Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Jesper Dangaard Brouer | 1810 | 47.93% | 15 | 23.44% |
Lorenzo Bianconi | 699 | 18.51% | 5 | 7.81% |
Lin Yun Sheng | 435 | 11.52% | 9 | 14.06% |
Joe Damato | 309 | 8.18% | 3 | 4.69% |
Jonathan Lemon | 224 | 5.93% | 2 | 3.12% |
Jakub Kiciński | 73 | 1.93% | 6 | 9.38% |
Ivan Khoronzhuk | 38 | 1.01% | 1 | 1.56% |
Toke Höiland-Jörgensen | 36 | 0.95% | 2 | 3.12% |
Ilias Apalodimas | 33 | 0.87% | 3 | 4.69% |
Saeed Mahameed | 29 | 0.77% | 2 | 3.12% |
Matteo Croce | 21 | 0.56% | 1 | 1.56% |
Matthew Wilcox | 21 | 0.56% | 2 | 3.12% |
Alexander Duyck | 13 | 0.34% | 1 | 1.56% |
Jie Wang | 9 | 0.24% | 2 | 3.12% |
Denis Kirjanov | 5 | 0.13% | 1 | 1.56% |
Li RongQing | 4 | 0.11% | 1 | 1.56% |
Alexander Lobakin | 4 | 0.11% | 2 | 3.12% |
DENG Qingfang | 4 | 0.11% | 1 | 1.56% |
Ben Hutchings | 3 | 0.08% | 1 | 1.56% |
Linus Torvalds (pre-git) | 3 | 0.08% | 2 | 3.12% |
Jian Shen | 2 | 0.05% | 1 | 1.56% |
Tariq Toukan | 1 | 0.03% | 1 | 1.56% |
Total | 3776 | 64 |
/* SPDX-License-Identifier: GPL-2.0 * * page_pool.c * Author: Jesper Dangaard Brouer <netoptimizer@brouer.com> * Copyright (C) 2016 Red Hat, Inc. */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/device.h> #include <net/page_pool/helpers.h> #include <net/xdp.h> #include <linux/dma-direction.h> #include <linux/dma-mapping.h> #include <linux/page-flags.h> #include <linux/mm.h> /* for put_page() */ #include <linux/poison.h> #include <linux/ethtool.h> #include <linux/netdevice.h> #include <trace/events/page_pool.h> #define DEFER_TIME (msecs_to_jiffies(1000)) #define DEFER_WARN_INTERVAL (60 * HZ) #define BIAS_MAX LONG_MAX #ifdef CONFIG_PAGE_POOL_STATS /* alloc_stat_inc is intended to be used in softirq context */ #define alloc_stat_inc(pool, __stat) (pool->alloc_stats.__stat++) /* recycle_stat_inc is safe to use when preemption is possible. */ #define recycle_stat_inc(pool, __stat) \ do { \ struct page_pool_recycle_stats __percpu *s = pool->recycle_stats; \ this_cpu_inc(s->__stat); \ } while (0) #define recycle_stat_add(pool, __stat, val) \ do { \ struct page_pool_recycle_stats __percpu *s = pool->recycle_stats; \ this_cpu_add(s->__stat, val); \ } while (0) static const char pp_stats[][ETH_GSTRING_LEN] = { "rx_pp_alloc_fast", "rx_pp_alloc_slow", "rx_pp_alloc_slow_ho", "rx_pp_alloc_empty", "rx_pp_alloc_refill", "rx_pp_alloc_waive", "rx_pp_recycle_cached", "rx_pp_recycle_cache_full", "rx_pp_recycle_ring", "rx_pp_recycle_ring_full", "rx_pp_recycle_released_ref", }; /** * page_pool_get_stats() - fetch page pool stats * @pool: pool from which page was allocated * @stats: struct page_pool_stats to fill in * * Retrieve statistics about the page_pool. This API is only available * if the kernel has been configured with ``CONFIG_PAGE_POOL_STATS=y``. * A pointer to a caller allocated struct page_pool_stats structure * is passed to this API which is filled in. The caller can then report * those stats to the user (perhaps via ethtool, debugfs, etc.). */ bool page_pool_get_stats(struct page_pool *pool, struct page_pool_stats *stats) { int cpu = 0; if (!stats) return false; /* The caller is responsible to initialize stats. */ stats->alloc_stats.fast += pool->alloc_stats.fast; stats->alloc_stats.slow += pool->alloc_stats.slow; stats->alloc_stats.slow_high_order += pool->alloc_stats.slow_high_order; stats->alloc_stats.empty += pool->alloc_stats.empty; stats->alloc_stats.refill += pool->alloc_stats.refill; stats->alloc_stats.waive += pool->alloc_stats.waive; for_each_possible_cpu(cpu) { const struct page_pool_recycle_stats *pcpu = per_cpu_ptr(pool->recycle_stats, cpu); stats->recycle_stats.cached += pcpu->cached; stats->recycle_stats.cache_full += pcpu->cache_full; stats->recycle_stats.ring += pcpu->ring; stats->recycle_stats.ring_full += pcpu->ring_full; stats->recycle_stats.released_refcnt += pcpu->released_refcnt; } return true; } EXPORT_SYMBOL(page_pool_get_stats); u8 *page_pool_ethtool_stats_get_strings(u8 *data) { int i; for (i = 0; i < ARRAY_SIZE(pp_stats); i++) { memcpy(data, pp_stats[i], ETH_GSTRING_LEN); data += ETH_GSTRING_LEN; } return data; } EXPORT_SYMBOL(page_pool_ethtool_stats_get_strings); int page_pool_ethtool_stats_get_count(void) { return ARRAY_SIZE(pp_stats); } EXPORT_SYMBOL(page_pool_ethtool_stats_get_count); u64 *page_pool_ethtool_stats_get(u64 *data, void *stats) { struct page_pool_stats *pool_stats = stats; *data++ = pool_stats->alloc_stats.fast; *data++ = pool_stats->alloc_stats.slow; *data++ = pool_stats->alloc_stats.slow_high_order; *data++ = pool_stats->alloc_stats.empty; *data++ = pool_stats->alloc_stats.refill; *data++ = pool_stats->alloc_stats.waive; *data++ = pool_stats->recycle_stats.cached; *data++ = pool_stats->recycle_stats.cache_full; *data++ = pool_stats->recycle_stats.ring; *data++ = pool_stats->recycle_stats.ring_full; *data++ = pool_stats->recycle_stats.released_refcnt; return data; } EXPORT_SYMBOL(page_pool_ethtool_stats_get); #else #define alloc_stat_inc(pool, __stat) #define recycle_stat_inc(pool, __stat) #define recycle_stat_add(pool, __stat, val) #endif static bool page_pool_producer_lock(struct page_pool *pool) __acquires(&pool->ring.producer_lock) { bool in_softirq = in_softirq(); if (in_softirq) spin_lock(&pool->ring.producer_lock); else spin_lock_bh(&pool->ring.producer_lock); return in_softirq; } static void page_pool_producer_unlock(struct page_pool *pool, bool in_softirq) __releases(&pool->ring.producer_lock) { if (in_softirq) spin_unlock(&pool->ring.producer_lock); else spin_unlock_bh(&pool->ring.producer_lock); } static int page_pool_init(struct page_pool *pool, const struct page_pool_params *params) { unsigned int ring_qsize = 1024; /* Default */ memcpy(&pool->p, params, sizeof(pool->p)); /* Validate only known flags were used */ if (pool->p.flags & ~(PP_FLAG_ALL)) return -EINVAL; if (pool->p.pool_size) ring_qsize = pool->p.pool_size; /* Sanity limit mem that can be pinned down */ if (ring_qsize > 32768) return -E2BIG; /* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL. * DMA_BIDIRECTIONAL is for allowing page used for DMA sending, * which is the XDP_TX use-case. */ if (pool->p.flags & PP_FLAG_DMA_MAP) { if ((pool->p.dma_dir != DMA_FROM_DEVICE) && (pool->p.dma_dir != DMA_BIDIRECTIONAL)) return -EINVAL; } if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) { /* In order to request DMA-sync-for-device the page * needs to be mapped */ if (!(pool->p.flags & PP_FLAG_DMA_MAP)) return -EINVAL; if (!pool->p.max_len) return -EINVAL; /* pool->p.offset has to be set according to the address * offset used by the DMA engine to start copying rx data */ } #ifdef CONFIG_PAGE_POOL_STATS pool->recycle_stats = alloc_percpu(struct page_pool_recycle_stats); if (!pool->recycle_stats) return -ENOMEM; #endif if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0) { #ifdef CONFIG_PAGE_POOL_STATS free_percpu(pool->recycle_stats); #endif return -ENOMEM; } atomic_set(&pool->pages_state_release_cnt, 0); /* Driver calling page_pool_create() also call page_pool_destroy() */ refcount_set(&pool->user_cnt, 1); if (pool->p.flags & PP_FLAG_DMA_MAP) get_device(pool->p.dev); return 0; } /** * page_pool_create() - create a page pool. * @params: parameters, see struct page_pool_params */ struct page_pool *page_pool_create(const struct page_pool_params *params) { struct page_pool *pool; int err; pool = kzalloc_node(sizeof(*pool), GFP_KERNEL, params->nid); if (!pool) return ERR_PTR(-ENOMEM); err = page_pool_init(pool, params); if (err < 0) { pr_warn("%s() gave up with errno %d\n", __func__, err); kfree(pool); return ERR_PTR(err); } return pool; } EXPORT_SYMBOL(page_pool_create); static void page_pool_return_page(struct page_pool *pool, struct page *page); noinline static struct page *page_pool_refill_alloc_cache(struct page_pool *pool) { struct ptr_ring *r = &pool->ring; struct page *page; int pref_nid; /* preferred NUMA node */ /* Quicker fallback, avoid locks when ring is empty */ if (__ptr_ring_empty(r)) { alloc_stat_inc(pool, empty); return NULL; } /* Softirq guarantee CPU and thus NUMA node is stable. This, * assumes CPU refilling driver RX-ring will also run RX-NAPI. */ #ifdef CONFIG_NUMA pref_nid = (pool->p.nid == NUMA_NO_NODE) ? numa_mem_id() : pool->p.nid; #else /* Ignore pool->p.nid setting if !CONFIG_NUMA, helps compiler */ pref_nid = numa_mem_id(); /* will be zero like page_to_nid() */ #endif /* Refill alloc array, but only if NUMA match */ do { page = __ptr_ring_consume(r); if (unlikely(!page)) break; if (likely(page_to_nid(page) == pref_nid)) { pool->alloc.cache[pool->alloc.count++] = page; } else { /* NUMA mismatch; * (1) release 1 page to page-allocator and * (2) break out to fallthrough to alloc_pages_node. * This limit stress on page buddy alloactor. */ page_pool_return_page(pool, page); alloc_stat_inc(pool, waive); page = NULL; break; } } while (pool->alloc.count < PP_ALLOC_CACHE_REFILL); /* Return last page */ if (likely(pool->alloc.count > 0)) { page = pool->alloc.cache[--pool->alloc.count]; alloc_stat_inc(pool, refill); } return page; } /* fast path */ static struct page *__page_pool_get_cached(struct page_pool *pool) { struct page *page; /* Caller MUST guarantee safe non-concurrent access, e.g. softirq */ if (likely(pool->alloc.count)) { /* Fast-path */ page = pool->alloc.cache[--pool->alloc.count]; alloc_stat_inc(pool, fast); } else { page = page_pool_refill_alloc_cache(pool); } return page; } static void page_pool_dma_sync_for_device(struct page_pool *pool, struct page *page, unsigned int dma_sync_size) { dma_addr_t dma_addr = page_pool_get_dma_addr(page); dma_sync_size = min(dma_sync_size, pool->p.max_len); dma_sync_single_range_for_device(pool->p.dev, dma_addr, pool->p.offset, dma_sync_size, pool->p.dma_dir); } static bool page_pool_dma_map(struct page_pool *pool, struct page *page) { dma_addr_t dma; /* Setup DMA mapping: use 'struct page' area for storing DMA-addr * since dma_addr_t can be either 32 or 64 bits and does not always fit * into page private data (i.e 32bit cpu with 64bit DMA caps) * This mapping is kept for lifetime of page, until leaving pool. */ dma = dma_map_page_attrs(pool->p.dev, page, 0, (PAGE_SIZE << pool->p.order), pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING); if (dma_mapping_error(pool->p.dev, dma)) return false; if (page_pool_set_dma_addr(page, dma)) goto unmap_failed; if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) page_pool_dma_sync_for_device(pool, page, pool->p.max_len); return true; unmap_failed: WARN_ON_ONCE("unexpected DMA address, please report to netdev@"); dma_unmap_page_attrs(pool->p.dev, dma, PAGE_SIZE << pool->p.order, pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING); return false; } static void page_pool_set_pp_info(struct page_pool *pool, struct page *page) { page->pp = pool; page->pp_magic |= PP_SIGNATURE; /* Ensuring all pages have been split into one fragment initially: * page_pool_set_pp_info() is only called once for every page when