parisc: fix cache-flushing

commit 57737c49dd72c96cfbcd4f66559f3ffc399aeb4f upstream.

This commit:
f8dae00684d678afa13041ef170cecfd1297ed40: parisc: Ensure full cache coherency for kmap/kunmap
caused negative caching side-effects, e.g. hanging processes with expect and
too many inequivalent alias messages from flush_dcache_page() on Debian 5 systems.

This patch now partly reverts it and has been in production use on our debian buildd
makeservers since a week without any major problems.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 2 insertions, 3 deletions

diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 2f9b751878ba..de65f66ea64e 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -132,7 +132,6 @@ void mark_rodata_ro(void);
 static inline void *kmap(struct page *page)
 {
         might_sleep();
-        flush_dcache_page(page);
         return page_address(page);
 }
 
@@ -144,7 +143,6 @@ static inline void kunmap(struct page *page)
 static inline void *kmap_atomic(struct page *page)
 {
         pagefault_disable();
-        flush_dcache_page(page);
         return page_address(page);
 }
 
diff --git a/arch/parisc/include/asm/page.h b/arch/parisc/include/asm/page.h
index c53fc63149e8..637fe031aa84 100644
--- a/arch/parisc/include/asm/page.h
+++ b/arch/parisc/include/asm/page.h
@@ -29,7 +29,8 @@ struct page;
 void clear_page_asm(void *page);
 void copy_page_asm(void *to, void *from);
 #define clear_user_page(vto, vaddr, page) clear_page_asm(vto)
-#define copy_user_page(vto, vfrom, vaddr, page) copy_page_asm(vto, vfrom)
+void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
+                        struct page *pg);
 
 /* #define CONFIG_PARISC_TMPALIAS */