[PATCH net-next v5 07/10] net: ibm/emac: allocate dummy net_device dynamically

Breno Leitao
2024-04-10T13:19:35Z

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>
---
drivers/net/ethernet/ibm/emac/mal.c | 14 +++++++++++---
drivers/net/ethernet/ibm/emac/mal.h | 2 +-
2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ibm/emac/mal.c b/drivers/net/ethernet/ibm/emac/mal.c
index 2439f7e96e05..d92dd9c83031 100644
--- a/drivers/net/ethernet/ibm/emac/mal.c
+++ b/drivers/net/ethernet/ibm/emac/mal.c
@@ -605,9 +605,13 @@ static int mal_probe(struct platform_device *ofdev)
INIT_LIST_HEAD(&mal->list);
spin_lock_init(&mal->lock);

- init_dummy_netdev(&mal->dummy_dev);
+ mal->dummy_dev = alloc_netdev_dummy(0);
+ if (!mal->dummy_dev) {
+ err = -ENOMEM;
+ goto fail_unmap;
+ }

- netif_napi_add_weight(&mal->dummy_dev, &mal->napi, mal_poll,
+ netif_napi_add_weight(mal->dummy_dev, &mal->napi, mal_poll,
CONFIG_IBM_EMAC_POLL_WEIGHT);

/* Load power-on reset defaults */
@@ -637,7 +641,7 @@ static int mal_probe(struct platform_device *ofdev)
GFP_KERNEL);
if (mal->bd_virt == NULL) {
err = -ENOMEM;
- goto fail_unmap;
+ goto fail_dummy;
}

for (i = 0; i < mal->num_tx_chans; ++i)
@@ -703,6 +707,8 @@ static int mal_probe(struct platform_device *ofdev)
free_irq(mal->serr_irq, mal);
fail2:
dma_free_coherent(&ofdev->dev, bd_size, mal->bd_virt, mal->bd_dma);
+ fail_dummy:
+ free_netdev(mal->dummy_dev);
fail_unmap:
dcr_unmap(mal->dcr_host, 0x100);
fail:
@@ -734,6 +740,8 @@ static void mal_remove(struct platform_device *ofdev)

mal_reset(mal);

+ free_netdev(mal->dummy_dev);
+
dma_free_coherent(&ofdev->dev,
sizeof(struct mal_descriptor) *
(NUM_TX_BUFF * mal->num_tx_chans +
diff --git a/drivers/net/ethernet/ibm/emac/mal.h b/drivers/net/ethernet/ibm/emac/mal.h
index d212373a72e7..e0ddc41186a2 100644
--- a/drivers/net/ethernet/ibm/emac/mal.h
+++ b/drivers/net/ethernet/ibm/emac/mal.h
@@ -205,7 +205,7 @@ struct mal_instance {
int index;
spinlock_t lock;

- struct net_device dummy_dev;
+ struct net_device *dummy_dev;

unsigned int features;
};
--
2.43.0