[PATCH net-next v5 06/10] net: ipa: allocate dummy net_device dynamically

Breno Leitao
2024-04-10T13:19:23Z

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..d70be15e95a6 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:
+ free_netdev(gsi->dummy_dev);
gsi_reg_exit(gsi);

return ret;
@@ -2399,6 +2402,7 @@ void gsi_exit(struct gsi *gsi)
{
mutex_destroy(&gsi->mutex);
gsi_channel_exit(gsi);
+ free_netdev(gsi->dummy_dev);
gsi_reg_exit(gsi);
}

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