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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2008-10-31 18:08:35 +0300
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-11-28 02:53:47 +0300
commit063b0a4207e43acbeff3d4b09f43e750e0212b48 (patch)
treeeb2a2c1faa732c763102040478830111fc13f2a5 /arch/arm/mm/copypage-v4wt.c
parentd73e60b7144a86baf0fdfcc9537a70bb4f72e11c (diff)
downloadlinux-063b0a4207e43acbeff3d4b09f43e750e0212b48.tar.xz
[ARM] copypage: provide our own copy_user_highpage()
We used to override the copy_user_page() function. However, this is not only inefficient, it also causes additional complexity for highmem support, since we convert from a struct page to a kernel direct mapped address and back to a struct page again. Moreover, with highmem support, we end up pointlessly setting up kmap entries for pages which we're going to remap. So, push the kmapping down into the copypage implementation files where it's required. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/copypage-v4wt.c')
-rw-r--r--arch/arm/mm/copypage-v4wt.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/arch/arm/mm/copypage-v4wt.c b/arch/arm/mm/copypage-v4wt.c
index d8ef39503ff0..86c2cfdbde03 100644
--- a/arch/arm/mm/copypage-v4wt.c
+++ b/arch/arm/mm/copypage-v4wt.c
@@ -11,18 +11,17 @@
* the only supported cache operation.
*/
#include <linux/init.h>
-
-#include <asm/page.h>
+#include <linux/highmem.h>
/*
- * ARMv4 optimised copy_user_page
+ * ARMv4 optimised copy_user_highpage
*
* Since we have writethrough caches, we don't have to worry about
* dirty data in the cache. However, we do have to ensure that
* subsequent reads are up to date.
*/
-void __attribute__((naked))
-v4wt_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
+static void __attribute__((naked))
+v4wt_copy_user_page(void *kto, const void *kfrom)
{
asm("\
stmfd sp!, {r4, lr} @ 2\n\
@@ -44,6 +43,18 @@ v4wt_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
: "I" (PAGE_SIZE / 64));
}
+void v4wt_copy_user_highpage(struct page *to, struct page *from,
+ unsigned long vaddr)
+{
+ void *kto, *kfrom;
+
+ kto = kmap_atomic(to, KM_USER0);
+ kfrom = kmap_atomic(from, KM_USER1);
+ v4wt_copy_user_page(kto, kfrom);
+ kunmap_atomic(kfrom, KM_USER1);
+ kunmap_atomic(kto, KM_USER0);
+}
+
/*
* ARMv4 optimised clear_user_page
*
@@ -73,5 +84,5 @@ v4wt_clear_user_page(void *kaddr, unsigned long vaddr)
struct cpu_user_fns v4wt_user_fns __initdata = {
.cpu_clear_user_page = v4wt_clear_user_page,
- .cpu_copy_user_page = v4wt_copy_user_page,
+ .cpu_copy_user_highpage = v4wt_copy_user_highpage,
};