Revert "net: stmmac: enable multiple buffers"

The commit aff3d9ef ("net: stmmac: enable multiple buffers") breaks
numerous boards. while some patch exists for fixing some of it,
dwmac-sunxi is still broken with it.
Since this patch is very huge, it will be better to split it in smaller
part.
Signed-off-by: NCorentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/chain_mode.c

@@ -26,15 +26,12 @@
 
 static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 {
-	struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)p;
+	struct stmmac_priv *priv = (struct stmmac_priv *)p;
+	unsigned int entry = priv->cur_tx;
+	struct dma_desc *desc = priv->dma_tx + entry;
 	unsigned int nopaged_len = skb_headlen(skb);
-	struct stmmac_priv *priv = tx_q->priv_data;
-	unsigned int entry = tx_q->cur_tx;
 	unsigned int bmax, des2;
 	unsigned int i = 1, len;
-	struct dma_desc *desc;
-
-	desc = tx_q->dma_tx + entry;
 
 	if (priv->plat->enh_desc)
 		bmax = BUF_SIZE_8KiB;
@@ -48,16 +45,16 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 	desc->des2 = cpu_to_le32(des2);
 	if (dma_mapping_error(priv->device, des2))
 		return -1;
-	tx_q->tx_skbuff_dma[entry].buf = des2;
-	tx_q->tx_skbuff_dma[entry].len = bmax;
+	priv->tx_skbuff_dma[entry].buf = des2;
+	priv->tx_skbuff_dma[entry].len = bmax;
 	/* do not close the descriptor and do not set own bit */
 	priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, STMMAC_CHAIN_MODE,
 					0, false);
 
 	while (len != 0) {
-		tx_q->tx_skbuff[entry] = NULL;
+		priv->tx_skbuff[entry] = NULL;
 		entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE);
-		desc = tx_q->dma_tx + entry;
+		desc = priv->dma_tx + entry;
 
 		if (len > bmax) {
 			des2 = dma_map_single(priv->device,
@@ -66,8 +63,8 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 			desc->des2 = cpu_to_le32(des2);
 			if (dma_mapping_error(priv->device, des2))
 				return -1;
-			tx_q->tx_skbuff_dma[entry].buf = des2;
-			tx_q->tx_skbuff_dma[entry].len = bmax;
+			priv->tx_skbuff_dma[entry].buf = des2;
+			priv->tx_skbuff_dma[entry].len = bmax;
 			priv->hw->desc->prepare_tx_desc(desc, 0, bmax, csum,
 							STMMAC_CHAIN_MODE, 1,
 							false);
@@ -80,8 +77,8 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 			desc->des2 = cpu_to_le32(des2);
 			if (dma_mapping_error(priv->device, des2))
 				return -1;
-			tx_q->tx_skbuff_dma[entry].buf = des2;
-			tx_q->tx_skbuff_dma[entry].len = len;
+			priv->tx_skbuff_dma[entry].buf = des2;
+			priv->tx_skbuff_dma[entry].len = len;
 			/* last descriptor can be set now */
 			priv->hw->desc->prepare_tx_desc(desc, 0, len, csum,
 							STMMAC_CHAIN_MODE, 1,
@@ -90,7 +87,7 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 		}
 	}
 
-	tx_q->cur_tx = entry;
+	priv->cur_tx = entry;
 
 	return entry;
 }
@@ -139,34 +136,32 @@ static void stmmac_init_dma_chain(void *des, dma_addr_t phy_addr,
 
 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p)
 {
-	struct stmmac_rx_queue *rx_q = (struct stmmac_rx_queue *)priv_ptr;
-	struct stmmac_priv *priv = rx_q->priv_data;
+	struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
 
 	if (priv->hwts_rx_en && !priv->extend_desc)
 		/* NOTE: Device will overwrite des3 with timestamp value if
 		 * 1588-2002 time stamping is enabled, hence reinitialize it
 		 * to keep explicit chaining in the descriptor.
 		 */
-		p->des3 = cpu_to_le32((unsigned int)(rx_q->dma_rx_phy +
-				      (((rx_q->dirty_rx) + 1) %
+		p->des3 = cpu_to_le32((unsigned int)(priv->dma_rx_phy +
+				      (((priv->dirty_rx) + 1) %
 				       DMA_RX_SIZE) *
 				      sizeof(struct dma_desc)));
 }
 
