linux-master/mm/zbud.c

138 	struct zbud_header *zhdr = page_address(page);
139 	zhdr->first_chunks = 0;
140 	zhdr->last_chunks = 0;
141 	INIT_LIST_HEAD(&zhdr->buddy);
142 	return zhdr;
146 static void free_zbud_page(struct zbud_header *zhdr)
148 	__free_page(virt_to_page(zhdr));
155 static unsigned long encode_handle(struct zbud_header *zhdr, enum buddy bud)
165 	handle = (unsigned long)zhdr;
170 		handle += PAGE_SIZE - (zhdr->last_chunks  << CHUNK_SHIFT);
181 static int num_free_chunks(struct zbud_header *zhdr)
187 	return NCHUNKS - zhdr->first_chunks - zhdr->last_chunks;
250 	struct zbud_header *zhdr = NULL;
264 			zhdr = list_first_entry(&pool->unbuddied[i],
266 			list_del(&zhdr->buddy);
267 			if (zhdr->first_chunks == 0)
282 	zhdr = init_zbud_page(page);
287 		zhdr->first_chunks = chunks;
289 		zhdr->last_chunks = chunks;
291 	if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0) {
293 		freechunks = num_free_chunks(zhdr);
294 		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
297 		list_add(&zhdr->buddy, &pool->buddied);
300 	*handle = encode_handle(zhdr, bud);
313 	struct zbud_header *zhdr;
317 	zhdr = handle_to_zbud_header(handle);
321 		zhdr->last_chunks = 0;
323 		zhdr->first_chunks = 0;
326 	list_del(&zhdr->buddy);
328 	if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) {
330 		free_zbud_page(zhdr);
334 		freechunks = num_free_chunks(zhdr);
335 		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);