--- /dev/null
+From 12bb508bfe5a564c36864b12253db23cac83bfa1 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Thu, 11 Mar 2021 13:35:21 +0100
+Subject: [PATCH] net: broadcom: bcm4908_enet: support TX interrupt
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+It appears that each DMA channel has its own interrupt and both rings
+can be configured (the same way) to handle interrupts.
+
+1. Make ring interrupts code generic (make it operate on given ring)
+2. Move napi to ring (so each has its own)
+3. Make IRQ handler generic (match ring against received IRQ number)
+4. Add (optional) support for TX interrupt
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/ethernet/broadcom/bcm4908_enet.c | 138 ++++++++++++++-----
+ 1 file changed, 103 insertions(+), 35 deletions(-)
+
+--- a/drivers/net/ethernet/broadcom/bcm4908_enet.c
++++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c
+@@ -54,6 +54,7 @@ struct bcm4908_enet_dma_ring {
+ int length;
+ u16 cfg_block;
+ u16 st_ram_block;
++ struct napi_struct napi;
+
+ union {
+ void *cpu_addr;
+@@ -67,8 +68,8 @@ struct bcm4908_enet_dma_ring {
+ struct bcm4908_enet {
+ struct device *dev;
+ struct net_device *netdev;
+- struct napi_struct napi;
+ void __iomem *base;
++ int irq_tx;
+
+ struct bcm4908_enet_dma_ring tx_ring;
+ struct bcm4908_enet_dma_ring rx_ring;
+@@ -123,24 +124,31 @@ static void enet_umac_set(struct bcm4908
+ * Helpers
+ */
+
+-static void bcm4908_enet_intrs_on(struct bcm4908_enet *enet)
++static void bcm4908_enet_set_mtu(struct bcm4908_enet *enet, int mtu)
+ {
+- enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_MASK, ENET_DMA_INT_DEFAULTS);
++ enet_umac_write(enet, UMAC_MAX_FRAME_LEN, mtu + ENET_MAX_ETH_OVERHEAD);
+ }
+
+-static void bcm4908_enet_intrs_off(struct bcm4908_enet *enet)
++/***
++ * DMA ring ops
++ */
++
++static void bcm4908_enet_dma_ring_intrs_on(struct bcm4908_enet *enet,
++ struct bcm4908_enet_dma_ring *ring)
+ {
+- enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_MASK, 0);
++ enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG_INT_MASK, ENET_DMA_INT_DEFAULTS);
+ }
+
+-static void bcm4908_enet_intrs_ack(struct bcm4908_enet *enet)
++static void bcm4908_enet_dma_ring_intrs_off(struct bcm4908_enet *enet,
++ struct bcm4908_enet_dma_ring *ring)
+ {
+- enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_STAT, ENET_DMA_INT_DEFAULTS);
++ enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG_INT_MASK, 0);
+ }
+
+-static void bcm4908_enet_set_mtu(struct bcm4908_enet *enet, int mtu)
++static void bcm4908_enet_dma_ring_intrs_ack(struct bcm4908_enet *enet,
++ struct bcm4908_enet_dma_ring *ring)
+ {
+- enet_umac_write(enet, UMAC_MAX_FRAME_LEN, mtu + ENET_MAX_ETH_OVERHEAD);
++ enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG_INT_STAT, ENET_DMA_INT_DEFAULTS);
+ }
+
+ /***
+@@ -414,11 +422,14 @@ static void bcm4908_enet_gmac_init(struc
+ static irqreturn_t bcm4908_enet_irq_handler(int irq, void *dev_id)
+ {
+ struct bcm4908_enet *enet = dev_id;
++ struct bcm4908_enet_dma_ring *ring;
+
+- bcm4908_enet_intrs_off(enet);
+- bcm4908_enet_intrs_ack(enet);
++ ring = (irq == enet->irq_tx) ? &enet->tx_ring : &enet->rx_ring;
+
+- napi_schedule(&enet->napi);
++ bcm4908_enet_dma_ring_intrs_off(enet, ring);
++ bcm4908_enet_dma_ring_intrs_ack(enet, ring);
++
