TI Davinci EMAC : Abstract Buffer address translation logic.

When programming the DMA engine, the next pointers must be
programmed with physical address as seen from the DMA master
address space. This address may be different from physical
address of the buffer RAM area. This patch abstracts the
buffer address translation logic.
Signed-off-by: Sriramakrishnan <srk@ti.com>
Acked-by: Chaithrika U S <chaithrika@ti.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

drivers/net/davinci_emac.c

@@ -464,6 +464,7 @@ struct emac_priv {
 	void __iomem *ctrl_base;
 	void __iomem *emac_ctrl_ram;
 	u32 ctrl_ram_size;
+	u32 hw_ram_addr;
 	struct emac_txch *txch[EMAC_DEF_MAX_TX_CH];
 	struct emac_rxch *rxch[EMAC_DEF_MAX_RX_CH];
 	u32 link; /* 1=link on, 0=link off */
@@ -497,11 +498,9 @@ static struct clk *emac_clk;
 static unsigned long emac_bus_frequency;
 static unsigned long mdio_max_freq;
 
-/* EMAC internal utility function */
-static inline u32 emac_virt_to_phys(void __iomem *addr)
-{
-	return (u32 __force) io_v2p(addr);
-}
+#define emac_virt_to_phys(addr, priv) \
+	(((u32 __force)(addr) - (u32 __force)(priv->emac_ctrl_ram)) \
+	+ priv->hw_ram_addr)
 
 /* Cache macros - Packet buffers would be from skb pool which is cached */
 #define EMAC_VIRT_NOCACHE(addr) (addr)
@@ -1309,7 +1308,7 @@ static int emac_tx_bdproc(struct emac_priv *priv, u32 ch, u32 budget)
 	curr_bd = txch->active_queue_head;
 	if (NULL == curr_bd) {
 		emac_write(EMAC_TXCP(ch),
-			   emac_virt_to_phys(txch->last_hw_bdprocessed));
+			   emac_virt_to_phys(txch->last_hw_bdprocessed, priv));
 		txch->no_active_pkts++;
 		spin_unlock_irqrestore(&priv->tx_lock, flags);
 		return 0;
@@ -1319,7 +1318,7 @@ static int emac_tx_bdproc(struct emac_priv *priv, u32 ch, u32 budget)
 	while ((curr_bd) &&
 	      ((frame_status & EMAC_CPPI_OWNERSHIP_BIT) == 0) &&
 	      (pkts_processed < budget)) {
-		emac_write(EMAC_TXCP(ch), emac_virt_to_phys(curr_bd));
+		emac_write(EMAC_TXCP(ch), emac_virt_to_phys(curr_bd, priv));
 		txch->active_queue_head = curr_bd->next;
 		if (frame_status & EMAC_CPPI_EOQ_BIT) {
 			if (curr_bd->next) {	/* misqueued packet */
@@ -1406,7 +1405,7 @@ static int emac_send(struct emac_priv *priv, struct emac_netpktobj *pkt, u32 ch)
 		txch->active_queue_tail = curr_bd;
 		if (1 != txch->queue_active) {
 			emac_write(EMAC_TXHDP(ch),
-					emac_virt_to_phys(curr_bd));
+					emac_virt_to_phys(curr_bd, priv));
 			txch->queue_active = 1;
 		}
 		++txch->queue_reinit;
@@ -1418,10 +1417,11 @@ static int emac_send(struct emac_priv *priv, struct emac_netpktobj *pkt, u32 ch)
 		tail_bd->next = curr_bd;
 		txch->active_queue_tail = curr_bd;
 		tail_bd = EMAC_VIRT_NOCACHE(tail_bd);
-		tail_bd->h_next = (int)emac_virt_to_phys(curr_bd);
+		tail_bd->h_next = (int)emac_virt_to_phys(curr_bd, priv);
 		frame_status = tail_bd->mode;
 		if (frame_status & EMAC_CPPI_EOQ_BIT) {
-			emac_write(EMAC_TXHDP(ch), emac_virt_to_phys(curr_bd));
+			emac_write(EMAC_TXHDP(ch),
+				emac_virt_to_phys(curr_bd, priv));
 			frame_status &= ~(EMAC_CPPI_EOQ_BIT);
 			tail_bd->mode = frame_status;
 			++txch->end_of_queue_add;
@@ -1611,7 +1611,8 @@ static int emac_init_rxch(struct emac_priv *priv, u32 ch, char *param)
 		}
 
