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Diffstat (limited to 'include/net/page_pool/types.h')
| -rw-r--r-- | include/net/page_pool/types.h | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h new file mode 100644 index 000000000..887e7946a --- /dev/null +++ b/include/net/page_pool/types.h @@ -0,0 +1,236 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _NET_PAGE_POOL_TYPES_H +#define _NET_PAGE_POOL_TYPES_H + +#include <linux/dma-direction.h> +#include <linux/ptr_ring.h> + +#define PP_FLAG_DMA_MAP BIT(0) /* Should page_pool do the DMA + * map/unmap + */ +#define PP_FLAG_DMA_SYNC_DEV BIT(1) /* If set all pages that the driver gets + * from page_pool will be + * DMA-synced-for-device according to + * the length provided by the device + * driver. + * Please note DMA-sync-for-CPU is still + * device driver responsibility + */ +#define PP_FLAG_PAGE_FRAG BIT(2) /* for page frag feature */ +#define PP_FLAG_ALL (PP_FLAG_DMA_MAP |\ + PP_FLAG_DMA_SYNC_DEV |\ + PP_FLAG_PAGE_FRAG) + +/* + * Fast allocation side cache array/stack + * + * The cache size and refill watermark is related to the network + * use-case. The NAPI budget is 64 packets. After a NAPI poll the RX + * ring is usually refilled and the max consumed elements will be 64, + * thus a natural max size of objects needed in the cache. + * + * Keeping room for more objects, is due to XDP_DROP use-case. As + * XDP_DROP allows the opportunity to recycle objects directly into + * this array, as it shares the same softirq/NAPI protection. If + * cache is already full (or partly full) then the XDP_DROP recycles + * would have to take a slower code path. + */ +#define PP_ALLOC_CACHE_SIZE 128 +#define PP_ALLOC_CACHE_REFILL 64 +struct pp_alloc_cache { + u32 count; + struct page *cache[PP_ALLOC_CACHE_SIZE]; +}; + +/** + * struct page_pool_params - page pool parameters + * @flags: PP_FLAG_DMA_MAP, PP_FLAG_DMA_SYNC_DEV, PP_FLAG_PAGE_FRAG + * @order: 2^order pages on allocation + * @pool_size: size of the ptr_ring + * @nid: NUMA node id to allocate from pages from + * @dev: device, for DMA pre-mapping purposes + * @napi: NAPI which is the sole consumer of pages, otherwise NULL + * @dma_dir: DMA mapping direction + * @max_len: max DMA sync memory size for PP_FLAG_DMA_SYNC_DEV + * @offset: DMA sync address offset for PP_FLAG_DMA_SYNC_DEV + */ +struct page_pool_params { + unsigned int flags; + unsigned int order; + unsigned int pool_size; + int nid; + struct device *dev; + struct napi_struct *napi; + enum dma_data_direction dma_dir; + unsigned int max_len; + unsigned int offset; +/* private: used by test code only */ + void (*init_callback)(struct page *page, void *arg); + void *init_arg; +}; + +#ifdef CONFIG_PAGE_POOL_STATS +/** + * struct page_pool_alloc_stats - allocation statistics + * @fast: successful fast path allocations + * @slow: slow path order-0 allocations + * @slow_high_order: slow path high order allocations + * @empty: ptr ring is empty, so a slow path allocation was forced + * @refill: an allocation which triggered a refill of the cache + * @waive: pages obtained from the ptr ring that cannot be added to + * the cache due to a NUMA mismatch + */ +struct page_pool_alloc_stats { + u64 fast; + u64 slow; + u64 slow_high_order; + u64 empty; + u64 refill; + u64 waive; +}; + +/** + * struct page_pool_recycle_stats - recycling (freeing) statistics + * @cached: recycling placed page in the page pool cache + * @cache_full: page pool cache was full + * @ring: page placed into the ptr ring + * @ring_full: page released from page pool because the ptr ring was full + * @released_refcnt: page released (and not recycled) because refcnt > 1 + */ +struct page_pool_recycle_stats { + u64 cached; + u64 