[PATCH 6.1 171/473] net: ethernet: cortina: Locking fixes

Greg Kroah-Hartman
2024-06-06T14:14:55Z

From: Linus Walleij <linus.walleij@linaro.org>

[ Upstream commit 812552808f7ff71133fc59768cdc253c5b8ca1bf ]

This fixes a probably long standing problem in the Cortina
Gemini ethernet driver: there are some paths in the code
where the IRQ registers are written without taking the proper
locks.

Fixes: 4d5ae32f5e1e ("net: ethernet: Add a driver for Gemini gigabit ethernet")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240509-gemini-ethernet-locking-v1-1-afd00a528b95@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/cortina/gemini.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c
index 7c0b0bc033c9c..19fb8c4caab87 100644
--- a/drivers/net/ethernet/cortina/gemini.c
+++ b/drivers/net/ethernet/cortina/gemini.c
@@ -1108,10 +1108,13 @@ static void gmac_tx_irq_enable(struct net_device *netdev,
{
struct gemini_ethernet_port *port = netdev_priv(netdev);
struct gemini_ethernet *geth = port->geth;
+ unsigned long flags;
u32 val, mask;

netdev_dbg(netdev, "%s device %d\n", __func__, netdev->dev_id);

+ spin_lock_irqsave(&geth->irq_lock, flags);
+
mask = GMAC0_IRQ0_TXQ0_INTS << (6 * netdev->dev_id + txq);

if (en)
@@ -1120,6 +1123,8 @@ static void gmac_tx_irq_enable(struct net_device *netdev,
val = readl(geth->base + GLOBAL_INTERRUPT_ENABLE_0_REG);
val = en ? val | mask : val & ~mask;
writel(val, geth->base + GLOBAL_INTERRUPT_ENABLE_0_REG);
+
+ spin_unlock_irqrestore(&geth->irq_lock, flags);
}

static void gmac_tx_irq(struct net_device *netdev, unsigned int txq_num)
@@ -1426,15 +1431,19 @@ static unsigned int gmac_rx(struct net_device *netdev, unsigned int budget)
union gmac_rxdesc_3 word3;
struct page *page = NULL;
unsigned int page_offs;
+ unsigned long flags;
unsigned short r, w;
union dma_rwptr rw;
dma_addr_t mapping;
int frag_nr = 0;

+ spin_lock_irqsave(&geth->irq_lock, flags);
rw.bits32 = readl(ptr_reg);
/* Reset interrupt as all packages until here are taken into account */
writel(DEFAULT_Q0_INT_BIT << netdev->dev_id,
geth->base + GLOBAL_INTERRUPT_STATUS_1_REG);
+ spin_unlock_irqrestore(&geth->irq_lock, flags);
+
r = rw.bits.rptr;
w = rw.bits.wptr;

@@ -1737,10 +1746,9 @@ static irqreturn_t gmac_irq(int irq, void *data)
gmac_update_hw_stats(netdev);

if (val & (GMAC0_RX_OVERRUN_INT_BIT << (netdev->dev_id * 8))) {
+ spin_lock(&geth->irq_lock);
writel(GMAC0_RXDERR_INT_BIT << (netdev->dev_id * 8),
geth->base + GLOBAL_INTERRUPT_STATUS_4_REG);
-
- spin_lock(&geth->irq_lock);
u64_stats_update_begin(&port->ir_stats_syncp);
++port->stats.rx_fifo_errors;
u64_stats_update_end(&port->ir_stats_syncp);
--
2.43.0