From 60df02b6ea4581d72eb7a3ab7204504a54059b72 Mon Sep 17 00:00:00 2001 From: Ansuel Smith Date: Fri, 14 May 2021 23:00:08 +0200 Subject: [PATCH] net: dsa: qca8k: dsa: qca8k: protect MASTER busy_wait with mdio mutex MDIO_MASTER operation have a dedicated busy wait that is not protected by the mdio mutex. This can cause situation where the MASTER operation is done and a normal operation is executed between the MASTER read/write and the MASTER busy_wait. Rework the qca8k_mdio_read/write function to address this issue by binding the lock for the whole MASTER operation and not only the mdio read/write common operation. Signed-off-by: Ansuel Smith Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/dsa/qca8k.c | 68 +++++++++++++++++++++++++++++++++-------- 1 file changed, 55 insertions(+), 13 deletions(-) --- a/drivers/net/dsa/qca8k.c +++ b/drivers/net/dsa/qca8k.c @@ -628,8 +628,31 @@ qca8k_port_to_phy(int port) } static int +qca8k_mdio_busy_wait(struct qca8k_priv *priv, u32 reg, u32 mask) +{ + u16 r1, r2, page; + u32 val; + int ret; + + qca8k_split_addr(reg, &r1, &r2, &page); + + ret = read_poll_timeout(qca8k_mii_read32, val, !(val & mask), 0, + QCA8K_BUSY_WAIT_TIMEOUT * USEC_PER_MSEC, false, + priv->bus, 0x10 | r2, r1); + + /* Check if qca8k_read has failed for a different reason + * before returnting -ETIMEDOUT + */ + if (ret < 0 && val < 0) + return val; + + return ret; +} + +static int qca8k_mdio_write(struct qca8k_priv *priv, int port, u32 regnum, u16 data) { + u16 r1, r2, page; u32 phy, val; int ret; @@ -645,12 +668,21 @@ qca8k_mdio_write(struct qca8k_priv *priv QCA8K_MDIO_MASTER_REG_ADDR(regnum) | QCA8K_MDIO_MASTER_DATA(data); - ret = qca8k_write(priv, QCA8K_MDIO_MASTER_CTRL, val); + qca8k_split_addr(QCA8K_MDIO_MASTER_CTRL, &r1, &r2, &page); + + mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED); + + ret = qca8k_set_page(priv->bus, page); if (ret) - return ret; + goto exit; + + qca8k_mii_write32(priv->bus, 0x10 | r2, r1, val); - ret = qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL, - QCA8K_MDIO_MASTER_BUSY); + ret = qca8k_mdio_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL, + QCA8K_MDIO_MASTER_BUSY); + +exit: + mutex_unlock(&priv->bus->mdio_lock); /* even if the busy_wait timeouts try to clear the MASTER_EN */ qca8k_reg_clear(priv, QCA8K_MDIO_MASTER_CTRL, @@ -662,6 +694,7 @@ qca8k_mdio_write(struct qca8k_priv *priv static int qca8k_mdio_read(struct qca8k_priv *priv, int port, u32 regnum) { + u16 r1, r2, page; u32 phy, val; int ret; @@ -676,21 +709,30 @@ qca8k_mdio_read(struct qca8k_priv *priv, QCA8K_MDIO_MASTER_READ | QCA8K_MDIO_MASTER_PHY_ADDR(phy) | QCA8K_MDIO_MASTER_REG_ADDR(regnum); - ret = qca8k_write(priv, QCA8K_MDIO_MASTER_CTRL, val); - if (ret) - return ret; + qca8k_split_addr(QCA8K_MDIO_MASTER_CTRL, &r1, &r2, &page); + + mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED); - ret = qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL, - QCA8K_MDIO_MASTER_BUSY); + ret = qca8k_set_page(priv->bus, page); if (ret) - return ret; + goto exit; - val = qca8k_read(priv, QCA8K_MDIO_MASTER_CTRL); - if (val < 0) - return val; + qca8k_mii_write32(priv->bus, 0x10 | r2, r1, val); + + ret = qca8k_mdio_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL, + QCA8K_MDIO_MASTER_BUSY); + if (ret) + goto exit; + val = qca8k_mii_read32(priv->bus, 0x10 | r2, r1); val &= QCA8K_MDIO_MASTER_DATA_MASK; +exit: + mutex_unlock(&priv->bus->mdio_lock); + + if (val >= 0) + val &= QCA8K_MDIO_MASTER_DATA_MASK; + /* even if the busy_wait timeouts try to clear the MASTER_EN */ qca8k_reg_clear(priv, QCA8K_MDIO_MASTER_CTRL, QCA8K_MDIO_MASTER_EN);