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authorJohn David Anglin <dave.anglin@bell.net>2013-02-03 22:59:09 +0000
committerHelge Deller <deller@gmx.de>2013-02-20 22:49:19 +0100
commit7633453978c54874849c5f40487ac9e14d43fc12 (patch)
tree552bc9a01785d2bcdca5cb283b6b2b3af5e3e5b8 /arch/parisc/include
parent93c3e913e104c9277e32a0d7e03f268d146c57ee (diff)
downloadop-kernel-dev-7633453978c54874849c5f40487ac9e14d43fc12.zip
op-kernel-dev-7633453978c54874849c5f40487ac9e14d43fc12.tar.gz
parisc: fixes and cleanups in page cache flushing (1/4)
This is the first patch in a series of 4, with which the page cache flushing of parisc will gets fixed and enhanced. This even fixes the nasty "minifail" bug (http://wiki.parisc-linux.org/TestCases?highlight=%28minifail%29) which prevented parisc to stay an official debian port. Basically the flush in copy_user_page together with the TLB patch from commit 7139bc1579901b53db7e898789e916ee2fb52d78 is what fixes the minifail bug. This patch still uses the TMPALIAS approach. The new copy_user_page implementation calls flush_dcache_page_asm to flush the user dcache page (crucial for minifail fix) via a kernel TMPALIAS mapping. After that, it just copies the page using the kernel mapping. It does a final flush if needed. Generally it is hard to avoid doing some cache flushes using the kernel mapping (e.g., copy_to_user_page and copy_from_user_page). This patch depends on a subsequent change to pacache.S implementing clear_page_asm and copy_page_asm. These are optimized routines to clear and copy a page. The calls in clear_user_page and copy_user_page could be replaced by calls to memset and memcpy, respectively. I tested prefetch optimizations in clear_page_asm and copy_page_asm but didn't see any significant performance improvement on rp3440. I'm not sure if these are routines are significantly faster than memset and/or memcpy, but they are there for further performance evaluation. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/include')
-rw-r--r--arch/parisc/include/asm/page.h20
1 files changed, 16 insertions, 4 deletions
diff --git a/arch/parisc/include/asm/page.h b/arch/parisc/include/asm/page.h
index 4e0e7db..b7adb2a 100644
--- a/arch/parisc/include/asm/page.h
+++ b/arch/parisc/include/asm/page.h
@@ -21,15 +21,27 @@
#include <asm/types.h>
#include <asm/cache.h>
-#define clear_page(page) memset((void *)(page), 0, PAGE_SIZE)
-#define copy_page(to,from) copy_user_page_asm((void *)(to), (void *)(from))
+#define clear_page(page) clear_page_asm((void *)(page))
+#define copy_page(to, from) copy_page_asm((void *)(to), (void *)(from))
struct page;
-void copy_user_page_asm(void *to, void *from);
+void clear_page_asm(void *page);
+void copy_page_asm(void *to, void *from);
+void clear_user_page(void *vto, unsigned long vaddr, struct page *pg);
void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *pg);
-void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
+
+/* #define CONFIG_PARISC_TMPALIAS */
+
+#ifdef CONFIG_PARISC_TMPALIAS
+void clear_user_highpage(struct page *page, unsigned long vaddr);
+#define clear_user_highpage clear_user_highpage
+struct vm_area_struct;
+void copy_user_highpage(struct page *to, struct page *from,
+ unsigned long vaddr, struct vm_area_struct *vma);
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE
+#endif
/*
* These are used to make use of C type-checking..
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