 		/* populate the hardware descriptor */
-		curr_bd->h_next = emac_virt_to_phys(rxch->active_queue_head);
+		curr_bd->h_next = emac_virt_to_phys(rxch->active_queue_head,
+				priv);
 		/* FIXME buff_ptr = dma_map_single(... data_ptr ...) */
 		curr_bd->buff_ptr = virt_to_phys(curr_bd->data_ptr);
 		curr_bd->off_b_len = rxch->buf_size;
@@ -1886,7 +1887,7 @@ static void emac_addbd_to_rx_queue(struct emac_priv *priv, u32 ch,
 		rxch->active_queue_tail = curr_bd;
 		if (0 != rxch->queue_active) {
 			emac_write(EMAC_RXHDP(ch),
-				   emac_virt_to_phys(rxch->active_queue_head));
+			   emac_virt_to_phys(rxch->active_queue_head, priv));
 			rxch->queue_active = 1;
 		}
 	} else {
@@ -1897,11 +1898,11 @@ static void emac_addbd_to_rx_queue(struct emac_priv *priv, u32 ch,
 		rxch->active_queue_tail = curr_bd;
 		tail_bd->next = curr_bd;
 		tail_bd = EMAC_VIRT_NOCACHE(tail_bd);
-		tail_bd->h_next = emac_virt_to_phys(curr_bd);
+		tail_bd->h_next = emac_virt_to_phys(curr_bd, priv);
 		frame_status = tail_bd->mode;
 		if (frame_status & EMAC_CPPI_EOQ_BIT) {
 			emac_write(EMAC_RXHDP(ch),
-					emac_virt_to_phys(curr_bd));
+					emac_virt_to_phys(curr_bd, priv));
 			frame_status &= ~(EMAC_CPPI_EOQ_BIT);
 			tail_bd->mode = frame_status;
 			++rxch->end_of_queue_add;
@@ -1994,7 +1995,7 @@ static int emac_rx_bdproc(struct emac_priv *priv, u32 ch, u32 budget)
 		curr_pkt->num_bufs = 1;
 		curr_pkt->pkt_length =
 			(frame_status & EMAC_RX_BD_PKT_LENGTH_MASK);
-		emac_write(EMAC_RXCP(ch), emac_virt_to_phys(curr_bd));
+		emac_write(EMAC_RXCP(ch), emac_virt_to_phys(curr_bd, priv));
 		++rxch->processed_bd;
 		last_bd = curr_bd;
 		curr_bd = last_bd->next;
@@ -2005,7 +2006,7 @@ static int emac_rx_bdproc(struct emac_priv *priv, u32 ch, u32 budget)
 			if (curr_bd) {
 				++rxch->mis_queued_packets;
 				emac_write(EMAC_RXHDP(ch),
-					   emac_virt_to_phys(curr_bd));
+					   emac_virt_to_phys(curr_bd, priv));
 			} else {
 				++rxch->end_of_queue;
 				rxch->queue_active = 0;
@@ -2106,7 +2107,7 @@ static int emac_hw_enable(struct emac_priv *priv)
 		emac_write(EMAC_RXINTMASKSET, BIT(ch));
 		rxch->queue_active = 1;
 		emac_write(EMAC_RXHDP(ch),
-			   emac_virt_to_phys(rxch->active_queue_head));
+			   emac_virt_to_phys(rxch->active_queue_head, priv));
 	}
 
 	/* Enable MII */
@@ -2702,6 +2703,12 @@ static int __devinit davinci_emac_probe(struct platform_device *pdev)
 	priv->ctrl_ram_size = pdata->ctrl_ram_size;
 	priv->emac_ctrl_ram = priv->remap_addr + pdata->ctrl_ram_offset;
 
+	if (pdata->hw_ram_addr)
+		priv->hw_ram_addr = pdata->hw_ram_addr;
+	else
+		priv->hw_ram_addr = (u32 __force)res->start +
+					pdata->ctrl_ram_offset;
+
 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	if (!res) {
 		dev_err(emac_dev, "DaVinci EMAC: Error getting irq res\n");

include/linux/davinci_emac.h

@@ -19,6 +19,7 @@ struct emac_platform_data {
 	u32 ctrl_reg_offset;
 	u32 ctrl_mod_reg_offset;
 	u32 ctrl_ram_offset;
+	u32 hw_ram_addr;
 	u32 mdio_reg_offset;
 	u32 ctrl_ram_size;
 	u32 phy_mask;