[ARM] pass vma for flush_anon_page()

Since get_user_pages() may be used with processes other than the
current process and calls flush_anon_page(), flush_anon_page() has to
cope in some way with non-current processes.

It may not be appropriate, or even desirable to flush a region of
virtual memory cache in the current process when that is different to
the process that we want the flush to occur for.

Therefore, pass the vma into flush_anon_page() so that the architecture
can work out whether the 'vmaddr' is for the current process or not.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Documentation/cachetlb.txt

@@ -373,14 +373,15 @@ maps this page at its virtual address.
 	likely that you will need to flush the instruction cache
 	for copy_to_user_page().
 
-  void flush_anon_page(struct page *page, unsigned long vmaddr)
+  void flush_anon_page(struct vm_area_struct *vma, struct page *page,
+                       unsigned long vmaddr)
   	When the kernel needs to access the contents of an anonymous
 	page, it calls this function (currently only
 	get_user_pages()).  Note: flush_dcache_page() deliberately
 	doesn't work for an anonymous page.  The default
 	implementation is a nop (and should remain so for all coherent
 	architectures).  For incoherent architectures, it should flush
-	the cache of the page at vmaddr in the current user process.
+	the cache of the page at vmaddr.
 
   void flush_kernel_dcache_page(struct page *page)
 	When the kernel needs to modify a user page is has obtained

include/asm-parisc/cacheflush.h

@@ -186,7 +186,7 @@ flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long
 }
 
 static inline void
-flush_anon_page(struct page *page, unsigned long vmaddr)
+flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
 {
 	if (PageAnon(page))
 		flush_user_dcache_page(vmaddr);

include/linux/highmem.h

@@ -8,7 +8,7 @@
 #include <asm/cacheflush.h>
 
 #ifndef ARCH_HAS_FLUSH_ANON_PAGE
-static inline void flush_anon_page(struct page *page, unsigned long vmaddr)
+static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
 {
 }
 #endif

mm/memory.c

@@ -1091,7 +1091,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 			if (pages) {
 				pages[i] = page;
 
-				flush_anon_page(page, start);
+				flush_anon_page(vma, page, start);
 				flush_dcache_page(page);
 			}
 			if (vmas)