[PATCH net-next v7 1/9] netmem: add niov->type attribute to distinguish different net_iov types

[Mina Almasry]

Later patches in the series adds TX net_iovs where there is no pp
associated, so we can't rely on niov->pp->mp_ops to tell what is the
type of the net_iov.

Add a type enum to the net_iov which tells us the net_iov type.

Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>

---

v7:
- New patch

---
 include/net/netmem.h | 15 ++++++++++++++-
 net/core/devmem.c    |  3 ++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/include/net/netmem.h b/include/net/netmem.h
index c61d5b21e7b4..16ef53ea713a 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -20,8 +20,21 @@ DECLARE_STATIC_KEY_FALSE(page_pool_mem_providers);
  */
 #define NET_IOV 0x01UL
 
+enum net_iov_type {
+	/* The unspecified type is temporary until the io_uring net_iovs being
+	 * worked on in parallel are migrated to specify their type, then this
+	 * can be deprecated.
+	 */
+	NET_IOV_UNSPECIFIED = 0,
+	NET_IOV_DMABUF,
+
+	/* Force size to unsigned long to make the NET_IOV_ASSERTS below pass.
+	 */
+	NET_IOV_MAX = ULONG_MAX,
+};
+
 struct net_iov {
-	unsigned long __unused_padding;
+	enum net_iov_type type;
 	unsigned long pp_magic;
 	struct page_pool *pp;
 	struct net_iov_area *owner;
diff --git a/net/core/devmem.c b/net/core/devmem.c
index 7c6e0b5b6acb..69c160ad3ebd 100644
--- a/net/core/devmem.c
+++ b/net/core/devmem.c
@@ -32,7 +32,7 @@ static const struct memory_provider_ops dmabuf_devmem_ops;
 
 bool net_is_devmem_iov(struct net_iov *niov)
 {
-	return niov->pp->mp_ops == &dmabuf_devmem_ops;
+	return niov->type == NET_IOV_DMABUF;
 }
 
 static void net_devmem_dmabuf_free_chunk_owner(struct gen_pool *genpool,
@@ -297,6 +297,7 @@ net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd,
 
 		for (i = 0; i < owner->area.num_niovs; i++) {
 			niov = &owner->area.niovs[i];
+			niov->type = NET_IOV_DMABUF;
 			niov->owner = &owner->area;
 			page_pool_set_dma_addr_netmem(net_iov_to_netmem(niov),
 						      net_devmem_get_dma_addr(niov));
-- 
2.49.0.rc0.332.g42c0ae87b1-goog