[PATCH 3/3] PCI: iproc: Add PCIe 32bit outbound memory configuration

[Srinath Mannam]

IPROC PCIe RC supports outbound memory mapping with SOC address inside
4GB address boundary, which is 32 bit AXI address.
This patch add the support.

Signed-off-by: Srinath Mannam <srinath.mannam@xxxxxxxxxxxx>
Signed-off-by: Abhishek Shah <abhishek.shah@xxxxxxxxxxxx>
Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
Reviewed-by: Vikram Prakash <vikram.prakash@xxxxxxxxxxxx>
---
 drivers/pci/controller/pcie-iproc.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
index ee89d56..4d0e63b 100644
--- a/drivers/pci/controller/pcie-iproc.c
+++ b/drivers/pci/controller/pcie-iproc.c
@@ -982,8 +982,25 @@ static int iproc_pcie_setup_ob(struct iproc_pcie *pcie, u64 axi_addr,
 			resource_size_t window_size =
 				ob_map->window_sizes[size_idx] * SZ_1M;
 
-			if (size < window_size)
-				continue;
+			/*
+			 * Keep iterating until we reach the last window and
+			 * with the minimal window size at index zero. In this
+			 * case, we take a compromise by mapping it using the
+			 * minimum window size that can be supported
+			 */
+			if (size < window_size) {
+				if (size_idx > 0 || window_idx > 0)
+					continue;
+
+				/*
+				 * For the corner case of reaching the minimal
+				 * window size that can be supported on the
+				 * last window
+				 */
+				axi_addr = ALIGN_DOWN(axi_addr, window_size);
+				pci_addr = ALIGN_DOWN(pci_addr, window_size);
+				size = window_size;
+			}
 
 			if (!IS_ALIGNED(axi_addr, window_size) ||
 			    !IS_ALIGNED(pci_addr, window_size)) {
-- 
2.7.4