it * is allocated from the page allocator and page_pool_fragment_page() * is dirtying the same cache line as the page->pp_magic above, so * the overhead is negligible. */ page_pool_fragment_page(page, 1); if (pool->p.init_callback) pool->p.init_callback(page, pool->p.init_arg); } static void page_pool_clear_pp_info(struct page *page) { page->pp_magic = 0; page->pp = NULL; } static struct page *__page_pool_alloc_page_order(struct page_pool *pool, gfp_t gfp) { struct page *page; gfp |= __GFP_COMP; page = alloc_pages_node(pool->p.nid, gfp, pool->p.order); if (unlikely(!page)) return NULL; if ((pool->p.flags & PP_FLAG_DMA_MAP) && unlikely(!page_pool_dma_map(pool, page))) { put_page(page); return NULL; } alloc_stat_inc(pool, slow_high_order); page_pool_set_pp_info(pool, page); /* Track how many pages are held 'in-flight' */ pool->pages_state_hold_cnt++; trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); return page; } /* slow path */ noinline static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, gfp_t gfp) { const int bulk = PP_ALLOC_CACHE_REFILL; unsigned int pp_flags = pool->p.flags; unsigned int pp_order = pool->p.order; struct page *page; int i, nr_pages; /* Don't support bulk alloc for high-order pages */ if (unlikely(pp_order)) return __page_pool_alloc_page_order(pool, gfp); /* Unnecessary as alloc cache is empty, but guarantees zero count */ if (unlikely(pool->alloc.count > 0)) return pool->alloc.cache[--pool->alloc.count]; /* Mark empty alloc.cache slots "empty" for alloc_pages_bulk_array */ memset(&pool->alloc.cache, 0, sizeof(void *) * bulk); nr_pages = alloc_pages_bulk_array_node(gfp, pool->p.nid, bulk, pool->alloc.cache); if (unlikely(!nr_pages)) return NULL; /* Pages have been filled into alloc.cache array, but count is zero and * page element have not been (possibly) DMA mapped. */ for (i = 0; i < nr_pages; i++) { page = pool->alloc.cache[i]; if ((pp_flags & PP_FLAG_DMA_MAP) && unlikely(!page_pool_dma_map(pool, page))) { put_page(page); continue; } page_pool_set_pp_info(pool, page); pool->alloc.cache[pool->alloc.count++] = page; /* Track how many pages are held 'in-flight' */ pool->pages_state_hold_cnt++; trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); } /* Return last page */ if (likely(pool->alloc.count > 0)) { page = pool->alloc.cache[--pool->alloc.count]; alloc_stat_inc(pool, slow); } else { page = NULL; } /* When page just alloc'ed is should/must have refcnt 1. */ return page; } /* For using page_pool replace: alloc_pages() API calls, but provide * synchronization guarantee for allocation side. */ struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp) { struct page *page; /* Fast-path: Get a page from cache */ page = __page_pool_get_cached(pool); if (page) return page; /* Slow-path: cache empty, do real allocation */ page = __page_pool_alloc_pages_slow(pool, gfp); return page; } EXPORT_SYMBOL(page_pool_alloc_pages); /* Calculate distance between two u32 values, valid if distance is below 2^(31) * https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution */ #define _distance(a, b) (s32)((a) - (b)) static s32 page_pool_inflight(struct page_pool *pool) { u32 release_cnt = atomic_read(&pool->pages_state_release_cnt); u32 hold_cnt = READ_ONCE(pool->pages_state_hold_cnt); s32 inflight; inflight = _distance(hold_cnt, release_cnt); trace_page_pool_release(pool, inflight, hold_cnt, release_cnt); WARN(inflight < 0, "Negative(%d) inflight packet-pages", inflight); return inflight; } /* Disconnects a page (from a page_pool). API users can have a need * to disconnect a page (from a page_pool), to allow it to be used as * a regular page (that will eventually be returned to the normal * page-allocator via put_page). */ static void page_pool_return_page(struct page_pool *pool, struct page *page) { dma_addr_t dma; int count; if (!