[PATCH v4 7/7] PCI: dwc: endpoint: Define the .map_align() controller operation

[Damien Le Moal <dlemoal@kernel.org>]

The function dw_pcie_prog_outbound_atu() used to program outbound ATU
entries for mapping RC PCI addresses to local CPU addresses does not
allow PCI addresses that are not aligned to the value of region_align
of struct dw_pcie. This value is determined from the iATU hardware
registers during probing of the iATU (done by dw_pcie_iatu_detect()).
This value is thus valid for all DWC PCIe controllers, and valid
regardless of the hardware configuration used when synthesizing the
DWC PCIe controller.

Handle this PCI address alignment constraint by defining the endpoint
controller .map_align() operation to calculate a mapping size and the
offset into the mapping based on the requested RC PCI address and size
to map.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/pci/controller/dwc/pcie-designware-ep.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 43ba5c6738df..501e527c188e 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -268,6 +268,20 @@ static int dw_pcie_find_index(struct dw_pcie_ep *ep, phys_addr_t addr,
 	return -EINVAL;
 }
 
+static int dw_pcie_ep_map_align(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+				struct pci_epc_map *map)
+{
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	size_t mask = pci->region_align - 1;
+
+	map->map_pci_addr = map->pci_addr & ~mask;
+	map->map_ofst = map->pci_addr & mask;
+	map->map_size = ALIGN(map->map_ofst + map->pci_size, ep->page_size);
+
+	return 0;
+}
+
 static void dw_pcie_ep_unmap_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 				  phys_addr_t addr)
 {
@@ -444,6 +458,7 @@ static const struct pci_epc_ops epc_ops = {
 	.write_header		= dw_pcie_ep_write_header,
 	.set_bar		= dw_pcie_ep_set_bar,
 	.clear_bar		= dw_pcie_ep_clear_bar,
+	.map_align		= dw_pcie_ep_map_align,
 	.map_addr		= dw_pcie_ep_map_addr,
 	.unmap_addr		= dw_pcie_ep_unmap_addr,
 	.set_msi		= dw_pcie_ep_set_msi,
-- 
2.46.2