| Message ID | 20210618160219.303092-1-jonathanh@nvidia.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Lorenzo Pieralisi |
| Headers | show |
| Series | PCI: tegra: Fix shiftTooManyBitsSigned warning for Tegra194 | expand |
On 18/06/2021 17:02, Jon Hunter wrote: > The cppcheck tool issues the following warning for the Tegra194 PCIe > driver ... > > $ 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); > ^ > The above warning occurs because the '1' is treated as a signed type > and so fix this by using the 'BIT' macro to ensure that this is defined > as a unsigned type. > > Fixes: c57247f940e8 PCI: tegra: Add support for PCIe endpoint mode in Tegra194 Looks like I messed up the format of the Fixes: tag and it should be ... Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194") > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > --- > 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 8fc08336f76e..3c1feeab104f 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; > } >
On Fri, Jun 18, 2021 at 05:02:19PM +0100, Jon Hunter wrote: > The cppcheck tool issues the following warning for the Tegra194 PCIe > driver ... > > $ 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); > ^ > The above warning occurs because the '1' is treated as a signed type > and so fix this by using the 'BIT' macro to ensure that this is defined > as a unsigned type. The subject and commit log should describe the problem we're fixing. The *warning* is not the problem; the problem is the undefined behavior. I'll fix this up, no need to repost for this. > Fixes: c57247f940e8 PCI: tegra: Add support for PCIe endpoint mode in Tegra194 > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > --- > 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 8fc08336f76e..3c1feeab104f 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; > } > -- > 2.25.1 >
On Fri, Jun 18, 2021 at 06:04:28PM -0500, Bjorn Helgaas wrote: > On Fri, Jun 18, 2021 at 05:02:19PM +0100, Jon Hunter wrote: > > The cppcheck tool issues the following warning for the Tegra194 PCIe > > driver ... > > > > $ 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); > > ^ > > The above warning occurs because the '1' is treated as a signed type > > and so fix this by using the 'BIT' macro to ensure that this is defined > > as a unsigned type. > > The subject and commit log should describe the problem we're fixing. > The *warning* is not the problem; the problem is the undefined > behavior. > > I'll fix this up, no need to repost for this. Hi Bjorn, I can fix it up myself, just wanted to ask if you merged it already, it does not look like but I thought I'd check. Thanks, Lorenzo > > Fixes: c57247f940e8 PCI: tegra: Add support for PCIe endpoint mode in Tegra194 > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > > --- > > 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 8fc08336f76e..3c1feeab104f 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; > > } > > -- > > 2.25.1 > >
On Wed, Jun 23, 2021 at 09:52:14AM +0100, Lorenzo Pieralisi wrote: > On Fri, Jun 18, 2021 at 06:04:28PM -0500, Bjorn Helgaas wrote: > > On Fri, Jun 18, 2021 at 05:02:19PM +0100, Jon Hunter wrote: > > > The cppcheck tool issues the following warning for the Tegra194 PCIe > > > driver ... > > > > > > $ 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); > > > ^ > > > The above warning occurs because the '1' is treated as a signed type > > > and so fix this by using the 'BIT' macro to ensure that this is defined > > > as a unsigned type. > > > > The subject and commit log should describe the problem we're fixing. > > The *warning* is not the problem; the problem is the undefined > > behavior. > > > > I'll fix this up, no need to repost for this. > > Hi Bjorn, > > I can fix it up myself, just wanted to ask if you merged it already, it > does not look like but I thought I'd check. Oops, sorry, I guess I dropped the ball on this one and didn't get it merged. When you do, can you update the subject as well, e.g., s/PCI: tegra/PCI: tegra194/ to differentiate from the other "tegra" driver? > > > Fixes: c57247f940e8 PCI: tegra: Add support for PCIe endpoint mode in Tegra194 > > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > > > --- > > > 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 8fc08336f76e..3c1feeab104f 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; > > > } > > > -- > > > 2.25.1 > > >
On Fri, 18 Jun 2021 17:02:19 +0100, Jon Hunter wrote: > The cppcheck tool issues the following warning for the Tegra194 PCIe > driver ... > > $ 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] > > [...] Applied to pci/tegra, thanks! [1/1] PCI: tegra194: Fix shiftTooManyBitsSigned warning for Tegra194 https://git.kernel.org/lpieralisi/pci/c/b1eca3a544 Thanks, Lorenzo
On Fri, Jun 18, 2021 at 06:04:28PM -0500, Bjorn Helgaas wrote: > On Fri, Jun 18, 2021 at 05:02:19PM +0100, Jon Hunter wrote: > > The cppcheck tool issues the following warning for the Tegra194 PCIe > > driver ... > > > > $ 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); > > ^ > > The above warning occurs because the '1' is treated as a signed type > > and so fix this by using the 'BIT' macro to ensure that this is defined > > as a unsigned type. > > The subject and commit log should describe the problem we're fixing. > The *warning* is not the problem; the problem is the undefined > behavior. > > I'll fix this up, no need to repost for this. I merged this from Lorenzo's branch, but I updated the commit log like this because the undefined behavior is the real problem: PCI: tegra194: Fix tegra_pcie_ep_raise_msi_irq() ill-defined shift 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> > > Fixes: c57247f940e8 PCI: tegra: Add support for PCIe endpoint mode in Tegra194 > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > > --- > > 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 8fc08336f76e..3c1feeab104f 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; > > } > > -- > > 2.25.1 > >
On Thu, Jun 24, 2021 at 06:01:50PM -0500, Bjorn Helgaas wrote: > On Fri, Jun 18, 2021 at 06:04:28PM -0500, Bjorn Helgaas wrote: > > On Fri, Jun 18, 2021 at 05:02:19PM +0100, Jon Hunter wrote: > > > The cppcheck tool issues the following warning for the Tegra194 PCIe > > > driver ... > > > > > > $ 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); > > > ^ > > > The above warning occurs because the '1' is treated as a signed type > > > and so fix this by using the 'BIT' macro to ensure that this is defined > > > as a unsigned type. > > > > The subject and commit log should describe the problem we're fixing. > > The *warning* is not the problem; the problem is the undefined > > behavior. I updated the commit log accordingly but I did not change the subject :-/ > > I'll fix this up, no need to repost for this. > > I merged this from Lorenzo's branch, but I updated the commit log like > this because the undefined behavior is the real problem: > > PCI: tegra194: Fix tegra_pcie_ep_raise_msi_irq() ill-defined shift Yep, I forgot to update the subject, thanks for doing that. Lorenzo > > 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> > > > > Fixes: c57247f940e8 PCI: tegra: Add support for PCIe endpoint mode in Tegra194 > > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > > > --- > > > 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 8fc08336f76e..3c1feeab104f 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; > > > } > > > -- > > > 2.25.1 > > >
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index 8fc08336f76e..3c1feeab104f 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; }
The cppcheck tool issues the following warning for the Tegra194 PCIe driver ... $ 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); ^ The above warning occurs because the '1' is treated as a signed type and so fix this by using the 'BIT' macro to ensure that this is defined as a unsigned type. Fixes: c57247f940e8 PCI: tegra: Add support for PCIe endpoint mode in Tegra194 Signed-off-by: Jon Hunter <jonathanh@nvidia.com> --- drivers/pci/controller/dwc/pcie-tegra194.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)