mm: support THPs in zero_user_segments

[linux-2.6-microblaze.git] / include / linux / highmem.h

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 14e6202..8e21fe8 100644 (file)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -284,13 +284,22 @@ static inline void clear_highpage(struct page *page)
        kunmap_atomic(kaddr);
 }
 
+/*
+ * If we pass in a base or tail page, we can zero up to PAGE_SIZE.
+ * If we pass in a head page, we can zero up to the size of the compound page.
+ */
+#if defined(CONFIG_HIGHMEM) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
+void zero_user_segments(struct page *page, unsigned start1, unsigned end1,
+               unsigned start2, unsigned end2);
+#else /* !HIGHMEM || !TRANSPARENT_HUGEPAGE */
 static inline void zero_user_segments(struct page *page,
-       unsigned start1, unsigned end1,
-       unsigned start2, unsigned end2)
+               unsigned start1, unsigned end1,
+               unsigned start2, unsigned end2)
 {
        void *kaddr = kmap_atomic(page);
+       unsigned int i;
 
-       BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
+       BUG_ON(end1 > page_size(page) || end2 > page_size(page));
 
        if (end1 > start1)
                memset(kaddr + start1, 0, end1 - start1);
@@ -299,8 +308,10 @@ static inline void zero_user_segments(struct page *page,
                memset(kaddr + start2, 0, end2 - start2);
 
        kunmap_atomic(kaddr);
-       flush_dcache_page(page);
+       for (i = 0; i < compound_nr(page); i++)
+               flush_dcache_page(page + i);
 }
+#endif /* !HIGHMEM || !TRANSPARENT_HUGEPAGE */
 
 static inline void zero_user_segment(struct page *page,
        unsigned start, unsigned end)