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

Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 26 ++++++++++++++++++++++++++
 include/linux/pci-epc.h             |  1 +
 include/linux/pci-epf.h             |  2 ++
 3 files changed, 29 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 1ecbe2b1d3bd..ca8f838fa51f 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -758,6 +758,32 @@ 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)
+{
+	struct pci_epf *epf;
+
+	if (!epc || IS_ERR(epc))
+		return;
+
+	mutex_lock(&epc->list_lock);
+	list_for_each_entry(epf, &epc->pci_epf, list) {
+		mutex_lock(&epf->lock);
+		if (epf->event_ops && epf->event_ops->bme)
+			epf->event_ops->bme(epf);
+		mutex_unlock(&epf->lock);
+	}
+	mutex_unlock(&epc->list_lock);
+}
+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 63a6cc5e5282..5cb694031072 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -205,6 +205,7 @@ 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, u8 vfunc_no,
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index f8e5a63d0c83..f34b3b32a0e7 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -72,11 +72,13 @@ struct pci_epf_ops {
  * @core_init: Callback for the EPC initialization complete event
  * @link_up: Callback for the EPC link up event
  * @link_down: Callback for the EPC link down event
+ * @bme: Callback for the EPC BME (Bus Master Enable) event
  */
 struct pci_epc_event_ops {
 	int (*core_init)(struct pci_epf *epf);
 	int (*link_up)(struct pci_epf *epf);
 	int (*link_down)(struct pci_epf *epf);
+	int (*bme)(struct pci_epf *epf);
 };
 
 /**
-- 
2.25.1

> @@ -72,11 +72,13 @@ struct pci_epf_ops {
>   * @core_init: Callback for the EPC initialization complete event
>   * @link_up: Callback for the EPC link up event
>   * @link_down: Callback for the EPC link down event
> + * @bme: Callback for the EPC BME (Bus Master Enable) event
>   */
>  struct pci_epc_event_ops {
>         int (*core_init)(struct pci_epf *epf);
>         int (*link_up)(struct pci_epf *epf);
>         int (*link_down)(struct pci_epf *epf);
> +       int (*bme)(struct pci_epf *epf);

I posted a doorbell from host to EP at
https://lore.kernel.org/imx/20230426203436.1277307-2-Frank.Li@nxp.com/T/#u

Can we consider consolidate these notification to one function and distinguished by
EVENT_ID in future?

Best regards
Frank Li

>  };
> 
>  /**
> --
> 2.25.1

On Fri, May 19, 2023 at 06:19:44PM +0000, Frank Li wrote:
> 
> > @@ -72,11 +72,13 @@ struct pci_epf_ops {
> >   * @core_init: Callback for the EPC initialization complete event
> >   * @link_up: Callback for the EPC link up event
> >   * @link_down: Callback for the EPC link down event
> > + * @bme: Callback for the EPC BME (Bus Master Enable) event
> >   */
> >  struct pci_epc_event_ops {
> >         int (*core_init)(struct pci_epf *epf);
> >         int (*link_up)(struct pci_epf *epf);
> >         int (*link_down)(struct pci_epf *epf);
> > +       int (*bme)(struct pci_epf *epf);
> 
> I posted a doorbell from host to EP at
> https://lore.kernel.org/imx/20230426203436.1277307-2-Frank.Li@nxp.com/T/#u
> 
> Can we consider consolidate these notification to one function and distinguished by
> EVENT_ID in future?
> 

My preference is to keep a separate callback for each event as it makes the code
look better instead of clubbing everything in a single callback separated by a
switch case.

- Mani

> Best regards
> Frank Li
> 
> >  };
> > 
> >  /**
> > --
> > 2.25.1
> 

-- 
மணிவண்ணன் சதாசிவம்

> >
> > Can we consider consolidate these notification to one function and
> distinguished by
> > EVENT_ID in future?
> >
> 
> My preference is to keep a separate callback for each event as it makes the
> code
> look better instead of clubbing everything in a single callback separated by a
> switch case.
> 

Okay, that is not big deal. I hope these can be merged into pci tree soon. 
So I can add more notification at layerscape platform.

> - Mani
> 
> > Best regards
> > Frank Li
> >
> > >  };
> > >
> > >  /**
> > > --
> > > 2.25.1
> >
> 
> --
> மணிவண்ணன் சதாசிவம்