The unrolled version of the internal ATU has been available since the DWC
PCIe v4.80a IP core, but it may not be enabled. Per [1], if unrolled ATU
is enabled, the PCIE_ATU_VIEWPORT does not exist and reads as 0xffffffff;
while if unrolled ATU is disabled, PCIE_ATU_VIEWPORT will contain some
zeros.
Simplify dw_pcie_iatu_unroll_enabled() by checking the value of
PCIE_ATU_VIEWPORT.
[1] DesignWare Cores, PCI Express Controller, Register Desciptions,
v.4.90a, December 2016, p.855
[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20220624143428.8334-10-Sergey.Semin@baikalelectronics.ru
Tested-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>
}
-static u8 dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci)
+static bool dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci)
{
u32 val;
val = dw_pcie_readl_dbi(pci, PCIE_ATU_VIEWPORT);
if (val == 0xffffffff)
- return 1;
+ return true;
- return 0;
+ return false;
}
static void dw_pcie_iatu_detect_regions_unroll(struct dw_pcie *pci)
struct device *dev = pci->dev;
struct platform_device *pdev = to_platform_device(dev);
- if (pci->version >= 0x480A || (!pci->version &&
- dw_pcie_iatu_unroll_enabled(pci))) {
- pci->iatu_unroll_enabled = true;
+ pci->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pci);
+ if (pci->iatu_unroll_enabled) {
if (!pci->atu_base) {
struct resource *res =
platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu");