Documentation/networking/page_pool.rst

1 .. SPDX-License-Identifier: GPL-2.0
8 per-page, but it can fallback on the regular page allocator APIs.
15 when it is safe to free a page_pool object.  Thus, API users
22 release the DMA mapping and inflight state accounting.
27 .. code-block:: none
29     +------------------+
31     +------------------+
37     +--------------------------------------------+
39     +--------------------------------------------+
45     +-----------------------+     +------------------------+
46     | alloc (and map) pages |     |  get page from cache   |
47     +-----------------------+     +------------------------+
51                                     |                    | from ptr-ring
54                           +-----------------+     +------------------+
55                           |   Fast cache    |     |  ptr-ring cache  |
56                           +-----------------+     +------------------+
72     * dev:        struct device. Used on DMA operations
73     * dma_dir:    DMA direction
74     * max_len:    max DMA sync memory size
75     * offset:     DMA address offset
83 * page_pool_put_full_page(): Similar to page_pool_put_page(), but will DMA sync
84   for the entire memory area configured in area pool->max_len.
87   must guarantee safe context (e.g NAPI), since it will recycle the page
96 * page_pool_get_dma_addr(): Retrieve the stored DMA address.
98 * page_pool_get_dma_dir(): Retrieve the stored DMA direction.
104 ------------
106 .. code-block:: c
114     /* internal DMA mapping in page_pool */
118     pp_params.dev = priv->dev;
131 -----------
134 .. code-block:: c
139     dma_dir = page_pool_get_dma_dir(dring->page_pool);
153 -------------
155 .. code-block:: c