[PATCH 4/4] net-next: mediatek: add support for IRQ grouping

From: John Crispin
Date: Wed Jun 15 2016 - 11:00:44 EST

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The ethernet core has 3 IRQs. Using the IRQ grouping registers we are able
to separate TX and RX IRQs, which allows us to service them on separate
cores. This patch splits the IRQ handler into 2 separate functions, one for
TX and another for RX. The TX housekeeping is split out into its own NAPI
handler.

Signed-off-by: John Crispin <john@xxxxxxxxxxx>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 156 +++++++++++++++++----------
drivers/net/ethernet/mediatek/mtk_eth_soc.h | 15 ++-
2 files changed, 111 insertions(+), 60 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index c7da00b..79fdb07 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -874,14 +874,13 @@ release_desc:
return done;
}

-static int mtk_poll_tx(struct mtk_eth *eth, int budget, bool *tx_again)
+static int mtk_poll_tx(struct mtk_eth *eth, int budget)
{
struct mtk_tx_ring *ring = &eth->tx_ring;
struct mtk_tx_dma *desc;
struct sk_buff *skb;
struct mtk_tx_buf *tx_buf;
- int total = 0, done = 0;
- unsigned int bytes = 0;
+ unsigned int bytes = 0, done = 0;
u32 cpu, dma;
static int condition;
int i;
@@ -933,63 +932,82 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget, bool *tx_again)
netdev_completed_queue(eth->netdev[i], done, bytes);
}

- /* read hw index again make sure no new tx packet */
- if (cpu != dma || cpu != mtk_r32(eth, MTK_QTX_DRX_PTR))
- *tx_again = true;
- else
- mtk_w32(eth, MTK_TX_DONE_INT, MTK_QMTK_INT_STATUS);
-
- if (!total)
- return 0;
-
if (mtk_queue_stopped(eth) &&
(atomic_read(&ring->free_count) > ring->thresh))
mtk_wake_queue(eth);

- return total;
+ return done;
}

-static int mtk_poll(struct napi_struct *napi, int budget)
+static void mtk_handle_status_irq(struct mtk_eth *eth)
{
- struct mtk_eth *eth = container_of(napi, struct mtk_eth, rx_napi);
- u32 status, status2, mask;
- int tx_done, rx_done;
- bool tx_again = false;
-
- status = mtk_r32(eth, MTK_QMTK_INT_STATUS);
- status2 = mtk_r32(eth, MTK_INT_STATUS2);
- tx_done = 0;
- rx_done = 0;
- tx_again = 0;
-
- if (status & MTK_TX_DONE_INT)
- tx_done = mtk_poll_tx(eth, budget, &tx_again);
-
- if (status & MTK_RX_DONE_INT)
- rx_done = mtk_poll_rx(napi, budget, eth);
+ u32 status2 = mtk_r32(eth, MTK_INT_STATUS2);

if (unlikely(status2 & (MTK_GDM1_AF | MTK_GDM2_AF))) {
mtk_stats_update(eth);
mtk_w32(eth, (MTK_GDM1_AF | MTK_GDM2_AF),
MTK_INT_STATUS2);
}
+}
+
+static int mtk_napi_tx(struct napi_struct *napi, int budget)
+{
+ struct mtk_eth *eth = container_of(napi, struct mtk_eth, tx_napi);
+ u32 status, mask;
+ int tx_done = 0;
+
+ mtk_handle_status_irq(eth);
+ mtk_w32(eth, MTK_TX_DONE_INT, MTK_QMTK_INT_STATUS);
+ tx_done = mtk_poll_tx(eth, budget);
+
+ if (unlikely(netif_msg_intr(eth))) {
+ status = mtk_r32(eth, MTK_QMTK_INT_STATUS);
+ mask = mtk_r32(eth, MTK_QDMA_INT_MASK);
+ dev_info(eth->dev,
+ "done tx %d, intr 0x%08x/0x%x\n",
+ tx_done, status, mask);
+ }
+
+ if (tx_done == budget)
+ return budget;
+
+ status = mtk_r32(eth, MTK_QMTK_INT_STATUS);
+ if (status & MTK_TX_DONE_INT)
+ return budget;
+
+ napi_complete(napi);
+ mtk_irq_enable(eth, MTK_TX_DONE_INT);
+
+ return tx_done;
+}
+
+static int mtk_napi_rx(struct napi_struct *napi, int budget)
+{
+ struct mtk_eth *eth = container_of(napi, struct mtk_eth, rx_napi);
+ u32 status, mask;
+ int rx_done = 0;
+
+ mtk_handle_status_irq(eth);
+ mtk_w32(eth, MTK_RX_DONE_INT, MTK_QMTK_INT_STATUS);
+ rx_done = mtk_poll_rx(napi, budget, eth);

