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-rw-r--r--arch/arm/lib/csumpartialcopygeneric.S331
1 files changed, 331 insertions, 0 deletions
diff --git a/arch/arm/lib/csumpartialcopygeneric.S b/arch/arm/lib/csumpartialcopygeneric.S
new file mode 100644
index 000000000..0fd5c10e9
--- /dev/null
+++ b/arch/arm/lib/csumpartialcopygeneric.S
@@ -0,0 +1,331 @@
+/* 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
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