diff mbox series

[1/5] PCI: endpoint: Add linkdown notifier support

Message ID 20210616115913.138778-2-manivannan.sadhasivam@linaro.org (mailing list archive)
State Changes Requested
Delegated to: Lorenzo Pieralisi
Headers show
Series PCI: endpoint: Add support for additional notifiers | expand

Commit Message

Manivannan Sadhasivam June 16, 2021, 11:59 a.m. UTC
Add support to notify the EPF device about the linkdown event from the
EPC device.

Usage:
======

EPC
---

```
static irqreturn_t pcie_ep_irq(int irq, void *data)
{
...
	case PCIE_EP_INT_LINK_DOWN:
		pci_epc_linkdown(epc);
		break;
...
}
```

EPF
---

```
static int pci_epf_notifier(struct notifier_block *nb, unsigned long val,
			    void *data)
{
...
	case LINK_DOWN:
		/* Handle link down event */
		break;
...
}
```

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 17 +++++++++++++++++
 include/linux/pci-epc.h             |  1 +
 include/linux/pci-epf.h             |  1 +
 3 files changed, 19 insertions(+)

Comments

Om Prakash Singh June 16, 2021, 6:22 p.m. UTC | #1
On 6/16/2021 5:29 PM, Manivannan Sadhasivam wrote:
> External email: Use caution opening links or attachments
> 
> 
> Add support to notify the EPF device about the linkdown event from the
> EPC device.
> 
> Usage:
> ======
> 
> EPC
> ---
> 
> ```
> static irqreturn_t pcie_ep_irq(int irq, void *data)
> {
> ...
>          case PCIE_EP_INT_LINK_DOWN:
>                  pci_epc_linkdown(epc);
>                  break;
Can you provide use case/scenario when epc will get LINK_DOWN interrupt?

> ...
> }
> ```
> 
> EPF
> ---
> 
> ```
> static int pci_epf_notifier(struct notifier_block *nb, unsigned long val,
>                              void *data)
> {
> ...
>          case LINK_DOWN:
>                  /* Handle link down event */
>                  break;
> ...
> }
> ```
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>   drivers/pci/endpoint/pci-epc-core.c | 17 +++++++++++++++++
>   include/linux/pci-epc.h             |  1 +
>   include/linux/pci-epf.h             |  1 +
>   3 files changed, 19 insertions(+)
> 
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index adec9bee72cf..f29d78c18438 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -641,6 +641,23 @@ void pci_epc_linkup(struct pci_epc *epc)
>   }
>   EXPORT_SYMBOL_GPL(pci_epc_linkup);
> 
> +/**
> + * pci_epc_linkdown() - Notify the EPF device that EPC device has dropped the
> + *                     connection with the Root Complex.
> + * @epc: the EPC device which has dropped the link with the host
> + *
> + * Invoke to Notify the EPF device that the EPC device has dropped the
> + * connection with the Root Complex.
> + */
> +void pci_epc_linkdown(struct pci_epc *epc)
> +{
> +       if (!epc || IS_ERR(epc))
> +               return;
> +
> +       atomic_notifier_call_chain(&epc->notifier, LINK_DOWN, NULL);
> +}
> +EXPORT_SYMBOL_GPL(pci_epc_linkdown);
> +
>   /**
>    * pci_epc_init_notify() - Notify the EPF device that EPC device's core
>    *                        initialization is completed.
> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> index b82c9b100e97..23590efc13e7 100644
> --- a/include/linux/pci-epc.h
> +++ b/include/linux/pci-epc.h
> @@ -202,6 +202,7 @@ void pci_epc_destroy(struct pci_epc *epc);
>   int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
>                      enum pci_epc_interface_type type);
>   void pci_epc_linkup(struct pci_epc *epc);
> +void pci_epc_linkdown(struct pci_epc *epc);
>   void pci_epc_init_notify(struct pci_epc *epc);
>   void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
>                          enum pci_epc_interface_type type);
> diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
> index 6833e2160ef1..e9ad634b1575 100644
> --- a/include/linux/pci-epf.h
> +++ b/include/linux/pci-epf.h
> @@ -20,6 +20,7 @@ enum pci_epc_interface_type;
>   enum pci_notify_event {
>          CORE_INIT,
>          LINK_UP,
> +       LINK_DOWN,
>   };
> 
>   enum pci_barno {
> --
> 2.25.1
>
Manivannan Sadhasivam June 16, 2021, 6:30 p.m. UTC | #2
On Wed, Jun 16, 2021 at 11:52:28PM +0530, Om Prakash Singh wrote:
> 
> 
> On 6/16/2021 5:29 PM, Manivannan Sadhasivam wrote:
> > External email: Use caution opening links or attachments
> > 
> > 
> > Add support to notify the EPF device about the linkdown event from the
> > EPC device.
> > 
> > Usage:
> > ======
> > 
> > EPC
> > ---
> > 
> > ```
> > static irqreturn_t pcie_ep_irq(int irq, void *data)
> > {
> > ...
> >          case PCIE_EP_INT_LINK_DOWN:
> >                  pci_epc_linkdown(epc);
> >                  break;
> Can you provide use case/scenario when epc will get LINK_DOWN interrupt?
> 

During host shutdown/reboot epc will get LINK_DOWN interrupt. And in our MHI
function we need to catch that for handling the SYSERR state as per the spec.

