[PATCH 5.12 207/292] PCI: tegra194: Fix tegra_pcie_ep_raise_msi_irq() ill-defined shift
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-07-19 18:09:26
Also in:
lkml
Subsystem:
pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers:
Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds
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 (local)
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 <redacted>
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 8dee6d3f33a7..fb1df066a236 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; }
--
2.30.2