ionic: clean up page handling code

The internal page handling can be cleaned up by passing our
local page struct rather than dma addresses, and by putting
more of the mgmt code into the alloc and free routines.

Co-developed-by: Neel Patel <neel@pensando.io>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/pensando/ionic/ionic_txrx.c

@@ -266,40 +266,49 @@ void ionic_rx_flush(struct ionic_cq *cq)
 				   work_done, IONIC_INTR_CRED_RESET_COALESCE);
 }
 
-static struct page *ionic_rx_page_alloc(struct ionic_queue *q,
-					dma_addr_t *dma_addr)
+static int ionic_rx_page_alloc(struct ionic_queue *q,
+			       struct ionic_page_info *page_info)
 {
 	struct ionic_lif *lif = q->lif;
 	struct ionic_rx_stats *stats;
 	struct net_device *netdev;
 	struct device *dev;
-	struct page *page;
 
 	netdev = lif->netdev;
 	dev = lif->ionic->dev;
 	stats = q_to_rx_stats(q);
-	page = alloc_page(GFP_ATOMIC);
-	if (unlikely(!page)) {
-		net_err_ratelimited("%s: Page alloc failed on %s!\n",
+
+	if (unlikely(!page_info)) {
+		net_err_ratelimited("%s: %s invalid page_info in alloc\n",
+				    netdev->name, q->name);
+		return -EINVAL;
+	}
+
+	page_info->page = dev_alloc_page();
+	if (unlikely(!page_info->page)) {
+		net_err_ratelimited("%s: %s page alloc failed\n",
 				    netdev->name, q->name);
 		stats->alloc_err++;
-		return NULL;
+		return -ENOMEM;
 	}
 
-	*dma_addr = dma_map_page(dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
-	if (unlikely(dma_mapping_error(dev, *dma_addr))) {
-		__free_page(page);
-		net_err_ratelimited("%s: DMA single map failed on %s!\n",
+	page_info->dma_addr = dma_map_page(dev, page_info->page, 0, PAGE_SIZE,
+					   DMA_FROM_DEVICE);
+	if (unlikely(dma_mapping_error(dev, page_info->dma_addr))) {
+		put_page(page_info->page);
+		page_info->dma_addr = 0;
+		page_info->page = NULL;
+		net_err_ratelimited("%s: %s dma map failed\n",
 				    netdev->name, q->name);
 		stats->dma_map_err++;
-		return NULL;
+		return -EIO;
 	}
 
-	return page;
+	return 0;
 }
 
-static void ionic_rx_page_free(struct ionic_queue *q, struct page *page,
-			       dma_addr_t dma_addr)
+static void ionic_rx_page_free(struct ionic_queue *q,
+			       struct ionic_page_info *page_info)
 {
 	struct ionic_lif *lif = q->lif;
 	struct net_device *netdev;
@@ -308,15 +317,23 @@ static void ionic_rx_page_free(struct ionic_queue *q, struct page *page,
 	netdev = lif->netdev;
 	dev = lif->ionic->dev;
 
-	if (unlikely(!page)) {
-		net_err_ratelimited("%s: Trying to free unallocated buffer on %s!\n",
+	if (unlikely(!page_info)) {
+		net_err_ratelimited("%s: %s invalid page_info in free\n",
 				    netdev->name, q->name);
 		return;
 	}
 
-	dma_unmap_page(dev, dma_addr, PAGE_SIZE, DMA_FROM_DEVICE);
+	if (unlikely(!page_info->page)) {
+		net_err_ratelimited("%s: %s invalid page in free\n",
+				    netdev->name, q->name);
+		return;
+	}
 
-	__free_page(page);
+	dma_unmap_page(dev, page_info->dma_addr, PAGE_SIZE, DMA_FROM_DEVICE);
+
+	put_page(page_info->page);
+	page_info->dma_addr = 0;
+	page_info->page = NULL;
 }
 
 void ionic_rx_fill(struct ionic_queue *q)
@@ -352,8 +369,7 @@ void ionic_rx_fill(struct ionic_queue *q)
 		desc->opcode = (nfrags > 1) ? IONIC_RXQ_DESC_OPCODE_SG :
 					      IONIC_RXQ_DESC_OPCODE_SIMPLE;
 		desc_info->npages = nfrags;
-		page_info->page = ionic_rx_page_alloc(q, &page_info->dma_addr);
-		if (unlikely(!page_info->page)) {
+		if (unlikely(ionic_rx_page_alloc(q, page_info))) {
 			desc->addr = 0;
 			desc->len = 0;
 			return;
@@ -370,8 +386,7 @@ void ionic_rx_fill(struct ionic_queue *q)
 				continue;
 
 			sg_elem = &sg_desc->elems[j];
-			page_info->page = ionic_rx_page_alloc(q, &page_info->dma_addr);
-			if (unlikely(!page_info->page)) {
+			if (unlikely(ionic_rx_page_alloc(q, page_info))) {
 				sg_elem->addr = 0;
 				sg_elem->len = 0;
 				return;
@@ -409,14 +424,8 @@ void ionic_rx_empty(struct ionic_queue *q)
 		desc->addr = 0;
 		desc->len = 0;
 
-		for (i = 0; i < desc_info->npages; i++) {
-			if (likely(desc_info->pages[i].page)) {
-				ionic_rx_page_free(q, desc_info->pages[i].page,
-						   desc_info->pages[i].dma_addr);
-				desc_info->pages[i].page = NULL;
-				desc_info->pages[i].dma_addr = 0;
-			}
-		}
+		for (i = 0; i < desc_info->npages; i++)
+			ionic_rx_page_free(q, &desc_info->pages[i]);
 
 		desc_info->cb_arg = NULL;
 		idx = (idx + 1) & (q->num_descs - 1);