if (unlikely(netif_msg_intr(eth))) {
+ status = mtk_r32(eth, MTK_QMTK_INT_STATUS);
mask = mtk_r32(eth, MTK_QDMA_INT_MASK);
- netdev_info(eth->netdev[0],
- "done tx %d, rx %d, intr 0x%08x/0x%x\n",
- tx_done, rx_done, status, mask);
+ dev_info(eth->dev,
+ "done rx %d, intr 0x%08x/0x%x\n",
+ rx_done, status, mask);
}

- if (tx_again || rx_done == budget)
+ if (rx_done == budget)
return budget;

status = mtk_r32(eth, MTK_QMTK_INT_STATUS);
- if (status & (tx_intr | rx_intr))
+ if (status & MTK_RX_DONE_INT)
return budget;

napi_complete(napi);
- mtk_irq_enable(eth, MTK_RX_DONE_INT | MTK_RX_DONE_INT);
+ mtk_irq_enable(eth, MTK_RX_DONE_INT);

return rx_done;
}
@@ -1225,22 +1243,26 @@ static void mtk_tx_timeout(struct net_device *dev)
schedule_work(&eth->pending_work);
}

-static irqreturn_t mtk_handle_irq(int irq, void *_eth)
+static irqreturn_t mtk_handle_irq_rx(int irq, void *_eth)
{
struct mtk_eth *eth = _eth;
- u32 status;

- status = mtk_r32(eth, MTK_QMTK_INT_STATUS);
- if (unlikely(!status))
- return IRQ_NONE;
+ if (likely(napi_schedule_prep(&eth->rx_napi))) {
+ __napi_schedule(&eth->rx_napi);
+ mtk_irq_disable(eth, MTK_RX_DONE_INT);
+ }

- if (likely(status & (MTK_RX_DONE_INT | MTK_TX_DONE_INT))) {
- if (likely(napi_schedule_prep(&eth->rx_napi)))
- __napi_schedule(&eth->rx_napi);
- } else {
- mtk_w32(eth, status, MTK_QMTK_INT_STATUS);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t mtk_handle_irq_tx(int irq, void *_eth)
+{
+ struct mtk_eth *eth = _eth;
+
+ if (likely(napi_schedule_prep(&eth->tx_napi))) {
+ __napi_schedule(&eth->tx_napi);
+ mtk_irq_disable(eth, MTK_TX_DONE_INT);
}
- mtk_irq_disable(eth, (MTK_RX_DONE_INT | MTK_TX_DONE_INT));

return IRQ_HANDLED;
}
@@ -1253,7 +1275,7 @@ static void mtk_poll_controller(struct net_device *dev)
u32 int_mask = MTK_TX_DONE_INT | MTK_RX_DONE_INT;

mtk_irq_disable(eth, int_mask);
- mtk_handle_irq(dev->irq, dev);
+ mtk_handle_irq(dev->irq[0], dev);
mtk_irq_enable(eth, int_mask);
}
#endif
@@ -1289,6 +1311,7 @@ static int mtk_open(struct net_device *dev)
if (err)
return err;