 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
 {
-	struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)priv_ptr;
-	struct stmmac_priv *priv = tx_q->priv_data;
-	unsigned int entry = tx_q->dirty_tx;
+	struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
+	unsigned int entry = priv->dirty_tx;
 
-	if (tx_q->tx_skbuff_dma[entry].last_segment && !priv->extend_desc &&
+	if (priv->tx_skbuff_dma[entry].last_segment && !priv->extend_desc &&
 	    priv->hwts_tx_en)
 		/* NOTE: Device will overwrite des3 with timestamp value if
 		 * 1588-2002 time stamping is enabled, hence reinitialize it
 		 * to keep explicit chaining in the descriptor.
 		 */
-		p->des3 = cpu_to_le32((unsigned int)((tx_q->dma_tx_phy +
-				      ((tx_q->dirty_tx + 1) % DMA_TX_SIZE))
+		p->des3 = cpu_to_le32((unsigned int)((priv->dma_tx_phy +
+				      ((priv->dirty_tx + 1) % DMA_TX_SIZE))
 				      * sizeof(struct dma_desc)));
 }
 

drivers/net/ethernet/stmicro/stmmac/ring_mode.c

@@ -26,17 +26,16 @@
 
 static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 {
-	struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)p;
+	struct stmmac_priv *priv = (struct stmmac_priv *)p;
+	unsigned int entry = priv->cur_tx;
+	struct dma_desc *desc;
 	unsigned int nopaged_len = skb_headlen(skb);
-	struct stmmac_priv *priv = tx_q->priv_data;
-	unsigned int entry = tx_q->cur_tx;
 	unsigned int bmax, len, des2;
-	struct dma_desc *desc;
 
 	if (priv->extend_desc)
-		desc = (struct dma_desc *)(tx_q->dma_etx + entry);
+		desc = (struct dma_desc *)(priv->dma_etx + entry);
 	else
-		desc = tx_q->dma_tx + entry;
+		desc = priv->dma_tx + entry;
 
 	if (priv->plat->enh_desc)
 		bmax = BUF_SIZE_8KiB;
@@ -53,29 +52,29 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 		if (dma_mapping_error(priv->device, des2))
 			return -1;
 
-		tx_q->tx_skbuff_dma[entry].buf = des2;
-		tx_q->tx_skbuff_dma[entry].len = bmax;
-		tx_q->tx_skbuff_dma[entry].is_jumbo = true;
+		priv->tx_skbuff_dma[entry].buf = des2;
+		priv->tx_skbuff_dma[entry].len = bmax;
+		priv->tx_skbuff_dma[entry].is_jumbo = true;
 
 		desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
 		priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum,
 						STMMAC_RING_MODE, 0, false);
-		tx_q->tx_skbuff[entry] = NULL;
+		priv->tx_skbuff[entry] = NULL;
 		entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE);
 
 		if (priv->extend_desc)
-			desc = (struct dma_desc *)(tx_q->dma_etx + entry);
+			desc = (struct dma_desc *)(priv->dma_etx + entry);
 		else
-			desc = tx_q->dma_tx + entry;
+			desc = priv->dma_tx + entry;
 
 		des2 = dma_map_single(priv->device, skb->data + bmax, len,
 				      DMA_TO_DEVICE);
 		desc->des2 = cpu_to_le32(des2);
 		if (dma_mapping_error(priv->device, des2))
 			return -1;
-		tx_q->tx_skbuff_dma[entry].buf = des2;
-		tx_q->tx_skbuff_dma[entry].len = len;
-		tx_q->tx_skbuff_dma[entry].is_jumbo = true;
+		priv->tx_skbuff_dma[entry].buf = des2;
+		priv->tx_skbuff_dma[entry].len = len;
+		priv->tx_skbuff_dma[entry].is_jumbo = true;
 
 		desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
 		priv->hw->desc->prepare_tx_desc(desc, 0, len, csum,
@@ -86,15 +85,15 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 		desc->des2 = cpu_to_le32(des2);
 		if (dma_mapping_error(priv->device, des2))
 			return -1;
-		tx_q->tx_skbuff_dma[entry].buf = des2;
-		tx_q->tx_skbuff_dma[entry].len = nopaged_len;
-		tx_q->tx_skbuff_dma[entry].is_jumbo = true;
+		priv->tx_skbuff_dma[entry].buf = des2;
+		priv->tx_skbuff_dma[entry].len = nopaged_len;
+		priv->tx_skbuff_dma[entry].is_jumbo = true;
 		desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
 		priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum,
 						STMMAC_RING_MODE, 0, true);
 	}
 
