From: Felix Fietkau <nbd@openwrt.org>
Date: Sun, 12 Apr 2015 23:28:38 +0200
Subject: [PATCH] bgmac: drop ring->num_slots

The ring size is always known at compile time, so make the code a bit
more efficient

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---

--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -123,7 +123,7 @@ bgmac_dma_tx_add_buf(struct bgmac *bgmac
 	struct bgmac_dma_desc *dma_desc;
 	u32 ctl1;
 
-	if (i == ring->num_slots - 1)
+	if (i == BGMAC_TX_RING_SLOTS - 1)
 		ctl0 |= BGMAC_DESC_CTL0_EOT;
 
 	ctl1 = len & BGMAC_DESC_CTL1_LEN;
@@ -382,7 +382,7 @@ static void bgmac_dma_rx_setup_desc(stru
 	struct bgmac_dma_desc *dma_desc = ring->cpu_base + desc_idx;
 	u32 ctl0 = 0, ctl1 = 0;
 
-	if (desc_idx == ring->num_slots - 1)
+	if (desc_idx == BGMAC_RX_RING_SLOTS - 1)
 		ctl0 |= BGMAC_DESC_CTL0_EOT;
 	ctl1 |= BGMAC_RX_BUF_SIZE & BGMAC_DESC_CTL1_LEN;
 	/* Is there any BGMAC device that requires extension? */
@@ -521,7 +521,7 @@ static void bgmac_dma_tx_ring_free(struc
 	struct bgmac_slot_info *slot;
 	int i;
 
-	for (i = 0; i < ring->num_slots; i++) {
+	for (i = 0; i < BGMAC_TX_RING_SLOTS; i++) {
 		int len = dma_desc[i].ctl1 & BGMAC_DESC_CTL1_LEN;
 
 		slot = &ring->slots[i];
@@ -546,7 +546,7 @@ static void bgmac_dma_rx_ring_free(struc
 	struct bgmac_slot_info *slot;
 	int i;
 
-	for (i = 0; i < ring->num_slots; i++) {
+	for (i = 0; i < BGMAC_RX_RING_SLOTS; i++) {
 		slot = &ring->slots[i];
 		if (!slot->dma_addr)
 			continue;
@@ -560,7 +560,8 @@ static void bgmac_dma_rx_ring_free(struc
 }
 
 static void bgmac_dma_ring_desc_free(struct bgmac *bgmac,
-				     struct bgmac_dma_ring *ring)
+				     struct bgmac_dma_ring *ring,
+				     int num_slots)
 {
 	struct device *dma_dev = bgmac->core->dma_dev;
 	int size;
@@ -569,7 +570,7 @@ static void bgmac_dma_ring_desc_free(str
 	    return;
 
 	/* Free ring of descriptors */
-	size = ring->num_slots * sizeof(struct bgmac_dma_desc);
+	size = num_slots * sizeof(struct bgmac_dma_desc);
 	dma_free_coherent(dma_dev, size, ring->cpu_base,
 			  ring->dma_base);
 }
@@ -590,10 +591,12 @@ static void bgmac_dma_free(struct bgmac
 	int i;
 
 	for (i = 0; i < BGMAC_MAX_TX_RINGS; i++)
-		bgmac_dma_ring_desc_free(bgmac, &bgmac->tx_ring[i]);
+		bgmac_dma_ring_desc_free(bgmac, &bgmac->tx_ring[i],
+					 BGMAC_TX_RING_SLOTS);
 
 	for (i = 0; i < BGMAC_MAX_RX_RINGS; i++)
-		bgmac_dma_ring_desc_free(bgmac, &bgmac->rx_ring[i]);
+		bgmac_dma_ring_desc_free(bgmac, &bgmac->rx_ring[i],
+					 BGMAC_RX_RING_SLOTS);
 }
 
 static int bgmac_dma_alloc(struct bgmac *bgmac)
@@ -616,11 +619,10 @@ static int bgmac_dma_alloc(struct bgmac
 
 	for (i = 0; i < BGMAC_MAX_TX_RINGS; i++) {
 		ring = &bgmac->tx_ring[i];
-		ring->num_slots = BGMAC_TX_RING_SLOTS;
 		ring->mmio_base = ring_base[i];
 
 		/* Alloc ring of descriptors */
-		size = ring->num_slots * sizeof(struct bgmac_dma_desc);
+		size = BGMAC_TX_RING_SLOTS * sizeof(struct bgmac_dma_desc);
 		ring->cpu_base = dma_zalloc_coherent(dma_dev, size,
 						     &ring->dma_base,
 						     GFP_KERNEL);
@@ -642,11 +644,10 @@ static int bgmac_dma_alloc(struct bgmac
 
 	for (i = 0; i < BGMAC_MAX_RX_RINGS; i++) {
 		ring = &bgmac->rx_ring[i];
-		ring->num_slots = BGMAC_RX_RING_SLOTS;
 		ring->mmio_base = ring_base[i];
 
 		/* Alloc ring of descriptors */
-		size = ring->num_slots * sizeof(struct bgmac_dma_desc);
+		size = BGMAC_RX_RING_SLOTS * sizeof(struct bgmac_dma_desc);
 		ring->cpu_base = dma_zalloc_coherent(dma_dev, size,
 						     &ring->dma_base,
 						     GFP_KERNEL);
@@ -709,7 +710,7 @@ static int bgmac_dma_init(struct bgmac *
 
 		ring->start = 0;
 		ring->end = 0;
-		for (j = 0; j < ring->num_slots; j++) {
+		for (j = 0; j < BGMAC_RX_RING_SLOTS; j++) {
 			err = bgmac_dma_rx_skb_for_slot(bgmac, &ring->slots[j]);
 			if (err)
 				goto error;
--- a/drivers/net/ethernet/broadcom/bgmac.h
+++ b/drivers/net/ethernet/broadcom/bgmac.h
@@ -419,11 +419,10 @@ struct bgmac_dma_ring {
 	u32 start;
 	u32 end;
 
-	u16 num_slots;
-	u16 mmio_base;
 	struct bgmac_dma_desc *cpu_base;
 	dma_addr_t dma_base;
 	u32 index_base; /* Used for unaligned rings only, otherwise 0 */
+	u16 mmio_base;
 	bool unaligned;
 
 	struct bgmac_slot_info slots[BGMAC_RX_RING_SLOTS];