+ napi_enable(&eth->tx_napi);
napi_enable(&eth->rx_napi);
mtk_irq_enable(eth, MTK_TX_DONE_INT | MTK_RX_DONE_INT);
}
@@ -1337,6 +1360,7 @@ static int mtk_stop(struct net_device *dev)
return 0;

mtk_irq_disable(eth, MTK_TX_DONE_INT | MTK_RX_DONE_INT);
+ napi_disable(&eth->tx_napi);
napi_disable(&eth->rx_napi);

mtk_stop_dma(eth, MTK_QDMA_GLO_CFG);
@@ -1374,7 +1398,11 @@ static int __init mtk_hw_init(struct mtk_eth *eth)
/* Enable RX VLan Offloading */
mtk_w32(eth, 1, MTK_CDMP_EG_CTRL);

- err = devm_request_irq(eth->dev, eth->irq, mtk_handle_irq, 0,
+ err = devm_request_irq(eth->dev, eth->irq[1], mtk_handle_irq_tx, 0,
+ dev_name(eth->dev), eth);
+ if (err)
+ return err;
+ err = devm_request_irq(eth->dev, eth->irq[2], mtk_handle_irq_rx, 0,
dev_name(eth->dev), eth);
if (err)
return err;
@@ -1390,7 +1418,11 @@ static int __init mtk_hw_init(struct mtk_eth *eth)
mtk_w32(eth, 0, MTK_RST_GL);

/* FE int grouping */
- mtk_w32(eth, 0, MTK_FE_INT_GRP);
+ mtk_w32(eth, MTK_TX_DONE_INT, MTK_PDMA_INT_GRP1);
+ mtk_w32(eth, MTK_RX_DONE_INT, MTK_PDMA_INT_GRP2);
+ mtk_w32(eth, MTK_TX_DONE_INT, MTK_QDMA_INT_GRP1);
+ mtk_w32(eth, MTK_RX_DONE_INT, MTK_QDMA_INT_GRP2);
+ mtk_w32(eth, 0x21021000, MTK_FE_INT_GRP);

for (i = 0; i < 2; i++) {
u32 val = mtk_r32(eth, MTK_GDMA_FWD_CFG(i));
@@ -1438,7 +1470,9 @@ static void mtk_uninit(struct net_device *dev)
phy_disconnect(mac->phy_dev);
mtk_mdio_cleanup(eth);
mtk_irq_disable(eth, ~0);
- free_irq(dev->irq, dev);
+ free_irq(eth->irq[0], dev);
+ free_irq(eth->irq[1], dev);
+ free_irq(eth->irq[2], dev);
}

static int mtk_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
@@ -1712,10 +1746,10 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
dev_err(eth->dev, "error bringing up device\n");
goto free_netdev;
}
- eth->netdev[id]->irq = eth->irq;
+ eth->netdev[id]->irq = eth->irq[0];
netif_info(eth, probe, eth->netdev[id],
"mediatek frame engine at 0x%08lx, irq %d\n",
- eth->netdev[id]->base_addr, eth->netdev[id]->irq);
+ eth->netdev[id]->base_addr, eth->irq[0]);

return 0;

@@ -1732,6 +1766,7 @@ static int mtk_probe(struct platform_device *pdev)
struct mtk_soc_data *soc;
struct mtk_eth *eth;
int err;
+ int i;

match = of_match_device(of_mtk_match, &pdev->dev);
soc = (struct mtk_soc_data *)match->data;
@@ -1767,10 +1802,12 @@ static int mtk_probe(struct platform_device *pdev)
return PTR_ERR(eth->rstc);
}

