PCI: endpoint: Add linkdown notifier support

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

Link: https://lore.kernel.org/r/20230602114756.36586-5-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 0cf602c..e0570b5 100644 (file)
--- 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 301bb0e..63a6cc5 100644 (file)
--- 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 a3bad37..73d783a 100644 (file)
--- 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);
 };
 
 /**