[PATCH wireless-next] wifi: ath12k: allocate dummy net_device dynamically

Breno Leitao
2024-05-03T10:04:51Z

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 struct ath12k_ext_irq_grp by converting it
into a pointer. Then use the leverage alloc_netdev_dummy() to allocate
the net_device object at ath12k_pci_ext_irq_config().

The free of the device occurs at ath12k_pci_free_ext_irq().

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

This is *very* similar to the same changes in ath11k commit
bca592ead82528b ("wifi: ath11k: allocate dummy net_device dynamically")

Signed-off-by: Breno Leitao <leitao@debian.org>
---
drivers/net/wireless/ath/ath12k/core.h | 2 +-
drivers/net/wireless/ath/ath12k/pci.c | 14 +++++++++++---
2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
index 97e5a0ccd233..71c67f47d0ad 100644
--- a/drivers/net/wireless/ath/ath12k/core.h
+++ b/drivers/net/wireless/ath/ath12k/core.h
@@ -144,7 +144,7 @@ struct ath12k_ext_irq_grp {
u32 grp_id;
u64 timestamp;
struct napi_struct napi;
- struct net_device napi_ndev;
+ struct net_device *napi_ndev;
};

struct ath12k_smbios_bdf {
diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c
index 14954bc05144..322f0ad1b12d 100644
--- a/drivers/net/wireless/ath/ath12k/pci.c
+++ b/drivers/net/wireless/ath/ath12k/pci.c
@@ -350,6 +350,7 @@ static void ath12k_pci_free_ext_irq(struct ath12k_base *ab)
free_irq(ab->irq_num[irq_grp->irqs[j]], irq_grp);

netif_napi_del(&irq_grp->napi);
+ free_netdev(irq_grp->napi_ndev);
}
}

@@ -560,7 +561,7 @@ static irqreturn_t ath12k_pci_ext_interrupt_handler(int irq, void *arg)
static int ath12k_pci_ext_irq_config(struct ath12k_base *ab)
{
struct ath12k_pci *ab_pci = ath12k_pci_priv(ab);
- int i, j, ret, num_vectors = 0;
+ int i, j, n, ret, num_vectors = 0;
u32 user_base_data = 0, base_vector = 0, base_idx;

base_idx = ATH12K_PCI_IRQ_CE0_OFFSET + CE_COUNT_MAX;
@@ -577,8 +578,11 @@ static int ath12k_pci_ext_irq_config(struct ath12k_base *ab)

irq_grp->ab = ab;
irq_grp->grp_id = i;
- init_dummy_netdev(&irq_grp->napi_ndev);
- netif_napi_add(&irq_grp->napi_ndev, &irq_grp->napi,
+ irq_grp->napi_ndev = alloc_netdev_dummy(0);
+ if (!irq_grp->napi_ndev)
+ return -ENOMEM;
+
+ netif_napi_add(irq_grp->napi_ndev, &irq_grp->napi,
ath12k_pci_ext_grp_napi_poll);

if (ab->hw_params->ring_mask->tx[i] ||
@@ -611,6 +615,10 @@ static int ath12k_pci_ext_irq_config(struct ath12k_base *ab)
if (ret) {
ath12k_err(ab, "failed request irq %d: %d\n",
vector, ret);
+ for (n = 0; n <= i; n++) {
+ irq_grp = &ab->ext_irq_grp[n];
+ free_netdev(irq_grp->napi_ndev);
+ }
return ret;
}
}
--
2.43.0