[PATCH net-next] IB/hfi1: allocate dummy net_device dynamically

Breno Leitao
2024-04-26T08:56:15Z

Embedding net_device into structures prohibits the usage of flexible
arrays in the net_device structure. For more details, see the discussion
at [1].

Un-embed the net_device from struct hfi1_netdev_rx by converting it
into a pointer. Then use the leverage alloc_netdev() to allocate the
net_device object at hfi1_alloc_rx().

[1] https://lore.kernel.org/all/20240229225910.79e224cf@kernel.org/

Acked-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
---
Changelog

v5:
* Basically replaced the old alloc_netdev() by the new helper
alloc_netdev_dummy().
v4:
* Fix the changelog format
v3:
* Re-worded the comment, by removing the first paragraph.
v2:
* Free struct hfi1_netdev_rx allocation if alloc_netdev() fails
* Pass zero as the private size for alloc_netdev().
* Remove wrong reference for iwl in the comments
---

drivers/infiniband/hw/hfi1/netdev.h | 2 +-
drivers/infiniband/hw/hfi1/netdev_rx.c | 9 +++++++--
2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/netdev.h b/drivers/infiniband/hw/hfi1/netdev.h
index 8aa074670a9c..07c8f77c9181 100644
--- a/drivers/infiniband/hw/hfi1/netdev.h
+++ b/drivers/infiniband/hw/hfi1/netdev.h
@@ -49,7 +49,7 @@ struct hfi1_netdev_rxq {
* When 0 receive queues will be freed.
*/
struct hfi1_netdev_rx {
- struct net_device rx_napi;
+ struct net_device *rx_napi;
struct hfi1_devdata *dd;
struct hfi1_netdev_rxq *rxq;
int num_rx_q;
diff --git a/drivers/infiniband/hw/hfi1/netdev_rx.c b/drivers/infiniband/hw/hfi1/netdev_rx.c
index 720d4c85c9c9..8608044203bb 100644
--- a/drivers/infiniband/hw/hfi1/netdev_rx.c
+++ b/drivers/infiniband/hw/hfi1/netdev_rx.c
@@ -188,7 +188,7 @@ static int hfi1_netdev_rxq_init(struct hfi1_netdev_rx *rx)
int i;
int rc;
struct hfi1_devdata *dd = rx->dd;
- struct net_device *dev = &rx->rx_napi;
+ struct net_device *dev = rx->rx_napi;

rx->num_rx_q = dd->num_netdev_contexts;
rx->rxq = kcalloc_node(rx->num_rx_q, sizeof(*rx->rxq),
@@ -360,7 +360,11 @@ int hfi1_alloc_rx(struct hfi1_devdata *dd)
if (!rx)
return -ENOMEM;
rx->dd = dd;
- init_dummy_netdev(&rx->rx_napi);
+ rx->rx_napi = alloc_netdev_dummy(0);
+ if (!rx->rx_napi) {
+ kfree(rx);
+ return -ENOMEM;
+ }

xa_init(&rx->dev_tbl);
atomic_set(&rx->enabled, 0);
@@ -374,6 +378,7 @@ void hfi1_free_rx(struct hfi1_devdata *dd)
{
if (dd->netdev_rx) {
dd_dev_info(dd, "hfi1 rx freed\n");
+ free_netdev(dd->netdev_rx->rx_napi);
kfree(dd->netdev_rx);
dd->netdev_rx = NULL;
}
--
2.43.0