net: remove netdev_alloc_page and use __GFP_COLD

Given we dont use anymore the struct net_device *dev argument, and this
interface brings litle benefit, remove netdev_{alloc|free}_page(), to
debloat include/linux/skbuff.h a bit.

(Some drivers used a mix of these interfaces and alloc_pages())

When allocating a page given to device for DMA transfer (device to
memory), it makes sense to use a cold one (__GFP_COLD)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
CC: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/cdc-phonet.c b/drivers/net/usb/cdc-phonet.c
index a60d006..331e440 100644
--- a/drivers/net/usb/cdc-phonet.c
+++ b/drivers/net/usb/cdc-phonet.c
@@ -130,7 +130,7 @@
 	struct page *page;
 	int err;
 
-	page = __netdev_alloc_page(dev, gfp_flags);
+	page = alloc_page(gfp_flags);
 	if (!page)
 		return -ENOMEM;
 
@@ -140,7 +140,7 @@
 	err = usb_submit_urb(req, gfp_flags);
 	if (unlikely(err)) {
 		dev_dbg(&dev->dev, "RX submit error (%d)\n", err);
-		netdev_free_page(dev, page);
+		put_page(page);
 	}
 	return err;
 }
@@ -208,9 +208,9 @@
 	dev->stats.rx_errors++;
 resubmit:
 	if (page)
-		netdev_free_page(dev, page);
+		put_page(page);
 	if (req)
-		rx_submit(pnd, req, GFP_ATOMIC);
+		rx_submit(pnd, req, GFP_ATOMIC | __GFP_COLD);
 }
 
 static int usbpn_close(struct net_device *dev);
@@ -229,7 +229,7 @@
 	for (i = 0; i < rxq_size; i++) {
 		struct urb *req = usb_alloc_urb(0, GFP_KERNEL);
 
-		if (!req || rx_submit(pnd, req, GFP_KERNEL)) {
+		if (!req || rx_submit(pnd, req, GFP_KERNEL | __GFP_COLD)) {
 			usbpn_close(dev);
 			return -ENOMEM;
 		}