[PATCH 0/5] PCI: endpoint: Add support for additional notifiers

[PATCH 0/5] PCI: endpoint: Add support for additional notifiers

[Manivannan Sadhasivam]

Hello,

This series adds support for additional notifiers in the PCI endpoint
framework. The notifiers LINK_DOWN, BME, PME, and D_STATE are generic
for all PCI endpoints but there is also a custom notifier (CUSTOM) added
to pass the device/vendor specific events to EPF from EPC.

The example usage of all notifiers is provided in the commit description.

Thanks,
Mani

Manivannan Sadhasivam (5):
  PCI: endpoint: Add linkdown notifier support
  PCI: endpoint: Add BME notifier support
  PCI: endpoint: Add PME notifier support
  PCI: endpoint: Add D_STATE notifier support
  PCI: endpoint: Add custom notifier support

 drivers/pci/endpoint/pci-epc-core.c | 89 +++++++++++++++++++++++++++++
 include/linux/pci-epc.h             |  5 ++
 include/linux/pci-epf.h             |  5 ++
 3 files changed, 99 insertions(+)

-- 
2.25.1

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

[Manivannan Sadhasivam]

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(+)

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

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

[Om Prakash Singh]

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
> 

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

[Manivannan Sadhasivam]

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
> > 

[PATCH 2/5] PCI: endpoint: Add BME notifier support

[Manivannan Sadhasivam]

Add support to notify the EPF device about the Bus Master Enable (BME)
event received by the EPC device from the Root complex.

Usage:
======

EPC
---

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

EPF
---

```
static int pci_epf_notifier(struct notifier_block *nb, unsigned long val,
			    void *data)
{
...
	case BME:
		/* Handle BME 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 f29d78c18438..7e42a83a4877 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -675,6 +675,23 @@ void pci_epc_init_notify(struct pci_epc *epc)
 }
 EXPORT_SYMBOL_GPL(pci_epc_init_notify);
 
+/**
+ * pci_epc_bme_notify() - Notify the EPF device that the EPC device has received
+ *			  the BME event from the Root complex
+ * @epc: the EPC device that received the BME event
+ *
+ * Invoke to Notify the EPF device that the EPC device has received the Bus
+ * Master Enable (BME) event from the Root complex
+ */
+void pci_epc_bme_notify(struct pci_epc *epc)
+{
+	if (!epc || IS_ERR(epc))
+		return;
+
+	atomic_notifier_call_chain(&epc->notifier, BME, NULL);
+}
+EXPORT_SYMBOL_GPL(pci_epc_bme_notify);
+
 /**
  * pci_epc_destroy() - destroy the EPC device
  * @epc: the EPC device that has to be destroyed
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 23590efc13e7..6c2cff33f670 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -204,6 +204,7 @@ int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
 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_bme_notify(struct pci_epc *epc);
 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
 			enum pci_epc_interface_type type);
 int pci_epc_write_header(struct pci_epc *epc, u8 func_no,
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index e9ad634b1575..063a59a58e3c 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -21,6 +21,7 @@ enum pci_notify_event {
 	CORE_INIT,
 	LINK_UP,
 	LINK_DOWN,
+	BME,
 };
 
 enum pci_barno {
-- 
2.25.1

[PATCH 3/5] PCI: endpoint: Add PME notifier support

[Manivannan Sadhasivam]

Add support to notify the EPF device about the Power Management Event
(PME) received by the EPC device from the Root complex.

Usage:
======

EPC
---

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

EPF
---

