[PATCH net-next v5 04/10] net: marvell: prestera: allocate dummy net_device dynamically

Breno Leitao
2024-04-10T13:18:50Z

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 the private struct by converting it
into a pointer. Then use the leverage the new alloc_netdev_dummy()
helper to allocate and initialize dummy devices.

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

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Elad Nachman <enachman@marvell.com>
---
.../net/ethernet/marvell/prestera/prestera_rxtx.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c b/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c
index cc2a9ae794be..39d9bf82c115 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_rxtx.c
@@ -96,7 +96,7 @@ struct prestera_sdma {
struct dma_pool *desc_pool;
struct work_struct tx_work;
struct napi_struct rx_napi;
- struct net_device napi_dev;
+ struct net_device *napi_dev;
u32 map_addr;
u64 dma_mask;
/* protect SDMA with concurrent access from multiple CPUs */
@@ -654,13 +654,21 @@ static int prestera_sdma_switch_init(struct prestera_switch *sw)
if (err)
goto err_evt_register;

- init_dummy_netdev(&sdma->napi_dev);
+ sdma->napi_dev = alloc_netdev_dummy(0);
+ if (!sdma->napi_dev) {
+ dev_err(dev, "not able to initialize dummy device\n");
+ err = -ENOMEM;
+ goto err_alloc_dummy;
+ }

- netif_napi_add(&sdma->napi_dev, &sdma->rx_napi, prestera_sdma_rx_poll);
+ netif_napi_add(sdma->napi_dev, &sdma->rx_napi, prestera_sdma_rx_poll);
napi_enable(&sdma->rx_napi);

return 0;

+err_alloc_dummy:
+ prestera_hw_event_handler_unregister(sw, PRESTERA_EVENT_TYPE_RXTX,
+ prestera_rxtx_handle_event);
err_evt_register:
err_tx_init:
prestera_sdma_tx_fini(sdma);
@@ -677,6 +685,7 @@ static void prestera_sdma_switch_fini(struct prestera_switch *sw)

napi_disable(&sdma->rx_napi);
netif_napi_del(&sdma->rx_napi);
+ free_netdev(sdma->napi_dev);
prestera_hw_event_handler_unregister(sw, PRESTERA_EVENT_TYPE_RXTX,
prestera_rxtx_handle_event);
prestera_sdma_tx_fini(sdma);
--
2.43.0