2024-06-14 11:55:41

by Breno Leitao

[permalink] [raw]
Subject: [PATCH] wifi: mt76: un-embedd netdev from mt76_dev

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_devices from struct mt76_dev by converting them
into pointers, and allocating them dynamically. Use the leverage
alloc_netdev_dummy() to allocate the net_device object at
mt76_dma_init().

The free of the device occurs at mt76_dma_cleanup().

Link: https://lore.kernel.org/all/[email protected]/ [1]
Signed-off-by: Breno Leitao <[email protected]>
---

PS: Due to the lack of hardware, this patch was not tested on a real
hardware, unfortunately.

PS2: this is the last driver that is still using embedded netdevices.

drivers/net/wireless/mediatek/mt76/debugfs.c | 6 ++--
drivers/net/wireless/mediatek/mt76/dma.c | 31 +++++++++++++++----
drivers/net/wireless/mediatek/mt76/dma.h | 5 +++
drivers/net/wireless/mediatek/mt76/mt76.h | 4 +--
.../net/wireless/mediatek/mt76/mt7603/dma.c | 2 +-
.../net/wireless/mediatek/mt76/mt7615/dma.c | 6 ++--
.../net/wireless/mediatek/mt76/mt76x02_mmio.c | 2 +-
.../net/wireless/mediatek/mt76/mt7915/dma.c | 2 +-
.../net/wireless/mediatek/mt76/mt7921/pci.c | 2 +-
.../net/wireless/mediatek/mt76/mt7925/pci.c | 2 +-
.../net/wireless/mediatek/mt76/mt792x_dma.c | 2 +-
.../net/wireless/mediatek/mt76/mt7996/dma.c | 2 +-
12 files changed, 45 insertions(+), 21 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/debugfs.c b/drivers/net/wireless/mediatek/mt76/debugfs.c
index ae83be572b94..b6a2746c187d 100644
--- a/drivers/net/wireless/mediatek/mt76/debugfs.c
+++ b/drivers/net/wireless/mediatek/mt76/debugfs.c
@@ -33,8 +33,8 @@ mt76_napi_threaded_set(void *data, u64 val)
if (!mt76_is_mmio(dev))
return -EOPNOTSUPP;

- if (dev->napi_dev.threaded != val)
- return dev_set_threaded(&dev->napi_dev, val);
+ if (dev->napi_dev->threaded != val)
+ return dev_set_threaded(dev->napi_dev, val);

return 0;
}
@@ -44,7 +44,7 @@ mt76_napi_threaded_get(void *data, u64 *val)
{
struct mt76_dev *dev = data;

- *val = dev->napi_dev.threaded;
+ *val = dev->napi_dev->threaded;
return 0;
}

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index f4f88c444e21..bf67b1f2348a 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -916,7 +916,7 @@ int mt76_dma_rx_poll(struct napi_struct *napi, int budget)
struct mt76_dev *dev;
int qid, done = 0, cur;

- dev = container_of(napi->dev, struct mt76_dev, napi_dev);
+ dev = mt76_from_netdev(napi->dev);
qid = napi - dev->napi;

rcu_read_lock();
@@ -940,18 +940,35 @@ static int
mt76_dma_init(struct mt76_dev *dev,
int (*poll)(struct napi_struct *napi, int budget))
{
+ struct mt76_dev **priv;
int i;

- init_dummy_netdev(&dev->napi_dev);
- init_dummy_netdev(&dev->tx_napi_dev);
- snprintf(dev->napi_dev.name, sizeof(dev->napi_dev.name), "%s",
+ dev->napi_dev = alloc_netdev_dummy(sizeof(struct mt76_dev *));
+ if (!dev->napi_dev)
+ return -ENOMEM;
+
+ /* napi_dev private data points to mt76_dev parent, so, mt76_dev
+ * can be retrieved given napi_dev
+ */
+ priv = netdev_priv(dev->napi_dev);
+ *priv = dev;
+
+ dev->tx_napi_dev = alloc_netdev_dummy(sizeof(struct mt76_dev *));
+ if (!dev->tx_napi_dev) {
+ free_netdev(dev->napi_dev);
+ return -ENOMEM;
+ }
+ priv = netdev_priv(dev->tx_napi_dev);
+ *priv = dev;
+
+ snprintf(dev->napi_dev->name, sizeof(dev->napi_dev->name), "%s",
wiphy_name(dev->hw->wiphy));
- dev->napi_dev.threaded = 1;
+ dev->napi_dev->threaded = 1;
init_completion(&dev->mmio.wed_reset);
init_completion(&dev->mmio.wed_reset_complete);

mt76_for_each_q_rx(dev, i) {
- netif_napi_add(&dev->napi_dev, &dev->napi[i], poll);
+ netif_napi_add(dev->napi_dev, &dev->napi[i], poll);
mt76_dma_rx_fill(dev, &dev->q_rx[i], false);
napi_enable(&dev->napi[i]);
}
@@ -1019,5 +1036,7 @@ void mt76_dma_cleanup(struct mt76_dev *dev)

mt76_free_pending_txwi(dev);
mt76_free_pending_rxwi(dev);
+ free_netdev(dev->napi_dev);
+ free_netdev(dev->tx_napi_dev);
}
EXPORT_SYMBOL_GPL(mt76_dma_cleanup);
diff --git a/drivers/net/wireless/mediatek/mt76/dma.h b/drivers/net/wireless/mediatek/mt76/dma.h
index 1de5a2b20f74..6454a5eca13e 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.h
+++ b/drivers/net/wireless/mediatek/mt76/dma.h
@@ -116,4 +116,9 @@ mt76_dma_should_drop_buf(bool *drop, u32 ctrl, u32 buf1, u32 info)
}
}