(pool->p.flags & PP_FLAG_DMA_MAP)) /* Always account for inflight pages, even if we didn't * map them */ goto skip_dma_unmap; dma = page_pool_get_dma_addr(page); /* When page is unmapped, it cannot be returned to our pool */ dma_unmap_page_attrs(pool->p.dev, dma, PAGE_SIZE << pool->p.order, pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING); page_pool_set_dma_addr(page, 0); skip_dma_unmap: page_pool_clear_pp_info(page); /* This may be the last page returned, releasing the pool, so * it is not safe to reference pool afterwards. */ count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt); trace_page_pool_state_release(pool, page, count); put_page(page); /* An optimization would be to call __free_pages(page, pool->p.order) * knowing page is not part of page-cache (thus avoiding a * __page_cache_release() call). */ } static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page) { int ret; /* BH protection not needed if current is softirq */ if (in_softirq()) ret = ptr_ring_produce(&pool->ring, page); else ret = ptr_ring_produce_bh(&pool->ring, page); if (!ret) { recycle_stat_inc(pool, ring); return true; } return false; } /* Only allow direct recycling in special circumstances, into the * alloc side cache. E.g. during RX-NAPI processing for XDP_DROP use-case. * * Caller must provide appropriate safe context. */ static bool page_pool_recycle_in_cache(struct page *page, struct page_pool *pool) { if (unlikely(pool->alloc.count == PP_ALLOC_CACHE_SIZE)) { recycle_stat_inc(pool, cache_full); return false; } /* Caller MUST have verified/know (page_ref_count(page) == 1) */ pool->alloc.cache[pool->alloc.count++] = page; recycle_stat_inc(pool, cached); return true; } /* If the page refcnt == 1, this will try to recycle the page. * if PP_FLAG_DMA_SYNC_DEV is set, we'll try to sync the DMA area for * the configured size min(dma_sync_size, pool->max_len). * If the page refcnt != 1, then the page will be returned to memory * subsystem. */ static __always_inline struct page * __page_pool_put_page(struct page_pool *pool, struct page *page, unsigned int dma_sync_size, bool allow_direct) { lockdep_assert_no_hardirq(); /* This allocator is optimized for the XDP mode that uses * one-frame-per-page, but have fallbacks that act like the * regular page allocator APIs. * * refcnt == 1 means page_pool owns page, and can recycle it. * * page is NOT reusable when allocated when system is under * some pressure. (page_is_pfmemalloc) */ if (likely(page_ref_count(page) == 1 && !page_is_pfmemalloc(page))) { /* Read barrier done in page_ref_count / READ_ONCE */ if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) page_pool_dma_sync_for_device(pool, page, dma_sync_size); if (allow_direct && in_softirq() && page_pool_recycle_in_cache(page, pool)) return NULL; /* Page found as candidate for recycling */ return page; } /* Fallback/non-XDP mode: API user have elevated refcnt. * * Many drivers split up the page into fragments, and some * want to keep doing this to save memory and do refcnt based * recycling. Support this use case too, to ease drivers * switching between XDP/non-XDP. * * In-case page_pool maintains the DMA mapping, API user must * call page_pool_put_page once. In this elevated refcnt * case, the DMA is unmapped/released, as driver is likely * doing refcnt based recycle tricks, meaning another process * will be invoking put_page. */ recycle_stat_inc(pool, released_refcnt); page_pool_return_page(pool, page); return