xtensa: implement clear_user_highpage and copy_user_highpage

Existing clear_user_page and copy_user_page cannot be used with highmem
because they calculate physical page address from its virtual address
and do it incorrectly in case of high memory page mapped with
kmap_atomic. Also kmap is not needed, as most likely userspace mapping
color would be different from the kmapped color.

Provide clear_user_highpage and copy_user_highpage functions that
determine if temporary mapping is needed for the pages. Move most of the
logic of the former clear_user_page and copy_user_page to
xtensa/mm/cache.c only leaving temporary mapping setup, invalidation and
clearing/copying in the xtensa/mm/misc.S. Rename these functions to
clear_page_alias and copy_page_alias.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

2 files changed, 12 insertions, 2 deletions

diff --git a/arch/xtensa/include/asm/cacheflush.h b/arch/xtensa/include/asm/cacheflush.h
index 555a98a..e72aaca 100644
--- a/arch/xtensa/include/asm/cacheflush.h
+++ b/arch/xtensa/include/asm/cacheflush.h
@@ -37,6 +37,7 @@
  * specials for cache aliasing:
  *
  * __flush_invalidate_dcache_page_alias(vaddr,paddr)
+ * __invalidate_dcache_page_alias(vaddr,paddr)
  * __invalidate_icache_page_alias(vaddr,paddr)
  */
 
@@ -62,6 +63,7 @@ extern void __flush_invalidate_dcache_range(unsigned long, unsigned long);
 
 #if defined(CONFIG_MMU) && (DCACHE_WAY_SIZE > PAGE_SIZE)
 extern void __flush_invalidate_dcache_page_alias(unsigned long, unsigned long);
+extern void __invalidate_dcache_page_alias(unsigned long, unsigned long);
 #else
 static inline void __flush_invalidate_dcache_page_alias(unsigned long virt,
 							unsigned long phys) { }
diff --git a/arch/xtensa/include/asm/page.h b/arch/xtensa/include/asm/page.h
index 47f5823..11721cc 100644
--- a/arch/xtensa/include/asm/page.h
+++ b/arch/xtensa/include/asm/page.h
@@ -134,6 +134,7 @@ static inline __attribute_const__ int get_order(unsigned long size)
 #endif
 
 struct page;
+struct vm_area_struct;
 extern void clear_page(void *page);
 extern void copy_page(void *to, void *from);
 
@@ -143,8 +144,15 @@ extern void copy_page(void *to, void *from);
  */
 
 #if DCACHE_WAY_SIZE > PAGE_SIZE
-extern void clear_user_page(void*, unsigned long, struct page*);
-extern void copy_user_page(void*, void*, unsigned long, struct page*);
+extern void clear_page_alias(void *vaddr, unsigned long paddr);
+extern void copy_page_alias(void *to, void *from,
+			    unsigned long to_paddr, unsigned long from_paddr);
+
+#define clear_user_highpage clear_user_highpage
+void clear_user_highpage(struct page *page, unsigned long vaddr);
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE
+void copy_user_highpage(struct page *to, struct page *from,
+			unsigned long vaddr, struct vm_area_struct *vma);
 #else
 # define clear_user_page(page, vaddr, pg)	clear_page(page)
 # define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)