+/**
+ * pci_epc_stop() - stop the PCI link
+ * @epc: the link of the EPC device that has to be stopped
+ *
+ * Invoke to stop the PCI link
+ */
+void pci_epc_stop(struct pci_epc *epc)
+{
+	if (IS_ERR(epc) || !epc->ops->stop)
+		return;
+
+	spin_lock_irq(&epc->irq_lock);
+	epc->ops->stop(epc);
+	spin_unlock_irq(&epc->irq_lock);
+}
+EXPORT_SYMBOL_GPL(pci_epc_stop);

Can you elaborate on the synchronization strategy here?  It seems
like irq_lock is generally taken irq save and just around method
calls.  Wou;dn't it be better to leave locking to the methods
themselves?

+/**
+ * struct pci_epc - represents the PCI EPC device
+ * @dev: PCI EPC device
+ * @ops: function pointers for performing endpoint operations
+ * @mutex: mutex to protect pci_epc ops
+ */
+struct pci_epc {
+	struct device			dev;
+	/* support only single function PCI device for now */
+	struct pci_epf			*epf;
+	const struct pci_epc_ops	*ops;
+	spinlock_t			irq_lock;
+};

And this still documentes a mutex instead of the irq save spinlock,
while we're at it..

+/**
+ * struct pci_epf_bar - represents the BAR of EPF device
+ * @phys_addr: physical address that should be mapped to the BAR
+ * @size: the size of the address space present in BAR
+ */
+struct pci_epf_bar {
+	dma_addr_t	phys_addr;
+	size_t		size;
+};

Just curious: shouldn't this be a phys_addr_t instead of a dma_addr_t?


Otherwise this looks like a nice little framework to get started!