NULL; } void page_pool_put_defragged_page(struct page_pool *pool, struct page *page, unsigned int dma_sync_size, bool allow_direct) { page = __page_pool_put_page(pool, page, dma_sync_size, allow_direct); if (page && !page_pool_recycle_in_ring(pool, page)) { /* Cache full, fallback to free pages */ recycle_stat_inc(pool, ring_full); page_pool_return_page(pool, page); } } EXPORT_SYMBOL(page_pool_put_defragged_page); /** * page_pool_put_page_bulk() - release references on multiple pages * @pool: pool from which pages were allocated * @data: array holding page pointers * @count: number of pages in @data * * Tries to refill a number of pages into the ptr_ring cache holding ptr_ring * producer lock. If the ptr_ring is full, page_pool_put_page_bulk() * will release leftover pages to the page allocator. * page_pool_put_page_bulk() is suitable to be run inside the driver NAPI tx * completion loop for the XDP_REDIRECT use case. * * Please note the caller must not use data area after running * page_pool_put_page_bulk(), as this function overwrites it. */ void page_pool_put_page_bulk(struct page_pool *pool, void **data, int count) { int i, bulk_len = 0; bool in_softirq; for (i = 0; i < count; i++) { struct page *page = virt_to_head_page(data[i]); /* It is not the last user for the page frag case */ if (!page_pool_is_last_frag(page)) continue; page = __page_pool_put_page(pool, page, -1, false); /* Approved for bulk recycling in ptr_ring cache */ if (page) data[bulk_len++] = page; } if (unlikely(!bulk_len)) return; /* Bulk producer into ptr_ring page_pool cache */ in_softirq = page_pool_producer_lock(pool); for (i = 0; i < bulk_len; i++) { if (__ptr_ring_produce(&pool->ring, data[i])) { /* ring full */ recycle_stat_inc(pool, ring_full); break; } } recycle_stat_add(pool, ring, i); page_pool_producer_unlock(pool, in_softirq); /* Hopefully all pages was return into ptr_ring */ if (likely(i == bulk_len)) return; /* ptr_ring cache full, free remaining pages outside producer lock * since put_page() with refcnt == 1 can be an expensive operation */ for (; i < bulk_len; i++) page_pool_return_page(pool, data[i]); } EXPORT_SYMBOL(page_pool_put_page_bulk); static struct page *page_pool_drain_frag(struct page_pool *pool, struct page *page) { long drain_count = BIAS_MAX - pool->frag_users; /* Some user is still using the page frag */ if (likely(page_pool_defrag_page(page, drain_count))) return NULL; if (page_ref_count(page) == 1 && !page_is_pfmemalloc(page)) { if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) page_pool_dma_sync_for_device(pool, page, -1); return page; } page_pool_return_page(pool, page); return NULL; } static void page_pool_free_frag(struct page_pool *pool) { long drain_count = BIAS_MAX - pool->frag_users; struct page *page = pool->frag_page; pool->frag_page = NULL; if (!page || page_pool_defrag_page(page, drain_count)) return; page_pool_return_page(pool, page); } struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset, unsigned int size, gfp_t gfp) { unsigned int max_size = PAGE_SIZE << pool->p.order; struct page *page = pool->frag_page; if (WARN_ON(size > max_size)) return NULL; size = ALIGN(size, dma_get_cache_alignment()); *offset = pool->frag_offset; if (page && *offset + size > max_size) { page = page_pool_drain_frag(pool, page); if (page) { alloc_stat_inc(pool, fast); goto frag_reset; } } if (!page) { page = page_pool_alloc_pages(pool, gfp); if (unlikely(!page)) { pool->frag_page = NULL; return NULL; } pool->frag_page = page; frag_reset: pool->frag_users = 1; *offset = 0; pool->frag_offset = size; page_pool_fragment_page(page, BIAS_MAX); return page; } pool->frag_users++; pool->frag_offset = *offset + size; alloc_stat_inc(pool, fast); return page; } EXPORT_SYMBOL(page_pool_alloc_frag); static void page_pool_empty_ring(struct page_pool *pool) { struct page *page; /* Empty recycle ring */ while ((page = ptr_ring_consume_bh(&pool->ring))) { /* Verify the refcnt invariant of cached pages */ if (!