[PATCH v3] PCI: hosts: mark pcie/pci (msi) irq cascade handler as IRQF_NO_THREAD
Bjorn Helgaas
helgaas at kernel.org
Wed Jan 6 14:18:27 PST 2016
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 at ti.com>
> Cc: Bjorn Helgaas <bhelgaas at google.com>
> Cc: Jingoo Han <jingoohan1 at gmail.com>
> Cc: Kukjin Kim <kgene at kernel.org>
> Cc: Krzysztof Kozlowski <k.kozlowski at samsung.com>
> Cc: Richard Zhu <Richard.Zhu at freescale.com>
> Cc: Lucas Stach <l.stach at pengutronix.de>
> Cc: Thierry Reding <thierry.reding at gmail.com>
> Cc: Stephen Warren <swarren at wwwdotorg.org>
> Cc: Alexandre Courbot <gnurou at gmail.com>
> Cc: Simon Horman <horms at verge.net.au>
> Cc: Pratyush Anand <pratyush.anand at gmail.com>
> Cc: Michal Simek <michal.simek at xilinx.com>
> Cc: "Sören Brinkmann" <soren.brinkmann at xilinx.com>
> Cc: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
> Signed-off-by: Grygorii Strashko <grygorii.strashko at 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 at vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
More information about the linux-arm-kernel
mailing list