62  * freelists maintained in each pool. NCHUNKS_ORDER of 6 means that the
66  * 63 freelists per pool.
78 	int (*evict)(struct zbud_pool *pool, unsigned long handle);
82  * struct zbud_pool - stores metadata for each zbud pool
83  * @lock:	protects all pool fields and first|last_chunk fields of any
84  *		zbud page in the pool
92  * @pages_nr:	number of zbud pages in the pool.
94  *		pool creation time.
98  * This structure is allocated at pool creation time and maintains metadata
99  * pertaining to a particular zbud pool.
121  * @buddy:	links the zbud page into the unbuddied/buddied lists in the pool
122  * @lru:	links the zbud page into the lru list in the pool
172  * Pool lock should be held as this function accesses first|last_chunks
213  * zbud_create_pool() - create a new zbud pool
214  * @gfp:	gfp flags when allocating the zbud pool structure
215  * @ops:	user-defined operations for the zbud pool
217  * Return: pointer to the new zbud pool or NULL if the metadata allocation
222 	struct zbud_pool *pool;  in zbud_create_pool()  local
225 	pool = kzalloc(sizeof(struct zbud_pool), gfp);  in zbud_create_pool()
226 	if (!pool)  in zbud_create_pool()
228 	spin_lock_init(&pool->lock);  in zbud_create_pool()
230 		INIT_LIST_HEAD(&pool->unbuddied[i]);  in zbud_create_pool()
231 	INIT_LIST_HEAD(&pool->buddied);  in zbud_create_pool()
232 	INIT_LIST_HEAD(&pool->lru);  in zbud_create_pool()
233 	pool->pages_nr = 0;  in zbud_create_pool()
234 	pool->ops = ops;  in zbud_create_pool()
235 	return pool;  in zbud_create_pool()
239  * zbud_destroy_pool() - destroys an existing zbud pool
240  * @pool:	the zbud pool to be destroyed
242  * The pool should be emptied before this function is called.
244 static void zbud_destroy_pool(struct zbud_pool *pool)  in zbud_destroy_pool()  argument
246 	kfree(pool);  in zbud_destroy_pool()
251  * @pool:	zbud pool from which to allocate
253  * @gfp:	gfp flags used if the pool needs to grow
256  * This function will attempt to find a free region in the pool large enough to
259  * allocated and added to the pool to satisfy the request.
262  * as zbud pool pages.
265  * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
268 static int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,  in zbud_alloc()  argument
281 	spin_lock(&pool->lock);  in zbud_alloc()
285 		if (!list_empty(&pool->unbuddied[i])) {  in zbud_alloc()
286 			zhdr = list_first_entry(&pool->unbuddied[i],  in zbud_alloc()
298 	spin_unlock(&pool->lock);  in zbud_alloc()
302 	spin_lock(&pool->lock);  in zbud_alloc()
303 	pool->pages_nr++;  in zbud_alloc()
316 		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);  in zbud_alloc()
319 		list_add(&zhdr->buddy, &pool->buddied);  in zbud_alloc()
325 	list_add(&zhdr->lru, &pool->lru);  in zbud_alloc()
328 	spin_unlock(&pool->lock);  in zbud_alloc()
335  * @pool:	pool in which the allocation resided
343 static void zbud_free(struct zbud_pool *pool, unsigned long handle)  in zbud_free()  argument
348 	spin_lock(&pool->lock);  in zbud_free()
359 		spin_unlock(&pool->lock);  in zbud_free()
370 		pool->pages_nr--;  in zbud_free()
374 		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);  in zbud_free()
377 	spin_unlock(&pool->lock);  in zbud_free()
381  * zbud_reclaim_page() - evicts allocations from a pool page and frees it
382  * @pool:	pool from which a page will attempt to be evicted
395  * zbud_reclaim_page() will remove a zbud page from the pool LRU list and call
396  * the user-defined eviction handler with the pool and handle as arguments.