cache_full; + u64 ring; + u64 ring_full; + u64 released_refcnt; +}; + +/** + * struct page_pool_stats - combined page pool use statistics + * @alloc_stats: see struct page_pool_alloc_stats + * @recycle_stats: see struct page_pool_recycle_stats + * + * Wrapper struct for combining page pool stats with different storage + * requirements. + */ +struct page_pool_stats { + struct page_pool_alloc_stats alloc_stats; + struct page_pool_recycle_stats recycle_stats; +}; +#endif + +struct page_pool { + struct page_pool_params p; + + long frag_users; + struct page *frag_page; + unsigned int frag_offset; + u32 pages_state_hold_cnt; + + struct delayed_work release_dw; + void (*disconnect)(void *pool); + unsigned long defer_start; + unsigned long defer_warn; + +#ifdef CONFIG_PAGE_POOL_STATS + /* these stats are incremented while in softirq context */ + struct page_pool_alloc_stats alloc_stats; +#endif + u32 xdp_mem_id; + + /* + * Data structure for allocation side + * + * Drivers allocation side usually already perform some kind + * of resource protection. Piggyback on this protection, and + * require driver to protect allocation side. + * + * For NIC drivers this means, allocate a page_pool per + * RX-queue. As the RX-queue is already protected by + * Softirq/BH scheduling and napi_schedule. NAPI schedule + * guarantee that a single napi_struct will only be scheduled + * on a single CPU (see napi_schedule). + */ + struct pp_alloc_cache alloc ____cacheline_aligned_in_smp; + + /* Data structure for storing recycled pages. + * + * Returning/freeing pages is more complicated synchronization + * wise, because free's can happen on remote CPUs, with no + * association with allocation resource. + * + * Use ptr_ring, as it separates consumer and producer + * efficiently, it a way that doesn't bounce cache-lines. + * + * TODO: Implement bulk return pages into this structure. + */ + struct ptr_ring ring; + +#ifdef CONFIG_PAGE_POOL_STATS + /* recycle stats are per-cpu to avoid locking */ + struct page_pool_recycle_stats __percpu *recycle_stats; +#endif + atomic_t pages_state_release_cnt; + + /* A page_pool is strictly tied to a single RX-queue being + * protected by NAPI, due to above pp_alloc_cache. This + * refcnt serves purpose is to simplify drivers error handling. + */ + refcount_t user_cnt; + + u64 destroy_cnt; +}; + +struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp); +struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset, + unsigned int size, gfp_t gfp); +struct page_pool *page_pool_create(const struct page_pool_params *params); + +struct xdp_mem_info; + +#ifdef CONFIG_PAGE_POOL +void page_pool_unlink_napi(struct page_pool *pool); +void page_pool_destroy(struct page_pool *pool); +void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *), + struct xdp_mem_info *mem); +void page_pool_put_page_bulk(struct page_pool *pool, void **data, + int count); +#else +static inline void page_pool_unlink_napi(struct page_pool *pool) +{ +} + +static inline void page_pool_destroy(struct page_pool *pool) +{ +} + +static inline void page_pool_use_xdp_mem(struct page_pool *pool, + void (*disconnect)(void *), + struct xdp_mem_info *mem) +{ +} + +static inline void page_pool_put_page_bulk(struct page_pool *pool, void **data, + int count) +{ +} +#endif + +void page_pool_put_defragged_page(struct page_pool *pool, struct page *page, + unsigned int dma_sync_size, + bool allow_direct); + +static inline bool is_page_pool_compiled_in(void) +{ +#ifdef CONFIG_PAGE_POOL + return true; +#else + return false; +#endif +} + +/* Caller must provide appropriate safe context, e.g. NAPI. */ +void page_pool_update_nid(struct page_pool *pool, int new_nid); + +#endif /* _NET_PAGE_POOL_H */ |