bgmac: simplify dma init/cleanup

Instead of allocating buffers at device init time and initializing
descriptors at device open, do both at the same time (during open).
Free all buffers when closing the device.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Acked-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bgmac.c

@@ -562,18 +562,26 @@ static void bgmac_dma_ring_desc_free(struct bgmac *bgmac,
 			  ring->dma_base);
 }
 
-static void bgmac_dma_free(struct bgmac *bgmac)
+static void bgmac_dma_cleanup(struct bgmac *bgmac)
 {
 	int i;
 
-	for (i = 0; i < BGMAC_MAX_TX_RINGS; i++) {
+	for (i = 0; i < BGMAC_MAX_TX_RINGS; i++)
 		bgmac_dma_tx_ring_free(bgmac, &bgmac->tx_ring[i]);
-		bgmac_dma_ring_desc_free(bgmac, &bgmac->tx_ring[i]);
-	}
-	for (i = 0; i < BGMAC_MAX_RX_RINGS; i++) {
+
+	for (i = 0; i < BGMAC_MAX_RX_RINGS; i++)
 		bgmac_dma_rx_ring_free(bgmac, &bgmac->rx_ring[i]);
+}
+
+static void bgmac_dma_free(struct bgmac *bgmac)
+{
+	int i;
+
+	for (i = 0; i < BGMAC_MAX_TX_RINGS; i++)
+		bgmac_dma_ring_desc_free(bgmac, &bgmac->tx_ring[i]);
+
+	for (i = 0; i < BGMAC_MAX_RX_RINGS; i++)
 		bgmac_dma_ring_desc_free(bgmac, &bgmac->rx_ring[i]);
-	}
 }
 
 static int bgmac_dma_alloc(struct bgmac *bgmac)
@@ -621,8 +629,6 @@ static int bgmac_dma_alloc(struct bgmac *bgmac)
 	}
 
 	for (i = 0; i < BGMAC_MAX_RX_RINGS; i++) {
-		int j;
-
 		ring = &bgmac->rx_ring[i];
 		ring->num_slots = BGMAC_RX_RING_SLOTS;
 		ring->mmio_base = ring_base[i];
@@ -645,15 +651,6 @@ static int bgmac_dma_alloc(struct bgmac *bgmac)
 			ring->index_base = lower_32_bits(ring->dma_base);
 		else
 			ring->index_base = 0;
-
-		/* Alloc RX slots */
-		for (j = 0; j < ring->num_slots; j++) {
-			err = bgmac_dma_rx_skb_for_slot(bgmac, &ring->slots[j]);
-			if (err) {
-				bgmac_err(bgmac, "Can't allocate skb for slot in RX ring\n");
-				goto err_dma_free;
-			}
-		}
 	}
 
 	return 0;
@@ -663,10 +660,10 @@ static int bgmac_dma_alloc(struct bgmac *bgmac)
 	return -ENOMEM;
 }
 
-static void bgmac_dma_init(struct bgmac *bgmac)
+static int bgmac_dma_init(struct bgmac *bgmac)
 {
 	struct bgmac_dma_ring *ring;
-	int i;
+	int i, err;
 
 	for (i = 0; i < BGMAC_MAX_TX_RINGS; i++) {
 		ring = &bgmac->tx_ring[i];
@@ -698,8 +695,13 @@ static void bgmac_dma_init(struct bgmac *bgmac)
 		if (ring->unaligned)
 			bgmac_dma_rx_enable(bgmac, ring);
 
-		for (j = 0; j < ring->num_slots; j++)
+		for (j = 0; j < ring->num_slots; j++) {
+			err = bgmac_dma_rx_skb_for_slot(bgmac, &ring->slots[j]);
+			if (err)
+				goto error;
+
 			bgmac_dma_rx_setup_desc(bgmac, ring, j);
+		}
 
 		bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
 			    ring->index_base +
@@ -708,6 +710,12 @@ static void bgmac_dma_init(struct bgmac *bgmac)
 		ring->start = 0;
 		ring->end = 0;
 	}
+
+	return 0;
+
+error:
+	bgmac_dma_cleanup(bgmac);
+	return err;
 }
 
 /**************************************************
@@ -1183,11 +1191,8 @@ static void bgmac_enable(struct bgmac *bgmac)
 }
 
 /* http://bcm-v4.sipsolutions.net/mac-gbit/gmac/chipinit */
-static void bgmac_chip_init(struct bgmac *bgmac, bool full_init)
+static void bgmac_chip_init(struct bgmac *bgmac)
 {
-	struct bgmac_dma_ring *ring;
-	int i;
-
 	/* 1 interrupt per received frame */
 	bgmac_write(bgmac, BGMAC_INT_RECV_LAZY, 1 << BGMAC_IRL_FC_SHIFT);
 
@@ -1205,16 +1210,7 @@ static void bgmac_chip_init(struct bgmac *bgmac, bool full_init)
 
 	bgmac_write(bgmac, BGMAC_RXMAX_LENGTH, 32 + ETHER_MAX_LEN);
 
-	if (full_init) {
-		bgmac_dma_init(bgmac);
-		if (1) /* FIXME: is there any case we don't want IRQs? */
-			bgmac_chip_intrs_on(bgmac);
-	} else {
-		for (i = 0; i < BGMAC_MAX_RX_RINGS; i++) {
-			ring = &bgmac->rx_ring[i];
-			bgmac_dma_rx_enable(bgmac, ring);
-		}
-	}
+	bgmac_chip_intrs_on(bgmac);
 
 	bgmac_enable(bgmac);
 }
@@ -1274,23 +1270,27 @@ static int bgmac_open(struct net_device *net_dev)
 	int err = 0;
 
 	bgmac_chip_reset(bgmac);
+
+	err = bgmac_dma_init(bgmac);
+	if (err)
+		return err;
+
 	/* Specs say about reclaiming rings here, but we do that in DMA init */
-	bgmac_chip_init(bgmac, true);
+	bgmac_chip_init(bgmac);
 
 	err = request_irq(bgmac->core->irq, bgmac_interrupt, IRQF_SHARED,
 			  KBUILD_MODNAME, net_dev);
 	if (err < 0) {
 		bgmac_err(bgmac, "IRQ request error: %d!\n", err);
-		goto err_out;
+		bgmac_dma_cleanup(bgmac);
+		return err;
 	}
 	napi_enable(&bgmac->napi);
 
 	phy_start(bgmac->phy_dev);
 
 	netif_carrier_on(net_dev);
-
-err_out:
-	return err;
+	return 0;
 }
 
 static int bgmac_stop(struct net_device *net_dev)
@@ -1306,6 +1306,7 @@ static int bgmac_stop(struct net_device *net_dev)
 	free_irq(bgmac->core->irq, net_dev);
 
 	bgmac_chip_reset(bgmac);
+	bgmac_dma_cleanup(bgmac);
 
 	return 0;
 }