diff options
| author | Kees Cook <kees+treewide@kernel.org> | 2026-09-02 15:31:14 -0700 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2026-09-04 21:37:00 -0700 |
| commit | 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch) | |
| tree | c65086f9bdcd48c6360fb7cb4598bca084da1f32 /include/net/page_pool | |
| download | linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip | |
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci
This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.
Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.
Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'include/net/page_pool')
| -rw-r--r-- | include/net/page_pool/helpers.h | 525 | ||||
| -rw-r--r-- | include/net/page_pool/memory_provider.h | 47 | ||||
| -rw-r--r-- | include/net/page_pool/types.h | 320 |
3 files changed, 892 insertions, 0 deletions
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h new file mode 100644 index 000000000..e2730dd27 --- /dev/null +++ b/include/net/page_pool/helpers.h @@ -0,0 +1,525 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * page_pool/helpers.h + * Author: Jesper Dangaard Brouer <netoptimizer@brouer.com> + * Copyright (C) 2016 Red Hat, Inc. + */ + +/** + * DOC: page_pool allocator + * + * The page_pool allocator is optimized for recycling page or page fragment used + * by skb packet and xdp frame. + * + * Basic use involves replacing any alloc_pages() calls with page_pool_alloc(), + * which allocate memory with or without page splitting depending on the + * requested memory size. + * + * If the driver knows that it always requires full pages or its allocations are + * always smaller than half a page, it can use one of the more specific API + * calls: + * + * 1. page_pool_alloc_pages(): allocate memory without page splitting when + * driver knows that the memory it need is always bigger than half of the page + * allocated from page pool. There is no cache line dirtying for 'struct page' + * when a page is recycled back to the page pool. + * + * 2. page_pool_alloc_frag(): allocate memory with page splitting when driver + * knows that the memory it need is always smaller than or equal to half of the + * page allocated from page pool. Page splitting enables memory saving and thus + * avoids TLB/cache miss for data access, but there also is some cost to + * implement page splitting, mainly some cache line dirtying/bouncing for + * 'struct page' and atomic operation for page->pp_ref_count. + * + * The API keeps track of in-flight pages, in order to let API users know when + * it is safe to free a page_pool object, the API users must call + * page_pool_put_page() or page_pool_free_va() to free the page_pool object, or + * attach the page_pool object to a page_pool-aware object like skbs marked with + * skb_mark_for_recycle(). + * + * page_pool_put_page() may be called multiple times on the same page if a page + * is split into multiple fragments. For the last fragment, it will either + * recycle the page, or in case of page->_refcount > 1, it will release the DMA + * mapping and in-flight state accounting. + * + * dma_sync_single_range_for_device() is only called for the last fragment when + * page_pool is created with PP_FLAG_DMA_SYNC_DEV flag, so it depends on the + * last freed fragment to do the sync_for_device operation for all fragments in + * the same page when a page is split. The API user must setup pool->p.max_len + * and pool->p.offset correctly and ensure that page_pool_put_page() is called + * with dma_sync_size being -1 for fragment API. + */ +#ifndef _NET_PAGE_POOL_HELPERS_H +#define _NET_PAGE_POOL_HELPERS_H + +#include <linux/dma-mapping.h> + +#include <net/page_pool/types.h> +#include <net/net_debug.h> +#include <net/netmem.h> + +#ifdef CONFIG_PAGE_POOL_STATS +/* Deprecated driver-facing API, use netlink instead */ +int page_pool_ethtool_stats_get_count(void); +u8 *page_pool_ethtool_stats_get_strings(u8 *data); +u64 *page_pool_ethtool_stats_get(u64 *data, const void *stats); + +void page_pool_get_stats(const struct page_pool *pool, + struct page_pool_stats *stats); +#else +static inline int page_pool_ethtool_stats_get_count(void) +{ + return 0; +} + +static inline u8 *page_pool_ethtool_stats_get_strings(u8 *data) +{ + return data; +} + +static