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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/mm/copypage-v4wb.S
downloadconfigs-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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+/*
+ * 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 <linux/init.h>
+#include <asm/constants.h>
+
+ .text
+ .align 5
+/*
+ * 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.
+ */
+ENTRY(v4wb_copy_user_page)
+ stmfd sp!, {r4, lr} @ 2
+ mov r2, #PAGE_SZ/64 @ 1
+ ldmia r1!, {r3, r4, ip, lr} @ 4
+1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line
+ stmia r0!, {r3, r4, ip, lr} @ 4
+ ldmia r1!, {r3, r4, ip, lr} @ 4+1
+ stmia r0!, {r3, r4, ip, lr} @ 4
+ ldmia r1!, {r3, r4, ip, lr} @ 4
+ mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line
+ stmia r0!, {r3, r4, ip, lr} @ 4
+ ldmia r1!, {r3, r4, ip, lr} @ 4
+ subs r2, r2, #1 @ 1
+ stmia r0!, {r3, r4, ip, lr} @ 4
+ ldmneia r1!, {r3, r4, ip, lr} @ 4
+ bne 1b @ 1
+ mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB
+ ldmfd sp!, {r4, pc} @ 3
+
+ .align 5
+/*
+ * ARMv4 optimised clear_user_page
+ *
+ * Same story as above.
+ */
+ENTRY(v4wb_clear_user_page)
+ str lr, [sp, #-4]!
+ mov r1, #PAGE_SZ/64 @ 1
+ mov r2, #0 @ 1
+ mov r3, #0 @ 1
+ mov ip, #0 @ 1
+ mov lr, #0 @ 1
+1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line
+ stmia r0!, {r2, r3, ip, lr} @ 4
+ stmia r0!, {r2, r3, ip, lr} @ 4
+ mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line
+ stmia r0!, {r2, r3, ip, lr} @ 4
+ stmia r0!, {r2, r3, ip, lr} @ 4
+ subs r1, r1, #1 @ 1
+ bne 1b @ 1
+ mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB
+ ldr pc, [sp], #4
+
+ __INITDATA
+
+ .type v4wb_user_fns, #object
+ENTRY(v4wb_user_fns)
+ .long v4wb_clear_user_page
+ .long v4wb_copy_user_page
+ .size v4wb_user_fns, . - v4wb_user_fns