-	tx_q->cur_tx = entry;
+	priv->cur_tx = entry;
 
 	return entry;
 }
@@ -126,13 +125,12 @@ static void stmmac_init_desc3(struct dma_desc *p)
 
 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
 {
-	struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)priv_ptr;
-	struct stmmac_priv *priv = tx_q->priv_data;
-	unsigned int entry = tx_q->dirty_tx;
+	struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
+	unsigned int entry = priv->dirty_tx;
 
 	/* des3 is only used for jumbo frames tx or time stamping */
-	if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo ||
-		     (tx_q->tx_skbuff_dma[entry].last_segment &&
+	if (unlikely(priv->tx_skbuff_dma[entry].is_jumbo ||
+		     (priv->tx_skbuff_dma[entry].last_segment &&
 		      !priv->extend_desc && priv->hwts_tx_en)))
 		p->des3 = 0;
 }

drivers/net/ethernet/stmicro/stmmac/stmmac.h

@@ -46,35 +46,6 @@ struct stmmac_tx_info {
 	bool is_jumbo;
 };
 
-/* Frequently used values are kept adjacent for cache effect */
-struct stmmac_tx_queue {
-	u32 queue_index;
-	struct stmmac_priv *priv_data;
-	struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
-	struct dma_desc *dma_tx;
-	struct sk_buff **tx_skbuff;
-	struct stmmac_tx_info *tx_skbuff_dma;
-	unsigned int cur_tx;
-	unsigned int dirty_tx;
-	dma_addr_t dma_tx_phy;
-	u32 tx_tail_addr;
-};
-
-struct stmmac_rx_queue {
-	u32 queue_index;
-	struct stmmac_priv *priv_data;
-	struct dma_extended_desc *dma_erx;
-	struct dma_desc *dma_rx ____cacheline_aligned_in_smp;
-	struct sk_buff **rx_skbuff;
-	dma_addr_t *rx_skbuff_dma;
-	struct napi_struct napi ____cacheline_aligned_in_smp;
-	unsigned int cur_rx;
-	unsigned int dirty_rx;
-	u32 rx_zeroc_thresh;
-	dma_addr_t dma_rx_phy;
-	u32 rx_tail_addr;
-};
-
 struct stmmac_priv {
 	/* Frequently used values are kept adjacent for cache effect */
 	struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
@@ -85,22 +56,28 @@ struct stmmac_priv {
 	u32 tx_count_frames;
 	u32 tx_coal_frames;
 	u32 tx_coal_timer;
+	struct stmmac_tx_info *tx_skbuff_dma;
+	dma_addr_t dma_tx_phy;
 	int tx_coalesce;
 	int hwts_tx_en;
 	bool tx_path_in_lpi_mode;
 	struct timer_list txtimer;
 	bool tso;
 
-	/* TX Queue */
-	struct stmmac_tx_queue *tx_queue;
-
-	/* RX Queue */
-	struct stmmac_rx_queue *rx_queue;
-
+	struct dma_desc *dma_rx	____cacheline_aligned_in_smp;
+	struct dma_extended_desc *dma_erx;
+	struct sk_buff **rx_skbuff;
+	unsigned int cur_rx;
+	unsigned int dirty_rx;
 	unsigned int dma_buf_sz;
 	unsigned int rx_copybreak;
+	unsigned int rx_zeroc_thresh;
 	u32 rx_riwt;
 	int hwts_rx_en;
+	dma_addr_t *rx_skbuff_dma;
+	dma_addr_t dma_rx_phy;
+
+	struct napi_struct napi ____cacheline_aligned_in_smp;
 
 	void __iomem *ioaddr;
 	struct net_device *dev;
@@ -142,6 +119,8 @@ struct stmmac_priv {
 	spinlock_t ptp_lock;
 	void __iomem *mmcaddr;
 	void __iomem *ptpaddr;
+	u32 rx_tail_addr;
+	u32 tx_tail_addr;
 	u32 mss;
 
 #ifdef CONFIG_DEBUG_FS