240 			size_t pgfrom_base, size_t len)  in _shift_data_left_pages()  argument
246 	BUG_ON(pgfrom_base <= pgto_base);  in _shift_data_left_pages()
252 	pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);  in _shift_data_left_pages()
255 	pgfrom_base &= ~PAGE_MASK;  in _shift_data_left_pages()
262 		if (pgfrom_base >= PAGE_SIZE){  in _shift_data_left_pages()
263 			pgfrom_base = 0;  in _shift_data_left_pages()
270 		if (copy > (PAGE_SIZE - pgfrom_base))  in _shift_data_left_pages()
271 			copy = PAGE_SIZE - pgfrom_base;  in _shift_data_left_pages()
276 			memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);  in _shift_data_left_pages()
279 			memmove(vto + pgto_base, vto + pgfrom_base, copy);  in _shift_data_left_pages()
284 		pgfrom_base += copy;  in _shift_data_left_pages()
305 		size_t pgfrom_base, size_t len)  in _shift_data_right_pages()  argument
311 	BUG_ON(pgto_base <= pgfrom_base);  in _shift_data_right_pages()
317 	pgfrom_base += len;  in _shift_data_right_pages()
320 	pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);  in _shift_data_right_pages()
323 	pgfrom_base &= ~PAGE_MASK;  in _shift_data_right_pages()
331 		if (pgfrom_base == 0) {  in _shift_data_right_pages()
332 			pgfrom_base = PAGE_SIZE;  in _shift_data_right_pages()
339 		if (copy > pgfrom_base)  in _shift_data_right_pages()
340 			copy = pgfrom_base;  in _shift_data_right_pages()
342 		pgfrom_base -= copy;  in _shift_data_right_pages()
347 			memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);  in _shift_data_right_pages()
350 			memmove(vto + pgto_base, vto + pgfrom_base, copy);  in _shift_data_right_pages()