+static inline struct mt76_dev *mt76_from_netdev(struct net_device *dev)
+{
+ return *(struct mt76_dev **)netdev_priv(dev);
+}
+
#endif
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 11b9f22ca7f3..15f83b5adac7 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -831,8 +831,8 @@ struct mt76_dev {

struct mt76_mcu mcu;

- struct net_device napi_dev;
- struct net_device tx_napi_dev;
+ struct net_device *napi_dev;
+ struct net_device *tx_napi_dev;
spinlock_t rx_lock;
struct napi_struct napi[__MT_RXQ_MAX];
struct sk_buff_head rx_skb[__MT_RXQ_MAX];
diff --git a/drivers/net/wireless/mediatek/mt76/mt7603/dma.c b/drivers/net/wireless/mediatek/mt76/mt7603/dma.c
index 14304b063715..ea017f22fff2 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7603/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7603/dma.c
@@ -242,7 +242,7 @@ int mt7603_dma_init(struct mt7603_dev *dev)
if (ret)
return ret;

- netif_napi_add_tx(&dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
+ netif_napi_add_tx(dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
mt7603_poll_tx);
napi_enable(&dev->mt76.tx_napi);

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/dma.c b/drivers/net/wireless/mediatek/mt76/mt7615/dma.c
index e7135b2f1742..966e3d2c295f 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/dma.c
@@ -67,7 +67,7 @@ static int mt7615_poll_tx(struct napi_struct *napi, int budget)
{
struct mt7615_dev *dev;

- dev = container_of(napi, struct mt7615_dev, mt76.tx_napi);
+ dev = (struct mt7615_dev *)mt76_from_netdev(napi->dev);
if (!mt76_connac_pm_ref(&dev->mphy, &dev->pm)) {
napi_complete(napi);
queue_work(dev->mt76.wq, &dev->pm.wake_work);
@@ -89,7 +89,7 @@ static int mt7615_poll_rx(struct napi_struct *napi, int budget)
struct mt7615_dev *dev;
int done;

- dev = container_of(napi->dev, struct mt7615_dev, mt76.napi_dev);
+ dev = (struct mt7615_dev *)mt76_from_netdev(napi->dev);

if (!mt76_connac_pm_ref(&dev->mphy, &dev->pm)) {
napi_complete(napi);
@@ -282,7 +282,7 @@ int mt7615_dma_init(struct mt7615_dev *dev)
if (ret < 0)
return ret;

- netif_napi_add_tx(&dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
+ netif_napi_add_tx(dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
mt7615_poll_tx);
napi_enable(&dev->mt76.tx_napi);

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
index e5ad635d3c56..35b7ebc2c9c6 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
@@ -239,7 +239,7 @@ int mt76x02_dma_init(struct mt76x02_dev *dev)
if (ret)
return ret;

- netif_napi_add_tx(&dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
+ netif_napi_add_tx(dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
mt76x02_poll_tx);
napi_enable(&dev->mt76.tx_napi);

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/dma.c b/drivers/net/wireless/mediatek/mt76/mt7915/dma.c
index 0baa82c8df5a..0c62272fe7d0 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/dma.c
@@ -578,7 +578,7 @@ int mt7915_dma_init(struct mt7915_dev *dev, struct mt7915_phy *phy2)
if (ret < 0)
return ret;

- netif_napi_add_tx(&dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
+ netif_napi_add_tx(dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
mt7915_poll_tx);
napi_enable(&dev->mt76.tx_napi);

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
index f768e9389ac6..e75e7b6d3aaf 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
@@ -219,7 +219,7 @@ static int mt7921_dma_init(struct mt792x_dev *dev)
if (ret < 0)
return ret;

- netif_napi_add_tx(&dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
+ netif_napi_add_tx(dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
mt792x_poll_tx);
napi_enable(&dev->mt76.tx_napi);

diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/pci.c b/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
index 07b74d492ce1..577574fb7a1e 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
@@ -254,7 +254,7 @@ static int mt7925_dma_init(struct mt792x_dev *dev)
if (ret < 0)
return ret;

- netif_napi_add_tx(&dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
+ netif_napi_add_tx(dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
mt792x_poll_tx);
napi_enable(&dev->mt76.tx_napi);

diff --git a/drivers/net/wireless/mediatek/mt76/mt792x_dma.c b/drivers/net/wireless/mediatek/mt76/mt792x_dma.c
index 5cc2d59b774a..45aed1e1b1a6 100644
--- a/drivers/net/wireless/mediatek/mt76/mt792x_dma.c
+++ b/drivers/net/wireless/mediatek/mt76/mt792x_dma.c
@@ -340,7 +340,7 @@ int mt792x_poll_rx(struct napi_struct *napi, int budget)
struct mt792x_dev *dev;
int done;

- dev = container_of(napi->dev, struct mt792x_dev, mt76.napi_dev);
+ dev = (struct mt792x_dev *)mt76_from_netdev(napi->dev);

if (!mt76_connac_pm_ref(&dev->mphy, &dev->pm)) {
napi_complete(napi);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/dma.c b/drivers/net/wireless/mediatek/mt76/mt7996/dma.c
index 73e633d0d700..69a7d9b2e38b 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/dma.c
@@ -641,7 +641,7 @@ int mt7996_dma_init(struct mt7996_dev *dev)
if (ret < 0)
return ret;

- netif_napi_add_tx(&dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
+ netif_napi_add_tx(dev->mt76.tx_napi_dev, &dev->mt76.tx_napi,
mt7996_poll_tx);
napi_enable(&dev->mt76.tx_napi);

--
2.43.0