1 files changed, 39 insertions, 6 deletions

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 6e452bd8e7e3..e48d7f27b0b9 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -224,7 +224,13 @@ static inline
 struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma,
 				   unsigned long vaddr)
 {
-	return vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, 0, vma, vaddr);
+	struct folio *folio;
+
+	folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma, vaddr);
+	if (folio && user_alloc_needs_zeroing())
+		clear_user_highpage(&folio->page, vaddr);
+
+	return folio;
 }
 #endif
 
@@ -398,6 +404,33 @@ static inline void memcpy_page(struct page *dst_page, size_t dst_off,
 	kunmap_local(dst);
 }
 
+static inline void memcpy_folio(struct folio *dst_folio, size_t dst_off,
+		struct folio *src_folio, size_t src_off, size_t len)
+{
+	VM_BUG_ON(dst_off + len > folio_size(dst_folio));
+	VM_BUG_ON(src_off + len > folio_size(src_folio));
+
+	do {
+		char *dst = kmap_local_folio(dst_folio, dst_off);
+		const char *src = kmap_local_folio(src_folio, src_off);
+		size_t chunk = len;
+
+		if (folio_test_highmem(dst_folio) &&
+		    chunk > PAGE_SIZE - offset_in_page(dst_off))
+			chunk = PAGE_SIZE - offset_in_page(dst_off);
+		if (folio_test_highmem(src_folio) &&
+		    chunk > PAGE_SIZE - offset_in_page(src_off))
+			chunk = PAGE_SIZE - offset_in_page(src_off);
+		memcpy(dst, src, chunk);
+		kunmap_local(src);
+		kunmap_local(dst);
+
+		dst_off += chunk;
+		src_off += chunk;
+		len -= chunk;
+	} while (len > 0);
+}
+
 static inline void memset_page(struct page *page, size_t offset, int val,
 			       size_t len)
 {
@@ -455,7 +488,7 @@ static inline void memcpy_from_folio(char *to, struct folio *folio,
 		const char *from = kmap_local_folio(folio, offset);
 		size_t chunk = len;
 
-		if (folio_test_highmem(folio) &&
+		if (folio_test_partial_kmap(folio) &&
 		    chunk > PAGE_SIZE - offset_in_page(offset))
 			chunk = PAGE_SIZE - offset_in_page(offset);
 		memcpy(to, from, chunk);
@@ -483,7 +516,7 @@ static inline void memcpy_to_folio(struct folio *folio, size_t offset,
 		char *to = kmap_local_folio(folio, offset);
 		size_t chunk = len;
 
-		if (folio_test_highmem(folio) &&
+		if (folio_test_partial_kmap(folio) &&
 		    chunk > PAGE_SIZE - offset_in_page(offset))
 			chunk = PAGE_SIZE - offset_in_page(offset);
 		memcpy(to, from, chunk);
@@ -516,7 +549,7 @@ static inline __must_check void *folio_zero_tail(struct folio *folio,
 {
 	size_t len = folio_size(folio) - offset;
 
-	if (folio_test_highmem(folio)) {
+	if (folio_test_partial_kmap(folio)) {
 		size_t max = PAGE_SIZE - offset_in_page(offset);
 
 		while (len > max) {
@@ -554,7 +587,7 @@ static inline void folio_fill_tail(struct folio *folio, size_t offset,
 
 	VM_BUG_ON(offset + len > folio_size(folio));
 
-	if (folio_test_highmem(folio)) {
+	if (folio_test_partial_kmap(folio)) {
 		size_t max = PAGE_SIZE - offset_in_page(offset);
 
 		while (len > max) {
@@ -591,7 +624,7 @@ static inline size_t memcpy_from_file_folio(char *to, struct folio *folio,
 	size_t offset = offset_in_folio(folio, pos);
 	char *from = kmap_local_folio(folio, offset);
 
-	if (folio_test_highmem(folio)) {
+	if (folio_test_partial_kmap(folio)) {
 		offset = offset_in_page(offset);
 		len = min_t(size_t, len, PAGE_SIZE - offset);
 	} else