- eth->irq = platform_get_irq(pdev, 0);
- if (eth->irq < 0) {
- dev_err(&pdev->dev, "no IRQ resource found\n");
- return -ENXIO;
+ for (i = 0; i < 3; i++) {
+ eth->irq[i] = platform_get_irq(pdev, i);
+ if (eth->irq[i] < 0) {
+ dev_err(&pdev->dev, "no IRQ%d resource found\n", i);
+ return -ENXIO;
+ }
}

eth->clk_ethif = devm_clk_get(&pdev->dev, "ethif");
@@ -1811,7 +1848,9 @@ static int mtk_probe(struct platform_device *pdev)
* for NAPI to work
*/
init_dummy_netdev(&eth->dummy_dev);
- netif_napi_add(&eth->dummy_dev, &eth->rx_napi, mtk_poll,
+ netif_napi_add(&eth->dummy_dev, &eth->tx_napi, mtk_napi_tx,
+ MTK_NAPI_WEIGHT);
+ netif_napi_add(&eth->dummy_dev, &eth->rx_napi, mtk_napi_rx,
MTK_NAPI_WEIGHT);

platform_set_drvdata(pdev, eth);
@@ -1832,6 +1871,7 @@ static int mtk_remove(struct platform_device *pdev)
clk_disable_unprepare(eth->clk_gp1);
clk_disable_unprepare(eth->clk_gp2);

+ netif_napi_del(&eth->tx_napi);
netif_napi_del(&eth->rx_napi);
mtk_cleanup(eth);
platform_set_drvdata(pdev, NULL);
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 3159d2a..f82e3ac 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -68,6 +68,10 @@
/* Unicast Filter MAC Address Register - High */
#define MTK_GDMA_MAC_ADRH(x) (0x50C + (x * 0x1000))

+/* PDMA Interrupt grouping registers */
+#define MTK_PDMA_INT_GRP1 0xa50
+#define MTK_PDMA_INT_GRP2 0xa54
+
/* QDMA TX Queue Configuration Registers */
#define MTK_QTX_CFG(x) (0x1800 + (x * 0x10))
#define QDMA_RES_THRES 4
@@ -125,6 +129,11 @@
#define MTK_TX_DONE_INT (MTK_TX_DONE_INT0 | MTK_TX_DONE_INT1 | \
MTK_TX_DONE_INT2 | MTK_TX_DONE_INT3)

+/* QDMA Interrupt grouping registers */
+#define MTK_QDMA_INT_GRP1 0x1a20
+#define MTK_QDMA_INT_GRP2 0x1a24
+#define MTK_RLS_DONE_INT BIT(0)
+
/* QDMA Interrupt Status Register */
#define MTK_QDMA_INT_MASK 0x1A1C

@@ -356,7 +365,8 @@ struct mtk_rx_ring {
* @dma_refcnt: track how many netdevs are using the DMA engine
* @tx_ring: Pointer to the memore holding info about the TX ring
* @rx_ring: Pointer to the memore holding info about the RX ring
- * @rx_napi: The NAPI struct
+ * @tx_napi: The TX NAPI struct
+ * @rx_napi: The RX NAPI struct
* @scratch_ring: Newer SoCs need memory for a second HW managed TX ring
* @phy_scratch_ring: physical address of scratch_ring
* @scratch_head: The scratch memory that scratch_ring points to.
@@ -377,7 +387,7 @@ struct mtk_eth {
struct net_device dummy_dev;
struct net_device *netdev[MTK_MAX_DEVS];
struct mtk_mac *mac[MTK_MAX_DEVS];
- int irq;
+ int irq[3];
u32 msg_enable;
unsigned long sysclk;
struct regmap *ethsys;
@@ -385,6 +395,7 @@ struct mtk_eth {
atomic_t dma_refcnt;
struct mtk_tx_ring tx_ring;
struct mtk_rx_ring rx_ring;
+ struct napi_struct tx_napi;
struct napi_struct rx_napi;
struct mtk_tx_dma *scratch_ring;
dma_addr_t phy_scratch_ring;
--
1.7.10.4

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