1 files changed, 266 insertions, 0 deletions
diff --git a/src/arch/loong64/core/loong64_string.c b/src/arch/loong64/core/loong64_string.c
new file mode 100644
index 00000000..941b7e2b
--- /dev/null
+++ b/src/arch/loong64/core/loong64_string.c
@@ -0,0 +1,266 @@
+/*
+ * Copyright (C) 2016 Michael Brown <mbrown@fensystems.co.uk>.
+ * Copyright (c) 2023, Xiaotian Wu <wuxiaotian@loongson.cn>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+/** @file
+ *
+ * Optimised string operations
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <string.h>
+
+/**
+ * Copy memory area
+ *
+ * @v dest		Destination address
+ * @v src		Source address
+ * @v len		Length
+ * @ret dest		Destination address
+ */
+void loong64_memcpy ( void *dest, const void *src, size_t len ) {
+	void *discard_dest;
+	void *discard_end;
+	const void *discard_src;
+	size_t discard_offset;
+	unsigned long discard_data;
+	unsigned long discard_low;
+	unsigned long discard_high;
+
+	/* If length is too short, then just copy individual bytes.
+	 */
+	if ( len < 16 ) {
+		__asm__ __volatile__ ( "beqz %0, 2f\n\t"
+				       "\n1:\n\t"
+				       "addi.d %0, %0, -1\n\t"
+				       "ldx.b %1, %3, %0\n\t"
+				       "stx.b %1, %2, %0\n\t"
+				       "bnez %0, 1b\n\t"
+				       "\n2:\n\t"
+				       : "=&r" ( discard_offset ),
+					 "=&r" ( discard_data )
+				       : "r" ( dest ), "r" ( src ), "0" ( len )
+				       : "memory", "t0" );
+		return;
+	}
+
+	/* Copy 16 bytes at a time: one initial
+	 * potentially unaligned access, multiple destination-aligned
+	 * accesses, one final potentially unaligned access.
+	 */
+	__asm__ __volatile__ ( "ld.d %3, %1, 0\n\t"
+			       "ld.d %4, %1, 8\n\t"
+			       "addi.d %1, %1, 16\n\t"
+			       "st.d %3, %0, 0\n\t"
+			       "st.d %4, %0, 8\n\t"
+			       "addi.d %0, %0, 16\n\t"
+			       "andi %3, %0, 15\n\t"
+			       "sub.d %0, %0, %3\n\t"
+			       "sub.d %1, %1, %3\n\t"
+			       "addi.d $t0, $zero, 0xf\n\t"
+			       "andn %2, %5, $t0\n\t"
+			       "b 2f\n\t"
+			       "\n1:\n\t"
+			       "ld.d %3, %1, 0\n\t"
+			       "ld.d %4, %1, 8\n\t"
+			       "addi.d %1, %1, 16\n\t"
+			       "st.d %3, %0, 0\n\t"
+			       "st.d %4, %0, 8\n\t"
+			       "addi.d %0, %0, 16\n\t"
+			       "\n2:\n\t"
+			       "bne %0, %2, 1b\n\t"
+			       "ld.d %3, %6, -16\n\t"
+			       "ld.d %4, %6, -8\n\t"
+			       "st.d %3, %5, -16\n\t"
+			       "st.d %4, %5, -8\n\t"
+			       : "=&r" ( discard_dest ),
+				 "=&r" ( discard_src ),
+				 "=&r" ( discard_end ),
+				 "=&r" ( discard_low ),
+				 "=&r" ( discard_high )
+			       : "r" ( dest + len ), "r" ( src + len ),
+				 "0" ( dest ), "1" ( src )
+			       : "memory", "t0" );
+}
+
+/**
+ * Zero memory region
+ *
+ * @v dest		Destination region
+ * @v len		Length
+ */
+void loong64_bzero ( void *dest, size_t len ) {
+	size_t discard_offset;
+	void *discard_dest;
+	void *discard_end;
+
+	/* If length is too short, then just zero individual bytes.
+	 */
+	if ( len < 16 ) {
+		__asm__ __volatile__ ( "beqz %0, 2f\n\t"
+				       "\n1:\n\t"
+				       "addi.d %0, %0, -1\n\t"
+				       "stx.b $zero, %1, %0\n\t"
+				       "bnez %0, 1b\n\t"
+				       "\n2:\n\t"
+				       : "=&r" ( discard_offset )
+				       : "r" ( dest ), "0" ( len )
+				       : "memory" );
+		return;
+	}
+
+	/* To zero 16 bytes at a time: one initial
+	 * potentially unaligned access, multiple aligned accesses,
+	 * one final potentially unaligned access.
