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+/*
+ * 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