[PATCH v8 1/5] PCI: endpoint: Add dynamic_inbound_mapping EPC feature

[Koichiro Den <den@valinux.co.jp>]

Introduce a new EPC feature bit (dynamic_inbound_mapping) that indicates
whether an Endpoint Controller can update the inbound address
translation for a BAR without requiring the EPF driver to clear/reset
the BAR first.

Endpoint Function drivers (e.g. vNTB) can use this information to decide
whether it really is safe to call pci_epc_set_bar() multiple times to
update inbound mappings for the BAR.

Suggested-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
 include/linux/pci-epc.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 4286bfdbfdfa..4c8516756c56 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -223,6 +223,10 @@ struct pci_epc_bar_desc {
 /**
  * struct pci_epc_features - features supported by a EPC device per function
  * @linkup_notifier: indicate if the EPC device can notify EPF driver on link up
+ * @dynamic_inbound_mapping: indicate if the EPC device supports updating
+ *                           inbound mappings for an already configured BAR
+ *                           (i.e. allow calling pci_epc_set_bar() again
+ *                           without first calling pci_epc_clear_bar())
  * @msi_capable: indicate if the endpoint function has MSI capability
  * @msix_capable: indicate if the endpoint function has MSI-X capability
  * @intx_capable: indicate if the endpoint can raise INTx interrupts
@@ -231,6 +235,7 @@ struct pci_epc_bar_desc {
  */
 struct pci_epc_features {
 	unsigned int	linkup_notifier : 1;
+	unsigned int	dynamic_inbound_mapping : 1;
 	unsigned int	msi_capable : 1;
 	unsigned int	msix_capable : 1;
 	unsigned int	intx_capable : 1;
-- 
2.51.0