[PATCH v2 2/2] PCI: mediatek: Enlarge PCIe2AHB window size to support 4GB DRAM

[honghui.zhang]

From: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx>

The PCIE_AXI_WINDOW0 defines the translate window size for the request
from EP side. Request outside of this window will be treated as
unsupported request.

Enlarge this window size from fls(0xffffffff) to 2^33 to support 8GB
translate address range then EP DMA is capable of fully access 4GB
DRAM range(physical DRAM is start from 0x40000000).

Reported-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Honghui Zhang <honghui.zhang@xxxxxxxxxxxx>
---
 drivers/pci/controller/pcie-mediatek.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
index 01126b8..60326c4 100644
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -90,6 +90,12 @@
 #define AHB2PCIE_SIZE(x)	((x) & GENMASK(4, 0))
 #define PCIE_AXI_WINDOW0	0x448
 #define WIN_ENABLE		BIT(7)
+/*
+ * Define PCIe to AHB window size as 2^33 to support max 8GB address space
+ * translate, support least 4GB DRAM size access from EP DMA(physical DRAM
+ * start from 0x40000000).
+ */
+#define PCIE2AHB_SIZE	0x21
 
 /* PCIe V2 configuration transaction header */
 #define PCIE_CFG_HEADER0	0x460
@@ -713,7 +719,7 @@ static int mtk_pcie_startup_port_v2(struct mtk_pcie_port *port)
 	writel(val, port->base + PCIE_AHB_TRANS_BASE0_H);
 
 	/* Set PCIe to AXI translation memory space.*/
-	val = fls(0xffffffff) | WIN_ENABLE;
+	val = PCIE2AHB_SIZE | WIN_ENABLE;
 	writel(val, port->base + PCIE_AXI_WINDOW0);
 
 	return 0;
-- 
2.6.4