On 6/16/2021 5:29 PM, Manivannan Sadhasivam wrote:
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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@xxxxxxxxxx>
---
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
