1 files changed, 160 insertions, 0 deletions
diff --git a/arch/arm64/lib/crc32.S b/arch/arm64/lib/crc32.S
new file mode 100644
index 000000000..8340dccff
--- /dev/null
+++ b/arch/arm64/lib/crc32.S
@@ -0,0 +1,160 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Accelerated CRC32(C) using AArch64 CRC instructions
+ *
+ * Copyright (C) 2016 - 2018 Linaro Ltd <ard.biesheuvel@linaro.org>
+ */
+
+#include <linux/linkage.h>
+#include <asm/alternative.h>
+#include <asm/assembler.h>
+
+	.arch		armv8-a+crc
+
+	.macro		byteorder, reg, be
+	.if		\be
+CPU_LE( rev		\reg, \reg	)
+	.else
+CPU_BE( rev		\reg, \reg	)
+	.endif
+	.endm
+
+	.macro		byteorder16, reg, be
+	.if		\be
+CPU_LE( rev16		\reg, \reg	)
+	.else
+CPU_BE( rev16		\reg, \reg	)
+	.endif
+	.endm
+
+	.macro		bitorder, reg, be
+	.if		\be
+	rbit		\reg, \reg
+	.endif
+	.endm
+
+	.macro		bitorder16, reg, be
+	.if		\be
+	rbit		\reg, \reg
+	lsr		\reg, \reg, #16
+	.endif
+	.endm
+
+	.macro		bitorder8, reg, be
+	.if		\be
+	rbit		\reg, \reg
+	lsr		\reg, \reg, #24
+	.endif
+	.endm
+
+	.macro		__crc32, c, be=0
+	bitorder	w0, \be
+	cmp		x2, #16
+	b.lt		8f			// less than 16 bytes
+
+	and		x7, x2, #0x1f
+	and		x2, x2, #~0x1f
+	cbz		x7, 32f			// multiple of 32 bytes
+
+	and		x8, x7, #0xf
+	ldp		x3, x4, [x1]
+	add		x8, x8, x1
+	add		x1, x1, x7
+	ldp		x5, x6, [x8]
+	byteorder	x3, \be
+	byteorder	x4, \be
+	byteorder	x5, \be
+	byteorder	x6, \be
+	bitorder	x3, \be
+	bitorder	x4, \be
+	bitorder	x5, \be
+	bitorder	x6, \be
+
+	tst		x7, #8
+	crc32\c\()x	w8, w0, x3
+	csel		x3, x3, x4, eq
+	csel		w0, w0, w8, eq
+	tst		x7, #4
+	lsr		x4, x3, #32
+	crc32\c\()w	w8, w0, w3
+	csel		x3, x3, x4, eq
+	csel		w0, w0, w8, eq
+	tst		x7, #2
+	lsr		w4, w3, #16
+	crc32\c\()h	w8, w0, w3
+	csel		w3, w3, w4, eq
+	csel		w0, w0, w8, eq
+	tst		x7, #1
+	crc32\c\()b	w8, w0, w3
+	csel		w0, w0, w8, eq
+	tst		x7, #16
+	crc32\c\()x	w8, w0, x5
+	crc32\c\()x	w8, w8, x6
+	csel		w0, w0, w8, eq
+	cbz		x2, 0f
+
+32:	ldp		x3, x4, [x1], #32
+	sub		x2, x2, #32
+	ldp		x5, x6, [x1, #-16]
+	byteorder	x3, \be
+	byteorder	x4, \be
+	byteorder	x5, \be
+	byteorder	x6, \be
+	bitorder	x3, \be
+	bitorder	x4, \be
+	bitorder	x5, \be
+	bitorder	x6, \be
+	crc32\c\()x	w0, w0, x3
+	crc32\c\()x	w0, w0, x4
+	crc32\c\()x	w0, w0, x5
+	crc32\c\()x	w0, w0, x6
+	cbnz		x2, 32b
+0:	bitorder	w0, \be
+	ret
+
+8:	tbz		x2, #3, 4f
+	ldr		x3, [x1], #8
+	byteorder	x3, \be
+	bitorder	x3, \be
+	crc32\c\()x	w0, w0, x3
+4:	tbz		x2, #2, 2f
+	ldr		w3, [x1], #4
+	byteorder	w3, \be
+	bitorder	w3, \be
+	crc32\c\()w	w0, w0, w3
+2:	tbz		x2, #1, 1f
+	ldrh		w3, [x1], #2
+	byteorder16	w3, \be
+	bitorder16	w3, \be
+	crc32\c\()h	w0, w0, w3
+1:	tbz		x2, #0, 0f
+	ldrb		w3, [x1]
+	bitorder8	w3, \be
+	crc32\c\()b	w0, w0, w3
+0:	bitorder	w0, \be
+	ret
+	.endm
+
+	.align		5
+SYM_FUNC_START(crc32_le)
+alternative_if_not ARM64_HAS_CRC32
+	b		crc32_le_base
+alternative_else_nop_endif
+	__crc32
+SYM_FUNC_END(crc32_le)
+
+	.align		5
+SYM_FUNC_START(__crc32c_le)
+alternative_if_not ARM64_HAS_CRC32
+	b		__crc32c_le_base
+alternative_else_nop_endif
+	__crc32		c
+SYM_FUNC_END(__crc32c_le)
+
+	.align		5
+SYM_FUNC_START(crc32_be)
+alternative_if_not ARM64_HAS_CRC32
+	b		crc32_be_base
+alternative_else_nop_endif
+	__crc32		be=1
+SYM_FUNC_END(crc32_be)