diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index d6184f9855c8..048b8768e998 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1525,10 +1525,8 @@ static void free_dma_rx_desc_resources(struct stmmac_priv *priv) rx_q->dma_erx, rx_q->dma_rx_phy); kfree(rx_q->buf_pool); - if (rx_q->page_pool) { - page_pool_request_shutdown(rx_q->page_pool); + if (rx_q->page_pool) page_pool_destroy(rx_q->page_pool); - } } } diff --git a/include/net/page_pool.h b/include/net/page_pool.h index 2cbcdbdec254..1121faa99c12 100644 --- a/include/net/page_pool.h +++ b/include/net/page_pool.h @@ -70,7 +70,12 @@ struct page_pool_params { struct page_pool { struct page_pool_params p; - u32 pages_state_hold_cnt; + struct delayed_work release_dw; + void (*disconnect)(void *); + unsigned long defer_start; + unsigned long defer_warn; + + u32 pages_state_hold_cnt; /* * Data structure for allocation side @@ -129,26 +134,20 @@ inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool) struct page_pool *page_pool_create(const struct page_pool_params *params); -void __page_pool_free(struct page_pool *pool); -static inline void page_pool_free(struct page_pool *pool) -{ - /* 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 - __page_pool_free(pool); -#endif -} - -/* Drivers use this instead of page_pool_free */ +void page_pool_destroy(struct page_pool *pool); +void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *)); +#else static inline void page_pool_destroy(struct page_pool *pool) { - if (!pool) - return; - - page_pool_free(pool); } +static inline void page_pool_use_xdp_mem(struct page_pool *pool, + void (*disconnect)(void *)) +{ +} +#endif + /* Never call this directly, use helpers below */ void __page_pool_put_page(struct page_pool *pool, struct page *page, bool allow_direct); @@ -170,24 +169,6 @@ static inline void page_pool_recycle_direct(struct page_pool *pool, __page_pool_put_page(pool, page, true); } -/* API user MUST have disconnected alloc-side (not allowed to call - * page_pool_alloc_pages()) before calling this. The free-side can - * still run concurrently, to handle in-flight packet-pages. - * - * A request to shutdown can fail (with false) if there are still - * in-flight packet-pages. - */ -bool __page_pool_request_shutdown(struct page_pool *pool); -static inline bool page_pool_request_shutdown(struct page_pool *pool) -{ - bool safe_to_remove = false; - -#ifdef CONFIG_PAGE_POOL - safe_to_remove = __page_pool_request_shutdown(pool); -#endif - return safe_to_remove; -} - /* 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 @@ -216,11 +197,6 @@ static inline bool is_page_pool_compiled_in(void) #endif } -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); diff --git a/include/net/xdp_priv.h b/include/net/xdp_priv.h index 6a8cba6ea79a..a9d5b7603b89 100644 --- a/include/net/xdp_priv.h +++ b/include/net/xdp_priv.h @@ -12,12 +12,8 @@ struct xdp_mem_allocator { struct page_pool *page_pool; struct zero_copy_allocator *zc_alloc; }; - int disconnect_cnt; - unsigned long defer_start; struct rhash_head node; struct rcu_head rcu; - struct delayed_work defer_wq; - unsigned long defer_warn; }; #endif /* __LINUX_NET_XDP_PRIV_H__ */ diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h index 8c8420230a10..c79943e82a54 100644 --- a/include/trace/events/xdp.h +++ b/include/trace/events/xdp.h @@ -317,19 +317,15 @@ __MEM_TYPE_MAP(__MEM_TYPE_TP_FN) TRACE_EVENT(mem_disconnect, - TP_PROTO(const struct xdp_mem_allocator *xa, - bool safe_to_remove, bool force), + TP_PROTO(const struct xdp_mem_allocator *xa), - TP_ARGS(xa, safe_to_remove, force), + TP_ARGS(xa), TP_STRUCT__entry( __field(const struct xdp_mem_allocator *, xa) __field(u32, mem_id) __field(u32, mem_type) __field(const void *, allocator) - __field(bool, safe_to_remove) - __field(bool, force) - __field(int, disconnect_cnt) ), TP_fast_assign( @@ -337,19 +333,12 @@ TRACE_EVENT(mem_disconnect, __entry->mem_id = xa->mem.id; __entry->mem_type = xa->mem.type; __entry->allocator = xa->allocator; - __entry->safe_to_remove = safe_to_remove; - __entry->force = force; - __entry->disconnect_cnt = xa->disconnect_cnt; ), - TP_printk("mem_id=%d mem_type=%s allocator=%p" - " safe_to_remove=%s force=%s disconnect_cnt=%d", + TP_printk("mem_id=%d mem_type=%s allocator=%p", __entry->mem_id, __print_symbolic(__entry->mem_type, __MEM_TYPE_SYM_TAB), - __entry->allocator, - __entry->safe_to_remove ? "true" : "false", - __entry->force ? "true" : "false", - __entry->disconnect_cnt + __entry->allocator ) ); diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 