summaryrefslogtreecommitdiffstats
path: root/kernel/arch/arm/lib/copy_page.S
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/arch/arm/lib/copy_page.S')
-rw-r--r--kernel/arch/arm/lib/copy_page.S47
1 files changed, 47 insertions, 0 deletions
diff --git a/kernel/arch/arm/lib/copy_page.S b/kernel/arch/arm/lib/copy_page.S
new file mode 100644
index 000000000..6ee2f6706
--- /dev/null
+++ b/kernel/arch/arm/lib/copy_page.S
@@ -0,0 +1,47 @@
+/*
+ * linux/arch/arm/lib/copypage.S
+ *
+ * Copyright (C) 1995-1999 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 <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+#include <asm/cache.h>
+
+#define COPY_COUNT (PAGE_SZ / (2 * L1_CACHE_BYTES) PLD( -1 ))
+
+ .text
+ .align 5
+/*
+ * StrongARM optimised copy_page routine
+ * now 1.78bytes/cycle, was 1.60 bytes/cycle (50MHz bus -> 89MB/s)
+ * Note that we probably achieve closer to the 100MB/s target with
+ * the core clock switching.
+ */
+ENTRY(copy_page)
+ stmfd sp!, {r4, lr} @ 2
+ PLD( pld [r1, #0] )
+ PLD( pld [r1, #L1_CACHE_BYTES] )
+ mov r2, #COPY_COUNT @ 1
+ ldmia r1!, {r3, r4, ip, lr} @ 4+1
+1: PLD( pld [r1, #2 * L1_CACHE_BYTES])
+ PLD( pld [r1, #3 * L1_CACHE_BYTES])
+2:
+ .rept (2 * L1_CACHE_BYTES / 16 - 1)
+ stmia r0!, {r3, r4, ip, lr} @ 4
+ ldmia r1!, {r3, r4, ip, lr} @ 4
+ .endr
+ subs r2, r2, #1 @ 1
+ stmia r0!, {r3, r4, ip, lr} @ 4
+ ldmgtia r1!, {r3, r4, ip, lr} @ 4
+ bgt 1b @ 1
+ PLD( ldmeqia r1!, {r3, r4, ip, lr} )
+ PLD( beq 2b )
+ ldmfd sp!, {r4, pc} @ 3
+ENDPROC(copy_page)