networking: make skb_push & __skb_push return void pointers

It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.

Make these functions return void * and remove all the casts across
the tree, adding a (u8 *) cast only where the unsigned char pointer
was used directly, all done with the following spatch:

    @@
    expression SKB, LEN;
    typedef u8;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

    @@
    expression SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - fn(SKB, LEN)[0]
    + *(u8 *)fn(SKB, LEN)

Note that the last part there converts from push(...)[0] to the
more idiomatic *(u8 *)push(...).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 8 insertions, 10 deletions

diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c
index f2f4ccfdf8da..106d6f8d471a 100644
--- a/drivers/net/wireless/ath/ar5523/ar5523.c
+++ b/drivers/net/wireless/ath/ar5523/ar5523.c
@@ -829,8 +829,8 @@ static void ar5523_tx_work_locked(struct ar5523 *ar)
 		data->ar = ar;
 		data->urb = urb;
 
-		desc = (struct ar5523_tx_desc *)skb_push(skb, sizeof(*desc));
-		chunk = (struct ar5523_chunk *)skb_push(skb, sizeof(*chunk));
+		desc = skb_push(skb, sizeof(*desc));
+		chunk = skb_push(skb, sizeof(*chunk));
 
 		chunk->seqnum = 0;
 		chunk->flags = UATH_CFLAGS_FINAL;
diff --git a/drivers/net/wireless/ath/ath6kl/htc_pipe.c b/drivers/net/wireless/ath/ath6kl/htc_pipe.c
index b13d61111072..5c0ba83a44aa 100644
--- a/drivers/net/wireless/ath/ath6kl/htc_pipe.c
+++ b/drivers/net/wireless/ath/ath6kl/htc_pipe.c
@@ -228,8 +228,7 @@ static int htc_issue_packets(struct htc_target *target,
 		payload_len = packet->act_len;
 
 		/* setup HTC frame header */
-		htc_hdr = (struct htc_frame_hdr *) skb_push(skb,
-							    sizeof(*htc_hdr));
+		htc_hdr = skb_push(skb, sizeof(*htc_hdr));
 		if (!htc_hdr) {
 			WARN_ON_ONCE(1);
 			status = -EINVAL;
diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 12aa8abbcba4..0d9687a2aa98 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -199,7 +199,7 @@ static int hif_usb_send_mgmt(struct hif_device_usb *hif_dev,
 	cmd->skb = skb;
 	cmd->hif_dev = hif_dev;
 
-	hdr = (__le16 *) skb_push(skb, 4);
+	hdr = skb_push(skb, 4);
 	*hdr++ = cpu_to_le16(skb->len - 4);
 	*hdr++ = cpu_to_le16(ATH_USB_TX_STREAM_MODE_TAG);
 
diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c
index 9fa8970a1f7d..1bf63a4efb4c 100644
--- a/drivers/net/wireless/ath/ath9k/htc_hst.c
+++ b/drivers/net/wireless/ath/ath9k/htc_hst.c
@@ -26,8 +26,7 @@ static int htc_issue_send(struct htc_target *target, struct sk_buff* skb,
 	struct htc_endpoint *endpoint = &target->endpoint[epid];
 	int status;
 
-	hdr = (struct htc_frame_hdr *)
-		skb_push(skb, sizeof(struct htc_frame_hdr));
+	hdr = skb_push(skb, sizeof(struct htc_frame_hdr));
 	hdr->endpoint_id = epid;
 	hdr->flags = flags;
 	hdr->payload_len = cpu_to_be16(len);
diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
index c51c69b1ad96..85d09fdef8dc 100644
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -277,7 +277,7 @@ static int ath9k_wmi_cmd_issue(struct wmi *wmi,
 	struct wmi_cmd_hdr *hdr;
 	unsigned long flags;
 
-	hdr = (struct wmi_cmd_hdr *) skb_push(skb, sizeof(struct wmi_cmd_hdr));
+	hdr = skb_push(skb, sizeof(struct wmi_cmd_hdr));
 	hdr->command_id = cpu_to_be16(cmd);
 	hdr->seq_no = cpu_to_be16(++wmi->tx_seq_id);
 
diff --git a/drivers/net/wireless/ath/carl9170/tx.c b/drivers/net/wireless/ath/carl9170/tx.c
index 2bf04c9edc98..0cb5b58925dc 100644
--- a/drivers/net/wireless/ath/carl9170/tx.c
+++ b/drivers/net/wireless/ath/carl9170/tx.c
@@ -991,7 +991,7 @@ static int carl9170_tx_prepare(struct ar9170 *ar,
 	else
 		cvif = NULL;
 
-	txc = (void *)skb_push(skb, sizeof(*txc));
+	txc = skb_push(skb, sizeof(*txc));
 	memset(txc, 0, sizeof(*txc));
 
 	SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, txc->s.misc, hw_queue);
diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c
index edab4c0a900f..84d91606e6f3 100644
--- a/drivers/net/wireless/ath/wil6210/txrx.c
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -363,7 +363,7 @@ static void wil_rx_add_radiotap_header(struct wil6210_priv *wil,
 		return;
 	}
 
-	rtap_vendor = (void *)skb_push(skb, rtap_len);
+	rtap_vendor = skb_push(skb, rtap_len);
 	memset(rtap_vendor, 0, rtap_len);
 
 	rtap_vendor->rtap.rthdr.it_version = PKTHDR_RADIOTAP_VERSION;