+	 */
+
+	__asm__ __volatile__ ( "st.d $zero, %0, 0\n\t"
+			       "st.d $zero, %0, 8\n\t"
+			       "addi.d %0, %0, 16\n\t"
+			       "addi.w $t0, $zero, 15\n\t"
+			       "andn %0, %0, $t0\n\t"
+			       "addi.w $t0, $zero, 15\n\t"
+			       "andn %1, %2, $t0\n\t"
+			       "b 2f\n\t"
+			       "\n1:\n\t"
+			       "st.d $zero, %0, 0\n\t"
+			       "st.d $zero, %0, 8\n\t"
+			       "addi.d %0, %0, 16\n\t"
+			       "\n2:\n\t"
+			       "bne %0, %1, 1b\n\t"
+			       "st.d $zero, %2, -16\n\t"
+			       "st.d $zero, %2, -8\n\t"
+			       : "=&r" ( discard_dest ),
+				 "=&r" ( discard_end )
+			       : "r" ( dest + len ), "0" ( dest )
+			       : "memory", "t0" );
+}
+
+/**
+ * Fill memory region
+ *
+ * @v dest		Destination region
+ * @v len		Length
+ * @v character		Fill character
+ *
+ * The unusual parameter order is to allow for more efficient
+ * tail-calling to loong64_memset() when zeroing a region.
+ */
+void loong64_memset ( void *dest, size_t len, int character ) {
+	size_t discard_offset;
+
+	/* Use optimised zeroing code if applicable */
+	if ( character == 0 ) {
+		loong64_bzero ( dest, len );
+		return;
+	}
+
+	/* Fill one byte at a time.  Calling memset() with a non-zero
+	 * value is relatively rare and unlikely to be
+	 * performance-critical.
+	 */
+	__asm__ __volatile__ ( "beqz %0, 2f\n\t"
+			       "\n1:\n\t"
+			       "addi.d %0, %0, -1\n\t"
+			       "stx.b %2, %1, %0\n\t"
+			       "bnez %0, 1b\n\t"
+			       "\n2:\n\t"
+			       : "=&r" ( discard_offset )
+			       : "r" ( dest ), "r" ( character ), "0" ( len )
+			       : "memory" );
+}
+
+/**
+ * Copy (possibly overlapping) memory region forwards
+ *
+ * @v dest		Destination region
+ * @v src		Source region
+ * @v len		Length
+ */
+void loong64_memmove_forwards ( void *dest, const void *src, size_t len ) {
+	void *discard_dest;
+	const void *discard_src;
+	unsigned long discard_data;
+
+	/* Assume memmove() is not performance-critical, and perform a
+	 * bytewise copy for simplicity.
+	 */
+	__asm__ __volatile__ ( "b 2f\n\t"
+			       "\n1:\n\t"
+			       "ld.b %2, %1, 0\n\t"
+			       "addi.d %1, %1, 1\n\t"
+			       "st.b %2, %0, 0\n\t"
+			       "addi.d %0, %0, 1\n\t"
+			       "\n2:\n\t"
+			       "bne %0, %3, 1b\n\t"
+			       : "=&r" ( discard_dest ),
+				 "=&r" ( discard_src ),
+				 "=&r" ( discard_data )
+			       : "r" ( dest + len ), "0" ( dest ), "1" ( src )
+			       : "memory" );
+}
+
+/**
+ * Copy (possibly overlapping) memory region backwards
+ *
+ * @v dest		Destination region
+ * @v src		Source region
+ * @v len		Length
+ */
+void loong64_memmove_backwards ( void *dest, const void *src, size_t len ) {
+	size_t discard_offset;
+	unsigned long discard_data;
+
+	/* Assume memmove() is not performance-critical, and perform a
+	 * bytewise copy for simplicity.
+	 */
+	__asm__ __volatile__ ( "beqz %0, 2f\n\t"
+			       "\n1:\n\t"
+			       "addi.d %0, %0, -1\n\t"
+			       "ldx.b %1, %3, %0\n\t"
+			       "stx.b %1, %2, %0\n\t"
+			       "bnez %0, 1b\n\t"
+			       "\n2:\n\t"
+			       : "=&r" ( discard_offset ),
+				 "=&r" ( discard_data )
+			       : "r" ( dest ), "r" ( src ), "0" ( len )
+			       : "memory" );
+}
+
+/**
+ * Copy (possibly overlapping) memory region
+ *
+ * @v dest		Destination region
+ * @v src		Source region
+ * @v len		Length
+ */
+void loong64_memmove ( void *dest, const void *src, size_t len ) {
+
+	if ( dest <= src ) {
+		loong64_memmove_forwards ( dest, src, len );
+	} else {
+		loong64_memmove_backwards ( dest, src, len );
+	}
+}