(page_ref_count(page) == 1)) pr_crit("%s() page_pool refcnt %d violation\n", __func__, page_ref_count(page)); page_pool_return_page(pool, page); } } static void __page_pool_destroy(struct page_pool *pool) { if (pool->disconnect) pool->disconnect(pool); ptr_ring_cleanup(&pool->ring, NULL); if (pool->p.flags & PP_FLAG_DMA_MAP) put_device(pool->p.dev); #ifdef CONFIG_PAGE_POOL_STATS free_percpu(pool->recycle_stats); #endif kfree(pool); } static void page_pool_empty_alloc_cache_once(struct page_pool *pool) { struct page *page; if (pool->destroy_cnt) return; /* Empty alloc cache, assume caller made sure this is * no-longer in use, and page_pool_alloc_pages() cannot be * call concurrently. */ while (pool->alloc.count) { page = pool->alloc.cache[--pool->alloc.count]; page_pool_return_page(pool, page); } } static void page_pool_scrub(struct page_pool *pool) { page_pool_empty_alloc_cache_once(pool); pool->destroy_cnt++; /* No more consumers should exist, but producers could still * be in-flight. */ page_pool_empty_ring(pool); } static int page_pool_release(struct page_pool *pool) { int inflight; page_pool_scrub(pool); inflight = page_pool_inflight(pool); if (!inflight) __page_pool_destroy(pool); return inflight; } static void page_pool_release_retry(struct work_struct *wq) { struct delayed_work *dwq = to_delayed_work(wq); struct page_pool *pool = container_of(dwq, typeof(*pool), release_dw); int inflight; inflight = page_pool_release(pool); if (!inflight) return; /* Periodic warning */ if (time_after_eq(jiffies, pool->defer_warn)) { int sec = (s32)((u32)jiffies - (u32)pool->defer_start) / HZ; pr_warn("%s() stalled pool shutdown %d inflight %d sec\n", __func__, inflight, sec); pool->defer_warn = jiffies + DEFER_WARN_INTERVAL; } /* Still not ready to be disconnected, retry later */ schedule_delayed_work(&pool->release_dw, DEFER_TIME); } void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *), struct xdp_mem_info *mem) { refcount_inc(&pool->user_cnt); pool->disconnect = disconnect; pool->xdp_mem_id = mem->id; } void page_pool_unlink_napi(struct page_pool *pool) { if (!pool->p.napi) return; /* To avoid races with recycling and additional barriers make sure * pool and NAPI are unlinked when NAPI is disabled. */ WARN_ON(!test_bit(NAPI_STATE_SCHED, &pool->p.napi->state) || READ_ONCE(pool->p.napi->list_owner) != -1); WRITE_ONCE(pool->p.napi, NULL); } EXPORT_SYMBOL(page_pool_unlink_napi); void page_pool_destroy(struct page_pool *pool) { if (!pool) return; if (!page_pool_put(pool)) return; page_pool_unlink_napi(pool); page_pool_free_frag(pool); if (!page_pool_release(pool)) return; pool->defer_start = jiffies; pool->defer_warn = jiffies + DEFER_WARN_INTERVAL; INIT_DELAYED_WORK(&pool->release_dw, page_pool_release_retry); schedule_delayed_work(&pool->release_dw, DEFER_TIME); } EXPORT_SYMBOL(page_pool_destroy); /* Caller must provide appropriate safe context, e.g. NAPI. */ void page_pool_update_nid(struct page_pool *pool, int new_nid) { struct page *page; trace_page_pool_update_nid(pool, new_nid); pool->p.nid = new_nid; /* Flush pool alloc cache, as refill will check NUMA node */ while (pool->alloc.count) { page = pool->alloc.cache[--pool->alloc.count]; page_pool_return_page(pool, page); } } EXPORT_SYMBOL(page_pool_update_nid);
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