more davinci_emac sparse fixes

Update more of the RX and TX buffer descriptor (BD) handling to
properly distinguish between __iomem pointers and normal data
memory address space, getting rid of 32 "cast removes address
space of expression" messages.

This patch doesn't resolve all the issues sparse reports.  In fact
there are now 48 new "dereference of noderef expression" messages.
They mean that a patch is needed to convert BD member accessors to
use readl/writel calls.

Plus, there are several related issues that sparse won't warn about.
The initial i/o space addresses -- SRAM used for BDs, and controller
registers -- should come from ioremap.  Reverse mappings shouldn't
usually be needed, and if they are they should avoid io_v2p() and
virt_to_phys() calls.  And the need to use casts so often is wrong,
especially with __force annotations.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

drivers/net/davinci_emac.c

@@ -29,7 +29,7 @@
  */
 
 /** Pending Items in this driver:
- * 1. Replace emac mdio code with Linux generic mdio infrastructure
+ * 1. use ioremap(), remove davinci_readl()/etc, minimize __force
  * 2. Use Linux cache infrastcture for DMA'ed memory (dma_xxx functions)
  * 3. Add DM646x support (gigabit included)
 */
@@ -386,7 +386,7 @@ struct emac_tx_bd {
 	int buff_ptr;
 	int off_b_len;
 	int mode; /* SOP, EOP, ownership, EOQ, teardown,Qstarv, length */
-	void *next;
+	struct emac_tx_bd __iomem *next;
 	void *buf_token;
 };
 
@@ -402,10 +402,10 @@ struct emac_txch {
 	/* CPPI specific */
 	u32 alloc_size;
 	void __iomem *bd_mem;
-	struct emac_tx_bd *bd_pool_head;
-	struct emac_tx_bd *active_queue_head;
-	struct emac_tx_bd *active_queue_tail;
-	struct emac_tx_bd *last_hw_bdprocessed;
+	struct emac_tx_bd __iomem *bd_pool_head;
+	struct emac_tx_bd __iomem *active_queue_head;
+	struct emac_tx_bd __iomem *active_queue_tail;
+	struct emac_tx_bd __iomem *last_hw_bdprocessed;
 	u32 queue_active;
 	u32 teardown_pending;
 	u32 *tx_complete;
@@ -429,7 +429,7 @@ struct emac_rx_bd {
 	int buff_ptr;
 	int off_b_len;
 	int mode;
-	void *next;
+	struct emac_rx_bd __iomem *next;
 	void *data_ptr;
 	void *buf_token;
 };
@@ -448,9 +448,9 @@ struct emac_rxch {
 	/** CPPI specific */
 	u32 alloc_size;
 	void __iomem *bd_mem;
-	struct emac_rx_bd *bd_pool_head;
-	struct emac_rx_bd *active_queue_head;
-	struct emac_rx_bd *active_queue_tail;
+	struct emac_rx_bd __iomem *bd_pool_head;
+	struct emac_rx_bd __iomem *active_queue_head;
+	struct emac_rx_bd __iomem *active_queue_tail;
 	u32 queue_active;
 	u32 teardown_pending;
 
@@ -513,21 +513,13 @@ static struct clk *emac_clk;
 static unsigned long emac_bus_frequency;
 
 /* EMAC internal utility function */
-static inline u32 emac_virt_to_phys(struct emac_priv *priv, u32 addr)
+static inline u32 emac_virt_to_phys(void __iomem *addr)
 {
-	/* NOTE: must handle memory and IO addresses */
-	if ((addr >= (u32)(priv->emac_ctrl_ram)) &&
-		(addr < (u32)(priv->emac_ctrl_ram + priv->ctrl_ram_size)))
-		addr = io_v2p(addr);
-	else
-		addr = virt_to_phys((void *)addr);
-
-	return addr;
+	return (u32 __force) io_v2p(addr);
 }
 
 
 /* Cache macros - Packet buffers would be from skb pool which is cached */
-#define EMAC_VIRT2PHYS(priv, x) emac_virt_to_phys(priv, (u32)x)
 #define EMAC_VIRT_NOCACHE(addr) (addr)
 #define EMAC_CACHE_INVALIDATE(addr, size) \
 	dma_cache_maint((void *)addr, size, DMA_FROM_DEVICE)
@@ -1106,8 +1098,8 @@ static irqreturn_t emac_irq(int irq, void *dev_id)
 static int emac_init_txch(struct emac_priv *priv, u32 ch)
 {
 	u32 cnt, bd_size;
-	char *mem;
-	struct emac_tx_bd *curr_bd;
+	void __iomem *mem;
+	struct emac_tx_bd __iomem *curr_bd;
 	struct emac_txch *txch = NULL;
 
 	txch = kzalloc(sizeof(struct emac_txch), GFP_KERNEL);
@@ -1142,10 +1134,11 @@ static int emac_init_txch(struct emac_priv *priv, u32 ch)
 	memzero((void __force *)txch->bd_mem, txch->alloc_size);
 