5bc65587f1c4..dfc2501c35d9 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -18,6 +18,9 @@ #include +#define DEFER_TIME (msecs_to_jiffies(1000)) +#define DEFER_WARN_INTERVAL (60 * HZ) + static int page_pool_init(struct page_pool *pool, const struct page_pool_params *params) { @@ -193,22 +196,14 @@ 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 distance; + s32 inflight; - distance = _distance(hold_cnt, release_cnt); + inflight = _distance(hold_cnt, release_cnt); - trace_page_pool_inflight(pool, distance, hold_cnt, release_cnt); - return distance; -} - -static bool __page_pool_safe_to_destroy(struct page_pool *pool) -{ - s32 inflight = page_pool_inflight(pool); - - /* The distance should not be able to become negative */ + trace_page_pool_inflight(pool, inflight, hold_cnt, release_cnt); WARN(inflight < 0, "Negative(%d) inflight packet-pages", inflight); - return (inflight == 0); + return inflight; } /* Cleanup page_pool state from page */ @@ -216,6 +211,7 @@ static void __page_pool_clean_page(struct page_pool *pool, struct page *page) { dma_addr_t dma; + int count; if (!(pool->p.flags & PP_FLAG_DMA_MAP)) goto skip_dma_unmap; @@ -227,9 +223,11 @@ static void __page_pool_clean_page(struct page_pool *pool, DMA_ATTR_SKIP_CPU_SYNC); page->dma_addr = 0; skip_dma_unmap: - atomic_inc(&pool->pages_state_release_cnt); - trace_page_pool_state_release(pool, page, - atomic_read(&pool->pages_state_release_cnt)); + /* This may be the last page returned, releasing the pool, so + * it is not safe to reference pool afterwards. + */ + count = atomic_inc_return(&pool->pages_state_release_cnt); + trace_page_pool_state_release(pool, page, count); } /* unmap the page and clean our state */ @@ -338,31 +336,10 @@ static void __page_pool_empty_ring(struct page_pool *pool) } } -static void __warn_in_flight(struct page_pool *pool) +static void page_pool_free(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 distance; - - distance = _distance(hold_cnt, release_cnt); - - /* Drivers should fix this, but only problematic when DMA is used */ - WARN(1, "Still in-flight pages:%d hold:%u released:%u", - distance, hold_cnt, release_cnt); -} - -void __page_pool_free(struct page_pool *pool) -{ - /* Only last user actually free/release resources */ - if (!page_pool_put(pool)) - return; - - WARN(pool->alloc.count, "API usage violation"); - WARN(!ptr_ring_empty(&pool->ring), "ptr_ring is not empty"); - - /* Can happen due to forced shutdown */ - if (!__page_pool_safe_to_destroy(pool)) - __warn_in_flight(pool); + if (pool->disconnect) + pool->disconnect(pool); ptr_ring_cleanup(&pool->ring, NULL); @@ -371,12 +348,8 @@ void __page_pool_free(struct page_pool *pool) kfree(pool); } -EXPORT_SYMBOL(__page_pool_free); -/* Request to shutdown: release pages cached by page_pool, and check - * for in-flight pages - */ -bool __page_pool_request_shutdown(struct page_pool *pool) +static void page_pool_scrub(struct page_pool *pool) { struct page *page; @@ -393,7 +366,64 @@ bool __page_pool_request_shutdown(struct page_pool *pool) * be in-flight. */ __page_pool_empty_ring(pool); - - return __page_pool_safe_to_destroy(pool); } -EXPORT_SYMBOL(__page_pool_request_shutdown); + +static int page_pool_release(struct page_pool *pool) +{ + int inflight; + + page_pool_scrub(pool); + inflight = page_pool_inflight(pool); + if (!inflight) + page_pool_free(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 *)) +{ + refcount_inc(&pool->user_cnt); + pool->disconnect = disconnect; +} + +void page_pool_destroy(struct page_pool *pool) +{ + if (!pool) + return; + + if (!page_pool_put(pool)) + return; + + 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); diff --git a/net/core/xdp.c b/net/core/xdp.c index d7bf62ffbb5e..ac866ac65f2b 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -70,10 +70,6 @@ static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu) xa = container_of(rcu, struct xdp_mem_allocator, rcu); - /* Allocator have indicated safe to remove before this is called */ - if (xa->mem.type == MEM_TYPE_PAGE_POOL) - page_pool_free(xa->page_pool); - /* Allow this ID to be reused */ ida_simple_remove(&mem_id_pool, xa->mem.id); @@ -85,10 +81,41 @@ static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu) kfree(xa); } -static bool __mem_id_disconnect(int id, bool force) +static void mem_xa_remove(struct xdp_mem_allocator *xa) +{ + trace_mem_disconnect(xa); + + mutex_lock(&mem_id_lock); + + if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params)) + call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free); + + mutex_unlock(&mem_id_lock); +} + +static