inline u64 *page_pool_ethtool_stats_get(u64 *data, const void *stats) +{ + return data; +} +#endif + +/** + * page_pool_dev_alloc_pages() - allocate a page. + * @pool: pool from which to allocate + * + * Get a page from the page allocator or page_pool caches. + */ +static inline struct page *page_pool_dev_alloc_pages(struct page_pool *pool) +{ + gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN); + + return page_pool_alloc_pages(pool, gfp); +} + +/** + * page_pool_dev_alloc_frag() - allocate a page fragment. + * @pool: pool from which to allocate + * @offset: offset to the allocated page + * @size: requested size + * + * Get a page fragment from the page allocator or page_pool caches. + * + * Return: allocated page fragment, otherwise return NULL. + */ +static inline struct page *page_pool_dev_alloc_frag(struct page_pool *pool, + unsigned int *offset, + unsigned int size) +{ + gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN); + + return page_pool_alloc_frag(pool, offset, size, gfp); +} + +static inline netmem_ref page_pool_alloc_netmem(struct page_pool *pool, + unsigned int *offset, + unsigned int *size, gfp_t gfp) +{ + unsigned int max_size = PAGE_SIZE << pool->p.order; + netmem_ref netmem; + + if ((*size << 1) > max_size) { + *size = max_size; + *offset = 0; + return page_pool_alloc_netmems(pool, gfp); + } + + netmem = page_pool_alloc_frag_netmem(pool, offset, *size, gfp); + if (unlikely(!netmem)) + return 0; + + /* There is very likely not enough space for another fragment, so append + * the remaining size to the current fragment to avoid truesize + * underestimate problem. + */ + if (pool->frag_offset + *size > max_size) { + *size = max_size - *offset; + pool->frag_offset = max_size; + } + + return netmem; +} + +static inline netmem_ref page_pool_dev_alloc_netmem(struct page_pool *pool, + unsigned int *offset, + unsigned int *size) +{ + gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN; + + return page_pool_alloc_netmem(pool, offset, size, gfp); +} + +static inline netmem_ref page_pool_dev_alloc_netmems(struct page_pool *pool) +{ + gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN; + + return page_pool_alloc_netmems(pool, gfp); +} + +static inline struct page *page_pool_alloc(struct page_pool *pool, + unsigned int *offset, + unsigned int *size, gfp_t gfp) +{ + return netmem_to_page(page_pool_alloc_netmem(pool, offset, size, gfp)); +} + +/** + * page_pool_dev_alloc() - allocate a page or a page fragment. + * @pool: pool from which to allocate + * @offset: offset to the allocated page + * @size: in as the requested size, out as the allocated size + * + * Get a page or a page fragment from the page allocator or page_pool caches + * depending on the requested size in order to allocate memory with least memory + * utilization and performance penalty. + * + * Return: allocated page or page fragment, otherwise return NULL. + */ +static inline struct page *page_pool_dev_alloc(struct page_pool *pool, + unsigned int *offset, + unsigned int *size) +{ + gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN); + + return page_pool_alloc(pool, offset, size, gfp); +} + +static inline void *page_pool_alloc_va(struct page_pool *pool, + unsigned int *size, gfp_t gfp) +{ + unsigned int offset; + struct page *page; + + /* Mask off __GFP_HIGHMEM to ensure we can use page_address() */ + page = page_pool_alloc(pool, &offset, size, gfp & ~__GFP_HIGHMEM); + if (unlikely(!page)) + return NULL; + + return page_address(page) + offset; +} + +/** + * page_pool_dev_alloc_va() - allocate a page or a page fragment and return its + * va. + * @pool: pool from which to allocate + * @size: in as the requested size, out as the allocated size + * + * This is just a thin wrapper around the page_pool_alloc() API, and + * it returns va of the allocated page or page fragment. + * + * Return: the va for the allocated page or page fragment, otherwise return NULL. + */ +static inline void *page_pool_dev_alloc_va(struct page_pool *pool, + unsigned int *size) +{ + gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN); + + return page_pool_alloc_va(pool, size, gfp); +} + +/** + * page_pool_get_dma_dir() - Retrieve the stored DMA direction. + * @pool: pool from which page was allocated + * + * Get the stored dma direction. A