PCI: tegra194: Fix tegra_pcie_ep_raise_msi_irq() ill-defined shift

[ Upstream commit f67092eff2bd40650aad54a1a1910160f41d864a ]

tegra_pcie_ep_raise_msi_irq() shifted a signed 32-bit value left by 31
bits.  The behavior of this is implementation-defined.

Replace the shift by BIT(), which is well-defined.

Found by cppcheck:

  $ cppcheck --enable=all drivers/pci/controller/dwc/pcie-tegra194.c
  Checking drivers/pci/controller/dwc/pcie-tegra194.c ...

  drivers/pci/controller/dwc/pcie-tegra194.c:1829:23: portability: Shifting signed 32-bit value by 31 bits is implementation-defined behaviour. See condition at line 1826.  [shiftTooManyBitsSigned]

  appl_writel(pcie, (1 << irq), APPL_MSI_CTRL_1);
                     ^

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20210618160219.303092-1-jonathanh@nvidia.com
Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 8dee6d3f33a70da3f1aff723d3442b20ea1d6e72..fb1df066a23643dc22936cd933c7fcc96bc71e02 100644 (file)
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1826,7 +1826,7 @@ static int tegra_pcie_ep_raise_msi_irq(struct tegra_pcie_dw *pcie, u16 irq)
        if (unlikely(irq > 31))
                return -EINVAL;
 
-       appl_writel(pcie, (1 << irq), APPL_MSI_CTRL_1);
+       appl_writel(pcie, BIT(irq), APPL_MSI_CTRL_1);
 
        return 0;
 }