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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-xsc3.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-xsc3.c')
-rw-r--r--arch/arm/mm/copypage-xsc3.c24
1 files changed, 17 insertions, 7 deletions
diff --git a/arch/arm/mm/copypage-xsc3.c b/arch/arm/mm/copypage-xsc3.c
index 51ed502e5777..caa697ccd8db 100644
--- a/arch/arm/mm/copypage-xsc3.c
+++ b/arch/arm/mm/copypage-xsc3.c
@@ -11,8 +11,7 @@
* Author: Matt Gilbert (matthew.m.gilbert@intel.com)
*/
#include <linux/init.h>
-
-#include <asm/page.h>
+#include <linux/highmem.h>
/*
* General note:
@@ -21,18 +20,17 @@
*/
/*
- * XSC3 optimised copy_user_page
+ * XSC3 optimised copy_user_highpage
* 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.
*
*/
-void __attribute__((naked))
-xsc3_mc_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
+static void __attribute__((naked))
+xsc3_mc_copy_user_page(void *kto, const void *kfrom)
{
asm("\
stmfd sp!, {r4, r5, lr} \n\
@@ -72,6 +70,18 @@ xsc3_mc_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
: "I" (PAGE_SIZE / 64 - 1));
}
+void xsc3_mc_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);
+ xsc3_mc_copy_user_page(kto, kfrom);
+ kunmap_atomic(kfrom, KM_USER1);
+ kunmap_atomic(kto, KM_USER0);
+}
+
/*
* XScale optimised clear_user_page
* r0 = destination
@@ -98,5 +108,5 @@ xsc3_mc_clear_user_page(void *kaddr, unsigned long vaddr)
struct cpu_user_fns xsc3_mc_user_fns __initdata = {
.cpu_clear_user_page = xsc3_mc_clear_user_page,
- .cpu_copy_user_page = xsc3_mc_copy_user_page,
+ .cpu_copy_user_highpage = xsc3_mc_copy_user_highpage,
};