From 2481d206fae7884cd07014fd1318e63af35e99eb Mon Sep 17 00:00:00 2001 From: Ansuel Smith Date: Wed, 2 Feb 2022 01:03:33 +0100 Subject: [PATCH 14/16] net: dsa: qca8k: cache lo and hi for mdio write From Documentation, we can cache lo and hi the same way we do with the page. This massively reduce the mdio write as 3/4 of the time as we only require to write the lo or hi part for a mdio write. Signed-off-by: Ansuel Smith Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/dsa/qca8k.c | 61 +++++++++++++++++++++++++++++++++-------- drivers/net/dsa/qca8k.h | 5 ++++ 2 files changed, 54 insertions(+), 12 deletions(-) --- a/drivers/net/dsa/qca8k.c +++ b/drivers/net/dsa/qca8k.c @@ -89,6 +89,44 @@ qca8k_split_addr(u32 regaddr, u16 *r1, u } static int +qca8k_set_lo(struct qca8k_priv *priv, int phy_id, u32 regnum, u16 lo) +{ + u16 *cached_lo = &priv->mdio_cache.lo; + struct mii_bus *bus = priv->bus; + int ret; + + if (lo == *cached_lo) + return 0; + + ret = bus->write(bus, phy_id, regnum, lo); + if (ret < 0) + dev_err_ratelimited(&bus->dev, + "failed to write qca8k 32bit lo register\n"); + + *cached_lo = lo; + return 0; +} + +static int +qca8k_set_hi(struct qca8k_priv *priv, int phy_id, u32 regnum, u16 hi) +{ + u16 *cached_hi = &priv->mdio_cache.hi; + struct mii_bus *bus = priv->bus; + int ret; + + if (hi == *cached_hi) + return 0; + + ret = bus->write(bus, phy_id, regnum, hi); + if (ret < 0) + dev_err_ratelimited(&bus->dev, + "failed to write qca8k 32bit hi register\n"); + + *cached_hi = hi; + return 0; +} + +static int qca8k_mii_read32(struct mii_bus *bus, int phy_id, u32 regnum, u32 *val) { int ret; @@ -111,7 +149,7 @@ qca8k_mii_read32(struct mii_bus *bus, in } static void -qca8k_mii_write32(struct mii_bus *bus, int phy_id, u32 regnum, u32 val) +qca8k_mii_write32(struct qca8k_priv *priv, int phy_id, u32 regnum, u32 val) { u16 lo, hi; int ret; @@ -119,12 +157,9 @@ qca8k_mii_write32(struct mii_bus *bus, i lo = val & 0xffff; hi = (u16)(val >> 16); - ret = bus->write(bus, phy_id, regnum, lo); + ret = qca8k_set_lo(priv, phy_id, regnum, lo); if (ret >= 0) - ret = bus->write(bus, phy_id, regnum + 1, hi); - if (ret < 0) - dev_err_ratelimited(&bus->dev, - "failed to write qca8k 32bit register\n"); + ret = qca8k_set_hi(priv, phy_id, regnum + 1, hi); } static int @@ -400,7 +435,7 @@ qca8k_regmap_write(void *ctx, uint32_t r if (ret < 0) goto exit; - qca8k_mii_write32(bus, 0x10 | r2, r1, val); + qca8k_mii_write32(priv, 0x10 | r2, r1, val); exit: mutex_unlock(&bus->mdio_lock); @@ -433,7 +468,7 @@ qca8k_regmap_update_bits(void *ctx, uint val &= ~mask; val |= write_val; - qca8k_mii_write32(bus, 0x10 | r2, r1, val); + qca8k_mii_write32(priv, 0x10 | r2, r1, val); exit: mutex_unlock(&bus->mdio_lock); @@ -1117,14 +1152,14 @@ qca8k_mdio_write(struct qca8k_priv *priv if (ret) goto exit; - qca8k_mii_write32(bus, 0x10 | r2, r1, val); + qca8k_mii_write32(priv, 0x10 | r2, r1, val); ret = qca8k_mdio_busy_wait(bus, QCA8K_MDIO_MASTER_CTRL, QCA8K_MDIO_MASTER_BUSY); exit: /* even if the busy_wait timeouts try to clear the MASTER_EN */ - qca8k_mii_write32(bus, 0x10 | r2, r1, 0); + qca8k_mii_write32(priv, 0x10 | r2, r1, 0); mutex_unlock(&bus->mdio_lock); @@ -1154,7 +1189,7 @@ qca8k_mdio_read(struct qca8k_priv *priv, if (ret) goto exit; - qca8k_mii_write32(bus, 0x10 | r2, r1, val); + qca8k_mii_write32(priv, 0x10 | r2, r1, val); ret = qca8k_mdio_busy_wait(bus, QCA8K_MDIO_MASTER_CTRL, QCA8K_MDIO_MASTER_BUSY); @@ -1165,7 +1200,7 @@ qca8k_mdio_read(struct qca8k_priv *priv, exit: /* even if the busy_wait timeouts try to clear the MASTER_EN */ - qca8k_mii_write32(bus, 0x10 | r2, r1, 0); + qca8k_mii_write32(priv, 0x10 | r2, r1, 0); mutex_unlock(&bus->mdio_lock); @@ -3038,6 +3073,8 @@ qca8k_sw_probe(struct mdio_device *mdiod } priv->mdio_cache.page = 0xffff; + priv->mdio_cache.lo = 0xffff; + priv->mdio_cache.hi = 0xffff; /* Check the detected switch id */ ret = qca8k_read_switch_id(priv); --- a/drivers/net/dsa/qca8k.h +++ b/drivers/net/dsa/qca8k.h @@ -369,6 +369,11 @@ struct qca8k_mdio_cache { * mdio writes */ u16 page; +/* lo and hi can also be cached and from Documentation we can skip one + * extra mdio write if lo or hi is didn't change. + */ + u16 lo; + u16 hi; }; struct qca8k_priv {