Patchwork [upstream] PCI: Add PCI_DEV_FLAGS_USE_NON_MSI_INTX_IRQ to enable non MSI/INTx interrupt

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Submitter Shengzhou Liu
Date July 12, 2012, 10:02 a.m.
Message ID <1342087342-14748-1-git-send-email-Shengzhou.Liu@freescale.com>
Download mbox | patch
Permalink /patch/170628/
State Superseded
Headers show

Comments

Shengzhou Liu - July 12, 2012, 10:02 a.m.
On some platforms, in RC mode, root port has neither MSI/MSI-X nor INTx
interrupt generated, which are available only in EP mode on those platform.
In this case, we try to use other interrupt for port service driver to have
AER, Hot-plug, etc, services to work. (i.e. there is the shared error interrupt
on platform P1010/P3041/P4080 etc)

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
---
 drivers/pci/pcie/portdrv_core.c |   10 ++++++++--
 drivers/pci/quirks.c            |   12 ++++++++++++
 include/linux/pci.h             |    5 +++++
 3 files changed, 25 insertions(+), 2 deletions(-)
Kumar Gala - July 12, 2012, 12:16 p.m.
On Jul 12, 2012, at 5:02 AM, Shengzhou Liu wrote:

> On some platforms, in RC mode, root port has neither MSI/MSI-X nor INTx
> interrupt generated, which are available only in EP mode on those platform.
> In this case, we try to use other interrupt for port service driver to have
> AER, Hot-plug, etc, services to work. (i.e. there is the shared error interrupt
> on platform P1010/P3041/P4080 etc)
> 
> Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
> ---
> drivers/pci/pcie/portdrv_core.c |   10 ++++++++--
> drivers/pci/quirks.c            |   12 ++++++++++++
> include/linux/pci.h             |    5 +++++
> 3 files changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index 75915b3..837ad15 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -212,8 +212,14 @@ static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
> 	if (!pcie_port_enable_msix(dev, irqs, mask))
> 		return 0;
> 
> -	/* We're not going to use MSI-X, so try MSI and fall back to INTx */
> -	if (!pci_enable_msi(dev) || dev->pin)
> +	/*
> +	 * We're not going to use MSI-X, so try MSI and fall back to INTx.
> +	 * Eventually, if neither MSI/MSI-X nor INTx available, try other
> +	 * interrupt. (On some platforms, root port doesn't support generating
> +	 * MSI/MSI-X/INTx in RC mode)
> +	 */
> +	if (!pci_enable_msi(dev) || dev->pin || ((dev->dev_flags &
> +			PCI_DEV_FLAGS_USE_NON_MSI_INTX_IRQ) && dev->irq))
> 		irq = dev->irq;
> 
>  no_msi:
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 2a75216..df54e2f 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2640,6 +2640,18 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x1083,
> 			quirk_msi_intx_disable_bug);
> #endif /* CONFIG_PCI_MSI */
> 
> +/*
> + * Under some circumstances, root port has neither MSI/MSI-X nor INTx generated,
> + * so try other interrupt if supported.
> + */
> +static void __devinit quirk_enable_non_msi_intx_interrupt(struct pci_dev *dev)
> +{
> +	dev->dev_flags |= PCI_DEV_FLAGS_USE_NON_MSI_INTX_IRQ;
> +}
> +
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_FREESCALE, PCI_ANY_ID,
> +				quirk_enable_non_msi_intx_interrupt);
> +

This should be in arch/powerpc not here.  One reason is FSL has other PCIe implementations than exists on PPC that have this issue.  (ie the i.MXs support PCIe).

I'd put the addition of the quirk in a second patch as well.


> /* Allow manual resource allocation for PCI hotplug bridges
>  * via pci=hpmemsize=nnM and pci=hpiosize=nnM parameters. For
>  * some PCI-PCI hotplug bridges, like PLX 6254 (former HINT HB6),
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index d8c379d..f051a66 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -176,6 +176,11 @@ enum pci_dev_flags {
> 	PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2,
> 	/* Provide indication device is assigned by a Virtual Machine Manager */
> 	PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4,
> +	/*
> +	 * Use other interrupt (i.e. system shared interrupt) when MSI/MSI-X
> +	 * and INTx are not supported in RC mode on some platforms.
> +	 */
> +	PCI_DEV_FLAGS_USE_NON_MSI_INTX_IRQ = (__force pci_dev_flags_t) 8,
> };
> 
> enum pci_irq_reroute_variant {
> -- 
> 1.6.4
> 
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev

