[PATCH v2] PCI: dwc: Add upper limit address for outbound iATU

[Shradha Todi]

The size parameter is unsigned long type which can accept size > 4GB. In
that case, the upper limit address must be programmed. Add support to
program the upper limit address and set INCREASE_REGION_SIZE in case size >
4GB.

Signed-off-by: Shradha Todi <shradha.t@xxxxxxxxxxx>
---
v1: https://lkml.org/lkml/2020/12/20/187
v2:
   Addressed Rob's review comment and added PCI version check condition to
   avoid writing to reserved registers.

 drivers/pci/controller/dwc/pcie-designware.c | 9 +++++++--
 drivers/pci/controller/dwc/pcie-designware.h | 1 +
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 74590c7..1d62ca9 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -290,12 +290,17 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
 			   upper_32_bits(cpu_addr));
 	dw_pcie_writel_dbi(pci, PCIE_ATU_LIMIT,
 			   lower_32_bits(cpu_addr + size - 1));
+	if (pci->version >= 0x460A)
+		dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_LIMIT,
+				   upper_32_bits(cpu_addr + size - 1));
 	dw_pcie_writel_dbi(pci, PCIE_ATU_LOWER_TARGET,
 			   lower_32_bits(pci_addr));
 	dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_TARGET,
 			   upper_32_bits(pci_addr));
-	dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, type |
-			   PCIE_ATU_FUNC_NUM(func_no));
+	val = type | PCIE_ATU_FUNC_NUM(func_no);
+	val = ((upper_32_bits(size - 1)) && (pci->version >= 0x460A)) ?
+		val | PCIE_ATU_INCREASE_REGION_SIZE : val;
+	dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, val);
 	dw_pcie_writel_dbi(pci, PCIE_ATU_CR2, PCIE_ATU_ENABLE);
 
 	/*
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 8b905a2..7da79eb 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -102,6 +102,7 @@
 #define PCIE_ATU_DEV(x)			FIELD_PREP(GENMASK(23, 19), x)
 #define PCIE_ATU_FUNC(x)		FIELD_PREP(GENMASK(18, 16), x)
 #define PCIE_ATU_UPPER_TARGET		0x91C
+#define PCIE_ATU_UPPER_LIMIT		0x924
 
 #define PCIE_MISC_CONTROL_1_OFF		0x8BC
 #define PCIE_DBI_RO_WR_EN		BIT(0)
-- 
2.7.4