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authorIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>2019-07-09 00:34:28 +0300
committerDavid S. Miller <davem@davemloft.net>2019-07-08 14:58:04 -0700
commit1da4bbeffe41ba318812d7590955faee8636668b (patch)
tree17ca1d60db2d00c72bc573e3fa48597f4908e7d8 /net/core/page_pool.c
parent49db9228b8d83cbdef44b4757a393990f48b6d85 (diff)
downloadlinux-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.c8
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");