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-rw-r--r--include/linux/highmem.h56
1 files changed, 56 insertions, 0 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index d2c70d3772a3..44170f312ae7 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -276,4 +276,60 @@ static inline void copy_highpage(struct page *to, struct page *from)
#endif
+static inline void memcpy_page(struct page *dst_page, size_t dst_off,
+ struct page *src_page, size_t src_off,
+ size_t len)
+{
+ char *dst = kmap_local_page(dst_page);
+ char *src = kmap_local_page(src_page);
+
+ VM_BUG_ON(dst_off + len > PAGE_SIZE || src_off + len > PAGE_SIZE);
+ memcpy(dst + dst_off, src + src_off, len);
+ kunmap_local(src);
+ kunmap_local(dst);
+}
+
+static inline void memmove_page(struct page *dst_page, size_t dst_off,
+ struct page *src_page, size_t src_off,
+ size_t len)
+{
+ char *dst = kmap_local_page(dst_page);
+ char *src = kmap_local_page(src_page);
+
+ VM_BUG_ON(dst_off + len > PAGE_SIZE || src_off + len > PAGE_SIZE);
+ memmove(dst + dst_off, src + src_off, len);
+ kunmap_local(src);
+ kunmap_local(dst);
+}
+
+static inline void memset_page(struct page *page, size_t offset, int val,
+ size_t len)
+{
+ char *addr = kmap_local_page(page);
+
+ VM_BUG_ON(offset + len > PAGE_SIZE);
+ memset(addr + offset, val, len);
+ kunmap_local(addr);
+}
+
+static inline void memcpy_from_page(char *to, struct page *page,
+ size_t offset, size_t len)
+{
+ char *from = kmap_local_page(page);
+
+ VM_BUG_ON(offset + len > PAGE_SIZE);
+ memcpy(to, from + offset, len);
+ kunmap_local(from);
+}
+
+static inline void memcpy_to_page(struct page *page, size_t offset,
+ const char *from, size_t len)
+{
+ char *to = kmap_local_page(page);
+
+ VM_BUG_ON(offset + len > PAGE_SIZE);
+ memcpy(to + offset, from, len);
+ kunmap_local(to);
+}
+
#endif /* _LINUX_HIGHMEM_H */