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| author | Jakub Kicinski <kuba@kernel.org> | 2026-05-26 09:01:45 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-05-28 14:37:46 -0700 |
| commit | 427837e5fd85f49ca7cde8ff32544e1c9864ec84 (patch) | |
| tree | e6547aacd70cd839d91f64a1508e611942b1d919 /Documentation | |
| parent | 73ac86c5845d85164ec729dbc66b7bd28ed8be9b (diff) | |
| download | linux-next-history-427837e5fd85f49ca7cde8ff32544e1c9864ec84.tar.gz | |
docs: net: update devmem code examples
Update the code examples
- update the YNL sample with the latest(?) APIs
- struct dmabuf_tx_cmsg does not exist, use __u32 directly
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260526160151.2793354-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/devmem.rst | 27 |
1 files changed, 11 insertions, 16 deletions
diff --git a/Documentation/networking/devmem.rst b/Documentation/networking/devmem.rst index a6cd7236bfbd2..6a3f3c2ac19c4 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 @@ from offset 2000 into the dmabuf. The dmabuf to send from is tx_dmabuf_id:: 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); |