[PATCH] PCI/portdrv: Use cached copy of PCI_EXP_SLTCAP_HPC bit

[PATCH] PCI/portdrv: Use cached copy of PCI_EXP_SLTCAP_HPC bit

[Lukas Wunner]

We cache the PCI_EXP_SLTCAP_HPC bit in pci_dev->is_hotplug_bridge on
device probe, so there's no need to read it again on allocation of
port service devices.

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
---
 drivers/pci/pcie/portdrv_core.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 050069f..af7796d 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -254,7 +254,6 @@ static void cleanup_service_irqs(struct pci_dev *dev)
 static int get_port_device_capability(struct pci_dev *dev)
 {
 	int services = 0;
-	u32 reg32;
 	int cap_mask = 0;
 
 	if (pcie_ports_disabled)
@@ -269,19 +268,15 @@ static int get_port_device_capability(struct pci_dev *dev)
 		pcie_port_platform_notify(dev, &cap_mask);
 
 	/* Hot-Plug Capable */
-	if ((cap_mask & PCIE_PORT_SERVICE_HP) &&
-	    pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT) {
-		pcie_capability_read_dword(dev, PCI_EXP_SLTCAP, &reg32);
-		if (reg32 & PCI_EXP_SLTCAP_HPC) {
-			services |= PCIE_PORT_SERVICE_HP;
-			/*
-			 * Disable hot-plug interrupts in case they have been
-			 * enabled by the BIOS and the hot-plug service driver
-			 * is not loaded.
-			 */
-			pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
-				PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
-		}
+	if ((cap_mask & PCIE_PORT_SERVICE_HP)
+	    && dev->is_hotplug_bridge) {
+		services |= PCIE_PORT_SERVICE_HP;
+		/*
+		 * Disable hot-plug interrupts in case they have been enabled
+		 * by the BIOS and the hot-plug service driver is not loaded.
+		 */
+		pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
+			  PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
 	}
 	/* AER capable */
 	if ((cap_mask & PCIE_PORT_SERVICE_AER)
-- 
2.8.1

Re: [PATCH] PCI/portdrv: Use cached copy of PCI_EXP_SLTCAP_HPC bit

[Bjorn Helgaas]

On Wed, May 04, 2016 at 03:05:57PM +0200, Lukas Wunner wrote:
> We cache the PCI_EXP_SLTCAP_HPC bit in pci_dev->is_hotplug_bridge on
> device probe, so there's no need to read it again on allocation of
> port service devices.
> 
> No functional change intended.
> 
> Signed-off-by: Lukas Wunner <lukas@wunner.de>

Applied to pci/hotplug for v4.7, thanks, Lukas!

> ---
>  drivers/pci/pcie/portdrv_core.c | 23 +++++++++--------------
>  1 file changed, 9 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index 050069f..af7796d 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -254,7 +254,6 @@ static void cleanup_service_irqs(struct pci_dev *dev)
>  static int get_port_device_capability(struct pci_dev *dev)
>  {
>  	int services = 0;
> -	u32 reg32;
>  	int cap_mask = 0;
>  
>  	if (pcie_ports_disabled)
> @@ -269,19 +268,15 @@ static int get_port_device_capability(struct pci_dev *dev)
>  		pcie_port_platform_notify(dev, &cap_mask);
>  
>  	/* Hot-Plug Capable */
> -	if ((cap_mask & PCIE_PORT_SERVICE_HP) &&
> -	    pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT) {
> -		pcie_capability_read_dword(dev, PCI_EXP_SLTCAP, &reg32);
> -		if (reg32 & PCI_EXP_SLTCAP_HPC) {
> -			services |= PCIE_PORT_SERVICE_HP;
> -			/*
> -			 * Disable hot-plug interrupts in case they have been
> -			 * enabled by the BIOS and the hot-plug service driver
> -			 * is not loaded.
> -			 */
> -			pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
> -				PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
> -		}
> +	if ((cap_mask & PCIE_PORT_SERVICE_HP)
> +	    && dev->is_hotplug_bridge) {
> +		services |= PCIE_PORT_SERVICE_HP;
> +		/*
> +		 * Disable hot-plug interrupts in case they have been enabled
> +		 * by the BIOS and the hot-plug service driver is not loaded.
> +		 */
> +		pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
> +			  PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
>  	}
>  	/* AER capable */
>  	if ((cap_mask & PCIE_PORT_SERVICE_AER)
> -- 
> 2.8.1
> 
> --
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