diff mbox series

[v3,net-next,07/13] net: enetc: remove ERR050089 workaround for i.MX95

Message ID 20241017074637.1265584-8-wei.fang@nxp.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series add basic support for i.MX95 NETC | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 109 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-10-17--18-00 (tests: 776)

Commit Message

Wei Fang Oct. 17, 2024, 7:46 a.m. UTC 
From: Vladimir Oltean <vladimir.oltean@nxp.com>

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>
---
v2 changes: no changes
v3 changes: Change the title and refactor the commit message.
---
 .../net/ethernet/freescale/enetc/enetc_hw.h   | 34 +++++++++++++------
 .../ethernet/freescale/enetc/enetc_pci_mdio.c | 17 ++++++++++
 2 files changed, 41 insertions(+), 10 deletions(-)

Comments

Frank Li Oct. 17, 2024, 4:40 p.m. UTC | #1 
On Thu, Oct 17, 2024 at 03:46:31PM +0800, Wei Fang wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
>
> 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>

Reviewed-by: Frank Li <Frank.Li@nxp.com>

> ---
> v2 changes: no changes
> v3 changes: Change the title and refactor the commit message.
> ---
>  .../net/ethernet/freescale/enetc/enetc_hw.h   | 34 +++++++++++++------
>  .../ethernet/freescale/enetc/enetc_pci_mdio.c | 17 ++++++++++
>  2 files changed, 41 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
> index 1619943fb263..6a7b9b75d660 100644
> --- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
> +++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
> @@ -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
> diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c b/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
> index a1b595bd7993..2445e35a764a 100644
> --- a/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
> +++ b/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
> @@ -9,6 +9,9 @@
>  #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 int enetc_pci_mdio_probe(struct pci_dev *pdev,
>  				const struct pci_device_id *ent)
>  {
> @@ -62,6 +65,12 @@ static int enetc_pci_mdio_probe(struct pci_dev *pdev,
>  		goto err_pci_mem_reg;
>  	}
>
> +	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");
> +	}
> +
>  	err = of_mdiobus_register(bus, dev->of_node);
>  	if (err)
>  		goto err_mdiobus_reg;
> @@ -88,6 +97,14 @@ static void enetc_pci_mdio_remove(struct pci_dev *pdev)
>  	struct enetc_mdio_priv *mdio_priv;
>
>  	mdiobus_unregister(bus);
> +
> +	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");
> +	}
> +
>  	mdio_priv = bus->priv;
>  	iounmap(mdio_priv->hw->port);
>  	pci_release_region(pdev, 0);
> --
> 2.34.1
>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index 1619943fb263..6a7b9b75d660 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -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
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c b/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
index a1b595bd7993..2445e35a764a 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
@@ -9,6 +9,9 @@ 
 #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 int enetc_pci_mdio_probe(struct pci_dev *pdev,
 				const struct pci_device_id *ent)
 {
@@ -62,6 +65,12 @@  static int enetc_pci_mdio_probe(struct pci_dev *pdev,
 		goto err_pci_mem_reg;
 	}
 
+	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");
+	}
+
 	err = of_mdiobus_register(bus, dev->of_node);
 	if (err)
 		goto err_mdiobus_reg;
@@ -88,6 +97,14 @@  static void enetc_pci_mdio_remove(struct pci_dev *pdev)
 	struct enetc_mdio_priv *mdio_priv;
 
 	mdiobus_unregister(bus);
+
+	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");
+	}
+
 	mdio_priv = bus->priv;
 	iounmap(mdio_priv->hw->port);
 	pci_release_region(pdev, 0);