```
static int pci_epf_notifier(struct notifier_block *nb, unsigned long val,
			    void *data)
{
...
	case PME:
		pm_state = data;
		if (pm_state == PCIE_EP_PM_TURNOFF)
			/* Handle PM Turnoff event */
		break;
...
}
```

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 18 ++++++++++++++++++
 include/linux/pci-epc.h             |  1 +
 include/linux/pci-epf.h             |  1 +
 3 files changed, 20 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 7e42a83a4877..63fe90dbbba2 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -692,6 +692,24 @@ void pci_epc_bme_notify(struct pci_epc *epc)
 }
 EXPORT_SYMBOL_GPL(pci_epc_bme_notify);
 
+/**
+ * pci_epc_pme_notify() - Notify the EPF device that the EPC device has received
+ *			  the PME from the Root complex
+ * @epc: the EPC device that received the PME
+ * @data: Data for the PME notifier
+ *
+ * Invoke to Notify the EPF device that the EPC device has received the Power
+ * Management Event (PME) from the Root complex
+ */
+void pci_epc_pme_notify(struct pci_epc *epc, void *data)
+{
+	if (!epc || IS_ERR(epc))
+		return;
+
+	atomic_notifier_call_chain(&epc->notifier, PME, data);
+}
+EXPORT_SYMBOL_GPL(pci_epc_pme_notify);
+
 /**
  * pci_epc_destroy() - destroy the EPC device
  * @epc: the EPC device that has to be destroyed
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 6c2cff33f670..37dbcade1780 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -205,6 +205,7 @@ 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_bme_notify(struct pci_epc *epc);
+void pci_epc_pme_notify(struct pci_epc *epc, void *data);
 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
 			enum pci_epc_interface_type type);
 int pci_epc_write_header(struct pci_epc *epc, u8 func_no,
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 063a59a58e3c..c162a73eb836 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -22,6 +22,7 @@ enum pci_notify_event {
 	LINK_UP,
 	LINK_DOWN,
 	BME,
+	PME,
 };
 
 enum pci_barno {
-- 
2.25.1

[PATCH 4/5] PCI: endpoint: Add D_STATE notifier support

[Manivannan Sadhasivam]

Add support to notify the EPF device about the Device State (D_STATE)
event received by the EPC device from the Root complex.

Usage:
======

EPC
---

```
static irqreturn_t pcie_ep_irq(int irq, void *data)
{
...
	case PCIE_EP_INT_D_STATE:
		dstate = dw_pcie_readl_dbi(pci, DBI_CON_STATUS) & 0x3;
		pci_epc_d_state_notify(epc, dstate);
		break;
...
}
```

EPF
---

```
static int pci_epf_notifier(struct notifier_block *nb, unsigned long val,
			    void *data)
{
...
	case D_STATE:
		dstate = data;
		if (dstate == PCIE_EP_D0)
			/* Handle D0 event */
		else if (dstate == PCIE_EP_D3)
			/* Handle D3 event */
		break;
...
}
```

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 18 ++++++++++++++++++
 include/linux/pci-epc.h             |  1 +
 include/linux/pci-epf.h             |  1 +
 3 files changed, 20 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 63fe90dbbba2..b4a7bb3caa97 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -710,6 +710,24 @@ void pci_epc_pme_notify(struct pci_epc *epc, void *data)
 }
 EXPORT_SYMBOL_GPL(pci_epc_pme_notify);
 
+/**
+ * pci_epc_d_state_notify() - Notify the EPF device that the EPC device has
+ *			      received the Device State event from Root complex
+ * @epc: the EPC device that received the Device State event
+ * @data: Data for the D_STATE notifier
+ *
+ * Invoke to notify the EPF device that the EPC device has received the Device
+ * State (D_STATE) event from the Root complex
+ */
+void pci_epc_d_state_notify(struct pci_epc *epc, void *data)
+{
+	if (!epc || IS_ERR(epc))
+		return;
+
+	atomic_notifier_call_chain(&epc->notifier, D_STATE, data);
+}
+EXPORT_SYMBOL_GPL(pci_epc_d_state_notify);
+
 /**
  * pci_epc_destroy() - destroy the EPC device
  * @epc: the EPC device that has to be destroyed
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 37dbcade1780..94c66fae8a88 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -206,6 +206,7 @@ void pci_epc_linkdown(struct pci_epc *epc);
 void pci_epc_init_notify(struct pci_epc *epc);
 void pci_epc_bme_notify(struct pci_epc *epc);
 void pci_epc_pme_notify(struct pci_epc *epc, void *data);
+void pci_epc_d_state_notify(struct pci_epc *epc, void *data);
 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
 			enum pci_epc_interface_type type);
 int pci_epc_write_header(struct pci_epc *epc, u8 func_no,
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index c162a73eb836..ca020c080431 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -23,6 +23,7 @@ enum pci_notify_event {
 	LINK_DOWN,
 	BME,
 	PME,
+	D_STATE,
 };
 
 enum pci_barno {
-- 
2.25.1

[PATCH 5/5] PCI: endpoint: Add custom notifier support

[Manivannan Sadhasivam]

Add support for notifying the EPF device about the custom notifications
received by the EPC device from the Root complex. These notifications
are EPC/vendor specific and are shared with the specific EPF devices.

For instance, the Qcom EPC device generates events such as MHI_A7,
MHI_Q6, DEBUG, MMIO_WRITE, CFG_WRITE etc... These events can be passed
to the EPF device using this notifier.

EPC
---

