PCI: dwc: Set INCREASE_REGION_SIZE flag based on limit address

We program the 64-bit ATU limit address (in PCIE_ATU_LIMIT/
PCIE_ATU_UPPER_LIMIT or PCIE_ATU_UNR_LOWER_LIMIT/PCIE_ATU_UNR_UPPER_LIMIT),
but in addition, the PCIE_ATU_INCREASE_REGION_SIZE bit must be set if the
upper 32 bits of the limit address differ from the upper 32 bits of the
base address (see [1,2]).

5b4cf0f6 ("PCI: dwc: Add upper limit address for outbound iATU") set
PCIE_ATU_INCREASE_REGION_SIZE, but only when the *size* was greater than
4GB.  It did not set it when a smaller region crossed a 4GB boundary, e.g.,
[mem 0x0_f0000000-0x1_0fffffff].

Set PCIE_ATU_INCREASE_REGION_SIZE whenever PCIE_ATU_UPPER_LIMIT is
greater than PCIE_ATU_UPPER_BASE.

[1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port,
    v5.40a, March 2019, fig.3-36, p.175
[2] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port,
    v5.40a, March 2019, fig.3-37, p.176

[bhelgaas: commit log]
Fixes: 5b4cf0f6 ("PCI: dwc: Add upper limit address for outbound iATU")
Link: https://lore.kernel.org/r/20220624143428.8334-5-Sergey.Semin@baikalelectronics.ruTested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>

drivers/pci/controller/dwc/pcie-designware.c

@@ -287,8 +287,8 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no,
 	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_TARGET,
 				 upper_32_bits(pci_addr));
 	val = type | PCIE_ATU_FUNC_NUM(func_no);
-	val = upper_32_bits(size - 1) ?
-		val | PCIE_ATU_INCREASE_REGION_SIZE : val;
+	if (upper_32_bits(limit_addr) > upper_32_bits(cpu_addr))
+		val |= PCIE_ATU_INCREASE_REGION_SIZE;
 	if (pci->version == 0x490A)
 		val = dw_pcie_enable_ecrc(val);
 	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL1, val);
@@ -315,6 +315,7 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
 					u64 pci_addr, u64 size)
 {
 	u32 retries, val;
+	u64 limit_addr;
 
 	if (pci->ops && pci->ops->cpu_addr_fixup)
 		cpu_addr = pci->ops->cpu_addr_fixup(pci, cpu_addr);
@@ -325,6 +326,8 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
 		return;
 	}
 
+	limit_addr = cpu_addr + size - 1;
+
 	dw_pcie_writel_dbi(pci, PCIE_ATU_VIEWPORT,
 			   PCIE_ATU_REGION_OUTBOUND | index);
 	dw_pcie_writel_dbi(pci, PCIE_ATU_LOWER_BASE,
@@ -332,17 +335,18 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
 	dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_BASE,
 			   upper_32_bits(cpu_addr));
 	dw_pcie_writel_dbi(pci, PCIE_ATU_LIMIT,
-			   lower_32_bits(cpu_addr + size - 1));
+			   lower_32_bits(limit_addr));
 	if (pci->version >= 0x460A)
 		dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_LIMIT,
-				   upper_32_bits(cpu_addr + size - 1));
+				   upper_32_bits(limit_addr));
 	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));
 	val = type | PCIE_ATU_FUNC_NUM(func_no);
-	val = ((upper_32_bits(size - 1)) && (pci->version >= 0x460A)) ?
-		val | PCIE_ATU_INCREASE_REGION_SIZE : val;
+	if (upper_32_bits(limit_addr) > upper_32_bits(cpu_addr) &&
+	    pci->version >= 0x460A)
+		val |= PCIE_ATU_INCREASE_REGION_SIZE;
 	if (pci->version == 0x490A)
 		val = dw_pcie_enable_ecrc(val);
 	dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, val);