Thanks,
Mani

> > ...
> > }
> > ```
> > 
> > EPF
> > ---
> > 
> > ```
> > static int pci_epf_notifier(struct notifier_block *nb, unsigned long val,
> >                              void *data)
> > {
> > ...
> >          case LINK_DOWN:
> >                  /* Handle link down event */
> >                  break;
> > ...
> > }
> > ```
> > 
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >   drivers/pci/endpoint/pci-epc-core.c | 17 +++++++++++++++++
> >   include/linux/pci-epc.h             |  1 +
> >   include/linux/pci-epf.h             |  1 +
> >   3 files changed, 19 insertions(+)
> > 
> > diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> > index adec9bee72cf..f29d78c18438 100644
> > --- a/drivers/pci/endpoint/pci-epc-core.c
> > +++ b/drivers/pci/endpoint/pci-epc-core.c
> > @@ -641,6 +641,23 @@ void pci_epc_linkup(struct pci_epc *epc)
> >   }
> >   EXPORT_SYMBOL_GPL(pci_epc_linkup);
> > 
> > +/**
> > + * pci_epc_linkdown() - Notify the EPF device that EPC device has dropped the
> > + *                     connection with the Root Complex.
> > + * @epc: the EPC device which has dropped the link with the host
> > + *
> > + * Invoke to Notify the EPF device that the EPC device has dropped the
> > + * connection with the Root Complex.
> > + */
> > +void pci_epc_linkdown(struct pci_epc *epc)
> > +{
> > +       if (!epc || IS_ERR(epc))
> > +               return;
> > +
> > +       atomic_notifier_call_chain(&epc->notifier, LINK_DOWN, NULL);
> > +}
> > +EXPORT_SYMBOL_GPL(pci_epc_linkdown);
> > +
> >   /**
> >    * pci_epc_init_notify() - Notify the EPF device that EPC device's core
> >    *                        initialization is completed.
> > diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> > index b82c9b100e97..23590efc13e7 100644
> > --- a/include/linux/pci-epc.h
> > +++ b/include/linux/pci-epc.h
> > @@ -202,6 +202,7 @@ void pci_epc_destroy(struct pci_epc *epc);
> >   int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
> >                      enum pci_epc_interface_type type);
> >   void pci_epc_linkup(struct pci_epc *epc);
> > +void pci_epc_linkdown(struct pci_epc *epc);
> >   void pci_epc_init_notify(struct pci_epc *epc);
> >   void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
> >                          enum pci_epc_interface_type type);
> > diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
> > index 6833e2160ef1..e9ad634b1575 100644
> > --- a/include/linux/pci-epf.h
> > +++ b/include/linux/pci-epf.h
> > @@ -20,6 +20,7 @@ enum pci_epc_interface_type;
> >   enum pci_notify_event {
> >          CORE_INIT,
> >          LINK_UP,
> > +       LINK_DOWN,
> >   };
> > 
> >   enum pci_barno {
> > --
> > 2.25.1
> >
diff mbox series

Patch

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index adec9bee72cf..f29d78c18438 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -641,6 +641,23 @@  void pci_epc_linkup(struct pci_epc *epc)
 }
 EXPORT_SYMBOL_GPL(pci_epc_linkup);
 
+/**
+ * pci_epc_linkdown() - Notify the EPF device that EPC device has dropped the
+ *			connection with the Root Complex.
+ * @epc: the EPC device which has dropped the link with the host
+ *
+ * Invoke to Notify the EPF device that the EPC device has dropped the
+ * connection with the Root Complex.
+ */
+void pci_epc_linkdown(struct pci_epc *epc)
+{
+	if (!epc || IS_ERR(epc))
+		return;
+
+	atomic_notifier_call_chain(&epc->notifier, LINK_DOWN, NULL);
+}
+EXPORT_SYMBOL_GPL(pci_epc_linkdown);
+
 /**
  * pci_epc_init_notify() - Notify the EPF device that EPC device's core
  *			   initialization is completed.
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index b82c9b100e97..23590efc13e7 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -202,6 +202,7 @@  void pci_epc_destroy(struct pci_epc *epc);
 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
 		    enum pci_epc_interface_type type);
 void pci_epc_linkup(struct pci_epc *epc);
+void pci_epc_linkdown(struct pci_epc *epc);
 void pci_epc_init_notify(struct pci_epc *epc);
 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
 			enum pci_epc_interface_type type);
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 6833e2160ef1..e9ad634b1575 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -20,6 +20,7 @@  enum pci_epc_interface_type;
 enum pci_notify_event {
 	CORE_INIT,
 	LINK_UP,
+	LINK_DOWN,
 };
 
 enum pci_barno {