From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 86831a3f4cd4c924dd78cf0d6e4d73acacfe1b11 ]
The ERR050089 workaround causes performance degradation and potential functional issues (e.g., RCU stalls) under certain workloads. Since new SoCs like i.MX95 do not require this workaround, use a static key to compile out enetc_lock_mdio() and enetc_unlock_mdio() at runtime, improving performance and avoiding unnecessary logic.
Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: Wei Fang wei.fang@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/ethernet/freescale/enetc/enetc_hw.h | 34 +++++++++++++------ .../ethernet/freescale/enetc/enetc_pci_mdio.c | 28 +++++++++++++++ 2 files changed, 52 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h index 18ca1f42b1f75..a5e38804e2811 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h +++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h @@ -372,18 +372,22 @@ struct enetc_hw { */ extern rwlock_t enetc_mdio_lock;
+DECLARE_STATIC_KEY_FALSE(enetc_has_err050089); + /* use this locking primitive only on the fast datapath to * group together multiple non-MDIO register accesses to * minimize the overhead of the lock */ static inline void enetc_lock_mdio(void) { - read_lock(&enetc_mdio_lock); + if (static_branch_unlikely(&enetc_has_err050089)) + read_lock(&enetc_mdio_lock); }
static inline void enetc_unlock_mdio(void) { - read_unlock(&enetc_mdio_lock); + if (static_branch_unlikely(&enetc_has_err050089)) + read_unlock(&enetc_mdio_lock); }
/* use these accessors only on the fast datapath under @@ -392,14 +396,16 @@ static inline void enetc_unlock_mdio(void) */ static inline u32 enetc_rd_reg_hot(void __iomem *reg) { - lockdep_assert_held(&enetc_mdio_lock); + if (static_branch_unlikely(&enetc_has_err050089)) + lockdep_assert_held(&enetc_mdio_lock);
return ioread32(reg); }
static inline void enetc_wr_reg_hot(void __iomem *reg, u32 val) { - lockdep_assert_held(&enetc_mdio_lock); + if (static_branch_unlikely(&enetc_has_err050089)) + lockdep_assert_held(&enetc_mdio_lock);
iowrite32(val, reg); } @@ -428,9 +434,13 @@ static inline u32 _enetc_rd_mdio_reg_wa(void __iomem *reg) unsigned long flags; u32 val;
- write_lock_irqsave(&enetc_mdio_lock, flags); - val = ioread32(reg); - write_unlock_irqrestore(&enetc_mdio_lock, flags); + if (static_branch_unlikely(&enetc_has_err050089)) { + write_lock_irqsave(&enetc_mdio_lock, flags); + val = ioread32(reg); + write_unlock_irqrestore(&enetc_mdio_lock, flags); + } else { + val = ioread32(reg); + }
return val; } @@ -439,9 +449,13 @@ static inline void _enetc_wr_mdio_reg_wa(void __iomem *reg, u32 val) { unsigned long flags;
- write_lock_irqsave(&enetc_mdio_lock, flags); - iowrite32(val, reg); - write_unlock_irqrestore(&enetc_mdio_lock, flags); + if (static_branch_unlikely(&enetc_has_err050089)) { + write_lock_irqsave(&enetc_mdio_lock, flags); + iowrite32(val, reg); + write_unlock_irqrestore(&enetc_mdio_lock, flags); + } else { + iowrite32(val, reg); + } }
#ifdef ioread64 diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c b/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c index dafb26f81f95f..d3248881a9b7e 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c @@ -9,6 +9,28 @@ #define ENETC_MDIO_BUS_NAME ENETC_MDIO_DEV_NAME " Bus" #define ENETC_MDIO_DRV_NAME ENETC_MDIO_DEV_NAME " driver"
+DEFINE_STATIC_KEY_FALSE(enetc_has_err050089); +EXPORT_SYMBOL_GPL(enetc_has_err050089); + +static void enetc_emdio_enable_err050089(struct pci_dev *pdev) +{ + if (pdev->vendor == PCI_VENDOR_ID_FREESCALE && + pdev->device == ENETC_MDIO_DEV_ID) { + static_branch_inc(&enetc_has_err050089); + dev_info(&pdev->dev, "Enabled ERR050089 workaround\n"); + } +} + +static void enetc_emdio_disable_err050089(struct pci_dev *pdev) +{ + if (pdev->vendor == PCI_VENDOR_ID_FREESCALE && + pdev->device == ENETC_MDIO_DEV_ID) { + static_branch_dec(&enetc_has_err050089); + if (!static_key_enabled(&enetc_has_err050089.key)) + dev_info(&pdev->dev, "Disabled ERR050089 workaround\n"); + } +} + static int enetc_pci_mdio_probe(struct pci_dev *pdev, const struct pci_device_id *ent) { @@ -60,6 +82,8 @@ static int enetc_pci_mdio_probe(struct pci_dev *pdev, goto err_pci_mem_reg; }
+ enetc_emdio_enable_err050089(pdev); + err = of_mdiobus_register(bus, dev->of_node); if (err) goto err_mdiobus_reg; @@ -69,6 +93,7 @@ static int enetc_pci_mdio_probe(struct pci_dev *pdev, return 0;
err_mdiobus_reg: + enetc_emdio_disable_err050089(pdev); pci_release_region(pdev, 0); err_pci_mem_reg: pci_disable_device(pdev); @@ -86,6 +111,9 @@ static void enetc_pci_mdio_remove(struct pci_dev *pdev) struct enetc_mdio_priv *mdio_priv;
mdiobus_unregister(bus); + + enetc_emdio_disable_err050089(pdev); + mdio_priv = bus->priv; iounmap(mdio_priv->hw->port); pci_release_region(pdev, 0);