266 _shift_data_left_pages(struct page **pages, size_t pgto_base,  in _shift_data_left_pages()  argument
273 	BUG_ON(pgfrom_base <= pgto_base);  in _shift_data_left_pages()
278 	pgto = pages + (pgto_base >> PAGE_SHIFT);  in _shift_data_left_pages()
281 	pgto_base &= ~PAGE_MASK;  in _shift_data_left_pages()
285 		if (pgto_base >= PAGE_SIZE) {  in _shift_data_left_pages()
286 			pgto_base = 0;  in _shift_data_left_pages()
295 		if (copy > (PAGE_SIZE - pgto_base))  in _shift_data_left_pages()
296 			copy = PAGE_SIZE - pgto_base;  in _shift_data_left_pages()
303 			memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);  in _shift_data_left_pages()
306 			memmove(vto + pgto_base, vto + pgfrom_base, copy);  in _shift_data_left_pages()
310 		pgto_base += copy;  in _shift_data_left_pages()
331 _shift_data_right_pages(struct page **pages, size_t pgto_base,  in _shift_data_right_pages()  argument
338 	BUG_ON(pgto_base <= pgfrom_base);  in _shift_data_right_pages()
343 	pgto_base += len;  in _shift_data_right_pages()
346 	pgto = pages + (pgto_base >> PAGE_SHIFT);  in _shift_data_right_pages()
349 	pgto_base &= ~PAGE_MASK;  in _shift_data_right_pages()
354 		if (pgto_base == 0) {  in _shift_data_right_pages()
355 			pgto_base = PAGE_SIZE;  in _shift_data_right_pages()
364 		if (copy > pgto_base)  in _shift_data_right_pages()
365 			copy = pgto_base;  in _shift_data_right_pages()
368 		pgto_base -= copy;  in _shift_data_right_pages()
374 			memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);  in _shift_data_right_pages()
377 			memmove(vto + pgto_base, vto + pgfrom_base, copy);  in _shift_data_right_pages()