bnx2x: use the right build_skb() helper

build_skb() no longer accepts slab buffers. Since slab use is fairly
uncommon we prefer the drivers to call a separate slab_build_skb()
function appropriately.

bnx2x uses the old semantics where size of 0 meant buffer from slab.
It sets the fp->rx_frag_size to 0 for MTUs which don't fit in a page.
It needs to call slab_build_skb().

This fixes the WARN_ONCE() of incorrect API use seen with bnx2x.

Reported-by: Thomas Voegtle <[email protected]>
Link: https://lore.kernel.org/all/[email protected]/
Fixes: ce098da ("skbuff: Introduce slab_build_skb()")
Reviewed-by: Leon Romanovsky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

@@ -672,6 +672,18 @@ static int bnx2x_fill_frag_skb(struct bnx2x *bp, struct bnx2x_fastpath *fp,
 	return 0;
 }
 
+static struct sk_buff *
+bnx2x_build_skb(const struct bnx2x_fastpath *fp, void *data)
+{
+	struct sk_buff *skb;
+
+	if (fp->rx_frag_size)
+		skb = build_skb(data, fp->rx_frag_size);
+	else
+		skb = slab_build_skb(data);
+	return skb;
+}
+
 static void bnx2x_frag_free(const struct bnx2x_fastpath *fp, void *data)
 {
 	if (fp->rx_frag_size)
@@ -779,7 +791,7 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp,
 	dma_unmap_single(&bp->pdev->dev, dma_unmap_addr(rx_buf, mapping),
 			 fp->rx_buf_size, DMA_FROM_DEVICE);
 	if (likely(new_data))
-		skb = build_skb(data, fp->rx_frag_size);
+		skb = bnx2x_build_skb(fp, data);
 
 	if (likely(skb)) {
 #ifdef BNX2X_STOP_ON_ERROR
@@ -1046,7 +1058,7 @@ static int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget)
 						 dma_unmap_addr(rx_buf, mapping),
 						 fp->rx_buf_size,
 						 DMA_FROM_DEVICE);
-				skb = build_skb(data, fp->rx_frag_size);
+				skb = bnx2x_build_skb(fp, data);
 				if (unlikely(!skb)) {
 					bnx2x_frag_free(fp, data);
 					bnx2x_fp_qstats(bp, fp)->