diff options
Diffstat (limited to 'net/core/xdp.c')
| -rw-r--r-- | net/core/xdp.c | 123 |
1 files changed, 105 insertions, 18 deletions
diff --git a/net/core/xdp.c b/net/core/xdp.c index 8aab08b131d9..d7bf62ffbb5e 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -14,6 +14,8 @@ #include <net/page_pool.h> #include <net/xdp.h> +#include <net/xdp_priv.h> /* struct xdp_mem_allocator */ +#include <trace/events/xdp.h> #define REG_STATE_NEW 0x0 #define REG_STATE_REGISTERED 0x1 @@ -29,17 +31,6 @@ static int mem_id_next = MEM_ID_MIN; static bool mem_id_init; /* false */ static struct rhashtable *mem_id_ht; -struct xdp_mem_allocator { - struct xdp_mem_info mem; - union { - void *allocator; - struct page_pool *page_pool; - struct zero_copy_allocator *zc_alloc; - }; - struct rhash_head node; - struct rcu_head rcu; -}; - static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed) { const u32 *k = data; @@ -79,13 +70,13 @@ 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); - /* Notice, driver is expected to free the *allocator, - * e.g. page_pool, and MUST also use RCU free. - */ - /* Poison memory */ xa->mem.id = 0xFFFF; xa->mem.type = 0xF0F0; @@ -94,6 +85,64 @@ static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu) kfree(xa); } +static bool __mem_id_disconnect(int id, bool force) +{ + struct xdp_mem_allocator *xa; + bool safe_to_remove = true; + + mutex_lock(&mem_id_lock); + + xa = rhashtable_lookup_fast(mem_id_ht, &id, mem_id_rht_params); + if (!xa) { + mutex_unlock(&mem_id_lock); + WARN(1, "Request remove non-existing id(%d), driver bug?", id); + return true; + } + 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, safe_to_remove, force); + + if ((safe_to_remove || force) && + !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) { struct xdp_mem_allocator *xa; @@ -112,16 +161,30 @@ void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq) if (id == 0) return; + if (__mem_id_disconnect(id, false)) + return; + + /* 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 && !rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params)) - call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free); + if (!xa) { + mutex_unlock(&mem_id_lock); + return; + } + 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" */ @@ -301,12 +364,18 @@ int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, /* Insert allocator into ID lookup table */ ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node); if (IS_ERR(ptr)) { + ida_simple_remove(&mem_id_pool, xdp_rxq->mem.id); + xdp_rxq->mem.id = 0; errno = PTR_ERR(ptr); goto err; } + if (type == MEM_TYPE_PAGE_POOL) + page_pool_get(xdp_alloc->page_pool); + mutex_unlock(&mem_id_lock); + trace_mem_connect(xdp_alloc, xdp_rxq); return 0; err: mutex_unlock(&mem_id_lock); @@ -333,10 +402,13 @@ 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 (xa) { + 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); } rcu_read_unlock(); @@ -379,6 +451,21 @@ void xdp_return_buff(struct xdp_buff *xdp) } EXPORT_SYMBOL_GPL(xdp_return_buff); +/* Only called for MEM_TYPE_PAGE_POOL see xdp.h */ +void __xdp_release_frame(void *data, struct xdp_mem_info *mem) +{ + struct xdp_mem_allocator *xa; + struct page *page; + + rcu_read_lock(); + xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + page = virt_to_head_page(data); + if (xa) + page_pool_release_page(xa->page_pool, page); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(__xdp_release_frame); + int xdp_attachment_query(struct xdp_attachment_info *info, struct netdev_bpf *bpf) { |