From: Jon Hunter jonathanh@nvidia.com
[ 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 --- drivers/pci/controller/dwc/pcie-tegra194.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index fa6b12cfc043..3ec7b29d5dc7 100644 --- 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; }