++ napi_schedule(&ring->napi);
+
+ return IRQ_HANDLED;
+ }
+@@ -426,6 +437,8 @@ static irqreturn_t bcm4908_enet_irq_hand
+ static int bcm4908_enet_open(struct net_device *netdev)
+ {
+ struct bcm4908_enet *enet = netdev_priv(netdev);
++ struct bcm4908_enet_dma_ring *tx_ring = &enet->tx_ring;
++ struct bcm4908_enet_dma_ring *rx_ring = &enet->rx_ring;
+ struct device *dev = enet->dev;
+ int err;
+
+@@ -435,6 +448,17 @@ static int bcm4908_enet_open(struct net_
+ return err;
+ }
+
++ if (enet->irq_tx > 0) {
++ err = request_irq(enet->irq_tx, bcm4908_enet_irq_handler, 0,
++ "tx", enet);
++ if (err) {
++ dev_err(dev, "Failed to request IRQ %d: %d\n",
++ enet->irq_tx, err);
++ free_irq(netdev->irq, enet);
++ return err;
++ }
++ }
++
+ bcm4908_enet_gmac_init(enet);
+ bcm4908_enet_dma_reset(enet);
+ bcm4908_enet_dma_init(enet);
+@@ -443,14 +467,19 @@ static int bcm4908_enet_open(struct net_
+
+ enet_set(enet, ENET_DMA_CONTROLLER_CFG, ENET_DMA_CTRL_CFG_MASTER_EN);
+ enet_maskset(enet, ENET_DMA_CONTROLLER_CFG, ENET_DMA_CTRL_CFG_FLOWC_CH1_EN, 0);
+- bcm4908_enet_dma_rx_ring_enable(enet, &enet->rx_ring);
+
+- napi_enable(&enet->napi);
++ if (enet->irq_tx > 0) {
++ napi_enable(&tx_ring->napi);
++ bcm4908_enet_dma_ring_intrs_ack(enet, tx_ring);
++ bcm4908_enet_dma_ring_intrs_on(enet, tx_ring);
++ }
++
++ bcm4908_enet_dma_rx_ring_enable(enet, rx_ring);
++ napi_enable(&rx_ring->napi);
+ netif_carrier_on(netdev);
+ netif_start_queue(netdev);
+-
+- bcm4908_enet_intrs_ack(enet);
+- bcm4908_enet_intrs_on(enet);
++ bcm4908_enet_dma_ring_intrs_ack(enet, rx_ring);
++ bcm4908_enet_dma_ring_intrs_on(enet, rx_ring);
+
+ return 0;
+ }
+@@ -458,16 +487,20 @@ static int bcm4908_enet_open(struct net_
+ static int bcm4908_enet_stop(struct net_device *netdev)
+ {
+ struct bcm4908_enet *enet = netdev_priv(netdev);
++ struct bcm4908_enet_dma_ring *tx_ring = &enet->tx_ring;
++ struct bcm4908_enet_dma_ring *rx_ring = &enet->rx_ring;
+
+ netif_stop_queue(netdev);
+ netif_carrier_off(netdev);
+- napi_disable(&enet->napi);
++ napi_disable(&rx_ring->napi);
++ napi_disable(&tx_ring->napi);
+
+ bcm4908_enet_dma_rx_ring_disable(enet, &enet->rx_ring);
+ bcm4908_enet_dma_tx_ring_disable(enet, &enet->tx_ring);
+
+ bcm4908_enet_dma_uninit(enet);
+
++ free_irq(enet->irq_tx, enet);
+ free_irq(enet->netdev->irq, enet);
+
+ return 0;
+@@ -484,25 +517,19 @@ static int bcm4908_enet_start_xmit(struc
+ u32 tmp;
+
+ /* Free transmitted skbs */
+- while (ring->read_idx != ring->write_idx) {
+- buf_desc = &ring->buf_desc[ring->read_idx];
+- if (le32_to_cpu(buf_desc->ctl) & DMA_CTL_STATUS_OWN)
+- break;
+- slot = &ring->slots[ring->read_idx];
+-
+- dma_unmap_single(dev, slot->dma_addr, slot->len, DMA_TO_DEVICE);
+- dev_kfree_skb(slot->skb);
+- if (++ring->read_idx == ring->length)
+- ring->read_idx = 0;
+- }
++ if (enet->irq_tx < 0 &&
++ !(le32_to_cpu(ring->buf_desc[ring->read_idx].ctl) & DMA_CTL_STATUS_OWN))
++ napi_schedule(&enet->tx_ring.napi);
+
+ /* Don't use the last empty buf descriptor */
+ if (ring->read_idx <= ring->write_idx)
+ free_buf_descs = ring->read_idx - ring->write_idx + ring->length;
+ else
+ free_buf_descs = ring->read_idx - ring->write_idx;
+- if (free_buf_descs < 2)
++ if (free_buf_descs < 2) {
++ netif_stop_queue(netdev);
+ return NETDEV_TX_BUSY;
++ }
+
+ /* Hardware removes OWN bit after sending data */
