[PATCH net 5/8] net: bcmgenet: synchronize irq0 status between the isr and task

From: Doug Berger
Date: Thu Mar 09 2017 - 19:50:50 EST


From: Doug Berger <doug.berger@xxxxxxxxxxxx>

Add a spinlock to ensure that irq0_stat is not unintentionally altered
as the result of preemption. Also removed unserviced irq0 interrupts
and removed irq1_stat since there is no bottom half service for those
interrupts.

refs #SWLINUX-4311

Fixes: 1c1008c793fa ("net: bcmgenet: add main driver file")
Signed-off-by: Doug Berger <doug.berger@xxxxxxxxxxxx>
---
drivers/net/ethernet/broadcom/genet/bcmgenet.c | 73 ++++++++++++++------------
drivers/net/ethernet/broadcom/genet/bcmgenet.h | 6 ++-
2 files changed, 44 insertions(+), 35 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 475dc14931af..527cecaf12c1 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2506,24 +2506,28 @@ static int bcmgenet_init_dma(struct bcmgenet_priv *priv)
/* Interrupt bottom half */
static void bcmgenet_irq_task(struct work_struct *work)
{
+ unsigned long flags;
+ unsigned int status;
struct bcmgenet_priv *priv = container_of(
work, struct bcmgenet_priv, bcmgenet_irq_work);

netif_dbg(priv, intr, priv->dev, "%s\n", __func__);

- if (priv->irq0_stat & UMAC_IRQ_MPD_R) {
- priv->irq0_stat &= ~UMAC_IRQ_MPD_R;
+ spin_lock_irqsave(&priv->lock, flags);
+ status = priv->irq0_stat;
+ priv->irq0_stat = 0;
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ if (status & UMAC_IRQ_MPD_R) {
netif_dbg(priv, wol, priv->dev,
"magic packet detected, waking up\n");
bcmgenet_power_up(priv, GENET_POWER_WOL_MAGIC);
}

/* Link UP/DOWN event */
- if (priv->irq0_stat & UMAC_IRQ_LINK_EVENT) {
+ if (status & UMAC_IRQ_LINK_EVENT)
phy_mac_interrupt(priv->phydev,
- !!(priv->irq0_stat & UMAC_IRQ_LINK_UP));
- priv->irq0_stat &= ~UMAC_IRQ_LINK_EVENT;
- }
+ !!(status & UMAC_IRQ_LINK_UP));
}

/* bcmgenet_isr1: handle Rx and Tx priority queues */
@@ -2532,22 +2536,21 @@ static irqreturn_t bcmgenet_isr1(int irq, void *dev_id)
struct bcmgenet_priv *priv = dev_id;
struct bcmgenet_rx_ring *rx_ring;
struct bcmgenet_tx_ring *tx_ring;
- unsigned int index;
+ unsigned int index, status;

- /* Save irq status for bottom-half processing. */
- priv->irq1_stat =
- bcmgenet_intrl2_1_readl(priv, INTRL2_CPU_STAT) &
+ /* Read irq status */
+ status = bcmgenet_intrl2_1_readl(priv, INTRL2_CPU_STAT) &
~bcmgenet_intrl2_1_readl(priv, INTRL2_CPU_MASK_STATUS);

/* clear interrupts */
- bcmgenet_intrl2_1_writel(priv, priv->irq1_stat, INTRL2_CPU_CLEAR);
+ bcmgenet_intrl2_1_writel(priv, status, INTRL2_CPU_CLEAR);

netif_dbg(priv, intr, priv->dev,
- "%s: IRQ=0x%x\n", __func__, priv->irq1_stat);
+ "%s: IRQ=0x%x\n", __func__, status);

/* Check Rx priority queue interrupts */
for (index = 0; index < priv->hw_params->rx_queues; index++) {
- if (!(priv->irq1_stat & BIT(UMAC_IRQ1_RX_INTR_SHIFT + index)))
+ if (!(status & BIT(UMAC_IRQ1_RX_INTR_SHIFT + index)))
continue;

rx_ring = &priv->rx_rings[index];
@@ -2560,7 +2563,7 @@ static irqreturn_t bcmgenet_isr1(int irq, void *dev_id)

