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| author | Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> | 2019-07-09 00:34:28 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-07-08 14:58:04 -0700 |
| commit | 1da4bbeffe41ba318812d7590955faee8636668b (patch) | |
| tree | 17ca1d60db2d00c72bc573e3fa48597f4908e7d8 /net/core/page_pool.c | |
| parent | 49db9228b8d83cbdef44b4757a393990f48b6d85 (diff) | |
| download | linux-1da4bbeffe41ba318812d7590955faee8636668b.tar.bz2 | |
net: core: page_pool: add user refcnt and reintroduce page_pool_destroy
Jesper recently removed page_pool_destroy() (from driver invocation)
and moved shutdown and free of page_pool into xdp_rxq_info_unreg(),
in-order to handle in-flight packets/pages. This created an asymmetry
in drivers create/destroy pairs.
This patch reintroduce page_pool_destroy and add page_pool user
refcnt. This serves the purpose to simplify drivers error handling as
driver now drivers always calls page_pool_destroy() and don't need to
track if xdp_rxq_info_reg_mem_model() was unsuccessful.
This could be used for a special cases where a single RX-queue (with a
single page_pool) provides packets for two net_device'es, and thus
needs to register the same page_pool twice with two xdp_rxq_info
structures.
This patch is primarily to ease API usage for drivers. The recently
merged netsec driver, actually have a bug in this area, which is
solved by this API change.
This patch is a modified version of Ivan Khoronzhuk's original patch.
Link: https://lore.kernel.org/netdev/20190625175948.24771-2-ivan.khoronzhuk@linaro.org/
Fixes: 5c67bf0ec4d0 ("net: netsec: Use page_pool API")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/page_pool.c')
| -rw-r--r-- | net/core/page_pool.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/core/page_pool.c b/net/core/page_pool.c index b366f59885c1..3272dc7a8c81 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -49,6 +49,9 @@ static int page_pool_init(struct page_pool *pool, 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); @@ -70,6 +73,7 @@ struct page_pool *page_pool_create(const struct page_pool_params *params) kfree(pool); return ERR_PTR(err); } + return pool; } EXPORT_SYMBOL(page_pool_create); @@ -356,6 +360,10 @@ static void __warn_in_flight(struct page_pool *pool) 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"); |