| Message ID | 1449775100-30877-1-git-send-email-grygorii.strashko@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Grygorii, On Thu, Dec 10, 2015 at 09:18:20PM +0200, Grygorii Strashko wrote: > On -RT and if kernel is booting with "threadirqs" cmd line parameter > pcie/pci (msi) irq cascade handlers (like dra7xx_pcie_msi_irq_handler()) > will be forced threaded and, as result, will generate warnings like: > > WARNING: CPU: 1 PID: 82 at kernel/irq/handle.c:150 handle_irq_event_percpu+0x14c/0x174() > irq 460 handler irq_default_primary_handler+0x0/0x14 enabled interrupts > Backtrace: > (warn_slowpath_common) from [<c0043758>] (warn_slowpath_fmt+0x38/0x40) > (warn_slowpath_fmt) from [<c0085fd0>] (handle_irq_event_percpu+0x14c/0x174) > (handle_irq_event_percpu) from [<c008607c>] (handle_irq_event+0x84/0xb8) > (handle_irq_event) from [<c0089240>] (handle_simple_irq+0x90/0x118) > (handle_simple_irq) from [<c0085514>] (generic_handle_irq+0x30/0x44) > (generic_handle_irq) from [<c034a7d4>] (dra7xx_pcie_msi_irq_handler+0x7c/0x8c) > (dra7xx_pcie_msi_irq_handler) from [<c0086f08>] (irq_forced_thread_fn+0x28/0x5c) > (irq_forced_thread_fn) from [<c00871dc>] (irq_thread+0x128/0x204) > > This happens because all of them invoke generic_handle_irq() from the > requsted handler. generic_handle_irq grabs raw_locks and this needs to > run in raw-irq context. > > This issue was originally reproduced on TI dra7-evem, but, as was > identified during dicussion [1], other PCI(e) hosts can also suffer > from this issue. So let's fix all them at once and mark pcie/pci (msi) > irq cascade handlers IRQF_NO_THREAD explicitly. > > [1] https://lkml.org/lkml/2015/11/20/356 > > Cc: Kishon Vijay Abraham I <kishon@ti.com> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Jingoo Han <jingoohan1@gmail.com> > Cc: Kukjin Kim <kgene@kernel.org> > Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> > Cc: Richard Zhu <Richard.Zhu@freescale.com> > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: Thierry Reding <thierry.reding@gmail.com> > Cc: Stephen Warren <swarren@wwwdotorg.org> > Cc: Alexandre Courbot <gnurou@gmail.com> > Cc: Simon Horman <horms@verge.net.au> > Cc: Pratyush Anand <pratyush.anand@gmail.com> > Cc: Michal Simek <michal.simek@xilinx.com> > Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> > Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> > --- > Changes in v3: > - change applied to all affected pci(e) host drivers in drivers/pci/hosts. > After some invsetigation I've decided to not touch arch code - it is not easy > to identify all places which need to be fixed. > if it's still required - i can send separate patches for > arch/mips/pci/msi-octeon.c and arch/sparc/kernel/pci_msi.c. > Links > v2: https://lkml.org/lkml/2015/11/20/356 > v1: https://lkml.org/lkml/2015/11/5/593 > ref: https://lkml.org/lkml/2015/11/3/660 > > drivers/pci/host/pci-dra7xx.c | 13 ++++++++++++- > drivers/pci/host/pci-exynos.c | 3 ++- > drivers/pci/host/pci-imx6.c | 3 ++- > drivers/pci/host/pci-tegra.c | 2 +- > drivers/pci/host/pcie-rcar.c | 6 ++++-- > drivers/pci/host/pcie-spear13xx.c | 3 ++- > drivers/pci/host/pcie-xilinx.c | 3 ++- > 7 files changed, 25 insertions(+), 8 deletions(-) I applied this to pci/host for v4.5, thanks. I added a stable tag. I haven't seen any acks from the host driver guys, but I will still add them if I see any in the next few days. Bjorn > diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c > index 8c36880..0415192 100644 > --- a/drivers/pci/host/pci-dra7xx.c > +++ b/drivers/pci/host/pci-dra7xx.c > @@ -301,8 +301,19 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, > return -EINVAL; > } > > + /* > + * Mark dra7xx_pcie_msi IRQ as IRQF_NO_THREAD > + * On -RT and if kernel is booting with "threadirqs" cmd line parameter > + * the dra7xx_pcie_msi_irq_handler() will be forced threaded but, > + * in the same time, it's IRQ dispatcher and calls generic_handle_irq(), > + * which, in turn, will be resolved to handle_simple_irq() call. > + * The handle_simple_irq() expected