[PATCH net-next v13 1/9] netmem: add niov->type attribute to distinguish different net_iov types

Mina Almasry
2025-04-29T03:26:49Z

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@google.com>

---

v13:
- Fix nit: remove trailing comma at the end of enum (Christoph).

v8:
- Since io_uring zcrx is now in net-next, update io_uring net_iov type
setting and remove the NET_IOV_UNSPECIFIED type

v7:
- New patch

---
include/net/netmem.h | 11 ++++++++++-
io_uring/zcrx.c | 1 +
net/core/devmem.c | 3 ++-
3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/include/net/netmem.h b/include/net/netmem.h
index c61d5b21e7b42..973fdbcfef38b 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -20,8 +20,17 @@ DECLARE_STATIC_KEY_FALSE(page_pool_mem_providers);
*/
#define NET_IOV 0x01UL

+enum net_iov_type {
+ NET_IOV_DMABUF,
+ NET_IOV_IOURING,
+
+ /* 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/io_uring/zcrx.c b/io_uring/zcrx.c
index fe86606b9f304..a07ad38935c86 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -259,6 +259,7 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq,
niov->owner = &area->nia;
area->freelist[i] = i;
atomic_set(&area->user_refs[i], 0);
+ niov->type = NET_IOV_IOURING;
}

area->free_count = nr_iovs;
diff --git a/net/core/devmem.c b/net/core/devmem.c
index 6e27a47d04935..f5c3a7e6dbb7b 100644
--- a/net/core/devmem.c
+++ b/net/core/devmem.c
@@ -30,7 +30,7 @@ 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,
@@ -266,6 +266,7 @@ 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));
--
2.49.0.901.g37484f566f-goog