driver might decide to store this locally + * and avoid the extra cache line from page_pool to determine the direction. + */ +static inline enum dma_data_direction +page_pool_get_dma_dir(const struct page_pool *pool) +{ + return pool->p.dma_dir; +} + +static inline void page_pool_fragment_netmem(netmem_ref netmem, long nr) +{ + atomic_long_set(netmem_get_pp_ref_count_ref(netmem), nr); +} + +/** + * page_pool_fragment_page() - split a fresh page into fragments + * @page: page to split + * @nr: references to set + * + * pp_ref_count represents the number of outstanding references to the page, + * which will be freed using page_pool APIs (rather than page allocator APIs + * like put_page()). Such references are usually held by page_pool-aware + * objects like skbs marked for page pool recycling. + * + * This helper allows the caller to take (set) multiple references to a + * freshly allocated page. The page must be freshly allocated (have a + * pp_ref_count of 1). This is commonly done by drivers and + * "fragment allocators" to save atomic operations - either when they know + * upfront how many references they will need; or to take MAX references and + * return the unused ones with a single atomic dec(), instead of performing + * multiple atomic inc() operations. + */ +static inline void page_pool_fragment_page(struct page *page, long nr) +{ + page_pool_fragment_netmem(page_to_netmem(page), nr); +} + +static inline long page_pool_unref_netmem(netmem_ref netmem, long nr) +{ + atomic_long_t *pp_ref_count = netmem_get_pp_ref_count_ref(netmem); + long ret; + + /* If nr == pp_ref_count then we have cleared all remaining + * references to the page: + * 1. 'n == 1': no need to actually overwrite it. + * 2. 'n != 1': overwrite it with one, which is the rare case + * for pp_ref_count draining. + * + * The main advantage to doing this is that not only we avoid a atomic + * update, as an atomic_read is generally a much cheaper operation than + * an atomic update, especially when dealing with a page that may be + * referenced by only 2 or 3 users; but also unify the pp_ref_count + * handling by ensuring all pages have partitioned into only 1 piece + * initially, and only overwrite it when the page is partitioned into + * more than one piece. + */ + if (atomic_long_read(pp_ref_count) == nr) { + /* As we have ensured nr is always one for constant case using + * the BUILD_BUG_ON(), only need to handle the non-constant case + * here for pp_ref_count draining, which is a rare case. + */ + BUILD_BUG_ON(__builtin_constant_p(nr) && nr != 1); + if (!__builtin_constant_p(nr)) + atomic_long_set(pp_ref_count, 1); + + return 0; + } + + ret = atomic_long_sub_return(nr, pp_ref_count); + WARN_ON(ret < 0); + + /* We are the last user here too, reset pp_ref_count back to 1 to + * ensure all pages have been partitioned into 1 piece initially, + * this should be the rare case when the last two fragment users call + * page_pool_unref_page() currently. + */ + if (unlikely(!ret)) + atomic_long_set(pp_ref_count, 1); + + return ret; +} + +static inline long page_pool_unref_page(struct page *page, long nr) +{ + return page_pool_unref_netmem(page_to_netmem(page), nr); +} + +static inline void page_pool_ref_netmem(netmem_ref netmem) +{ + atomic_long_inc(netmem_get_pp_ref_count_ref(netmem)); +} + +static inline void page_pool_ref_page(struct page *page) +{ + page_pool_ref_netmem(page_to_netmem(page)); +} + +static inline bool page_pool_unref_and_test(netmem_ref netmem) +{ + /* If page_pool_unref_page() returns 0, we were the last user */ + return page_pool_unref_netmem(netmem, 1) == 0; +} + +static inline void page_pool_put_netmem(struct page_pool *pool, + netmem_ref netmem, + unsigned int dma_sync_size, + bool allow_direct) +{ + /* When page_pool isn't compiled-in, net/core/xdp.c doesn't + * allow registering MEM_TYPE_PAGE_POOL, but shield linker. + */ +#ifdef CONFIG_PAGE_POOL + if (!page_pool_unref_and_test(netmem)) + return; + + page_pool_put_unrefed_netmem(pool, netmem, dma_sync_size, allow_direct); +#endif +} + +/** + * page_pool_put_page() - release a reference to a page pool page + * @pool: pool from which page was allocated + * @page: page to release a reference on + * @dma_sync_size: how much of the page may have been touched by the device + * @allow_direct: released by the consumer, allow lockless caching + * + * The outcome of this depends on the page refcnt. If the driver bumps + * the refcnt > 1 this will unmap the page. If the page refcnt is 1 + * the allocator owns the page and will try to recycle it in one of the pool + * caches. If PP_FLAG_DMA_SYNC_DEV is set, the page will be synced for_device + * using dma_sync_single_range_for_device(). + */ +static inline void page_pool_put_page(struct page_pool *pool, + struct page *page, + unsigned int dma_sync_size, + bool allow_direct) +{ + page_pool_put_netmem(pool, page_to_netmem(page), dma_sync_size, + allow_direct); +} + +static inline void page_pool_put_full_netmem(struct page_pool *pool, + netmem_ref netmem, + bool allow_direct) +{ + page_pool_put_netmem(pool, netmem, -1, allow_direct); +} + +/** + * page_pool_put_full_page() - release a reference on a page pool page + * @pool: pool from which page was allocated + * @page: page to release a reference on + * @allow_direct: released by the consumer, allow lockless caching + * + * Similar to page_pool_put_page(), but will DMA sync the entire memory area + * as configured in &page_pool_params.max_len. + */ +static inline void page_pool_put_full_page(struct page_pool *pool, + struct page *page, bool allow_direct) +{ + page_pool_put_netmem(pool, page_to_netmem(page), -1, allow_direct); +} + +/** + * page_pool_recycle_direct() - release a reference on a page pool page + * @pool: pool from which page was allocated + * @page: page to release a reference on + * + * Similar to page_pool_put_full_page() but caller must guarantee safe context + * (e.g NAPI), since it will recycle the page directly into the pool fast cache. + */ +static inline void page_pool_recycle_direct(struct page_pool *pool, + struct page *page) +{ + page_pool_put_full_page(pool, page, true); +} + +static inline void page_pool_recycle_direct_netmem(struct page_pool *pool, + netmem_ref netmem) +{ + page_pool_put_full_netmem(pool, netmem, true); +} + +#define PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA \ + (sizeof(dma_addr_t) > sizeof(unsigned long)) + +/** + * page_pool_free_va() - free a va into the page_pool + * @pool: pool from which va was allocated + * @va: va to be freed + * @allow_direct: freed by the consumer, allow lockless caching + * + * Free a va allocated from page_pool_allo_va(). + */ +static inline void page_pool_free_va(struct page_pool *pool, void *va, + bool allow_direct) +{ + page_pool_put_page(pool, virt_to_head_page(va), -1, allow_direct); +} + +static inline dma_addr_t page_pool_get_dma_addr_netmem(netmem_ref netmem) +{ + dma_addr_t ret = netmem_get_dma_addr(netmem); + + if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) + ret <<= PAGE_SHIFT; + + return ret; +} + +/** + * page_pool_get_dma_addr() - Retrieve the stored DMA address. + * @page: page allocated from a page pool + * + * Fetch the DMA address of the page. The page pool to which the page belongs + * must had been created with PP_FLAG_DMA_MAP. + */ +static inline dma_addr_t page_pool_get_dma_addr(const struct page *page) +{ + return page_pool_get_dma_addr_netmem(page_to_netmem(page)); +} + +static inline void __page_pool_dma_sync_for_cpu(const struct page_pool *pool, + const dma_addr_t dma_addr, + u32 offset, u32 dma_sync_size) +{ + dma_sync_single_range_for_cpu(pool->p.dev, dma_addr, + offset + pool->p.offset, dma_sync_size, + page_pool_get_dma_dir(pool)); +} + +/** + * page_pool_dma_sync_for_cpu - sync Rx page for CPU after it's written by HW + * @pool: &page_pool the @page belongs to + * @page: page to sync + * @offset: offset from page start to "hard" start if using PP frags + * @dma_sync_size: size of the data written to the page + * + * Can be used as a shorthand to sync Rx pages before accessing them in the + * driver. Caller must ensure the pool was created with ``PP_FLAG_DMA_MAP``. + * Note that this version performs DMA sync unconditionally, even if the + * associated PP doesn't perform sync-for-device. + */ +static inline void page_pool_dma_sync_for_cpu(const struct page_pool *pool, + const struct page *page, + u32 offset, u32 dma_sync_size) +{ + __page_pool_dma_sync_for_cpu(pool, page_pool_get_dma_addr(page), offset, + dma_sync_size); +} + +static inline void +page_pool_dma_sync_netmem_for_cpu(const struct page_pool *pool, + const netmem_ref netmem, u32 offset, + u32 dma_sync_size) +{ + if (!pool->dma_sync_for_cpu) + return; + + __page_pool_dma_sync_for_cpu(pool, + page_pool_get_dma_addr_netmem(netmem), + offset, dma_sync_size); +} + +static inline void page_pool_get(struct page_pool *pool) +{ + refcount_inc(&pool->user_cnt); +} + +static inline bool page_pool_put(struct page_pool *pool) +{ + return refcount_dec_and_test(&pool->user_cnt); +} + +static inline void page_pool_nid_changed(struct page_pool *pool, int new_nid) +{ + if (unlikely(pool->p.nid != new_nid)) + page_pool_update_nid(pool, new_nid); +} + +/** + * page_pool_is_unreadable() - will allocated buffers be unreadable for the CPU + * @pool: queried page pool + * + * Check if page pool will return buffers which are unreadable to the CPU / + * kernel. This will only be the case if user space bound a memory provider (mp) + * which returns unreadable memory to the queue served by the page pool. + * If %PP_FLAG_ALLOW_UNREADABLE_NETMEM was set but there is no mp bound + * this helper will return false. See also netif_rxq_has_unreadable_mp(). + * + * Return: true if memory allocated by the page pool may be unreadable + */ +static inline bool page_pool_is_unreadable(struct page_pool *pool) +{ + return !!pool->mp_ops; +} + +#endif /* _NET_PAGE_POOL_HELPERS_H */ diff --git a/include/net/page_pool/memory_provider.h b/include/net/page_pool/memory_provider.h new file mode 100644 index 000000000..255ce4cfd --- /dev/null +++ b/include/net/page_pool/memory_provider.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_PAGE_POOL_MEMORY_PROVIDER_H +#define _NET_PAGE_POOL_MEMORY_PROVIDER_H + +#include <net/netmem.h> +#include <net/page_pool/types.h> + +struct netdev_rx_queue; +struct netlink_ext_ack; +struct sk_buff; + +struct memory_provider_ops { + netmem_ref (*alloc_netmems)(struct page_pool *pool, gfp_t gfp); + bool (*release_netmem)(struct page_pool *pool, netmem_ref netmem); + int (*init)(struct page_pool *pool); + void (*destroy)(struct page_pool *pool); + int (*nl_fill)(void *mp_priv, struct sk_buff *rsp, + struct netdev_rx_queue *rxq); + void (*uninstall)(void *mp_priv, struct netdev_rx_queue *rxq); +}; + +bool net_mp_niov_set_dma_addr(struct net_iov *niov, dma_addr_t addr); +void net_mp_niov_set_page_pool(struct page_pool *pool, struct net_iov *niov); +void net_mp_niov_clear_page_pool(struct net_iov *niov); + +int netif_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx, + const struct pp_memory_provider_params *p, + struct netlink_ext_ack *extack); +void netif_mp_close_rxq(struct net_device *dev, unsigned int rxq_idx, + const struct pp_memory_provider_params *old_p); + +/** + * net_mp_netmem_place_in_cache() - give a netmem to a page pool + * @pool: the page pool to place the netmem into + * @netmem: netmem to give + * + * Push an accounted netmem into the page pool's allocation cache. The caller + * must ensure that there is space in the cache. It should only be called off + * the mp_ops->alloc_netmems() path. + */ +static inline void net_mp_netmem_place_in_cache(struct page_pool *pool, + netmem_ref netmem) +{ + pool->alloc.cache[pool->alloc.count++] = netmem; +} + +#endif diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h new file mode 100644 index 000000000..03da13872 --- /dev/null +++ b/include/net/page_pool/types.h @@ -0,0 +1,320 @@ +/* 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> +#include <linux/types.h> +#include <linux/xarray.h> +#include <net/netmem.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_SYSTEM_POOL BIT(2) /* Global system page_pool */ + +/* Allow unreadable (net_iov backed) netmem in this page_pool. Drivers setting + * this must be able to support unreadable netmem, where netmem_address() would + * return NULL. This flag should not be set for header page_pools. + * + * If the driver sets PP_FLAG_ALLOW_UNREADABLE_NETMEM, it should also set + * page_pool_params.slow.queue_idx. + */ +#define PP_FLAG_ALLOW_UNREADABLE_NETMEM BIT(3) + +#define PP_FLAG_ALL (PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV | \ + PP_FLAG_SYSTEM_POOL | PP_FLAG_ALLOW_UNREADABLE_NETMEM) + +/* Index limit to stay within PP_DMA_INDEX_BITS for DMA indices */ +#define PP_DMA_INDEX_LIMIT