to be called with IRQ disabled, as > + * result kernle will display warning: > + * "irq XXX handler YYY+0x0/0x14 enabled interrupts". > + */ > ret = devm_request_irq(&pdev->dev, pp->irq, > - dra7xx_pcie_msi_irq_handler, IRQF_SHARED, > + dra7xx_pcie_msi_irq_handler, > + IRQF_SHARED | IRQF_NO_THREAD, > "dra7-pcie-msi", pp); > if (ret) { > dev_err(&pdev->dev, "failed to request irq\n"); > diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c > index 01095e1..d997d22 100644 > --- a/drivers/pci/host/pci-exynos.c > +++ b/drivers/pci/host/pci-exynos.c > @@ -522,7 +522,8 @@ static int __init exynos_add_pcie_port(struct pcie_port *pp, > > ret = devm_request_irq(&pdev->dev, pp->msi_irq, > exynos_pcie_msi_irq_handler, > - IRQF_SHARED, "exynos-pcie", pp); > + IRQF_SHARED | IRQF_NO_THREAD, > + "exynos-pcie", pp); > if (ret) { > dev_err(&pdev->dev, "failed to request msi irq\n"); > return ret; > diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c > index 22e8224..9ce7cd1 100644 > --- a/drivers/pci/host/pci-imx6.c > +++ b/drivers/pci/host/pci-imx6.c > @@ -537,7 +537,8 @@ static int __init imx6_add_pcie_port(struct pcie_port *pp, > > ret = devm_request_irq(&pdev->dev, pp->msi_irq, > imx6_pcie_msi_handler, > - IRQF_SHARED, "mx6-pcie-msi", pp); > + IRQF_SHARED | IRQF_NO_THREAD, > + "mx6-pcie-msi", pp); > if (ret) { > dev_err(&pdev->dev, "failed to request MSI irq\n"); > return ret; > diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c > index 3018ae5..3032311 100644 > --- a/drivers/pci/host/pci-tegra.c > +++ b/drivers/pci/host/pci-tegra.c > @@ -1288,7 +1288,7 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie) > > msi->irq = err; > > - err = request_irq(msi->irq, tegra_pcie_msi_irq, 0, > + err = request_irq(msi->irq, tegra_pcie_msi_irq, IRQF_NO_THREAD, > tegra_msi_irq_chip.name, pcie); > if (err < 0) { > dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); > diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c > index f4fa6c5..414c336 100644 > --- a/drivers/pci/host/pcie-rcar.c > +++ b/drivers/pci/host/pcie-rcar.c > @@ -720,14 +720,16 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie) > > /* Two irqs are for MSI, but they are also used for non-MSI irqs */ > err = devm_request_irq(&pdev->dev, msi->irq1, rcar_pcie_msi_irq, > - IRQF_SHARED, rcar_msi_irq_chip.name, pcie); > + IRQF_SHARED | IRQF_NO_THREAD, > + rcar_msi_irq_chip.name, pcie); > if (err < 0) { > dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); > goto err; > } > > err = devm_request_irq(&pdev->dev, msi->irq2, rcar_pcie_msi_irq, > - IRQF_SHARED, rcar_msi_irq_chip.name, pcie); > + IRQF_SHARED | IRQF_NO_THREAD, > + rcar_msi_irq_chip.name, pcie); > if (err < 0) { > dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); > goto err; > diff --git a/drivers/pci/host/pcie-spear13xx.c b/drivers/pci/host/pcie-spear13xx.c > index b95b756..a6cd823 100644 > --- a/drivers/pci/host/pcie-spear13xx.c > +++ b/drivers/pci/host/pcie-spear13xx.c > @@ -279,7 +279,8 @@ static int spear13xx_add_pcie_port(struct pcie_port *pp, > return -ENODEV; > } > ret = devm_request_irq(dev, pp->irq, spear13xx_pcie_irq_handler, > - IRQF_SHARED, "spear1340-pcie", pp); > + IRQF_SHARED | IRQF_NO_THREAD, > + "spear1340-pcie", pp); > if (ret) { > dev_err(dev, "failed to request irq %d\n", pp->irq); > return ret; > diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c > index 3c7a0d5..4cfa463 100644 > --- a/drivers/pci/host/pcie-xilinx.c > +++ b/drivers/pci/host/pcie-xilinx.c > @@ -781,7 +781,8 @@ static int xilinx_pcie_parse_dt(struct xilinx_pcie_port *port) > > port->irq = irq_of_parse_and_map(node, 0); > err = devm_request_irq(dev, port->irq, xilinx_pcie_intr_handler, > - IRQF_SHARED, "xilinx-pcie", port); > + IRQF_SHARED | IRQF_NO_THREAD, > + "xilinx-pcie", port); > if (err) { > dev_err(dev, "unable to request irq %d\n", port->irq); > return err; > -- > 2.6.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