```
static irqreturn_t pcie_ep_irq(int irq, void *data)
{
...
	case PCIE_EP_INT_MHI_A7:
		pci_epc_custom_notify(epc, PCIE_EP_INT_MHI_A7);
		break;
	case PCIE_EP_INT_MHI_Q6:
		pci_epc_custom_notify(epc, PCIE_EP_INT_MHI_Q6);
		break;
	case PCIE_EP_INT_MMIO_WRITE:
		pci_epc_custom_notify(epc, PCIE_EP_INT_MMIO_WRITE);
		break;
...
}
```

EPF
---

```
static int pci_epf_notifier(struct notifier_block *nb, unsigned long val,
			    void *data)
{
...
	case CUSTOM:
		cus_event = data;
		if (cus_event == PCIE_EP_INT_MHI_A7)
			/* Handle MHI A7 event */
		else if (cus_event == PCIE_EP_INT_MHI_Q6)
			/* Handle MHI Q6 event */
		else if (cus_event == PCIE_EP_INT_MMIO_WRITE)
			/* Handle MMIO WRITE event */
		break;
...
}
```

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 19 +++++++++++++++++++
 include/linux/pci-epc.h             |  1 +
 include/linux/pci-epf.h             |  1 +
 3 files changed, 21 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index b4a7bb3caa97..b963a4aa0af4 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -728,6 +728,25 @@ void pci_epc_d_state_notify(struct pci_epc *epc, void *data)
 }
 EXPORT_SYMBOL_GPL(pci_epc_d_state_notify);
 
+/**
+ * pci_epc_custom_notify() - Notify the EPF device that the EPC device has
+ *			     received the custom events from the Root complex
+ * @epc: EPC device that received the custom event
+ * @data: Data for the CUSTOM notifier
+ *
+ * Invoke to notify the EPF device that the EPC device has received the Custom
+ * event from the Root complex. The custom event is EPC/vendor specific and is
+ * shared with the EPF device.
+ */
+void pci_epc_custom_notify(struct pci_epc *epc, void *data)
+{
+	if (!epc || IS_ERR(epc))
+		return;
+
+	atomic_notifier_call_chain(&epc->notifier, CUSTOM, data);
+}
+EXPORT_SYMBOL_GPL(pci_epc_custom_notify);
+
 /**
  * pci_epc_destroy() - destroy the EPC device
  * @epc: the EPC device that has to be destroyed
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 94c66fae8a88..943d31a83f6e 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -207,6 +207,7 @@ void pci_epc_init_notify(struct pci_epc *epc);
 void pci_epc_bme_notify(struct pci_epc *epc);
 void pci_epc_pme_notify(struct pci_epc *epc, void *data);
 void pci_epc_d_state_notify(struct pci_epc *epc, void *data);
+void pci_epc_custom_notify(struct pci_epc *epc, void *data);
 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
 			enum pci_epc_interface_type type);
 int pci_epc_write_header(struct pci_epc *epc, u8 func_no,
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index ca020c080431..2fa3b90399b9 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -24,6 +24,7 @@ enum pci_notify_event {
 	BME,
 	PME,
 	D_STATE,
+	CUSTOM,
 };
 
 enum pci_barno {
-- 
2.25.1

Re: [PATCH 0/5] PCI: endpoint: Add support for additional notifiers

[Om Prakash Singh]

Hi Mani,
Adding more notifier types will surely help but I believe the list is 
not exhaustive. What you are trying here is to pass various 
vendor-specific epc interrupts to EPF driver. That can be taken care by 
a single notifier interface as well, "pci_epc_custom_notify" from your 
implementation. This also requires to have pre-defined values of "data" 
argument to standardize the interface.

your thoughts?

Thanks,
Om

On 6/16/2021 5:29 PM, Manivannan Sadhasivam wrote:
> External email: Use caution opening links or attachments
> 
> 
> Hello,
> 
> This series adds support for additional notifiers in the PCI endpoint