XA_LIMIT(1, BIT(PP_DMA_INDEX_BITS) - 1) + +/* + * 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. + * The refill watermark is set to 64 for 4KB pages, + * and scales to balance its size in bytes across page sizes. + * + * 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. + */ +#if PAGE_SIZE >= SZ_64K +#define PP_ALLOC_CACHE_REFILL 4 +#elif PAGE_SIZE >= SZ_16K +#define PP_ALLOC_CACHE_REFILL 16 +#else +#define PP_ALLOC_CACHE_REFILL 64 +#endif + +#define PP_ALLOC_CACHE_SIZE (PP_ALLOC_CACHE_REFILL * 2) +struct pp_alloc_cache { + u32 count; + netmem_ref cache[PP_ALLOC_CACHE_SIZE]; +}; + +/** + * struct page_pool_params - page pool parameters + * @fast: params accessed frequently on hotpath + * @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 + * @slow: params with slowpath access only (initialization and Netlink) + * @netdev: netdev this pool will serve (leave as NULL if none or multiple) + * @queue_idx: queue idx this page_pool is being created for. + * @flags: PP_FLAG_DMA_MAP, PP_FLAG_DMA_SYNC_DEV, PP_FLAG_SYSTEM_POOL, + * PP_FLAG_ALLOW_UNREADABLE_NETMEM. + */ +struct page_pool_params { + struct_group_tagged(page_pool_params_fast, fast, + 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; + ); + struct_group_tagged(page_pool_params_slow, slow, + struct net_device *netdev; + unsigned int queue_idx; + unsigned int flags; +/* private: used by test code only */ + void (*init_callback)(netmem_ref netmem, 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 + +/* The whole frag API block must stay within one cacheline. On 32-bit systems, + * sizeof(long) == sizeof(int), so that the block size is ``3 * sizeof(long)``. + * On 64-bit systems, the actual size is ``2 * sizeof(long) + sizeof(int)``. + * The closest pow-2 to both of them is ``4 * sizeof(long)``, so just use that + * one for simplicity. + * Having it aligned to a cacheline boundary may be excessive and doesn't bring + * any good. + */ +#define PAGE_POOL_FRAG_GROUP_ALIGN (4 * sizeof(long)) + +struct memory_provider_ops; + +struct pp_memory_provider_params { + void *mp_priv; + const struct memory_provider_ops *mp_ops; + u32 rx_page_size; +}; + +struct page_pool { + struct page_pool_params_fast p; + + int cpuid; + u32 pages_state_hold_cnt; + + bool has_init_callback:1; /* slow::init_callback is set */ + bool dma_map:1; /* Perform DMA mapping */ + bool dma_sync:1; /* Perform DMA sync for device */ + bool dma_sync_for_cpu:1; /* Perform DMA sync for cpu */ +#ifdef CONFIG_PAGE_POOL_STATS + bool system:1; /* This is a global percpu pool */ +#endif + + __cacheline_group_begin_aligned(frag, PAGE_POOL_FRAG_GROUP_ALIGN); + long frag_users; + netmem_ref frag_page; + unsigned int frag_offset; + __cacheline_group_end_aligned(frag, PAGE_POOL_FRAG_GROUP_ALIGN); + + 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; + + void *mp_priv; + const struct memory_provider_ops *mp_ops; + + struct xarray dma_mapped; + +#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; + + /* Slow/Control-path information follows */ + struct page_pool_params_slow slow; + /* User-facing fields, protected by page_pools_lock */ + struct { + struct hlist_node list; + ktime_t detach_time; + u32 id; + } user; +}; + +struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp); +netmem_ref page_pool_alloc_netmems(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); +netmem_ref page_pool_alloc_frag_netmem(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 page_pool *page_pool_create_percpu(const struct page_pool_params *params, + int cpuid); + +struct xdp_mem_info; + +#ifdef CONFIG_PAGE_POOL +void page_pool_enable_direct_recycling(struct page_pool *pool, + struct napi_struct *napi); +void page_pool_disable_direct_recycling(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 *), + const struct xdp_mem_info *mem); +void page_pool_put_netmem_bulk(netmem_ref *data, u32 count); +#else +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 *), + const struct xdp_mem_info *mem) +{ +} + +static inline void page_pool_put_netmem_bulk(netmem_ref *data, u32 count) +{ +} +#endif + +void page_pool_put_unrefed_netmem(struct page_pool *pool, netmem_ref netmem, + unsigned int dma_sync_size, + bool allow_direct); +void page_pool_put_unrefed_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 */ |
