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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2008-10-31 13:08:02 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-11-27 23:53:46 +0000
commitd73e60b7144a86baf0fdfcc9537a70bb4f72e11c (patch)
tree02155154caf6f1a5d6ce38f2a89ed67f875c7791 /arch/arm/mm/copypage-v4wb.c
parent487ff32082a9bd7489d8185cf7d7a2fdf18a22fa (diff)
[ARM] copypage: convert assembly files to C
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/copypage-v4wb.c')
-rw-r--r--arch/arm/mm/copypage-v4wb.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/arm/mm/copypage-v4wb.c b/arch/arm/mm/copypage-v4wb.c
new file mode 100644
index 00000000000..23021082296
--- /dev/null
+++ b/arch/arm/mm/copypage-v4wb.c
@@ -0,0 +1,83 @@
+/*
+ * linux/arch/arm/mm/copypage-v4wb.c
+ *
+ * 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.
+ */
+#include <linux/init.h>
+
+#include <asm/page.h>
+
+/*
+ * ARMv4 optimised copy_user_page
+ *
+ * We flush the destination cache lines just before we write the data into the
+ * corresponding address. Since the Dcache is read-allocate, this removes the
+ * Dcache aliasing issue. The writes will be forwarded to the write buffer,
+ * and merged as appropriate.
+ *
+ * Note: We rely on all ARMv4 processors implementing the "invalidate D line"
+ * instruction. If your processor does not supply this, you have to write your
+ * own copy_user_page that does the right thing.
+ */
+void __attribute__((naked))
+v4wb_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
+{
+ asm("\
+ stmfd sp!, {r4, lr} @ 2\n\
+ mov r2, %0 @ 1\n\
+ ldmia r1!, {r3, r4, ip, lr} @ 4\n\
+1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\n\
+ stmia r0!, {r3, r4, ip, lr} @ 4\n\
+ ldmia r1!, {r3, r4, ip, lr} @ 4+1\n\
+ stmia r0!, {r3, r4, ip, lr} @ 4\n\
+ ldmia r1!, {r3, r4, ip, lr} @ 4\n\
+ mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\n\
+ stmia r0!, {r3, r4, ip, lr} @ 4\n\
+ ldmia r1!, {r3, r4, ip, lr} @ 4\n\
+ subs r2, r2, #1 @ 1\n\
+ stmia r0!, {r3, r4, ip, lr} @ 4\n\
+ ldmneia r1!, {r3, r4, ip, lr} @ 4\n\
+ bne 1b @ 1\n\
+ mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB\n\
+ ldmfd sp!, {r4, pc} @ 3"
+ :
+ : "I" (PAGE_SIZE / 64));
+}
+
+/*
+ * ARMv4 optimised clear_user_page
+ *
+ * Same story as above.
+ */
+void __attribute__((naked))
+v4wb_clear_user_page(void *kaddr, unsigned long vaddr)
+{
+ asm("\
+ str lr, [sp, #-4]!\n\
+ mov r1, %0 @ 1\n\
+ mov r2, #0 @ 1\n\
+ mov r3, #0 @ 1\n\
+ mov ip, #0 @ 1\n\
+ mov lr, #0 @ 1\n\
+1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\n\
+ stmia r0!, {r2, r3, ip, lr} @ 4\n\
+ stmia r0!, {r2, r3, ip, lr} @ 4\n\
+ mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\n\
+ stmia r0!, {r2, r3, ip, lr} @ 4\n\
+ stmia r0!, {r2, r3, ip, lr} @ 4\n\
+ subs r1, r1, #1 @ 1\n\
+ bne 1b @ 1\n\
+ mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB\n\
+ ldr pc, [sp], #4"
+ :
+ : "I" (PAGE_SIZE / 64));
+}
+
+struct cpu_user_fns v4wb_user_fns __initdata = {
+ .cpu_clear_user_page = v4wb_clear_user_page,
+ .cpu_copy_user_page = v4wb_copy_user_page,
+};