Am Donnerstag, den 10.12.2015, 21:18 +0200 schrieb Grygorii Strashko: > On -RT and if kernel is booting with "threadirqs" cmd line parameter > pcie/pci (msi) irq cascade handlers (like dra7xx_pcie_msi_irq_handler()) > will be forced threaded and, as result, will generate warnings like: > > WARNING: CPU: 1 PID: 82 at kernel/irq/handle.c:150 handle_irq_event_percpu+0x14c/0x174() > irq 460 handler irq_default_primary_handler+0x0/0x14 enabled interrupts > Backtrace: > (warn_slowpath_common) from [<c0043758>] (warn_slowpath_fmt+0x38/0x40) > (warn_slowpath_fmt) from [<c0085fd0>] (handle_irq_event_percpu+0x14c/0x174) > (handle_irq_event_percpu) from [<c008607c>] (handle_irq_event+0x84/0xb8) > (handle_irq_event) from [<c0089240>] (handle_simple_irq+0x90/0x118) > (handle_simple_irq) from [<c0085514>] (generic_handle_irq+0x30/0x44) > (generic_handle_irq) from [<c034a7d4>] (dra7xx_pcie_msi_irq_handler+0x7c/0x8c) > (dra7xx_pcie_msi_irq_handler) from [<c0086f08>] (irq_forced_thread_fn+0x28/0x5c) > (irq_forced_thread_fn) from [<c00871dc>] (irq_thread+0x128/0x204) > > This happens because all of them invoke generic_handle_irq() from the > requsted handler. generic_handle_irq grabs raw_locks and this needs to > run in raw-irq context. > > This issue was originally reproduced on TI dra7-evem, but, as was > identified during dicussion [1], other PCI(e) hosts can also suffer > from this issue. So let's fix all them at once and mark pcie/pci (msi) > irq cascade handlers IRQF_NO_THREAD explicitly. > > [1] https://lkml.org/lkml/2015/11/20/356 > > Cc: Kishon Vijay Abraham I <kishon@ti.com> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Jingoo Han <jingoohan1@gmail.com> > Cc: Kukjin Kim <kgene@kernel.org> > Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> > Cc: Richard Zhu <Richard.Zhu@freescale.com> > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: Thierry Reding <thierry.reding@gmail.com> > Cc: Stephen Warren <swarren@wwwdotorg.org> > Cc: Alexandre Courbot <gnurou@gmail.com> > Cc: Simon Horman <horms@verge.net.au> > Cc: Pratyush Anand <pratyush.anand@gmail.com> > Cc: Michal Simek <michal.simek@xilinx.com> > Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> > Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Sorry this fell through the cracks, so here is my late Acked-by: Lucas Stach <l.stach@pengutronix.de> for the imx6 part. > --- > Changes in v3: > - change applied to all affected pci(e) host drivers in drivers/pci/hosts. > After some invsetigation I've decided to not touch arch code - it is not easy > to identify all places which need to be fixed. > if it's still required - i can send separate patches for > arch/mips/pci/msi-octeon.c and arch/sparc/kernel/pci_msi.c. > Links > v2: https://lkml.org/lkml/2015/11/20/356 > v1: https://lkml.org/lkml/2015/11/5/593 > ref: https://lkml.org/lkml/2015/11/3/660 > > drivers/pci/host/pci-dra7xx.c | 13 ++++++++++++- > drivers/pci/host/pci-exynos.c | 3 ++- > drivers/pci/host/pci-imx6.c | 3 ++- > drivers/pci/host/pci-tegra.c | 2 +- > drivers/pci/host/pcie-rcar.c | 6 ++++-- > drivers/pci/host/pcie-spear13xx.c | 3 ++- > drivers/pci/host/pcie-xilinx.c | 3 ++- > 7 files changed, 25 insertions(+), 8 deletions(-) > > diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c > index 8c36880..0415192 100644 > --- a/drivers/pci/host/pci-dra7xx.c > +++ b/drivers/pci/host/pci-dra7xx.c > @@ -301,8 +301,19 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, > return -EINVAL; > } > > + /* > + * Mark dra7xx_pcie_msi IRQ as IRQF_NO_THREAD > + * On -RT and if kernel is booting with "threadirqs" cmd line parameter > + * the dra7xx_pcie_msi_irq_handler() will be forced threaded but, > + * in the same time, it's IRQ dispatcher and calls generic_handle_irq(), > + * which, in turn, will be resolved to handle_simple_irq() call. > + * The handle_simple_irq() expected to be called with IRQ disabled, as > + * result kernle will display warning: > + * "irq XXX handler YYY+0x0/0x14 enabled interrupts". > + */ > ret = devm_request_irq(&pdev->dev, pp->irq, > - dra7xx_pcie_msi_irq_handler, IRQF_SHARED, > + dra7xx_pcie_msi_irq_handler, > + IRQF_SHARED | IRQF_NO_THREAD, > "dra7-pcie-msi", pp); > if (ret) { > dev_err(&pdev->dev, "failed to request irq\n"); > diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c > index 01095e1..d997d22 100644 > --- a/drivers/pci/host/pci-exynos.c > +++ b/drivers/pci/host/pci-exynos.c > @@ -522,7 +522,8 @@ static int __init exynos_add_pcie_port(struct pcie_port *pp, > > ret = devm_request_irq(&pdev->dev, pp->msi_irq, > exynos_pcie_msi_irq_handler, > - IRQF_SHARED, "exynos-pcie", pp); > + IRQF_SHARED | IRQF_NO_THREAD, > + "exynos-pcie", pp); > if (ret) { > dev_err(&pdev->dev, "failed to request msi irq\n"); > return ret; > diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c > index 22e8224..9ce7cd1 100644 > --- a/drivers/pci/host/pci-imx6.c > +++ b/drivers/pci/host/pci-imx6.c > @@ -537,7 +537,8 @@ static int __init imx6_add_pcie_port(struct pcie_port *pp, > > ret = devm_request_irq(&pdev->dev, pp->msi_irq, > imx6_pcie_msi_handler, > - IRQF_SHARED, "mx6-pcie-msi", pp); > + IRQF_SHARED | IRQF_NO_THREAD, > + "mx6-pcie-msi", pp); > if (ret) { > dev_err(&pdev->dev, "failed to request MSI irq\n"); > return ret; > diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c > index 3018ae5..3032311 100644 > --- a/drivers/pci/host/pci-tegra.c > +++ b/drivers/pci/host/pci-tegra.c > @@ -1288,7 +1288,7 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie) > > msi->irq = err; > > - err = request_irq(msi->irq, tegra_pcie_msi_irq, 0, > + err = request_irq(msi->irq, tegra_pcie_msi_irq, IRQF_NO_THREAD, > tegra_msi_irq_chip.name, pcie); > if (err < 0) { > dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); > diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c > index f4fa6c5..414c336 100644 > --- a/drivers/pci/host/pcie-rcar.c > +++ b/drivers/pci/host/pcie-rcar.c > @@ -720,14 +720,16 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie) > > /* Two irqs are for MSI, but they are also used for non-MSI irqs */ > err = devm_request_irq(&pdev->dev, msi->irq1, rcar_pcie_msi_irq, > - IRQF_SHARED, rcar_msi_irq_chip.name, pcie); > + IRQF_SHARED | IRQF_NO_THREAD, > + rcar_msi_irq_chip.name, pcie); > if (err < 0) { > dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); > goto err; > } > > err = devm_request_irq(&pdev->dev, msi->irq2, rcar_pcie_msi_irq, > - IRQF_SHARED, rcar_msi_irq_chip.name, pcie); > + IRQF_SHARED | IRQF_NO_THREAD, > + rcar_msi_irq_chip.name, pcie); > if (err < 0) { > dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); > goto err; > diff --git a/drivers/pci/host/pcie-spear13xx.c b/drivers/pci/host/pcie-spear13xx.c > index b95b756..a6cd823 100644 > --- a/drivers/pci/host/pcie-spear13xx.c > +++ b/drivers/pci/host/pcie-spear13xx.c > @@ -279,7 +279,8 @@ static int spear13xx_add_pcie_port(struct pcie_port *pp, > return -ENODEV; > } > ret = devm_request_irq(dev, pp->irq, spear13xx_pcie_irq_handler, > - IRQF_SHARED, "spear1340-pcie", pp); > + IRQF_SHARED | IRQF_NO_THREAD, > + "spear1340-pcie", pp); > if (ret) { > dev_err(dev, "failed to request irq %d\n", pp->irq); > return ret; > diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c > index 3c7a0d5..4cfa463 100644 > --- a/drivers/pci/host/pcie-xilinx.c > +++ b/drivers/pci/host/pcie-xilinx.c > @@ -781,7 +781,8 @@ static int xilinx_pcie_parse_dt(struct xilinx_pcie_port *port) > > port->irq = irq_of_parse_and_map(node, 0); > err = devm_request_irq(dev, port->irq, xilinx_pcie_intr_handler, > - IRQF_SHARED, "xilinx-pcie", port); > + IRQF_SHARED | IRQF_NO_THREAD, > + "xilinx-pcie", port); > if (err) { > dev_err(dev, "unable to request irq %d\n", port->irq); > return err;
