[PATCH net-next v6 07/10] net: ibm/emac: allocate dummy net_device dynamically

From: Breno Leitao <leitao@debian.org>
To: aleksander.lobakin@intel.com, kuba@kernel.org,
	davem@davemloft.net, pabeni@redhat.com, edumazet@google.com,
	elder@kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, nbd@nbd.name,
	sean.wang@mediatek.com, Mark-MC.Lee@mediatek.com,
	lorenzo@kernel.org, taras.chornyi@plvision.eu,
	ath11k@lists.infradead.org, ath10k@lists.infradead.org,
	linux-wireless@vger.kernel.org, geomatsi@gmail.com,
	kvalo@kernel.org
Cc: quic_jjohnson@quicinc.com, leon@kernel.org,
	dennis.dalessandro@cornelisnetworks.com,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, idosch@idosch.org, leitao@debian.org,
	"Tariq Toukan" <tariqt@nvidia.com>,
	"Alex Elder" <elder@linaro.org>,
	"Nick Child" <nnac123@linux.ibm.com>,
	"Rob Herring" <robh@kernel.org>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Christian Marangi" <ansuelsmth@gmail.com>
Subject: [PATCH net-next v6 07/10] net: ibm/emac: allocate dummy net_device dynamically
Date: Thu, 11 Apr 2024 06:59:31 -0700	[thread overview]
Message-ID: <20240411135952.1096696-8-leitao@debian.org> (raw)
In-Reply-To: <20240411135952.1096696-1-leitao@debian.org>

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

