Re: [PATCH net-next 07/11] net: devmem: support TX over NETMEM_TX_NO_DMA devices
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-05-01 00:57:27
Also in:
bpf, linux-doc, linux-kselftest, linux-rdma, lkml
On Tue, 28 Apr 2026 15:42:04 -0700 Bobby Eshleman wrote:
shinfo = skb_shinfo(skb); + if (shinfo->nr_frags == 0) + goto out;
Feels tempting to cover the NETMEM_TX_NO_DMA / NETMEM_TX_NONE cases here before we even look at the frags?
- if (shinfo->nr_frags > 0) {
- niov = netmem_to_net_iov(skb_frag_netmem(&shinfo->frags[0]));
- if (net_is_devmem_iov(niov) &&
- READ_ONCE(net_devmem_iov_binding(niov)->dev) != dev)
+ niov = netmem_to_net_iov(skb_frag_netmem(&shinfo->frags[0]));
+ if (!net_is_devmem_iov(niov))
+ goto out;
+
+ binding = net_devmem_iov_binding(niov);
+
+ switch (dev->netmem_tx) {
+ case NETMEM_TX_DMA:
+ if (READ_ONCE(binding->dev) != dev)
goto out_free;
+ break;
+ case NETMEM_TX_NO_DMA:
+ break;
+ default: /* NETMEM_TX_NONE */
+ goto out_free;
}