* Bjorn Helgaas | 2016-01-06 16:18:27 [-0600]: >Hi Bjorn, >> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c >> index 8c36880..0415192 100644 >> --- a/drivers/pci/host/pci-dra7xx.c >> +++ b/drivers/pci/host/pci-dra7xx.c >> @@ -301,8 +301,19 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, >> return -EINVAL; >> } >> >> + /* >> + * Mark dra7xx_pcie_msi IRQ as IRQF_NO_THREAD >> + * On -RT and if kernel is booting with "threadirqs" cmd line parameter >> + * the dra7xx_pcie_msi_irq_handler() will be forced threaded but, >> + * in the same time, it's IRQ dispatcher and calls generic_handle_irq(), >> + * which, in turn, will be resolved to handle_simple_irq() call. >> + * The handle_simple_irq() expected to be called with IRQ disabled, as >> + * result kernle will display warning: >> + * "irq XXX handler YYY+0x0/0x14 enabled interrupts". >> + */ could you _please_ remove this coment? This kind of comment (if at all) should be part of the commit message (which is the case more or less). >> ret = devm_request_irq(&pdev->dev, pp->irq, >> - dra7xx_pcie_msi_irq_handler, IRQF_SHARED, >> + dra7xx_pcie_msi_irq_handler, >> + IRQF_SHARED | IRQF_NO_THREAD, >> "dra7-pcie-msi", pp); >> if (ret) { >> dev_err(&pdev->dev, "failed to request irq\n"); >> diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c Sebastian
On Wed, Jan 13, 2016 at 02:39:04PM +0100, Sebastian Andrzej Siewior wrote: > * Bjorn Helgaas | 2016-01-06 16:18:27 [-0600]: > > >Hi Bjorn, > > >> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c > >> index 8c36880..0415192 100644 > >> --- a/drivers/pci/host/pci-dra7xx.c > >> +++ b/drivers/pci/host/pci-dra7xx.c > >> @@ -301,8 +301,19 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, > >> return -EINVAL; > >> } > >> > >> + /* > >> + * Mark dra7xx_pcie_msi IRQ as IRQF_NO_THREAD > >> + * On -RT and if kernel is booting with "threadirqs" cmd line parameter > >> + * the dra7xx_pcie_msi_irq_handler() will be forced threaded but, > >> + * in the same time, it's IRQ dispatcher and calls generic_handle_irq(), > >> + * which, in turn, will be resolved to handle_simple_irq() call. > >> + * The handle_simple_irq() expected to be called with IRQ disabled, as > >> + * result kernle will display warning: > >> + * "irq XXX handler YYY+0x0/0x14 enabled interrupts". > >> + */ > > could you _please_ remove this coment? This kind of comment (if at all) > should be part of the commit message (which is the case more or less). IIRC, Grygorii specifically wanted to keep this comment in dra7xx, but I do agree that this level of detail is more appropriate for a changelog. If Grygorii and Kishon don't object, I can update the patch to remove it. > >> ret = devm_request_irq(&pdev->dev, pp->irq, > >> - dra7xx_pcie_msi_irq_handler, IRQF_SHARED, > >> + dra7xx_pcie_msi_irq_handler, > >> + IRQF_SHARED | IRQF_NO_THREAD, > >> "dra7-pcie-msi", pp); > >> if (ret) { > >> dev_err(&pdev->dev, "failed to request irq\n"); > >> diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c > > Sebastian > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On 01/13/2016 07:50 PM, Bjorn Helgaas wrote: > On Wed, Jan 13, 2016 at 02:39:04PM +0100, Sebastian Andrzej Siewior wrote: >> * Bjorn Helgaas | 2016-01-06 16:18:27 [-0600]: >> >>> Hi Bjorn, >> >>>> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c >>>> index 8c36880..0415192 100644 >>>> --- a/drivers/pci/host/pci-dra7xx.c >>>> +++ b/drivers/pci/host/pci-dra7xx.c >>>> @@ -301,8 +301,19 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, >>>> return -EINVAL; >>>> } >>>> >>>> + /* >>>> + * Mark dra7xx_pcie_msi IRQ as IRQF_NO_THREAD >>>> + * On -RT and if kernel is booting with "threadirqs" cmd line parameter >>>> + * the dra7xx_pcie_msi_irq_handler() will be forced threaded but, >>>> + * in the same time, it's IRQ dispatcher and calls generic_handle_irq(), >>>> + * which, in turn, will be resolved to handle_simple_irq() call. >>>> + * The handle_simple_irq() expected to be called with IRQ disabled, as >>>> + * result kernle will display warning: >>>> + * "irq XXX handler YYY+0x0/0x14 enabled interrupts". >>>> + */ >> >> could you _please_ remove this coment? This kind of comment (if at all) >> should be part of the commit message (which is the case more or less). > > IIRC, Grygorii specifically wanted to keep this comment in dra7xx, but True. > I do agree that this level of detail is more appropriate for a changelog. > > If Grygorii and Kishon don't object, I can update the patch to remove it. But no objections from my side. Thanks a lot.
