X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=arch%2Fx86%2Flib%2Fstring.c;h=6c66431ed93b3d4943954f0e07a04a0acf665c77;hb=e94019ede750f2807b5a211ba39beb05bba5714d;hp=f2ea7e4e338608799d6f7debe93ed8ab0e994512;hpb=dbaef6ef33912a863f9fb550857028fb96e42c59;p=oweals%2Fu-boot.git

diff --git a/arch/x86/lib/string.c b/arch/x86/lib/string.c
index f2ea7e4e33..6c66431ed9 100644
--- a/arch/x86/lib/string.c
+++ b/arch/x86/lib/string.c
@@ -3,30 +3,14 @@
  * This file is part of the GNU C Library.
  * Copyright (c) 2011 The Chromium OS Authors.
  *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * 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 (at your option) 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., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 /* From glibc-2.14, sysdeps/i386/memset.c */
 
-#include <compiler.h>
-#include <asm/string.h>
 #include <linux/types.h>
+#include <linux/compiler.h>
+#include <asm/string.h>
 
 typedef uint32_t op_t;
 
@@ -85,3 +69,64 @@ void *memset(void *dstpp, int c, size_t len)
 
 	return dstpp;
 }
+
+#define	OP_T_THRES	8
+#define OPSIZ	(sizeof(op_t))
+
+#define BYTE_COPY_FWD(dst_bp, src_bp, nbytes)				  \
+do {									  \
+	int __d0;							  \
+	asm volatile(							  \
+		/* Clear the direction flag, so copying goes forward.  */ \
+		"cld\n"							  \
+		/* Copy bytes.  */					  \
+		"rep\n"							  \
+		"movsb" :						  \
+		"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) :		  \
+		"0" (dst_bp), "1" (src_bp), "2" (nbytes) :		  \
+		"memory");						  \
+} while (0)
+
+#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes)		  \
+do {									  \
+	int __d0;							  \
+	asm volatile(							  \
+		/* Clear the direction flag, so copying goes forward.  */ \
+		"cld\n"							  \
+		/* Copy longwords.  */					  \
+		"rep\n"							  \
+		"movsl" :						  \
+		"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) :		  \
+		"0" (dst_bp), "1" (src_bp), "2" ((nbytes) / 4) :	  \
+		"memory");						  \
+	(nbytes_left) = (nbytes) % 4;					  \
+} while (0)
+
+void *memcpy(void *dstpp, const void *srcpp, size_t len)
+{
+	unsigned long int dstp = (long int)dstpp;
+	unsigned long int srcp = (long int)srcpp;
+
+	/* Copy from the beginning to the end.  */
+
+	/* If there not too few bytes to copy, use word copy.  */
+	if (len >= OP_T_THRES) {
+		/* Copy just a few bytes to make DSTP aligned.  */
+		len -= (-dstp) % OPSIZ;
+		BYTE_COPY_FWD(dstp, srcp, (-dstp) % OPSIZ);
+
+		/* Copy from SRCP to DSTP taking advantage of the known
+		 * alignment of DSTP.  Number of bytes remaining is put
+		 * in the third argument, i.e. in LEN.  This number may
+		 * vary from machine to machine.
+		 */
+		WORD_COPY_FWD(dstp, srcp, len, len);
+
+		/* Fall out and copy the tail.  */
+	}
+
+	/* There are just a few bytes to copy. Use byte memory operations. */
+	BYTE_COPY_FWD(dstp, srcp, len);
+
+	return dstpp;
+}