok, the dst pointer is now 32bit aligned, and we know
| * that we must have more than 4 bytes to copy. Note
| * that C contains the carry from the dst alignment above.
| */
|
| tst src, #3 @ Test source alignment
| bne .Lsrc_not_aligned
|
| /* Routine for src & dst aligned */
|
| bics ip, len, #15
| beq 2f
|
| 1: load4l r4, r5, r6, r7
| stmia dst!, {r4, r5, r6, r7}
| adcs sum, sum, r4
| adcs sum, sum, r5
| adcs sum, sum, r6
| adcs sum, sum, r7
| sub ip, ip, #16
| teq ip, #0
| bne 1b
|
| 2: ands ip, len, #12
| beq 4f
| tst ip, #8
| beq 3f
| load2l r4, r5
| stmia dst!, {r4, r5}
| adcs sum, sum, r4
| adcs sum, sum, r5
| tst ip, #4
| beq 4f
|
| 3: load1l r4
| str r4, [dst], #4
| adcs sum, sum, r4
|
| 4: ands len, len, #3
| beq .Ldone
| load1l r4
| tst len, #2
| mov r5, r4, get_byte_0
| beq .Lexit
| adcs sum, sum, r4, lspush #16
| strb r5, [dst], #1
| mov r5, r4, get_byte_1
| strb r5, [dst], #1
| mov r5, r4, get_byte_2
| .Lexit: tst len, #1
| strbne r5, [dst], #1
| andne r5, r5, #255
| adcsne sum, sum, r5, put_byte_0
|
| /*
| * If the dst pointer was not 16-bit aligned, we
| * need to rotate the checksum here to get around
| * the inefficient byte manipulations in the
| * architecture independent code.
| */
| .Ldone: adc r0, sum, #0
| ldr sum, [sp, #0] @ dst
| tst sum, #1
| movne r0, r0, ror #8
| load_regs
|
| .Lsrc_not_aligned:
| adc sum, sum, #0 @ include C from dst alignment
| and ip, src, #3
| bic src, src, #3
| load1l r5
| cmp ip, #2
| beq .Lsrc2_aligned
| bhi .Lsrc3_aligned
| mov r4, r5, lspull #8 @ C = 0
| bics ip, len, #15
| beq 2f
| 1: load4l r5, r6, r7, r8
| orr r4, r4, r5, lspush #24
| mov r5, r5, lspull #8
| orr r5, r5, r6, lspush #24
| mov r6, r6, lspull #8
| orr r6, r6, r7, lspush #24
| mov r7, r7, lspull #8
| orr r7, r7, r8, lspush #24
| stmia dst!, {r4, r5, r6, r7}
| adcs sum, sum, r4
| adcs sum, sum, r5
| adcs sum, sum, r6
| adcs sum, sum, r7
| mov r4, r8, lspull #8
| sub ip, ip, #16
| teq ip, #0
| bne 1b
| 2: ands ip, len, #12
| beq 4f
| tst ip, #8
| beq 3f
| load2l r5, r6
| orr r4, r4, r5, lspush #24
| mov r5, r5, lspull #8
| orr r5, r5, r6, lspush #24
| stmia dst!, {r4, r5}
| adcs sum, sum, r4
| adcs sum, sum, r5
| mov r4, r6, lspull #8
| tst ip, #4
| beq 4f
| 3: load1l r5
| orr r4, r4, r5, lspush #24
| str r4, [dst], #4
| adcs sum, sum, r4
| mov r4, r5, lspull #8
| 4: ands len, len, #3
| beq .Ldone
| mov r5, r4, get_byte_0
| tst len, #2
| beq .Lexit
| adcs sum, sum, r4, lspush #16
| strb r5, [dst], #1
| mov r5, r4, get_byte_1
| strb r5, [dst], #1
| mov r5, r4, get_byte_2
| b .Lexit
|
| .Lsrc2_aligned: mov r4, r5, lspull #16
| adds sum, sum, #0
| bics ip, len, #15
| beq 2f
| 1: load4l r5, r6, r7, r8
| orr r4, r4, r5, lspush #16
| mov r5, r5, lspull #16
| orr r5, r5, r6, lspush #16
| mov r6, r6, lspull #16
| orr r6, r6, r7, lspush #16
| mov r7, r7, lspull #16
| orr r7, r7, r8, lspush #16
| stmia dst!, {r4, r5, r6, r7}
| adcs sum, sum, r4
| adcs sum, sum, r5
| adcs sum, sum, r6
| adcs sum, sum, r7
| mov r4, r8, lspull #16
| sub ip, ip, #16
| teq ip, #0
| bne 1b
| 2: ands ip, len, #12
| beq 4f
| tst ip, #8
| beq 3f
| load2l r5, r6
| orr r4, r4, r5, lspush #16
| mov r5, r5, lspull #16
| orr r5, r5, r6, lspush #16
| stmia dst!, {r4, r5}
| adcs sum, sum, r4
| adcs sum, sum, r5
| mov r4, r6, lspull #16
| tst ip, #4
| beq 4f
| 3: load1l r5
| orr r4, r4, r5, lspush #16
| str r4, [dst], #4
| adcs sum, sum, r4
| mov r4, r5, lspull #16
| 4: ands len, len, #3
| beq .Ldone
| mov r5, r4, get_byte_0
| tst len, #2
| beq .Lexit
| adcs sum, sum, r4
| strb r5, [dst], #1
| mov r5, r4, get_byte_1
| strb r5, [dst], #1
| tst len, #1
| beq .Ldone
| load1b r5
| b .Lexit
|
| .Lsrc3_aligned: mov r4, r5, lspull #24
| adds sum, sum, #0
| bics ip, len, #15
| beq 2f
| 1: load4l r5, r6, r7, r8
| orr r4, r4, r5, lspush #8
| mov r5, r5, lspull #24
| orr r5, r5, r6, lspush #8
| mov r6, r6, lspull #24
| orr r6, r6, r7, lspush #8
| mov r7, r7, lspull #24
| orr r7, r7, r8, lspush #8
| stmia dst!, {r4, r5, r6, r7}
| adcs sum, sum, r4
| adcs sum, sum, r5
| adcs sum, sum, r6
| adcs sum, sum, r7
| mov r4, r8, lspull #24
| sub ip, ip, #16
| teq ip, #0
| bne 1b
| 2: ands ip, len, #12
| beq 4f
| tst ip, #8
| beq 3f
| load2l r5, r6
| orr r4, r4, r5, lspush #8
| mov r5, r5, lspull #24
| orr r5, r5, r6, lspush #8
| stmia dst!, {r4, r5}
| adcs sum, sum, r4
| adcs sum, sum, r5
| mov r4, r6, lspull #24
| tst ip, #4
| beq 4f
| 3: load1l r5
| orr r4, r4, r5, lspush #8
| str r4, [dst], #4
| adcs sum, sum, r4
| mov r4, r5, lspull #24
| 4: ands len, len, #3
| beq .Ldone
| mov r5, r4, get_byte_0
| tst len, #2
| beq .Lexit
| strb r5, [dst], #1
| adcs sum, sum, r4
| load1l r4
| mov r5, r4, get_byte_0
| strb r5, [dst], #1
| adcs sum, sum, r4, lspush #24
| mov r5, r4, get_byte_1
| b .Lexit
| FN_EXIT
|
|
