ixgbe: cleanup ixgbe_clean_rx_irq

The code for ixgbe_clean_rx_irq was much more tangled up than it needed to
be in terms of logic statements and unused variables.  This change
untangles much of that and drops several unused variables such as cleaned
which was being returned but never checked.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ixgbe/ixgbe_main.c

@@ -1128,14 +1128,18 @@ void ixgbe_alloc_rx_buffers(struct ixgbe_ring *rx_ring, u16 cleaned_count)
 	}
 }
 
-static inline u16 ixgbe_get_hdr_info(union ixgbe_adv_rx_desc *rx_desc)
+static inline u16 ixgbe_get_hlen(union ixgbe_adv_rx_desc *rx_desc)
 {
-	return rx_desc->wb.lower.lo_dword.hs_rss.hdr_info;
-}
-
-static inline u16 ixgbe_get_pkt_info(union ixgbe_adv_rx_desc *rx_desc)
-{
-	return rx_desc->wb.lower.lo_dword.hs_rss.pkt_info;
+	/* HW will not DMA in data larger than the given buffer, even if it
+	 * parses the (NFS, of course) header to be larger.  In that case, it
+	 * fills the header buffer and spills the rest into the page.
+	 */
+	u16 hdr_info = le16_to_cpu(rx_desc->wb.lower.lo_dword.hs_rss.hdr_info);
+	u16 hlen = (hdr_info &  IXGBE_RXDADV_HDRBUFLEN_MASK) >>
+		    IXGBE_RXDADV_HDRBUFLEN_SHIFT;
+	if (hlen > IXGBE_RX_HDR_SIZE)
+		hlen = IXGBE_RX_HDR_SIZE;
+	return hlen;
 }
 
 static inline u32 ixgbe_get_rsc_count(union ixgbe_adv_rx_desc *rx_desc)
@@ -1182,7 +1186,7 @@ struct ixgbe_rsc_cb {
 
 #define IXGBE_RSC_CB(skb) ((struct ixgbe_rsc_cb *)(skb)->cb)
 
-static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
+static void ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 			       struct ixgbe_ring *rx_ring,
 			       int *work_done, int work_to_do)
 {
@@ -1190,49 +1194,40 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 	union ixgbe_adv_rx_desc *rx_desc, *next_rxd;
 	struct ixgbe_rx_buffer *rx_buffer_info, *next_buffer;
 	struct sk_buff *skb;
-	unsigned int i, rsc_count = 0;
-	u32 len, staterr;
-	u16 hdr_info;
-	bool cleaned = false;
-	int cleaned_count = 0;
 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
+	const int current_node = numa_node_id();
+	unsigned int rsc_count = 0;
 #ifdef IXGBE_FCOE
 	int ddp_bytes = 0;
 #endif /* IXGBE_FCOE */
+	u32 staterr;
+	u16 i;
+	u16 cleaned_count = 0;
 
 	i = rx_ring->next_to_clean;
 	rx_desc = IXGBE_RX_DESC_ADV(rx_ring, i);
 	staterr = le32_to_cpu(rx_desc->wb.upper.status_error);
-	rx_buffer_info = &rx_ring->rx_buffer_info[i];
 
 	while (staterr & IXGBE_RXD_STAT_DD) {
 		u32 upper_len = 0;
-		if (*work_done >= work_to_do)
-			break;
-		(*work_done)++;
 
 		rmb(); /* read descriptor and rx_buffer_info after status DD */
-		if (ring_is_ps_enabled(rx_ring)) {
-			hdr_info = le16_to_cpu(ixgbe_get_hdr_info(rx_desc));
-			len = (hdr_info & IXGBE_RXDADV_HDRBUFLEN_MASK) >>
-			       IXGBE_RXDADV_HDRBUFLEN_SHIFT;
-			upper_len = le16_to_cpu(rx_desc->wb.upper.length);
-			if ((len > IXGBE_RX_HDR_SIZE) ||
-			    (upper_len && !(hdr_info & IXGBE_RXDADV_SPH)))
-				len = IXGBE_RX_HDR_SIZE;
-		} else {
-			len = le16_to_cpu(rx_desc->wb.upper.length);
-		}
 
-		cleaned = true;
+		rx_buffer_info = &rx_ring->rx_buffer_info[i];
+
 		skb = rx_buffer_info->skb;
-		prefetch(skb->data);
 		rx_buffer_info->skb = NULL;
+		prefetch(skb->data);
 
+		if (ring_is_rsc_enabled(rx_ring))
+			rsc_count = ixgbe_get_rsc_count(rx_desc);
+
+		/* if this is a skb from previous receive DMA will be 0 */
 		if (rx_buffer_info->dma) {
-			if ((adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED) &&
-			    (!(staterr & IXGBE_RXD_STAT_EOP)) &&
-				 (!(skb->prev))) {
+			u16 hlen;
+			if (rsc_count &&
+			    !(staterr & IXGBE_RXD_STAT_EOP) &&
+			    !skb->prev) {
 				/*
 				 * When HWRSC is enabled, delay unmapping
 				 * of the first packet. It carries the
@@ -1249,7 +1244,18 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 						 DMA_FROM_DEVICE);
 			}
 			rx_buffer_info->dma = 0;
-			skb_put(skb, len);
+
+			if (ring_is_ps_enabled(rx_ring)) {
+				hlen = ixgbe_get_hlen(rx_desc);
+				upper_len = le16_to_cpu(rx_desc->wb.upper.length);
+			} else {
+				hlen = le16_to_cpu(rx_desc->wb.upper.length);
+			}
+
+			skb_put(skb, hlen);
+		} else {
+			/* assume packet split since header is unmapped */
+			upper_len = le16_to_cpu(rx_desc->wb.upper.length);
 		}
 
 		if (upper_len) {
@@ -1263,11 +1269,11 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 					   rx_buffer_info->page_offset,
 					   upper_len);
 
