[RESEND PATCH net-next] netmem: remove the pp fields from net_iov

From: Byungchul Park

Date: Tue Feb 24 2026 - 01:14:50 EST


Now that the pp fields in net_iov have no users, remove them from
net_iov and clean up.

Signed-off-by: Byungchul Park <byungchul@xxxxxx>
---
The original post was:

https://lore.kernel.org/all/20251121040047.71921-1-byungchul@xxxxxx/

1/3 was covered by Pavel's patch:

commit f0243d2b86b97 ("io_uring/zcrx: convert to use netmem_desc").

2/3 was taken by Jakub and merged:

commit df59bb5b9af3f ("netmem, devmem, tcp: access pp fields through
@desc in net_iov")

Now that io-uring and net core changes converge in one tree, I'm
resending the 3/3, which is what Jakub asked:

https://lore.kernel.org/all/20251124184729.7e365941@xxxxxxxxxx/
---
include/net/netmem.h | 38 +-------------------------------------
1 file changed, 1 insertion(+), 37 deletions(-)

diff --git a/include/net/netmem.h b/include/net/netmem.h
index a96b3e5e5574..a6d65ced5231 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -93,23 +93,7 @@ enum net_iov_type {
* supported.
*/
struct net_iov {
- union {
- struct netmem_desc desc;
-
- /* XXX: The following part should be removed once all
- * the references to them are converted so as to be
- * accessed via netmem_desc e.g. niov->desc.pp instead
- * of niov->pp.
- */
- struct {
- unsigned long _flags;
- unsigned long pp_magic;
- struct page_pool *pp;
- unsigned long _pp_mapping_pad;
- unsigned long dma_addr;
- atomic_long_t pp_ref_count;
- };
- };
+ struct netmem_desc desc;
struct net_iov_area *owner;
enum net_iov_type type;
};
@@ -123,26 +107,6 @@ struct net_iov_area {
unsigned long base_virtual;
};

-/* net_iov is union'ed with struct netmem_desc mirroring struct page, so
- * the page_pool can access these fields without worrying whether the
- * underlying fields are accessed via netmem_desc or directly via
- * net_iov, until all the references to them are converted so as to be
- * accessed via netmem_desc e.g. niov->desc.pp instead of niov->pp.
- *
- * The non-net stack fields of struct page are private to the mm stack
- * and must never be mirrored to net_iov.
- */
-#define NET_IOV_ASSERT_OFFSET(desc, iov) \
- static_assert(offsetof(struct netmem_desc, desc) == \
- offsetof(struct net_iov, iov))
-NET_IOV_ASSERT_OFFSET(_flags, _flags);
-NET_IOV_ASSERT_OFFSET(pp_magic, pp_magic);
-NET_IOV_ASSERT_OFFSET(pp, pp);
-NET_IOV_ASSERT_OFFSET(_pp_mapping_pad, _pp_mapping_pad);
-NET_IOV_ASSERT_OFFSET(dma_addr, dma_addr);
-NET_IOV_ASSERT_OFFSET(pp_ref_count, pp_ref_count);
-#undef NET_IOV_ASSERT_OFFSET
-
static inline struct net_iov_area *net_iov_owner(const struct net_iov *niov)
{
return niov->owner;
--
2.17.1