From 7633453978c54874849c5f40487ac9e14d43fc12 Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Sun, 3 Feb 2013 22:59:09 +0000 Subject: 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 Signed-off-by: Helge Deller --- arch/parisc/include/asm/page.h | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'arch/parisc/include') diff --git a/arch/parisc/include/asm/page.h b/arch/parisc/include/asm/page.h index 4e0e7dbf0f3..b7adb2ac049 100644 --- a/arch/parisc/include/asm/page.h +++ b/arch/parisc/include/asm/page.h @@ -21,15 +21,27 @@ #include #include -#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.. -- cgit v1.2.3