arm: Use optimized memcpy and memset from linux

Using optimized versions of memset and memcpy from linux brings a quite
noticeable speed (x2 or better) improvement for these two functions.

Here are some numbers for test done with jadecpu

                           | HEAD(1)| HEAD(1)| HEAD(2)| HEAD(2)|
                           |        | +patch |        | +patch |
---------------------------+--------+--------+--------+--------+
Reset to prompt            |  438ms |  330ms |  228ms |  120ms |
                           |        |        |        |        |
TFTP a 3MB img             | 4782ms | 3428ms | 3245ms | 2820ms |
                           |        |        |        |        |
FATLOAD USB a 3MB img*     | 8515ms | 8510ms | ------ | ------ |
                           |        |        |        |        |
BOOTM LZO img in RAM       | 3473ms | 3168ms |  592ms |  592ms |
 where CRC is              |  615ms |  615ms |   54ms |   54ms |
 uncompress                | 2460ms | 2462ms |  450ms |  451ms |
 final boot_elf            |  376ms |   68ms |   65ms |   65ms |
                           |        |        |        |        |
BOOTM LZO img in FLASH     | 3207ms | 2902ms | 1050ms | 1050ms |
 where CRC is              |  600ms |  600ms |  135ms |  135ms |
 uncompress                | 2209ms | 2211ms |  828ms |  828ms |
                           |        |        |        |        |
Copy 1.4MB from NOR to RAM |  134ms |   72ms |  120ms |   70ms |

(1) No dcache
(2) dcache enabled in board_init
*Does not work when dcache is on

Size impact:

C version:
   text    data     bss     dec     hex filename
 202862   18912  266456  488230   77326 u-boot

ASM version:
   text    data     bss     dec     hex filename
 203798   18912  266288  488998   77626 u-boot
222712  u-boot.bin

Signed-off-by: Matthias Weisser <weisserm@arcor.de>
diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S
new file mode 100644
index 0000000..0cdf895
--- /dev/null
+++ b/arch/arm/lib/memset.S
@@ -0,0 +1,126 @@
+/*
+ *  linux/arch/arm/lib/memset.S
+ *
+ *  Copyright (C) 1995-2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  ASM optimised string functions
+ */
+#include <asm/assembler.h>
+
+	.text
+	.align	5
+	.word	0
+
+1:	subs	r2, r2, #4		@ 1 do we have enough
+	blt	5f			@ 1 bytes to align with?
+	cmp	r3, #2			@ 1
+	strltb	r1, [r0], #1		@ 1
+	strleb	r1, [r0], #1		@ 1
+	strb	r1, [r0], #1		@ 1
+	add	r2, r2, r3		@ 1 (r2 = r2 - (4 - r3))
+/*
+ * The pointer is now aligned and the length is adjusted.  Try doing the
+ * memset again.
+ */
+
+.globl memset
+memset:
+	ands	r3, r0, #3		@ 1 unaligned?
+	bne	1b			@ 1
+/*
+ * we know that the pointer in r0 is aligned to a word boundary.
+ */
+	orr	r1, r1, r1, lsl #8
+	orr	r1, r1, r1, lsl #16
+	mov	r3, r1
+	cmp	r2, #16
+	blt	4f
+
+#if ! CALGN(1)+0
+
+/*
+ * We need an extra register for this loop - save the return address and
+ * use the LR
+ */
+	str	lr, [sp, #-4]!
+	mov	ip, r1
+	mov	lr, r1
+
+2:	subs	r2, r2, #64
+	stmgeia	r0!, {r1, r3, ip, lr}	@ 64 bytes at a time.
+	stmgeia	r0!, {r1, r3, ip, lr}
+	stmgeia	r0!, {r1, r3, ip, lr}
+	stmgeia	r0!, {r1, r3, ip, lr}
+	bgt	2b
+	ldmeqfd	sp!, {pc}		@ Now <64 bytes to go.
+/*
+ * No need to correct the count; we're only testing bits from now on
+ */
+	tst	r2, #32
+	stmneia	r0!, {r1, r3, ip, lr}
+	stmneia	r0!, {r1, r3, ip, lr}
+	tst	r2, #16
+	stmneia	r0!, {r1, r3, ip, lr}
+	ldr	lr, [sp], #4
+
+#else
+
+/*
+ * This version aligns the destination pointer in order to write
+ * whole cache lines at once.
+ */
+
+	stmfd	sp!, {r4-r7, lr}
+	mov	r4, r1
+	mov	r5, r1
+	mov	r6, r1
+	mov	r7, r1
+	mov	ip, r1
+	mov	lr, r1
+
+	cmp	r2, #96
+	tstgt	r0, #31
+	ble	3f
+
+	and	ip, r0, #31
+	rsb	ip, ip, #32
+	sub	r2, r2, ip
+	movs	ip, ip, lsl #(32 - 4)
+	stmcsia	r0!, {r4, r5, r6, r7}
+	stmmiia	r0!, {r4, r5}
+	tst	ip, #(1 << 30)
+	mov	ip, r1
+	strne	r1, [r0], #4
+
+3:	subs	r2, r2, #64
+	stmgeia	r0!, {r1, r3-r7, ip, lr}
+	stmgeia	r0!, {r1, r3-r7, ip, lr}
+	bgt	3b
+	ldmeqfd	sp!, {r4-r7, pc}
+
+	tst	r2, #32
+	stmneia	r0!, {r1, r3-r7, ip, lr}
+	tst	r2, #16
+	stmneia	r0!, {r4-r7}
+	ldmfd	sp!, {r4-r7, lr}
+
+#endif
+
+4:	tst	r2, #8
+	stmneia	r0!, {r1, r3}
+	tst	r2, #4
+	strne	r1, [r0], #4
+/*
+ * When we get here, we've got less than 4 bytes to zero.  We
+ * may have an unaligned pointer as well.
+ */
+5:	tst	r2, #2
+	strneb	r1, [r0], #1
+	strneb	r1, [r0], #1
+	tst	r2, #1
+	strneb	r1, [r0], #1
+	mov	pc, lr