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net: enetc: remove ERR050089 workaround for i.MX95

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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>
This commit is contained in:
Vladimir Oltean 2024-10-30 17:39:18 +08:00 committed by David S. Miller
parent 3774409fd4
commit 86831a3f4c
2 changed files with 52 additions and 10 deletions
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34
drivers/net/ethernet/freescale/enetc/enetc_hw.h
View File

@ -396,18 +396,22 @@ 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
@ -416,14 +420,16 @@ 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);
}
@ -452,9 +458,13 @@ 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;
}
@ -463,9 +473,13 @@ 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

28
drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
View File

@ -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)
{
@ -62,6 +84,8 @@ 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;
@ -71,6 +95,7 @@ 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);
@ -88,6 +113,9 @@ 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);