+ buf_desc = &ring->buf_desc[ring->write_idx];
+@@ -539,9 +566,10 @@ static int bcm4908_enet_start_xmit(struc
+ return NETDEV_TX_OK;
+ }
+
+-static int bcm4908_enet_poll(struct napi_struct *napi, int weight)
++static int bcm4908_enet_poll_rx(struct napi_struct *napi, int weight)
+ {
+- struct bcm4908_enet *enet = container_of(napi, struct bcm4908_enet, napi);
++ struct bcm4908_enet_dma_ring *rx_ring = container_of(napi, struct bcm4908_enet_dma_ring, napi);
++ struct bcm4908_enet *enet = container_of(rx_ring, struct bcm4908_enet, rx_ring);
+ struct device *dev = enet->dev;
+ int handled = 0;
+
+@@ -590,7 +618,7 @@ static int bcm4908_enet_poll(struct napi
+
+ if (handled < weight) {
+ napi_complete_done(napi, handled);
+- bcm4908_enet_intrs_on(enet);
++ bcm4908_enet_dma_ring_intrs_on(enet, rx_ring);
+ }
+
+ /* Hardware could disable ring if it run out of descriptors */
+@@ -599,6 +627,42 @@ static int bcm4908_enet_poll(struct napi
+ return handled;
+ }
+
++static int bcm4908_enet_poll_tx(struct napi_struct *napi, int weight)
++{
++ struct bcm4908_enet_dma_ring *tx_ring = container_of(napi, struct bcm4908_enet_dma_ring, napi);
++ struct bcm4908_enet *enet = container_of(tx_ring, struct bcm4908_enet, tx_ring);
++ struct bcm4908_enet_dma_ring_bd *buf_desc;
++ struct bcm4908_enet_dma_ring_slot *slot;
++ struct device *dev = enet->dev;
++ unsigned int bytes = 0;
++ int handled = 0;
++
++ while (handled < weight && tx_ring->read_idx != tx_ring->write_idx) {
++ buf_desc = &tx_ring->buf_desc[tx_ring->read_idx];
++ if (le32_to_cpu(buf_desc->ctl) & DMA_CTL_STATUS_OWN)
++ break;
++ slot = &tx_ring->slots[tx_ring->read_idx];
++
++ dma_unmap_single(dev, slot->dma_addr, slot->len, DMA_TO_DEVICE);
++ dev_kfree_skb(slot->skb);
++ bytes += slot->len;
++ if (++tx_ring->read_idx == tx_ring->length)
++ tx_ring->read_idx = 0;
++
++ handled++;
++ }
++
++ if (handled < weight) {
++ napi_complete_done(napi, handled);
++ bcm4908_enet_dma_ring_intrs_on(enet, tx_ring);
++ }
++
++ if (netif_queue_stopped(enet->netdev))
++ netif_wake_queue(enet->netdev);
++
++ return handled;
++}
++
+ static int bcm4908_enet_change_mtu(struct net_device *netdev, int new_mtu)
+ {
+ struct bcm4908_enet *enet = netdev_priv(netdev);
+@@ -642,6 +706,8 @@ static int bcm4908_enet_probe(struct pla
+ if (netdev->irq < 0)
+ return netdev->irq;
+
++ enet->irq_tx = platform_get_irq_byname(pdev, "tx");
++
+ dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
+
+ err = bcm4908_enet_dma_alloc(enet);
+@@ -658,7 +724,8 @@ static int bcm4908_enet_probe(struct pla
+ netdev->min_mtu = ETH_ZLEN;
+ netdev->mtu = ETH_DATA_LEN;
+ netdev->max_mtu = ENET_MTU_MAX;
+- netif_napi_add(netdev, &enet->napi, bcm4908_enet_poll, 64);
++ netif_tx_napi_add(netdev, &enet->tx_ring.napi, bcm4908_enet_poll_tx, NAPI_POLL_WEIGHT);
++ netif_napi_add(netdev, &enet->rx_ring.napi, bcm4908_enet_poll_rx, NAPI_POLL_WEIGHT);
+
+ err = register_netdev(netdev);
+ if (err) {
+@@ -676,7 +743,8 @@ static int bcm4908_enet_remove(struct pl
+ struct bcm4908_enet *enet = platform_get_drvdata(pdev);
+
+ unregister_netdev(enet->netdev);
+- netif_napi_del(&enet->napi);
++ netif_napi_del(&enet->rx_ring.napi);
++ netif_napi_del(&enet->tx_ring.napi);
+ bcm4908_enet_dma_free(enet);
+
+ return 0;
projects / openwrt / staging / ynezz.git / commitdiff