 	/* initialize the BD linked list */
-	mem = (char *)(((u32) txch->bd_mem + 0xF) & ~0xF);
+	mem = (void __force __iomem *)
+			(((u32 __force) txch->bd_mem + 0xF) & ~0xF);
 	txch->bd_pool_head = NULL;
 	for (cnt = 0; cnt < txch->num_bd; cnt++) {
-		curr_bd = (struct emac_tx_bd *) (mem + (cnt * bd_size));
+		curr_bd = mem + (cnt * bd_size);
 		curr_bd->next = txch->bd_pool_head;
 		txch->bd_pool_head = curr_bd;
 	}
@@ -1224,7 +1217,7 @@ static void emac_txch_teardown(struct emac_priv *priv, u32 ch)
 {
 	u32 teardown_cnt = 0xFFFFFFF0; /* Some high value */
 	struct emac_txch *txch = priv->txch[ch];
-	struct emac_tx_bd *curr_bd;
+	struct emac_tx_bd __iomem *curr_bd;
 
 	while ((emac_read(EMAC_TXCP(ch)) & EMAC_TEARDOWN_VALUE) !=
 	       EMAC_TEARDOWN_VALUE) {
@@ -1242,8 +1235,8 @@ static void emac_txch_teardown(struct emac_priv *priv, u32 ch)
 	if (1 == txch->queue_active) {
 		curr_bd = txch->active_queue_head;
 		while (curr_bd != NULL) {
-			emac_net_tx_complete(priv, &(curr_bd->buf_token),
-					     1, ch);
+			emac_net_tx_complete(priv, (void __force *)
+					&curr_bd->buf_token, 1, ch);
 			if (curr_bd != txch->active_queue_tail)
 				curr_bd = curr_bd->next;
 			else
@@ -1297,7 +1290,7 @@ static int emac_tx_bdproc(struct emac_priv *priv, u32 ch, u32 budget,
 	u32 frame_status;
 	u32 pkts_processed = 0;
 	u32 tx_complete_cnt = 0;
-	struct emac_tx_bd *curr_bd;
+	struct emac_tx_bd __iomem *curr_bd;
 	struct emac_txch *txch = priv->txch[ch];
 	u32 *tx_complete_ptr = txch->tx_complete;
 
@@ -1315,7 +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_VIRT2PHYS(priv, txch->last_hw_bdprocessed));
+			   emac_virt_to_phys(txch->last_hw_bdprocessed));
 		txch->no_active_pkts++;
 		spin_unlock_irqrestore(&priv->tx_lock, flags);
 		return (0);
@@ -1325,7 +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_VIRT2PHYS(priv, curr_bd));
+		emac_write(EMAC_TXCP(ch), emac_virt_to_phys(curr_bd));
 		txch->active_queue_head = curr_bd->next;
 		if (frame_status & EMAC_CPPI_EOQ_BIT) {
 			if (curr_bd->next) {	/* misqueued packet */
@@ -1377,7 +1370,7 @@ static int emac_tx_bdproc(struct emac_priv *priv, u32 ch, u32 budget,
 static int emac_send(struct emac_priv *priv, struct emac_netpktobj *pkt, u32 ch)
 {
 	unsigned long flags;
-	struct emac_tx_bd *curr_bd;
+	struct emac_tx_bd __iomem *curr_bd;
 	struct emac_txch *txch;
 	struct emac_netbufobj *buf_list;
 
@@ -1400,7 +1393,8 @@ static int emac_send(struct emac_priv *priv, struct emac_netpktobj *pkt, u32 ch)
 
 	txch->bd_pool_head = curr_bd->next;
 	curr_bd->buf_token = buf_list->buf_token;
-	curr_bd->buff_ptr = EMAC_VIRT2PHYS(priv, (int *)buf_list->data_ptr);
+	/* FIXME buff_ptr = dma_map_single(... data_ptr ...) */
+	curr_bd->buff_ptr = virt_to_phys(buf_list->data_ptr);
 	curr_bd->off_b_len = buf_list->length;
 	curr_bd->h_next = 0;
 	curr_bd->next = NULL;
@@ -1416,23 +1410,22 @@ 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_VIRT2PHYS(priv, curr_bd));
+					emac_virt_to_phys(curr_bd));
 			txch->queue_active = 1;
 		}
 		++txch->queue_reinit;
 	} else {
-		register struct emac_tx_bd *tail_bd;
+		register struct emac_tx_bd __iomem *tail_bd;
 		register u32 frame_status;
 