415 static int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)  in zbud_reclaim_page()  argument
421 	spin_lock(&pool->lock);  in zbud_reclaim_page()
422 	if (!pool->ops || !pool->ops->evict || list_empty(&pool->lru) ||  in zbud_reclaim_page()
424 		spin_unlock(&pool->lock);  in zbud_reclaim_page()
428 		zhdr = list_last_entry(&pool->lru, struct zbud_header, lru);  in zbud_reclaim_page()
443 		spin_unlock(&pool->lock);  in zbud_reclaim_page()
447 			ret = pool->ops->evict(pool, first_handle);  in zbud_reclaim_page()
452 			ret = pool->ops->evict(pool, last_handle);  in zbud_reclaim_page()
457 		spin_lock(&pool->lock);  in zbud_reclaim_page()
465 			pool->pages_nr--;  in zbud_reclaim_page()
466 			spin_unlock(&pool->lock);  in zbud_reclaim_page()
472 			list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);  in zbud_reclaim_page()
475 			list_add(&zhdr->buddy, &pool->buddied);  in zbud_reclaim_page()
479 		list_add(&zhdr->lru, &pool->lru);  in zbud_reclaim_page()
481 	spin_unlock(&pool->lock);  in zbud_reclaim_page()
487  * @pool:	pool in which the allocation resides
497 static void *zbud_map(struct zbud_pool *pool, unsigned long handle)  in zbud_map()  argument
504  * @pool:	pool in which the allocation resides
507 static void zbud_unmap(struct zbud_pool *pool, unsigned long handle)  in zbud_unmap()  argument
512  * zbud_get_pool_size() - gets the zbud pool size in pages
513  * @pool:	pool whose size is being queried
515  * Returns: size in pages of the given pool.  The pool lock need not be
518 static u64 zbud_get_pool_size(struct zbud_pool *pool)  in zbud_get_pool_size()  argument
520 	return pool->pages_nr;  in zbud_get_pool_size()
527 static int zbud_zpool_evict(struct zbud_pool *pool, unsigned long handle)  in zbud_zpool_evict()  argument
529 	if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict)  in zbud_zpool_evict()
530 		return pool->zpool_ops->evict(pool->zpool, handle);  in zbud_zpool_evict()
543 	struct zbud_pool *pool;  in zbud_zpool_create()  local
545 	pool = zbud_create_pool(gfp, zpool_ops ? &zbud_zpool_ops : NULL);  in zbud_zpool_create()
546 	if (pool) {  in zbud_zpool_create()
547 		pool->zpool = zpool;  in zbud_zpool_create()
548 		pool->zpool_ops = zpool_ops;  in zbud_zpool_create()
550 	return pool;  in zbud_zpool_create()
553 static void zbud_zpool_destroy(void *pool)  in zbud_zpool_destroy()  argument
555 	zbud_destroy_pool(pool);  in zbud_zpool_destroy()
558 static int zbud_zpool_malloc(void *pool, size_t size, gfp_t gfp,  in zbud_zpool_malloc()  argument
561 	return zbud_alloc(pool, size, gfp, handle);  in zbud_zpool_malloc()
563 static void zbud_zpool_free(void *pool, unsigned long handle)  in zbud_zpool_free()  argument
565 	zbud_free(pool, handle);  in zbud_zpool_free()
568 static int zbud_zpool_shrink(void *pool, unsigned int pages,  in zbud_zpool_shrink()  argument
575 		ret = zbud_reclaim_page(pool, 8);  in zbud_zpool_shrink()
587 static void *zbud_zpool_map(void *pool, unsigned long handle,  in zbud_zpool_map()  argument
590 	return zbud_map(pool, handle);  in zbud_zpool_map()
592 static void zbud_zpool_unmap(void *pool, unsigned long handle)  in zbud_zpool_unmap()  argument
594 	zbud_unmap(pool, handle);  in zbud_zpool_unmap()
597 static u64 zbud_zpool_total_size(void *pool)  in zbud_zpool_total_size()  argument
599 	return zbud_get_pool_size(pool) * PAGE_SIZE;  in zbud_zpool_total_size()