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From: Breno Leitao <leitao@debian.org>
To: aleksander.lobakin@intel.com,
	kuba@kernel.org,
	davem@davemloft.net,
	pabeni@redhat.com,
	edumazet@google.com,
	Alex Elder <elder@kernel.org>
Cc: quic_jjohnson@quicinc.com,
	kvalo@kernel.org,
	leon@kernel.org,
	dennis.dalessandro@cornelisnetworks.com,
	linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org
Subject: [PATCH net-next v2 4/5] net: ipa: allocate dummy net_device dynamically
Date: Thu, 28 Mar 2024 16:52:04 -0700
Message-ID: <20240328235214.4079063-5-leitao@debian.org>
In-Reply-To: <20240328235214.4079063-1-leitao@debian.org>
References: <20240328235214.4079063-1-leitao@debian.org>
Precedence: bulk
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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/ipa/gsi.c | 12 ++++++++----
 drivers/net/ipa/gsi.h |  2 +-
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 9a0b1fe4a93a..d2db54cbd46d 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -1730,10 +1730,10 @@ static int gsi_channel_setup_one(struct gsi *gsi, u32 channel_id)
 	gsi_channel_program(channel, true);
 
 	if (channel->toward_ipa)
-		netif_napi_add_tx(&gsi->dummy_dev, &channel->napi,
+		netif_napi_add_tx(gsi->dummy_dev, &channel->napi,
 				  gsi_channel_poll);
 	else
-		netif_napi_add(&gsi->dummy_dev, &channel->napi,
+		netif_napi_add(gsi->dummy_dev, &channel->napi,
 			       gsi_channel_poll);
 
 	return 0;
@@ -2369,12 +2369,14 @@ int gsi_init(struct gsi *gsi, struct platform_device *pdev,
 	/* GSI uses NAPI on all channels.  Create a dummy network device
 	 * for the channel NAPI contexts to be associated with.
 	 */
-	init_dummy_netdev(&gsi->dummy_dev);
+	gsi->dummy_dev = alloc_netdev_dummy(0);
+	if (!gsi->dummy_dev)
+		return -ENOMEM;
 	init_completion(&gsi->completion);
 
 	ret = gsi_reg_init(gsi, pdev);
 	if (ret)
-		return ret;
+		goto err_reg_exit;
 
 	ret = gsi_irq_init(gsi, pdev);	/* No matching exit required */
 	if (ret)
@@ -2389,6 +2391,7 @@ int gsi_init(struct gsi *gsi, struct platform_device *pdev,
 	return 0;
 
 err_reg_exit:
+	kfree(gsi->dummy_dev);
 	gsi_reg_exit(gsi);
 
 	return ret;
@@ -2400,6 +2403,7 @@ void gsi_exit(struct gsi *gsi)
 	mutex_destroy(&gsi->mutex);
 	gsi_channel_exit(gsi);
 	gsi_reg_exit(gsi);
+	kfree(gsi->dummy_dev);
 }
 
 /* The maximum number of outstanding TREs on a channel.  This limits
diff --git a/drivers/net/ipa/gsi.h b/drivers/net/ipa/gsi.h
index 42063b227c18..6b7ec2a39676 100644
--- a/drivers/net/ipa/gsi.h
+++ b/drivers/net/ipa/gsi.h
@@ -155,7 +155,7 @@ struct gsi {
 	struct mutex mutex;		/* protects commands, programming */
 	struct gsi_channel channel[GSI_CHANNEL_COUNT_MAX];
 	struct gsi_evt_ring evt_ring[GSI_EVT_RING_COUNT_MAX];
-	struct net_device dummy_dev;	/* needed for NAPI */
+	struct net_device *dummy_dev;	/* needed for NAPI */
 };
 
 /**
-- 
2.43.0