> framework. The notifiers LINK_DOWN, BME, PME, and D_STATE are generic
> for all PCI endpoints but there is also a custom notifier (CUSTOM) added
> to pass the device/vendor specific events to EPF from EPC.
> 
> The example usage of all notifiers is provided in the commit description.
> 
> Thanks,
> Mani
> 
> Manivannan Sadhasivam (5):
>    PCI: endpoint: Add linkdown notifier support
>    PCI: endpoint: Add BME notifier support
>    PCI: endpoint: Add PME notifier support
>    PCI: endpoint: Add D_STATE notifier support
>    PCI: endpoint: Add custom notifier support
> 
>   drivers/pci/endpoint/pci-epc-core.c | 89 +++++++++++++++++++++++++++++
>   include/linux/pci-epc.h             |  5 ++
>   include/linux/pci-epf.h             |  5 ++
>   3 files changed, 99 insertions(+)
> 
> --
> 2.25.1
> 

Re: [PATCH 0/5] PCI: endpoint: Add support for additional notifiers

[Manivannan Sadhasivam]

Hi,

On Thu, Jun 17, 2021 at 12:42:07AM +0530, Om Prakash Singh wrote:
> Hi Mani,
> Adding more notifier types will surely help but I believe the list is not
> exhaustive. What you are trying here is to pass various vendor-specific epc
> interrupts to EPF driver. That can be taken care by a single notifier
> interface as well, "pci_epc_custom_notify" from your implementation.

That's what I initially thought eventhough not all the notifiers are
vendor specific. But Kishon suggested to add notifiers for generic ones
such as BME, PME etc... and that sounded reasonable to me.

> This
> also requires to have pre-defined values of "data" argument to standardize
> the interface.
> 

No, I don't think we can standardize the arguments to "custom" notifier.
The custom notifier is supposed to deal with vendor specific events and
I don't see any benefit on standardizing it. I see it more like an
opaque driver_data field where we pass driver specific arguments.

Thanks,
Mani

> your thoughts?
> 
> Thanks,
> Om
> 
> On 6/16/2021 5:29 PM, Manivannan Sadhasivam wrote:
> > External email: Use caution opening links or attachments
> > 
> > 
> > Hello,
> > 
> > This series adds support for additional notifiers in the PCI endpoint
> > framework. The notifiers LINK_DOWN, BME, PME, and D_STATE are generic
> > for all PCI endpoints but there is also a custom notifier (CUSTOM) added
> > to pass the device/vendor specific events to EPF from EPC.
> > 
> > The example usage of all notifiers is provided in the commit description.
> > 
> > Thanks,
> > Mani
> > 
> > Manivannan Sadhasivam (5):
> >    PCI: endpoint: Add linkdown notifier support
> >    PCI: endpoint: Add BME notifier support
> >    PCI: endpoint: Add PME notifier support
> >    PCI: endpoint: Add D_STATE notifier support
> >    PCI: endpoint: Add custom notifier support
> > 
> >   drivers/pci/endpoint/pci-epc-core.c | 89 +++++++++++++++++++++++++++++
> >   include/linux/pci-epc.h             |  5 ++
> >   include/linux/pci-epf.h             |  5 ++
> >   3 files changed, 99 insertions(+)
> > 
> > --
> > 2.25.1
> > 

Re: [PATCH 0/5] PCI: endpoint: Add support for additional notifiers

[Manivannan Sadhasivam]

On Wed, Jun 16, 2021 at 05:29:08PM +0530, Manivannan Sadhasivam wrote:
> Hello,
> 
> This series adds support for additional notifiers in the PCI endpoint
> framework. The notifiers LINK_DOWN, BME, PME, and D_STATE are generic
> for all PCI endpoints but there is also a custom notifier (CUSTOM) added
> to pass the device/vendor specific events to EPF from EPC.
> 
