On Tue, Feb 13, 2024 at 5:24 AM Pavel Begunkov [off-list ref] wrote:

On 12/18/23 02:40, Mina Almasry wrote:

quoted

Implement netdev devmem allocator. The allocator takes a given struct
netdev_dmabuf_binding as input and allocates net_iov from that
binding.

The allocation simply delegates to the binding's genpool for the
allocation logic and wraps the returned memory region in a net_iov
struct.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Kaiyuan Zhang <redacted>
Signed-off-by: Mina Almasry <redacted>

---

v1:
- Rename devmem -> dmabuf (David).

---
  include/net/devmem.h | 12 ++++++++++++
  include/net/netmem.h | 26 ++++++++++++++++++++++++++
  net/core/dev.c       | 38 ++++++++++++++++++++++++++++++++++++++
  3 files changed, 76 insertions(+)

...

quoted

diff --git a/include/net/netmem.h b/include/net/netmem.h
index 45eb42d9990b..7fce2efc8707 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h

@@ -14,8 +14,34 @@

  struct net_iov {
      struct dmabuf_genpool_chunk_owner *owner;
+     unsigned long dma_addr;
  };

+static inline struct dmabuf_genpool_chunk_owner *
+net_iov_owner(const struct net_iov *niov)
+{
+     return niov->owner;
+}
+
+static inline unsigned int net_iov_idx(const struct net_iov *niov)
+{
+     return niov - net_iov_owner(niov)->niovs;
+}
+
+static inline dma_addr_t net_iov_dma_addr(const struct net_iov *niov)
+{
+     struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov);
+
+     return owner->base_dma_addr +
+            ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT);

Looks like it should have been niov->dma_addr

Yes, indeed. Thanks for catching.

quoted

+}
+
+static inline struct netdev_dmabuf_binding *
+net_iov_binding(const struct net_iov *niov)
+{
+     return net_iov_owner(niov)->binding;
+}
+
  /* netmem */

  struct netmem {

...

--
Pavel Begunkov

-- 
Thanks,
Mina