 		tail_bd = txch->active_queue_tail;
 		tail_bd->next = curr_bd;
 		txch->active_queue_tail = curr_bd;
 		tail_bd = EMAC_VIRT_NOCACHE(tail_bd);
-		tail_bd->h_next = (int)EMAC_VIRT2PHYS(priv, curr_bd);
+		tail_bd->h_next = (int)emac_virt_to_phys(curr_bd);
 		frame_status = tail_bd->mode;
 		if (frame_status & EMAC_CPPI_EOQ_BIT) {
-			emac_write(EMAC_TXHDP(ch),
-					EMAC_VIRT2PHYS(priv, curr_bd));
+			emac_write(EMAC_TXHDP(ch), emac_virt_to_phys(curr_bd));
 			frame_status &= ~(EMAC_CPPI_EOQ_BIT);
 			tail_bd->mode = frame_status;
 			++txch->end_of_queue_add;
@@ -1572,8 +1565,8 @@ static void *emac_net_alloc_rx_buf(struct emac_priv *priv, int buf_size,
 static int emac_init_rxch(struct emac_priv *priv, u32 ch, char *param)
 {
 	u32 cnt, bd_size;
-	char *mem;
-	struct emac_rx_bd *curr_bd;
+	void __iomem *mem;
+	struct emac_rx_bd __iomem *curr_bd;
 	struct emac_rxch *rxch = NULL;
 
 	rxch = kzalloc(sizeof(struct emac_rxch), GFP_KERNEL);
@@ -1588,9 +1581,8 @@ static int emac_init_rxch(struct emac_priv *priv, u32 ch, char *param)
 	rxch->teardown_pending = 0;
 
 	/* save mac address */
-	mem = param;
 	for (cnt = 0; cnt < 6; cnt++)
-		rxch->mac_addr[cnt] = mem[cnt];
+		rxch->mac_addr[cnt] = param[cnt];
 
 	/* allocate buffer descriptor pool align every BD on four word
 	 * boundry for future requirements */
@@ -1602,16 +1594,17 @@ static int emac_init_rxch(struct emac_priv *priv, u32 ch, char *param)
 	rxch->pkt_queue.buf_list = &rxch->buf_queue;
 
 	/* allocate RX buffer and initialize the BD linked list */
-	mem = (char *)(((u32) rxch->bd_mem + 0xF) & ~0xF);
+	mem = (void __force __iomem *)
+			(((u32 __force) rxch->bd_mem + 0xF) & ~0xF);
 	rxch->active_queue_head = NULL;
-	rxch->active_queue_tail = (struct emac_rx_bd *) mem;
+	rxch->active_queue_tail = mem;
 	for (cnt = 0; cnt < rxch->num_bd; cnt++) {
-		curr_bd = (struct emac_rx_bd *) (mem + (cnt * bd_size));
+		curr_bd = mem + (cnt * bd_size);
 		/* for future use the last parameter contains the BD ptr */
-		curr_bd->data_ptr = (void *)(emac_net_alloc_rx_buf(priv,
+		curr_bd->data_ptr = emac_net_alloc_rx_buf(priv,
 				    rxch->buf_size,
-				    (void **)&curr_bd->buf_token,
-				    EMAC_DEF_RX_CH));
+				    (void __force **)&curr_bd->buf_token,
+				    EMAC_DEF_RX_CH);
 		if (curr_bd->data_ptr == NULL) {
 			dev_err(EMAC_DEV, "DaVinci EMAC: RX buf mem alloc " \
 				"failed for ch %d\n", ch);
@@ -1620,15 +1613,16 @@ static int emac_init_rxch(struct emac_priv *priv, u32 ch, char *param)
 		}
 
 		/* populate the hardware descriptor */
-		curr_bd->h_next = EMAC_VIRT2PHYS(priv, rxch->active_queue_head);
-		curr_bd->buff_ptr = EMAC_VIRT2PHYS(priv, curr_bd->data_ptr);
+		curr_bd->h_next = emac_virt_to_phys(rxch->active_queue_head);
+		/* 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;
 		curr_bd->mode = EMAC_CPPI_OWNERSHIP_BIT;
 
 		/* write back to hardware memory */
 		BD_CACHE_WRITEBACK_INVALIDATE((u32) curr_bd,
 					      EMAC_BD_LENGTH_FOR_CACHE);
-		curr_bd->next = (void *) rxch->active_queue_head;
+		curr_bd->next = rxch->active_queue_head;
 		rxch->active_queue_head = curr_bd;
 	}
 