> The example usage of all notifiers is provided in the commit description.
> 

Ping on this series!

Thanks,
Mani

> Thanks,
> Mani
> 
> Manivannan Sadhasivam (5):
>   PCI: endpoint: Add linkdown notifier support
>   PCI: endpoint: Add BME notifier support
>   PCI: endpoint: Add PME notifier support
>   PCI: endpoint: Add D_STATE notifier support
>   PCI: endpoint: Add custom notifier support
> 
>  drivers/pci/endpoint/pci-epc-core.c | 89 +++++++++++++++++++++++++++++
>  include/linux/pci-epc.h             |  5 ++
>  include/linux/pci-epf.h             |  5 ++
>  3 files changed, 99 insertions(+)
> 
> -- 
> 2.25.1
> 

Re: [PATCH 0/5] PCI: endpoint: Add support for additional notifiers

[Kishon Vijay Abraham I]

Hi Manivannan,

On 16/06/21 5:29 pm, Manivannan Sadhasivam wrote:
> Hello,
> 
> This series adds support for additional notifiers in the PCI endpoint
> framework. The notifiers LINK_DOWN, BME, PME, and D_STATE are generic
> for all PCI endpoints but there is also a custom notifier (CUSTOM) added
> to pass the device/vendor specific events to EPF from EPC.
> 
> The example usage of all notifiers is provided in the commit description.

In my earlier comment I didn't mean you to provide example usage in
commit description. Rather to be used in a existing endpoint controller
driver and handled in endpoint function drivers. Otherwise no point in
adding them to the upstream kernel.

Thanks
Kishon

> 
> Thanks,
> Mani
> 
> Manivannan Sadhasivam (5):
>   PCI: endpoint: Add linkdown notifier support
>   PCI: endpoint: Add BME notifier support
>   PCI: endpoint: Add PME notifier support
>   PCI: endpoint: Add D_STATE notifier support
>   PCI: endpoint: Add custom notifier support
> 
>  drivers/pci/endpoint/pci-epc-core.c | 89 +++++++++++++++++++++++++++++
>  include/linux/pci-epc.h             |  5 ++
>  include/linux/pci-epf.h             |  5 ++
>  3 files changed, 99 insertions(+)
> 

Re: [PATCH 0/5] PCI: endpoint: Add support for additional notifiers

[Manivannan Sadhasivam]

On Thu, Aug 19, 2021 at 07:45:06PM +0530, Kishon Vijay Abraham I wrote:
> Hi Manivannan,
> 
> On 16/06/21 5:29 pm, Manivannan Sadhasivam wrote:
> > Hello,
> > 
> > This series adds support for additional notifiers in the PCI endpoint
> > framework. The notifiers LINK_DOWN, BME, PME, and D_STATE are generic
> > for all PCI endpoints but there is also a custom notifier (CUSTOM) added
> > to pass the device/vendor specific events to EPF from EPC.
> > 
> > The example usage of all notifiers is provided in the commit description.
> 
> In my earlier comment I didn't mean you to provide example usage in
> commit description. Rather to be used in a existing endpoint controller
> driver and handled in endpoint function drivers. Otherwise no point in
> adding them to the upstream kernel.
> 

Oh, sorry then I must have misinterpreted your comments. I'll submit this series
along with the MHI stack that makes use of these notifiers.

Thanks,
Mani

> Thanks
> Kishon
> 
> > 
> > Thanks,
> > Mani
> > 
> > Manivannan Sadhasivam (5):
> >   PCI: endpoint: Add linkdown notifier support
> >   PCI: endpoint: Add BME notifier support
> >   PCI: endpoint: Add PME notifier support
> >   PCI: endpoint: Add D_STATE notifier support
> >   PCI: endpoint: Add custom notifier support
> > 
> >  drivers/pci/endpoint/pci-epc-core.c | 89 +++++++++++++++++++++++++++++
> >  include/linux/pci-epc.h             |  5 ++
> >  include/linux/pci-epf.h             |  5 ++
> >  3 files changed, 99 insertions(+)
> >