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Diffstat (limited to 'include/net/page_pool.h')
-rw-r--r--include/net/page_pool.h14
1 files changed, 12 insertions, 2 deletions
diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index 813c93499f20..ddfa0b328677 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -277,6 +277,16 @@ void page_pool_put_defragged_page(struct page_pool *pool, struct page *page,
unsigned int dma_sync_size,
bool allow_direct);
+/* pp_frag_count represents the number of writers who can update the page
+ * either by updating skb->data or via DMA mappings for the device.
+ * We can't rely on the page refcnt for that as we don't know who might be
+ * holding page references and we can't reliably destroy or sync DMA mappings
+ * of the fragments.
+ *
+ * When pp_frag_count reaches 0 we can either recycle the page if the page
+ * refcnt is 1 or return it back to the memory allocator and destroy any
+ * mappings we have.
+ */
static inline void page_pool_fragment_page(struct page *page, long nr)
{
atomic_long_set(&page->pp_frag_count, nr);
@@ -386,7 +396,7 @@ static inline void page_pool_nid_changed(struct page_pool *pool, int new_nid)
static inline void page_pool_ring_lock(struct page_pool *pool)
__acquires(&pool->ring.producer_lock)
{
- if (in_serving_softirq())
+ if (in_softirq())
spin_lock(&pool->ring.producer_lock);
else
spin_lock_bh(&pool->ring.producer_lock);
@@ -395,7 +405,7 @@ static inline void page_pool_ring_lock(struct page_pool *pool)
static inline void page_pool_ring_unlock(struct page_pool *pool)
__releases(&pool->ring.producer_lock)
{
- if (in_serving_softirq())
+ if (in_softirq())
spin_unlock(&pool->ring.producer_lock);
else
spin_unlock_bh(&pool->ring.producer_lock);