/* Check Tx priority queue interrupts */
for (index = 0; index < priv->hw_params->tx_queues; index++) {
- if (!(priv->irq1_stat & BIT(index)))
+ if (!(status & BIT(index)))
continue;

tx_ring = &priv->tx_rings[index];
@@ -2580,19 +2583,20 @@ static irqreturn_t bcmgenet_isr0(int irq, void *dev_id)
struct bcmgenet_priv *priv = dev_id;
struct bcmgenet_rx_ring *rx_ring;
struct bcmgenet_tx_ring *tx_ring;
+ unsigned int status;
+ unsigned long flags;

- /* Save irq status for bottom-half processing. */
- priv->irq0_stat =
- bcmgenet_intrl2_0_readl(priv, INTRL2_CPU_STAT) &
+ /* Read irq status */
+ status = bcmgenet_intrl2_0_readl(priv, INTRL2_CPU_STAT) &
~bcmgenet_intrl2_0_readl(priv, INTRL2_CPU_MASK_STATUS);

/* clear interrupts */
- bcmgenet_intrl2_0_writel(priv, priv->irq0_stat, INTRL2_CPU_CLEAR);
+ bcmgenet_intrl2_0_writel(priv, status, INTRL2_CPU_CLEAR);

netif_dbg(priv, intr, priv->dev,
- "IRQ=0x%x\n", priv->irq0_stat);
+ "IRQ=0x%x\n", status);

- if (priv->irq0_stat & UMAC_IRQ_RXDMA_DONE) {
+ if (status & UMAC_IRQ_RXDMA_DONE) {
rx_ring = &priv->rx_rings[DESC_INDEX];

if (likely(napi_schedule_prep(&rx_ring->napi))) {
@@ -2601,7 +2605,7 @@ static irqreturn_t bcmgenet_isr0(int irq, void *dev_id)
}
}

- if (priv->irq0_stat & UMAC_IRQ_TXDMA_DONE) {
+ if (status & UMAC_IRQ_TXDMA_DONE) {
tx_ring = &priv->tx_rings[DESC_INDEX];

if (likely(napi_schedule_prep(&tx_ring->napi))) {
@@ -2610,22 +2614,23 @@ static irqreturn_t bcmgenet_isr0(int irq, void *dev_id)
}
}

- if (priv->irq0_stat & (UMAC_IRQ_PHY_DET_R |
- UMAC_IRQ_PHY_DET_F |
- UMAC_IRQ_LINK_EVENT |
- UMAC_IRQ_HFB_SM |
- UMAC_IRQ_HFB_MM |
- UMAC_IRQ_MPD_R)) {
- /* all other interested interrupts handled in bottom half */
- schedule_work(&priv->bcmgenet_irq_work);
- }
-
if ((priv->hw_params->flags & GENET_HAS_MDIO_INTR) &&
- priv->irq0_stat & (UMAC_IRQ_MDIO_DONE | UMAC_IRQ_MDIO_ERROR)) {
- priv->irq0_stat &= ~(UMAC_IRQ_MDIO_DONE | UMAC_IRQ_MDIO_ERROR);
+ status & (UMAC_IRQ_MDIO_DONE | UMAC_IRQ_MDIO_ERROR)) {
wake_up(&priv->wq);
}

+ /* all other interested interrupts handled in bottom half */
+ status &= (UMAC_IRQ_LINK_EVENT |
+ UMAC_IRQ_MPD_R);
+ if (status) {
+ /* Save irq status for bottom-half processing. */
+ spin_lock_irqsave(&priv->lock, flags);
+ priv->irq0_stat |= status;
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ schedule_work(&priv->bcmgenet_irq_work);
+ }
+
return IRQ_HANDLED;
}

@@ -3327,6 +3332,8 @@ static int bcmgenet_probe(struct platform_device *pdev)
goto err;
}

+ spin_lock_init(&priv->lock);
+
SET_NETDEV_DEV(dev, &pdev->dev);
dev_set_drvdata(&pdev->dev, dev);
ether_addr_copy(dev->dev_addr, macaddr);
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
index d5fb0d772dcd..db7f289d65ae 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
@@ -623,11 +623,13 @@ struct bcmgenet_priv {
struct work_struct bcmgenet_irq_work;
int irq0;
int irq1;
- unsigned int irq0_stat;
- unsigned int irq1_stat;
int wol_irq;
bool wol_irq_disabled;

+ /* shared status */
+ spinlock_t lock;
+ unsigned int irq0_stat;
+
/* HW descriptors/checksum variables */
bool desc_64b_en;
bool desc_rxchk_en;
--
2.11.1