[PATCH] wifi: ath11k: allocate dummy net_device dynamically

Breno Leitao
2024-03-19T18:57:48Z

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 ath11k_ext_irq_grp by converting it
into a pointer. Then use the leverage alloc_netdev() to allocate the
net_device object at ath11k_ahb_config_ext_irq() for ahb, and
ath11k_pcic_ext_irq_config() for pcic.

The free of the device occurs at ath11k_ahb_free_ext_irq() for the ahb
case, and ath11k_pcic_free_ext_irq() for the pcic case.

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

Signed-off-by: Breno Leitao <leitao@debian.org>
---
drivers/net/wireless/ath/ath11k/ahb.c | 8 ++++++--
drivers/net/wireless/ath/ath11k/core.h | 2 +-
drivers/net/wireless/ath/ath11k/pcic.c | 21 +++++++++++++++++----
3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/ahb.c b/drivers/net/wireless/ath/ath11k/ahb.c
index 7c0a23517949..a8d89f510f62 100644
--- a/drivers/net/wireless/ath/ath11k/ahb.c
+++ b/drivers/net/wireless/ath/ath11k/ahb.c
@@ -442,6 +442,7 @@ static void ath11k_ahb_free_ext_irq(struct ath11k_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);
}
}

@@ -533,8 +534,11 @@ static int ath11k_ahb_config_ext_irq(struct ath11k_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(0, "dummy", NET_NAME_UNKNOWN,
+ init_dummy_netdev);
+ if (!irq_grp->napi_ndev)
+ return -ENOMEM;
+ netif_napi_add(irq_grp->napi_ndev, &irq_grp->napi,
ath11k_ahb_ext_grp_napi_poll);

for (j = 0; j < ATH11K_EXT_IRQ_NUM_MAX; j++) {
diff --git a/drivers/net/wireless/ath/ath11k/core.h b/drivers/net/wireless/ath/ath11k/core.h
index b3fb74a226fb..590307ca7a11 100644
--- a/drivers/net/wireless/ath/ath11k/core.h
+++ b/drivers/net/wireless/ath/ath11k/core.h
@@ -174,7 +174,7 @@ struct ath11k_ext_irq_grp {
u64 timestamp;
bool napi_enabled;
struct napi_struct napi;
- struct net_device napi_ndev;
+ struct net_device *napi_ndev;
};

enum ath11k_smbios_cc_type {
diff --git a/drivers/net/wireless/ath/ath11k/pcic.c b/drivers/net/wireless/ath/ath11k/pcic.c
index add4db4c50bc..ebb1d0432d94 100644
--- a/drivers/net/wireless/ath/ath11k/pcic.c
+++ b/drivers/net/wireless/ath/ath11k/pcic.c
@@ -316,6 +316,7 @@ static void ath11k_pcic_free_ext_irq(struct ath11k_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);
}
}

@@ -558,7 +559,7 @@ ath11k_pcic_get_msi_irq(struct ath11k_base *ab, unsigned int vector)

static int ath11k_pcic_ext_irq_config(struct ath11k_base *ab)
{
- int i, j, ret, num_vectors = 0;
+ int i, j, n, ret, num_vectors = 0;
u32 user_base_data = 0, base_vector = 0;
unsigned long irq_flags;

@@ -578,8 +579,11 @@ static int ath11k_pcic_ext_irq_config(struct ath11k_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(0, "dummy", NET_NAME_UNKNOWN,
+ init_dummy_netdev);
+ if (!irq_grp->napi_ndev)
+ return -ENOMEM;
+ netif_napi_add(irq_grp->napi_ndev, &irq_grp->napi,
ath11k_pcic_ext_grp_napi_poll);

if (ab->hw_params.ring_mask->tx[i] ||
@@ -601,8 +605,13 @@ static int ath11k_pcic_ext_irq_config(struct ath11k_base *ab)
int vector = (i % num_vectors) + base_vector;
int irq = ath11k_pcic_get_msi_irq(ab, vector);

- if (irq < 0)
+ if (irq < 0) {
+ for (n = 0; n <= i; n++) {
+ irq_grp = &ab->ext_irq_grp[n];
+ free_netdev(irq_grp->napi_ndev);
+ }
return irq;
+ }

ab->irq_num[irq_idx] = irq;

@@ -615,6 +624,10 @@ static int ath11k_pcic_ext_irq_config(struct ath11k_base *ab)
if (ret) {
ath11k_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