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Scott Wood - July 12, 2012, 4:07 p.m.
On 07/12/2012 05:02 AM, Shengzhou Liu wrote:
> On some platforms, in RC mode, root port has neither MSI/MSI-X nor INTx
> interrupt generated, which are available only in EP mode on those platform.
> In this case, we try to use other interrupt for port service driver to have
> AER, Hot-plug, etc, services to work. (i.e. there is the shared error interrupt
> on platform P1010/P3041/P4080 etc)
> 
> Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
> ---
>  drivers/pci/pcie/portdrv_core.c |   10 ++++++++--
>  drivers/pci/quirks.c            |   12 ++++++++++++
>  include/linux/pci.h             |    5 +++++
>  3 files changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index 75915b3..837ad15 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -212,8 +212,14 @@ static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
>  	if (!pcie_port_enable_msix(dev, irqs, mask))
>  		return 0;
>  
> -	/* We're not going to use MSI-X, so try MSI and fall back to INTx */
> -	if (!pci_enable_msi(dev) || dev->pin)
> +	/*
> +	 * We're not going to use MSI-X, so try MSI and fall back to INTx.
> +	 * Eventually, if neither MSI/MSI-X nor INTx available, try other
> +	 * interrupt. (On some platforms, root port doesn't support generating
> +	 * MSI/MSI-X/INTx in RC mode)
> +	 */
> +	if (!pci_enable_msi(dev) || dev->pin || ((dev->dev_flags &
> +			PCI_DEV_FLAGS_USE_NON_MSI_INTX_IRQ) && dev->irq))
>  		irq = dev->irq;

I'd still like to hear someone say what specifically would go wrong if
we just did s/dev->pin/dev->irq/ (and even that much seems to be only
because the code is using a non-standard indicator of an invalid IRQ).
When would dev->irq contain a non-zero value that is not usable?

-Scott

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Patch

diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 75915b3..837ad15 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -212,8 +212,14 @@  static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
 	if (!pcie_port_enable_msix(dev, irqs, mask))
 		return 0;
 
-	/* We're not going to use MSI-X, so try MSI and fall back to INTx */
-	if (!pci_enable_msi(dev) || dev->pin)
+	/*
+	 * We're not going to use MSI-X, so try MSI and fall back to INTx.
+	 * Eventually, if neither MSI/MSI-X nor INTx available, try other
+	 * interrupt. (On some platforms, root port doesn't support generating
+	 * MSI/MSI-X/INTx in RC mode)
+	 */
+	if (!pci_enable_msi(dev) || dev->pin || ((dev->dev_flags &
+			PCI_DEV_FLAGS_USE_NON_MSI_INTX_IRQ) && dev->irq))
 		irq = dev->irq;
 
  no_msi:
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 2a75216..df54e2f 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2640,6 +2640,18 @@  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x1083,
 			quirk_msi_intx_disable_bug);
 #endif /* CONFIG_PCI_MSI */
 
+/*
+ * Under some circumstances, root port has neither MSI/MSI-X nor INTx generated,
+ * so try other interrupt if supported.
+ */
+static void __devinit quirk_enable_non_msi_intx_interrupt(struct pci_dev *dev)
+{
+	dev->dev_flags |= PCI_DEV_FLAGS_USE_NON_MSI_INTX_IRQ;
+}
+
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_FREESCALE, PCI_ANY_ID,
+				quirk_enable_non_msi_intx_interrupt);
+
 /* Allow manual resource allocation for PCI hotplug bridges
  * via pci=hpmemsize=nnM and pci=hpiosize=nnM parameters. For
  * some PCI-PCI hotplug bridges, like PLX 6254 (former HINT HB6),
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d8c379d..f051a66 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -176,6 +176,11 @@  enum pci_dev_flags {
 	PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2,
 	/* Provide indication device is assigned by a Virtual Machine Manager */
 	PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4,
+	/*
+	 * Use other interrupt (i.e. system shared interrupt) when MSI/MSI-X
+	 * and INTx are not supported in RC mode on some platforms.
+	 */
+	PCI_DEV_FLAGS_USE_NON_MSI_INTX_IRQ = (__force pci_dev_flags_t) 8,
 };
 
 enum pci_irq_reroute_variant {