[PATCH v3 3/7] PCI: endpoint: Add linkdown notifier support

Manivannan Sadhasivam
2023-03-14T04:46:58Z

Add support to notify the EPF device about the linkdown event from the
EPC device.

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 9440d9811eea..e3a6b5554c1c 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -706,6 +706,32 @@ 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)
+{
+ 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->link_down)
+ epf->event_ops->link_down(epf);
+ mutex_unlock(&epf->lock);
+ }
+ mutex_unlock(&epc->list_lock);
+}
+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 301bb0e53707..63a6cc5e5282 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -203,6 +203,7 @@ 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 bc613f0df7e3..f8e5a63d0c83 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -71,10 +71,12 @@ struct pci_epf_ops {
* struct pci_epf_event_ops - Callbacks for capturing the EPC events
* @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
*/
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);
};

/**
--
2.25.1