Re: [PATCH net-next v12 07/13] memory-provider: dmabuf devmem memory provider
From: Pavel Begunkov <asml.silence@gmail.com>
Date: 2024-06-17 14:45:43
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On 6/13/24 02:35, Mina Almasry wrote:
Implement a memory provider that allocates dmabuf devmem in the form of net_iov. The provider receives a reference to the struct netdev_dmabuf_binding via the pool->mp_priv pointer. The driver needs to set this pointer for the provider in the net_iov. The provider obtains a reference on the netdev_dmabuf_binding which guarantees the binding and the underlying mapping remains alive until the provider is destroyed. Usage of PP_FLAG_DMA_MAP is required for this memory provide such that the page_pool can provide the driver with the dma-addrs of the devmem. Support for PP_FLAG_DMA_SYNC_DEV is omitted for simplicity & p.order != 0. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <redacted> Signed-off-by: Mina Almasry <redacted>
Comments below, apart from them Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
quoted hunk ↗ jump to hunk
diff --git a/net/core/devmem.c b/net/core/devmem.c index f4fd9b9dbb675..d3843eade5fc2 100644 --- a/net/core/devmem.c +++ b/net/core/devmem.c@@ -17,6 +17,7 @@
...
+
+bool mp_dmabuf_devmem_release_page(struct page_pool *pool, netmem_ref netmem)
+{
+ WARN_ON_ONCE(!netmem_is_net_iov(netmem));
+ WARN_ON_ONCE(atomic_long_read(netmem_get_pp_ref_count_ref(netmem)) !=
+ 1);If you're adding it anyway, maybe "if (warn) return" ?
quoted hunk ↗ jump to hunk
+ + page_pool_clear_pp_info(netmem); + + net_devmem_free_dmabuf(netmem_to_net_iov(netmem)); + + /* We don't want the page pool put_page()ing our net_iovs. */ + return false; +} + #endifdiff --git a/net/core/page_pool.c b/net/core/page_pool.c index 1152e3547795a..22e3c58648d42 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c@@ -13,6 +13,7 @@
...
quoted hunk ↗ jump to hunk
@@ -269,7 +275,25 @@ static int page_pool_init(struct page_pool *pool, if (pool->dma_map) get_device(pool->p.dev); + if (pool->p.queue) + pool->mp_priv = READ_ONCE(pool->p.queue->mp_params.mp_priv); + + if (pool->mp_priv) { + err = mp_dmabuf_devmem_init(pool); + if (err) { + pr_warn("%s() mem-provider init failed %d\n", __func__, + err); + goto free_ptr_ring;
Should also free stats, look up free_percpu(pool->recycle_stats); -- Pavel Begunkov