-			if ((rx_ring->rx_buf_len > (PAGE_SIZE / 2)) ||
-			    (page_count(rx_buffer_info->page) != 1))
-				rx_buffer_info->page = NULL;
-			else
+			if ((page_count(rx_buffer_info->page) == 1) &&
+			    (page_to_nid(rx_buffer_info->page) == current_node))
 				get_page(rx_buffer_info->page);
+			else
+				rx_buffer_info->page = NULL;
 
 			skb->len += upper_len;
 			skb->data_len += upper_len;
@@ -1282,9 +1288,6 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 		prefetch(next_rxd);
 		cleaned_count++;
 
-		if (ring_is_rsc_enabled(rx_ring))
-			rsc_count = ixgbe_get_rsc_count(rx_desc);
-
 		if (rsc_count) {
 			u32 nextp = (staterr & IXGBE_RXDADV_NEXTP_MASK) >>
 				     IXGBE_RXDADV_NEXTP_SHIFT;
@@ -1293,31 +1296,7 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 			next_buffer = &rx_ring->rx_buffer_info[i];
 		}
 
-		if (staterr & IXGBE_RXD_STAT_EOP) {
-			if (skb->prev)
-				skb = ixgbe_transform_rsc_queue(skb,
-						&(rx_ring->rx_stats.rsc_count));
-			if (ring_is_rsc_enabled(rx_ring)) {
-				if (IXGBE_RSC_CB(skb)->delay_unmap) {
-					dma_unmap_single(rx_ring->dev,
-							 IXGBE_RSC_CB(skb)->dma,
-							 rx_ring->rx_buf_len,
-							 DMA_FROM_DEVICE);
-					IXGBE_RSC_CB(skb)->dma = 0;
-					IXGBE_RSC_CB(skb)->delay_unmap = false;
-				}
-				if (ring_is_ps_enabled(rx_ring))
-					rx_ring->rx_stats.rsc_count +=
-						 skb_shinfo(skb)->nr_frags;
-				else
-					rx_ring->rx_stats.rsc_count++;
-				rx_ring->rx_stats.rsc_flush++;
-			}
-			u64_stats_update_begin(&rx_ring->syncp);
-			rx_ring->stats.packets++;
-			rx_ring->stats.bytes += skb->len;
-			u64_stats_update_end(&rx_ring->syncp);
-		} else {
+		if (!(staterr & IXGBE_RXD_STAT_EOP)) {
 			if (ring_is_ps_enabled(rx_ring)) {
 				rx_buffer_info->skb = next_buffer->skb;
 				rx_buffer_info->dma = next_buffer->dma;
@@ -1331,8 +1310,32 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 			goto next_desc;
 		}
 
+		if (skb->prev)
+			skb = ixgbe_transform_rsc_queue(skb,
+						&(rx_ring->rx_stats.rsc_count));
+
+		if (ring_is_rsc_enabled(rx_ring)) {
+			if (IXGBE_RSC_CB(skb)->delay_unmap) {
+				dma_unmap_single(rx_ring->dev,
+						 IXGBE_RSC_CB(skb)->dma,
+						 rx_ring->rx_buf_len,
+						 DMA_FROM_DEVICE);
+				IXGBE_RSC_CB(skb)->dma = 0;
+				IXGBE_RSC_CB(skb)->delay_unmap = false;
+			}
+			if (ring_is_ps_enabled(rx_ring))
+				rx_ring->rx_stats.rsc_count +=
+					 skb_shinfo(skb)->nr_frags;
+			else
+				rx_ring->rx_stats.rsc_count++;
+			rx_ring->rx_stats.rsc_flush++;
+		}
+
+		/* ERR_MASK will only have valid bits if EOP set */
 		if (staterr & IXGBE_RXDADV_ERR_FRAME_ERR_MASK) {
-			dev_kfree_skb_irq(skb);
+			/* trim packet back to size 0 and recycle it */
+			__pskb_trim(skb, 0);
+			rx_buffer_info->skb = skb;
 			goto next_desc;
 		}
 
@@ -1356,6 +1359,10 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 next_desc:
 		rx_desc->wb.upper.status_error = 0;
 
+		(*work_done)++;
+		if (*work_done >= work_to_do)
+			break;
+
 		/* return some buffers to hardware, one at a time is too slow */
 		if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
 			ixgbe_alloc_rx_buffers(rx_ring, cleaned_count);
@@ -1364,8 +1371,6 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 
 		/* use prefetched values */
 		rx_desc = next_rxd;
-		rx_buffer_info = &rx_ring->rx_buffer_info[i];
-
 		staterr = le32_to_cpu(rx_desc->wb.upper.status_error);
 	}
 
@@ -1392,8 +1397,10 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 
 	rx_ring->total_packets += total_rx_packets;
 	rx_ring->total_bytes += total_rx_bytes;
-
-	return cleaned;
+	u64_stats_update_begin(&rx_ring->syncp);
+	rx_ring->stats.packets += total_rx_packets;
+	rx_ring->stats.bytes += total_rx_bytes;
+	u64_stats_update_end(&rx_ring->syncp);
 }
 
 static int ixgbe_clean_rxonly(struct napi_struct *, int);