1 files changed, 113 insertions, 0 deletions
diff --git a/arch/arm/mm/copypage-xscale.S b/arch/arm/mm/copypage-xscale.S
new file mode 100644
index 0000000000000..bb277316ef52d
--- /dev/null
+++ b/arch/arm/mm/copypage-xscale.S
@@ -0,0 +1,113 @@
+/*
+ *  linux/arch/arm/lib/copypage-xscale.S
+ *
+ *  Copyright (C) 2001 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.
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/constants.h>
+
+/*
+ * General note:
+ *  We don't really want write-allocate cache behaviour for these functions
+ *  since that will just eat through 8K of the cache.
+ */
+
+	.text
+	.align	5
+/*
+ * XScale optimised copy_user_page
+ *  r0 = destination
+ *  r1 = source
+ *  r2 = virtual user address of ultimate destination page
+ *
+ * The source page may have some clean entries in the cache already, but we
+ * can safely ignore them - break_cow() will flush them out of the cache
+ * if we eventually end up using our copied page.
+ *
+ * What we could do is use the mini-cache to buffer reads from the source
+ * page.  We rely on the mini-cache being smaller than one page, so we'll
+ * cycle through the complete cache anyway.
+ */
+ENTRY(xscale_mc_copy_user_page)
+	stmfd	sp!, {r4, r5, lr}
+	mov	r5, r0
+	mov	r0, r1
+	bl	map_page_minicache
+	mov	r1, r5
+	mov	lr, #PAGE_SZ/64-1
+
+	/*
+	 * Strangely enough, best performance is achieved
+	 * when prefetching destination as well.  (NP)
+	 */
+	pld	[r0, #0]
+	pld	[r0, #32]
+	pld	[r1, #0]
+	pld	[r1, #32]
+
+1:	pld	[r0, #64]
+	pld	[r0, #96]
+	pld	[r1, #64]
+	pld	[r1, #96]
+
+2:	ldrd	r2, [r0], #8
+	ldrd	r4, [r0], #8
+	mov	ip, r1
+	strd	r2, [r1], #8
+	ldrd	r2, [r0], #8
+	strd	r4, [r1], #8
+	ldrd	r4, [r0], #8
+	strd	r2, [r1], #8
+	strd	r4, [r1], #8
+	mcr	p15, 0, ip, c7, c10, 1		@ clean D line
+	ldrd	r2, [r0], #8
+	mcr	p15, 0, ip, c7, c6, 1		@ invalidate D line
+	ldrd	r4, [r0], #8
+	mov	ip, r1
+	strd	r2, [r1], #8
+	ldrd	r2, [r0], #8
+	strd	r4, [r1], #8
+	ldrd	r4, [r0], #8
+	strd	r2, [r1], #8
+	strd	r4, [r1], #8
+	mcr	p15, 0, ip, c7, c10, 1		@ clean D line
+	subs	lr, lr, #1
+	mcr	p15, 0, ip, c7, c6, 1		@ invalidate D line
+	bgt	1b
+	beq	2b
+
+	ldmfd	sp!, {r4, r5, pc}
+
+	.align	5
+/*
+ * XScale optimised clear_user_page
+ *  r0 = destination
+ *  r1 = virtual user address of ultimate destination page
+ */
+ENTRY(xscale_mc_clear_user_page)
+	mov	r1, #PAGE_SZ/32
+	mov	r2, #0
+	mov	r3, #0
+1:	mov	ip, r0
+	strd	r2, [r0], #8
+	strd	r2, [r0], #8
+	strd	r2, [r0], #8
+	strd	r2, [r0], #8
+	mcr	p15, 0, ip, c7, c10, 1		@ clean D line
+	subs	r1, r1, #1
+	mcr	p15, 0, ip, c7, c6, 1		@ invalidate D line
+	bne	1b
+	mov	pc, lr
+
+	__INITDATA
+
+	.type	xscale_mc_user_fns, #object
+ENTRY(xscale_mc_user_fns)
+	.long	xscale_mc_clear_user_page
+	.long	xscale_mc_copy_user_page
+	.size	xscale_mc_user_fns, . - xscale_mc_user_fns