[PATCH v2 1/4] PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address

[Frank Li <Frank.Li@nxp.com>]

ntb_mw_set_trans() will set memory map window after endpoint function
driver bind. The inbound map address need be updated dynamically when
using NTB by PCIe Root Port and PCIe Endpoint connection.

Checking if iatu already assigned to the BAR, if yes, using assigned iatu
number to update inbound address map and skip set BAR's register.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Change from V1:
 - improve commit message

 drivers/pci/controller/dwc/pcie-designware-ep.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 998b698f40858..cad5d9ea7cc6c 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -161,7 +161,11 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, u8 func_no,
 	u32 free_win;
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 
-	free_win = find_first_zero_bit(ep->ib_window_map, pci->num_ib_windows);
+	if (!ep->bar_to_atu[bar])
+		free_win = find_first_zero_bit(ep->ib_window_map, pci->num_ib_windows);
+	else
+		free_win = ep->bar_to_atu[bar];
+
 	if (free_win >= pci->num_ib_windows) {
 		dev_err(pci->dev, "No free inbound window\n");
 		return -EINVAL;
@@ -215,6 +219,7 @@ static void dw_pcie_ep_clear_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 	dw_pcie_disable_atu(pci, atu_index, DW_PCIE_REGION_INBOUND);
 	clear_bit(atu_index, ep->ib_window_map);
 	ep->epf_bar[bar] = NULL;
+	ep->bar_to_atu[bar] = 0;
 }
 
 static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
@@ -244,6 +249,9 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 	if (ret)
 		return ret;
 
+	if (ep->epf_bar[bar])
+		return 0;
+
 	dw_pcie_dbi_ro_wr_en(pci);
 
 	dw_pcie_writel_dbi2(pci, reg, lower_32_bits(size - 1));
-- 
2.24.0.rc1