Hi, On Thursday 14 January 2016 12:18 AM, Grygorii Strashko wrote: > On 01/13/2016 07:50 PM, Bjorn Helgaas wrote: >> On Wed, Jan 13, 2016 at 02:39:04PM +0100, Sebastian Andrzej Siewior wrote: >>> * Bjorn Helgaas | 2016-01-06 16:18:27 [-0600]: >>> >>>> Hi Bjorn, >>> >>>>> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c >>>>> index 8c36880..0415192 100644 >>>>> --- a/drivers/pci/host/pci-dra7xx.c >>>>> +++ b/drivers/pci/host/pci-dra7xx.c >>>>> @@ -301,8 +301,19 @@ static int __init dra7xx_add_pcie_port(struct >>>>> dra7xx_pcie *dra7xx, >>>>> return -EINVAL; >>>>> } >>>>> >>>>> + /* >>>>> + * Mark dra7xx_pcie_msi IRQ as IRQF_NO_THREAD >>>>> + * On -RT and if kernel is booting with "threadirqs" cmd line parameter >>>>> + * the dra7xx_pcie_msi_irq_handler() will be forced threaded but, >>>>> + * in the same time, it's IRQ dispatcher and calls generic_handle_irq(), >>>>> + * which, in turn, will be resolved to handle_simple_irq() call. >>>>> + * The handle_simple_irq() expected to be called with IRQ disabled, as >>>>> + * result kernle will display warning: >>>>> + * "irq XXX handler YYY+0x0/0x14 enabled interrupts". >>>>> + */ >>> >>> could you _please_ remove this coment? This kind of comment (if at all) >>> should be part of the commit message (which is the case more or less). >> >> IIRC, Grygorii specifically wanted to keep this comment in dra7xx, but > > True. > >> I do agree that this level of detail is more appropriate for a changelog. >> >> If Grygorii and Kishon don't object, I can update the patch to remove it. > > But no objections from my side. Thanks a lot. I don't have any objections. Thanks Kishon
On Thu, Jan 14, 2016 at 11:49:24AM +0530, Kishon Vijay Abraham I wrote: > Hi, > > On Thursday 14 January 2016 12:18 AM, Grygorii Strashko wrote: > > On 01/13/2016 07:50 PM, Bjorn Helgaas wrote: > >> On Wed, Jan 13, 2016 at 02:39:04PM +0100, Sebastian Andrzej Siewior wrote: > >>> * Bjorn Helgaas | 2016-01-06 16:18:27 [-0600]: > >>> > >>>> Hi Bjorn, > >>> > >>>>> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c > >>>>> index 8c36880..0415192 100644 > >>>>> --- a/drivers/pci/host/pci-dra7xx.c > >>>>> +++ b/drivers/pci/host/pci-dra7xx.c > >>>>> @@ -301,8 +301,19 @@ static int __init dra7xx_add_pcie_port(struct > >>>>> dra7xx_pcie *dra7xx, > >>>>> return -EINVAL; > >>>>> } > >>>>> > >>>>> + /* > >>>>> + * Mark dra7xx_pcie_msi IRQ as IRQF_NO_THREAD > >>>>> + * On -RT and if kernel is booting with "threadirqs" cmd line parameter > >>>>> + * the dra7xx_pcie_msi_irq_handler() will be forced threaded but, > >>>>> + * in the same time, it's IRQ dispatcher and calls generic_handle_irq(), > >>>>> + * which, in turn, will be resolved to handle_simple_irq() call. > >>>>> + * The handle_simple_irq() expected to be called with IRQ disabled, as > >>>>> + * result kernle will display warning: > >>>>> + * "irq XXX handler YYY+0x0/0x14 enabled interrupts". > >>>>> + */ > >>> > >>> could you _please_ remove this coment? This kind of comment (if at all) > >>> should be part of the commit message (which is the case more or less). > >> > >> IIRC, Grygorii specifically wanted to keep this comment in dra7xx, but > > > > True. > > > >> I do agree that this level of detail is more appropriate for a changelog. > >> > >> If Grygorii and Kishon don't object, I can update the patch to remove it. > > > > But no objections from my side. Thanks a lot. > > I don't have any objections. OK, I dropped it, thanks guys! Bjorn
diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c index 8c36880..0415192 100644 --- a/drivers/pci/host/pci-dra7xx.c +++ b/drivers/pci/host/pci-dra7xx.c @@ -301,8 +301,19 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, return -EINVAL; } + /* + * Mark dra7xx_pcie_msi IRQ as IRQF_NO_THREAD + * On -RT and if kernel is booting with "threadirqs" cmd line parameter + * the dra7xx_pcie_msi_irq_handler() will be forced threaded but, + * in the same time, it's IRQ dispatcher and calls generic_handle_irq(), + * which, in turn, will be resolved to handle_simple_irq() call. + * The handle_simple_irq() expected to be called with IRQ disabled, as + * result kernle will display warning: + * "irq XXX handler YYY+0x0/0x14 enabled interrupts". + */ ret = devm_request_irq(&pdev->dev, pp->irq, - dra7xx_pcie_msi_irq_handler, IRQF_SHARED, + dra7xx_pcie_msi_irq_handler, + IRQF_SHARED | IRQF_NO_THREAD, "dra7-pcie-msi", pp); if (ret) { dev_err(&pdev->dev, "failed to request irq\n"); diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c index 01095e1..d997d22 100644 --- a/drivers/pci/host/pci-exynos.c +++ b/drivers/pci/host/pci-exynos.c @@ -522,7 +522,8 @@ static int __init exynos_add_pcie_port(struct pcie_port *pp, ret = devm_request_irq(&pdev->dev, pp->msi_irq, exynos_pcie_msi_irq_handler, - IRQF_SHARED, "exynos-pcie", pp); + IRQF_SHARED | IRQF_NO_THREAD, + "exynos-pcie", pp); if (ret) { dev_err(&pdev->dev, "failed to request msi irq\n"); return ret; diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index 22e8224..9ce7cd1 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -537,7 +537,8 @@ static int __init imx6_add_pcie_port(struct pcie_port *pp, ret = devm_request_irq(&pdev->dev, pp->msi_irq, imx6_pcie_msi_handler, - IRQF_SHARED, "mx6-pcie-msi", pp); + IRQF_SHARED | IRQF_NO_THREAD, + "mx6-pcie-msi", pp); if (ret) { dev_err(&pdev->dev, "failed to request MSI irq\n"); return ret; diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c index 3018ae5..3032311 100644 --- a/drivers/pci/host/pci-tegra.c +++ b/drivers/pci/host/pci-tegra.c @@ -1288,7 +1288,7 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie) msi->irq = err; - err = request_irq(msi->irq, tegra_pcie_msi_irq, 0, + err = request_irq(msi->irq, tegra_pcie_msi_irq, IRQF_NO_THREAD, tegra_msi_irq_chip.name, pcie); if (err < 0) { dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c index f4fa6c5..414c336 100644 --- a/drivers/pci/host/pcie-rcar.c +++ b/drivers/pci/host/pcie-rcar.c @@ -720,14 +720,16 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie) /* Two irqs are for MSI, but they are also used for non-MSI irqs */ err = devm_request_irq(&pdev->dev, msi->irq1, rcar_pcie_msi_irq, - IRQF_SHARED, rcar_msi_irq_chip.name, pcie); + IRQF_SHARED | IRQF_NO_THREAD, + rcar_msi_irq_chip.name, pcie); if (err < 0) { dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); goto err; } err = devm_request_irq(&pdev->dev, msi->irq2, rcar_pcie_msi_irq, - IRQF_SHARED, rcar_msi_irq_chip.name, pcie); + IRQF_SHARED | IRQF_NO_THREAD, + rcar_msi_irq_chip.name, pcie); if (err < 0) { dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); goto err; diff --git a/drivers/pci/host/pcie-spear13xx.c b/drivers/pci/host/pcie-spear13xx.c index b95b756..a6cd823 100644 --- a/drivers/pci/host/pcie-spear13xx.c +++ b/drivers/pci/host/pcie-spear13xx.c @@ -279,7 +279,8 @@ static int spear13xx_add_pcie_port(struct pcie_port *pp, return -ENODEV; } ret = devm_request_irq(dev, pp->irq, spear13xx_pcie_irq_handler, - IRQF_SHARED, "spear1340-pcie", pp); + IRQF_SHARED | IRQF_NO_THREAD, + "spear1340-pcie", pp); if (ret) { dev_err(dev, "failed to request irq %d\n", pp->irq); return ret; diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c index 3c7a0d5..4cfa463 100644 --- a/drivers/pci/host/pcie-xilinx.c +++ b/drivers/pci/host/pcie-xilinx.c @@ -781,7 +781,8 @@ static int xilinx_pcie_parse_dt(struct xilinx_pcie_port *port) port->irq = irq_of_parse_and_map(node, 0); err = devm_request_irq(dev, port->irq, xilinx_pcie_intr_handler, - IRQF_SHARED, "xilinx-pcie", port); + IRQF_SHARED | IRQF_NO_THREAD, + "xilinx-pcie", port); if (err) { dev_err(dev, "unable to request irq %d\n", port->irq); return err;
On -RT and if kernel is booting with "threadirqs" cmd line parameter pcie/pci (msi) irq cascade handlers (like dra7xx_pcie_msi_irq_handler()) will be forced threaded and, as result, will generate warnings like: WARNING: CPU: 1 PID: 82 at kernel/irq/handle.c:150 handle_irq_event_percpu+0x14c/0x174() irq 460 handler irq_default_primary_handler+0x0/0x14 enabled interrupts Backtrace: (warn_slowpath_common) from [<c0043758>] (warn_slowpath_fmt+0x38/0x40) (warn_slowpath_fmt) from [<c0085fd0>] (handle_irq_event_percpu+0x14c/0x174) (handle_irq_event_percpu) from [<c008607c>] (handle_irq_event+0x84/0xb8) (handle_irq_event) from [<c0089240>] (handle_simple_irq+0x90/0x118) (handle_simple_irq) from [<c0085514>] (generic_handle_irq+0x30/0x44) (generic_handle_irq) from [<c034a7d4>] (dra7xx_pcie_msi_irq_handler+0x7c/0x8c) (dra7xx_pcie_msi_irq_handler) from [<c0086f08>] (irq_forced_thread_fn+0x28/0x5c) (irq_forced_thread_fn) from [<c00871dc>] (irq_thread+0x128/0x204) This happens because all of them invoke generic_handle_irq() from the requsted handler. generic_handle_irq grabs raw_locks and this needs to run in raw-irq context. This issue was originally reproduced on TI dra7-evem, but, as was identified during dicussion [1], other PCI(e) hosts can also suffer from this issue. So let's fix all them at once and mark pcie/pci (msi) irq cascade handlers IRQF_NO_THREAD explicitly. [1] https://lkml.org/lkml/2015/11/20/356 Cc: Kishon Vijay Abraham I <kishon@ti.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Jingoo Han <jingoohan1@gmail.com> Cc: Kukjin Kim <kgene@kernel.org> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: Richard Zhu <Richard.Zhu@freescale.com> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Simon Horman <horms@verge.net.au> Cc: Pratyush Anand <pratyush.anand@gmail.com> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> --- Changes in v3: - change applied to all affected pci(e) host drivers in drivers/pci/hosts. After some invsetigation I've decided to not touch arch code - it is not easy to identify all places which need to be fixed. if it's still required - i can send separate patches for arch/mips/pci/msi-octeon.c and arch/sparc/kernel/pci_msi.c. Links v2: https://lkml.org/lkml/2015/11/20/356 v1: https://lkml.org/lkml/2015/11/5/593 ref: https://lkml.org/lkml/2015/11/3/660 drivers/pci/host/pci-dra7xx.c | 13 ++++++++++++- drivers/pci/host/pci-exynos.c | 3 ++- drivers/pci/host/pci-imx6.c | 3 ++- drivers/pci/host/pci-tegra.c | 2 +- drivers/pci/host/pcie-rcar.c | 6 ++++-- drivers/pci/host/pcie-spear13xx.c | 3 ++- drivers/pci/host/pcie-xilinx.c | 3 ++- 7 files changed, 25 insertions(+), 8 deletions(-)