@@ -1698,7 +1692,7 @@ static void emac_stop_rxch(struct emac_priv *priv, u32 ch)
 static void emac_cleanup_rxch(struct emac_priv *priv, u32 ch)
 {
 	struct emac_rxch *rxch = priv->rxch[ch];
-	struct emac_rx_bd *curr_bd;
+	struct emac_rx_bd __iomem *curr_bd;
 
 	if (rxch) {
 		/* free the receive buffers previously allocated */
@@ -1863,14 +1857,15 @@ static int emac_dev_setmac_addr(struct net_device *ndev, void *addr)
  *
  */
 static void emac_addbd_to_rx_queue(struct emac_priv *priv, u32 ch,
-				   struct emac_rx_bd *curr_bd, char *buffer,
-				   void *buf_token)
+		struct emac_rx_bd __iomem *curr_bd,
+		char *buffer, void *buf_token)
 {
 	struct emac_rxch *rxch = priv->rxch[ch];
 
 	/* populate the hardware descriptor */
 	curr_bd->h_next = 0;
-	curr_bd->buff_ptr = EMAC_VIRT2PHYS(priv, buffer);
+	/* FIXME buff_ptr = dma_map_single(... buffer ...) */
+	curr_bd->buff_ptr = virt_to_phys(buffer);
 	curr_bd->off_b_len = rxch->buf_size;
 	curr_bd->mode = EMAC_CPPI_OWNERSHIP_BIT;
 	curr_bd->next = NULL;
@@ -1884,22 +1879,22 @@ 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_VIRT2PHYS(priv, rxch->active_queue_head));
+			   emac_virt_to_phys(rxch->active_queue_head));
 		rxch->queue_active = 1;
 	}
 	} else {
-		struct emac_rx_bd *tail_bd;
+		struct emac_rx_bd __iomem *tail_bd;
 		u32 frame_status;
 
 		tail_bd = rxch->active_queue_tail;
 		rxch->active_queue_tail = curr_bd;
-		tail_bd->next = (void *)curr_bd;
+		tail_bd->next = curr_bd;
 		tail_bd = EMAC_VIRT_NOCACHE(tail_bd);
-		tail_bd->h_next = EMAC_VIRT2PHYS(priv, curr_bd);
+		tail_bd->h_next = emac_virt_to_phys(curr_bd);
 		frame_status = tail_bd->mode;
 		if (frame_status & EMAC_CPPI_EOQ_BIT) {
 			emac_write(EMAC_RXHDP(ch),
-					EMAC_VIRT2PHYS(priv, curr_bd));
+					emac_virt_to_phys(curr_bd));
 			frame_status &= ~(EMAC_CPPI_EOQ_BIT);
 			tail_bd->mode = frame_status;
 			++rxch->end_of_queue_add;
@@ -1956,7 +1951,8 @@ static int emac_rx_bdproc(struct emac_priv *priv, u32 ch, u32 budget,
 	u32 frame_status;
 	u32 pkts_processed = 0;
 	char *new_buffer;
-	struct emac_rx_bd *curr_bd, *last_bd;
+	struct emac_rx_bd __iomem *curr_bd;
+	struct emac_rx_bd __iomem *last_bd;
 	struct emac_netpktobj *curr_pkt, pkt_obj;
 	struct emac_netbufobj buf_obj;
 	struct emac_netbufobj *rx_buf_obj;
@@ -1978,9 +1974,9 @@ static int emac_rx_bdproc(struct emac_priv *priv, u32 ch, u32 budget,
 	       ((frame_status & EMAC_CPPI_OWNERSHIP_BIT) == 0) &&
 	       (pkts_processed < budget)) {
 
-		new_buffer = (void *)(emac_net_alloc_rx_buf(priv,
+		new_buffer = emac_net_alloc_rx_buf(priv,
 					EMAC_DEF_MAX_FRAME_SIZE,
-					&new_buf_token, EMAC_DEF_RX_CH));
+					&new_buf_token, EMAC_DEF_RX_CH);
 		if (unlikely(NULL == new_buffer)) {
 			++rxch->out_of_rx_buffers;
 			goto end_emac_rx_bdproc;
@@ -1995,7 +1991,7 @@ 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_VIRT2PHYS(priv, curr_bd));
+		emac_write(EMAC_RXCP(ch), emac_virt_to_phys(curr_bd));
 		++rxch->processed_bd;
 		last_bd = curr_bd;
 		curr_bd = last_bd->next;
@@ -2006,7 +2002,7 @@ 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_VIRT2PHYS(priv, curr_bd));
+					   emac_virt_to_phys(curr_bd));
 			} else {
 				++rxch->end_of_queue;
 				rxch->queue_active = 0;
@@ -2112,7 +2108,7 @@ static int emac_hw_enable(struct emac_priv *priv)
 		emac_write(EMAC_RXINTMASKSET, (1 << ch));
 		rxch->queue_active = 1;
 		emac_write(EMAC_RXHDP(ch),
-			   EMAC_VIRT2PHYS(priv, rxch->active_queue_head));
+			   emac_virt_to_phys(rxch->active_queue_head));
 	}
 
 	/* Enable MII */