From: Jakub Kicinski <kuba@kernel.org>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com,
andrew+netdev@lunn.ch, horms@kernel.org, corbet@lwn.net,
vladimir.oltean@nxp.com, willemb@google.com,
sdf.kernel@gmail.com, ecree.xilinx@gmail.com,
jesse.brandeburg@intel.com, linux-doc@vger.kernel.org,
Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH net-next 04/10] docs: net: update devmem code examples
Date: Tue, 26 May 2026 09:01:45 -0700 [thread overview]
Message-ID: <20260526160151.2793354-5-kuba@kernel.org> (raw)
In-Reply-To: <20260526160151.2793354-1-kuba@kernel.org>
Update the code examples
- update the YNL sample with the latest(?) APIs
- struct dmabuf_tx_cmsg does not exist, use __u32 directly
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
Documentation/networking/devmem.rst | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/Documentation/networking/devmem.rst b/Documentation/networking/devmem.rst
index a6cd7236bfbd..6a3f3c2ac19c 100644
--- a/Documentation/networking/devmem.rst
+++ b/Documentation/networking/devmem.rst
@@ -103,24 +103,22 @@ The user must bind a dmabuf to any number of RX queues on a given NIC using
the netlink API::
/* Bind dmabuf to NIC RX queue 15 */
- struct netdev_queue *queues;
- queues = malloc(sizeof(*queues) * 1);
+ struct netdev_queue_id *queues;
- queues[0]._present.type = 1;
- queues[0]._present.idx = 1;
- queues[0].type = NETDEV_RX_QUEUE_TYPE_RX;
- queues[0].idx = 15;
+ queues = netdev_queue_id_alloc(1);
+ netdev_queue_id_set_type(&queues[0], NETDEV_QUEUE_TYPE_RX);
+ netdev_queue_id_set_id(&queues[0], 15);
*ys = ynl_sock_create(&ynl_netdev_family, &yerr);
req = netdev_bind_rx_req_alloc();
netdev_bind_rx_req_set_ifindex(req, 1 /* ifindex */);
- netdev_bind_rx_req_set_dmabuf_fd(req, dmabuf_fd);
- __netdev_bind_rx_req_set_queues(req, queues, n_queue_index);
+ netdev_bind_rx_req_set_fd(req, dmabuf_fd);
+ __netdev_bind_rx_req_set_queues(req, queues, 1);
rsp = netdev_bind_rx(*ys, req);
- dmabuf_id = rsp->dmabuf_id;
+ dmabuf_id = rsp->id;
The netlink API returns a dmabuf_id: a unique ID that refers to this dmabuf
@@ -302,13 +300,12 @@ The user should create a msghdr where,
* iov_base is set to the offset into the dmabuf to start sending from
* iov_len is set to the number of bytes to be sent from the dmabuf
-The user passes the dma-buf id to send from via the dmabuf_tx_cmsg.dmabuf_id.
+The user passes the dma-buf id to send from as a u32 cmsg payload.
The example below sends 1024 bytes from offset 100 into the dmabuf, and 2048
from offset 2000 into the dmabuf. The dmabuf to send from is tx_dmabuf_id::
- char ctrl_data[CMSG_SPACE(sizeof(struct dmabuf_tx_cmsg))];
- struct dmabuf_tx_cmsg ddmabuf;
+ char ctrl_data[CMSG_SPACE(sizeof(__u32))];
struct msghdr msg = {};
struct cmsghdr *cmsg;
struct iovec iov[2];
@@ -327,11 +324,9 @@ The example below sends 1024 bytes from offset 100 into the dmabuf, and 2048
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_DEVMEM_DMABUF;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct dmabuf_tx_cmsg));
+ cmsg->cmsg_len = CMSG_LEN(sizeof(__u32));
- ddmabuf.dmabuf_id = tx_dmabuf_id;
-
- *((struct dmabuf_tx_cmsg *)CMSG_DATA(cmsg)) = ddmabuf;
+ *((__u32 *)CMSG_DATA(cmsg)) = tx_dmabuf_id;
sendmsg(socket_fd, &msg, MSG_ZEROCOPY);
--
2.54.0
next prev parent reply other threads:[~2026-05-26 16:02 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-26 16:01 [PATCH net-next 00/10] docs: net: updates for old and cobwebbed docs Jakub Kicinski
2026-05-26 16:01 ` [PATCH net-next 01/10] docs: net: netdevices: small fixes and clarifications Jakub Kicinski
2026-05-26 22:12 ` Stanislav Fomichev
2026-05-26 16:01 ` [PATCH net-next 02/10] docs: net: fix minor issues with driver guide Jakub Kicinski
2026-05-26 16:01 ` [PATCH net-next 03/10] docs: net: statistics: fix kernel-internal stats list Jakub Kicinski
2026-05-26 16:01 ` Jakub Kicinski [this message]
2026-05-26 22:17 ` [PATCH net-next 04/10] docs: net: update devmem code examples Stanislav Fomichev
2026-05-26 16:01 ` [PATCH net-next 05/10] docs: net: fix minor issues with the NAPI guide Jakub Kicinski
2026-05-26 16:01 ` [PATCH net-next 06/10] docs: net: refresh netdev feature guidance Jakub Kicinski
2026-05-26 18:41 ` Maxime Chevallier
2026-05-26 22:35 ` Jakub Kicinski
2026-05-27 7:53 ` Maxime Chevallier
2026-05-26 16:01 ` [PATCH net-next 07/10] docs: net: fix minor issues with checksum offloads Jakub Kicinski
2026-05-26 16:01 ` [PATCH net-next 08/10] docs: net: add Rx notes to the checksum guide Jakub Kicinski
2026-05-26 18:56 ` Willem de Bruijn
2026-05-26 16:01 ` [PATCH net-next 09/10] docs: net: render the checksum comment in checksum-offloads.rst Jakub Kicinski
2026-05-26 18:56 ` Willem de Bruijn
2026-05-26 16:01 ` [PATCH net-next 10/10] docs: net: fix minor issues with segmentation offloads Jakub Kicinski
2026-05-26 18:48 ` [PATCH net-next 00/10] docs: net: updates for old and cobwebbed docs Randy Dunlap
2026-05-26 22:37 ` Jakub Kicinski
2026-05-26 22:40 ` Jakub Kicinski
2026-05-27 0:51 ` Randy Dunlap
2026-05-27 1:15 ` Jakub Kicinski
2026-05-27 2:39 ` Randy Dunlap
2026-05-27 14:48 ` Jakub Kicinski
2026-05-28 22:10 ` patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260526160151.2793354-5-kuba@kernel.org \
--to=kuba@kernel.org \
--cc=andrew+netdev@lunn.ch \
--cc=corbet@lwn.net \
--cc=davem@davemloft.net \
--cc=ecree.xilinx@gmail.com \
--cc=edumazet@google.com \
--cc=horms@kernel.org \
--cc=jesse.brandeburg@intel.com \
--cc=linux-doc@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sdf.kernel@gmail.com \
--cc=vladimir.oltean@nxp.com \
--cc=willemb@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.