void mem_allocator_disconnect(void *allocator) +{ + struct xdp_mem_allocator *xa; + struct rhashtable_iter iter; + + rhashtable_walk_enter(mem_id_ht, &iter); + do { + rhashtable_walk_start(&iter); + + while ((xa = rhashtable_walk_next(&iter)) && !IS_ERR(xa)) { + if (xa->allocator == allocator) + mem_xa_remove(xa); + } + + rhashtable_walk_stop(&iter); + + } while (xa == ERR_PTR(-EAGAIN)); + rhashtable_walk_exit(&iter); +} + +static void mem_id_disconnect(int id) { struct xdp_mem_allocator *xa; - bool safe_to_remove = true; mutex_lock(&mem_id_lock); @@ -96,51 +123,15 @@ static bool __mem_id_disconnect(int id, bool force) if (!xa) { mutex_unlock(&mem_id_lock); WARN(1, "Request remove non-existing id(%d), driver bug?", id); - return true; + return; } - xa->disconnect_cnt++; - /* Detects in-flight packet-pages for page_pool */ - if (xa->mem.type == MEM_TYPE_PAGE_POOL) - safe_to_remove = page_pool_request_shutdown(xa->page_pool); + trace_mem_disconnect(xa); - trace_mem_disconnect(xa, safe_to_remove, force); - - if ((safe_to_remove || force) && - !rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params)) + if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params)) call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free); mutex_unlock(&mem_id_lock); - return (safe_to_remove|force); -} - -#define DEFER_TIME (msecs_to_jiffies(1000)) -#define DEFER_WARN_INTERVAL (30 * HZ) -#define DEFER_MAX_RETRIES 120 - -static void mem_id_disconnect_defer_retry(struct work_struct *wq) -{ - struct delayed_work *dwq = to_delayed_work(wq); - struct xdp_mem_allocator *xa = container_of(dwq, typeof(*xa), defer_wq); - bool force = false; - - if (xa->disconnect_cnt > DEFER_MAX_RETRIES) - force = true; - - if (__mem_id_disconnect(xa->mem.id, force)) - return; - - /* Periodic warning */ - if (time_after_eq(jiffies, xa->defer_warn)) { - int sec = (s32)((u32)jiffies - (u32)xa->defer_start) / HZ; - - pr_warn("%s() stalled mem.id=%u shutdown %d attempts %d sec\n", - __func__, xa->mem.id, xa->disconnect_cnt, sec); - xa->defer_warn = jiffies + DEFER_WARN_INTERVAL; - } - - /* Still not ready to be disconnected, retry later */ - schedule_delayed_work(&xa->defer_wq, DEFER_TIME); } void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq) @@ -153,38 +144,21 @@ void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq) return; } - if (xdp_rxq->mem.type != MEM_TYPE_PAGE_POOL && - xdp_rxq->mem.type != MEM_TYPE_ZERO_COPY) { - return; - } - if (id == 0) return; - if (__mem_id_disconnect(id, false)) - return; + if (xdp_rxq->mem.type == MEM_TYPE_ZERO_COPY) + return mem_id_disconnect(id); - /* Could not disconnect, defer new disconnect attempt to later */ - mutex_lock(&mem_id_lock); - - xa = rhashtable_lookup_fast(mem_id_ht, &id, mem_id_rht_params); - if (!xa) { - mutex_unlock(&mem_id_lock); - return; + if (xdp_rxq->mem.type == MEM_TYPE_PAGE_POOL) { + rcu_read_lock(); + xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params); + page_pool_destroy(xa->page_pool); + rcu_read_unlock(); } - xa->defer_start = jiffies; - xa->defer_warn = jiffies + DEFER_WARN_INTERVAL; - - INIT_DELAYED_WORK(&xa->defer_wq, mem_id_disconnect_defer_retry); - mutex_unlock(&mem_id_lock); - schedule_delayed_work(&xa->defer_wq, DEFER_TIME); } EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model); -/* This unregister operation will also cleanup and destroy the - * allocator. The page_pool_free() operation is first called when it's - * safe to remove, possibly deferred to a workqueue. - */ void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq) { /* Simplify driver cleanup code paths, allow unreg "unused" */ @@ -371,7 +345,7 @@ int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, } if (type == MEM_TYPE_PAGE_POOL) - page_pool_get(xdp_alloc->page_pool); + page_pool_use_xdp_mem(allocator, mem_allocator_disconnect); mutex_unlock(&mem_id_lock); @@ -402,15 +376,8 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct, /* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */ xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); page = virt_to_head_page(data); - if (likely(xa)) { - napi_direct &= !xdp_return_frame_no_direct(); - page_pool_put_page(xa->page_pool, page, napi_direct); - } else { - /* Hopefully stack show who to blame for late return */ - WARN_ONCE(1, "page_pool gone mem.id=%d", mem->id); - trace_mem_return_failed(mem, page); - put_page(page); - } + napi_direct &= !xdp_return_frame_no_direct(); + page_pool_put_page(xa->page_pool, page, napi_direct); rcu_read_unlock(); break; case MEM_TYPE_PAGE_SHARED: