| Message ID | 20220721064720.10762-1-johan+linaro@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] PCI: qcom: Add support for modular builds | expand |
On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > Allow the Qualcomm PCIe controller driver to be built as a module, which > is useful for multi-platform kernels as well as during development. > > Reviewed-by: Rob Herring <robh@kernel.org> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Applied to pci/ctrl/qcom for v5.20, thanks! > --- > > Changes in v2 > - rebase on next-20220720 (adjust context) > - add Rob and Mani's reviewed-by tags > > > drivers/pci/controller/dwc/Kconfig | 2 +- > drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++--- > 2 files changed, 34 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig > index 62ce3abf0f19..230f56d1a268 100644 > --- a/drivers/pci/controller/dwc/Kconfig > +++ b/drivers/pci/controller/dwc/Kconfig > @@ -168,7 +168,7 @@ config PCI_HISI > Hip05 and Hip06 SoCs > > config PCIE_QCOM > - bool "Qualcomm PCIe controller" > + tristate "Qualcomm PCIe controller" > depends on OF && (ARCH_QCOM || COMPILE_TEST) > depends on PCI_MSI_IRQ_DOMAIN > select PCIE_DW_HOST > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > index 5ed164c2afa3..d176c635016b 100644 > --- a/drivers/pci/controller/dwc/pcie-qcom.c > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > @@ -16,7 +16,7 @@ > #include <linux/io.h> > #include <linux/iopoll.h> > #include <linux/kernel.h> > -#include <linux/init.h> > +#include <linux/module.h> > #include <linux/of_device.h> > #include <linux/of_gpio.h> > #include <linux/pci.h> > @@ -1518,6 +1518,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) > return ret; > } > > +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie) > +{ > + qcom_ep_reset_assert(pcie); > + if (pcie->cfg->ops->post_deinit) > + pcie->cfg->ops->post_deinit(pcie); > + phy_power_off(pcie->phy); > + pcie->cfg->ops->deinit(pcie); > +} > + > static const struct dw_pcie_host_ops qcom_pcie_dw_ops = { > .host_init = qcom_pcie_host_init, > }; > @@ -1752,6 +1761,22 @@ static int qcom_pcie_probe(struct platform_device *pdev) > return ret; > } > > +static int qcom_pcie_remove(struct platform_device *pdev) > +{ > + struct qcom_pcie *pcie = platform_get_drvdata(pdev); > + struct device *dev = &pdev->dev; > + > + dw_pcie_host_deinit(&pcie->pci->pp); > + qcom_pcie_host_deinit(pcie); > + > + phy_exit(pcie->phy); > + > + pm_runtime_put_sync(dev); > + pm_runtime_disable(dev); > + > + return 0; > +} > + > static const struct of_device_id qcom_pcie_match[] = { > { .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg }, > { .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg }, > @@ -1771,6 +1796,7 @@ static const struct of_device_id qcom_pcie_match[] = { > { .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg }, > { } > }; > +MODULE_DEVICE_TABLE(of, qcom_pcie_match); > > static void qcom_fixup_class(struct pci_dev *dev) > { > @@ -1786,10 +1812,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class); > > static struct platform_driver qcom_pcie_driver = { > .probe = qcom_pcie_probe, > + .remove = qcom_pcie_remove, > .driver = { > .name = "qcom-pcie", > - .suppress_bind_attrs = true, > .of_match_table = qcom_pcie_match, > }, > }; > -builtin_platform_driver(qcom_pcie_driver); > +module_platform_driver(qcom_pcie_driver); > + > +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>"); > +MODULE_DESCRIPTION("Qualcomm PCIe root complex driver"); > +MODULE_LICENSE("GPL"); > -- > 2.35.1 >
On Thu, Jul 21, 2022 at 02:35:13PM -0500, Bjorn Helgaas wrote: > On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > > Allow the Qualcomm PCIe controller driver to be built as a module, which > > is useful for multi-platform kernels as well as during development. > > > > Reviewed-by: Rob Herring <robh@kernel.org> > > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > > Applied to pci/ctrl/qcom for v5.20, thanks! I'm going to drop this one for now, since the module vs remove discussion [1] is still ongoing. This patch actually makes it both *modular* and *removable*. I think the modular part is uncontroversial and valuable by itself. If you want to just make it modular and *non*-removable, I think that would be fine and we can add removability next cycle if we think it's safe. [1] https://lore.kernel.org/r/20220721195433.GA1747571@bhelgaas > > Changes in v2 > > - rebase on next-20220720 (adjust context) > > - add Rob and Mani's reviewed-by tags > > > > > > drivers/pci/controller/dwc/Kconfig | 2 +- > > drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++--- > > 2 files changed, 34 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig > > index 62ce3abf0f19..230f56d1a268 100644 > > --- a/drivers/pci/controller/dwc/Kconfig > > +++ b/drivers/pci/controller/dwc/Kconfig > > @@ -168,7 +168,7 @@ config PCI_HISI > > Hip05 and Hip06 SoCs > > > > config PCIE_QCOM > > - bool "Qualcomm PCIe controller" > > + tristate "Qualcomm PCIe controller" > > depends on OF && (ARCH_QCOM || COMPILE_TEST) > > depends on PCI_MSI_IRQ_DOMAIN > > select PCIE_DW_HOST > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > > index 5ed164c2afa3..d176c635016b 100644 > > --- a/drivers/pci/controller/dwc/pcie-qcom.c > > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > > @@ -16,7 +16,7 @@ > > #include <linux/io.h> > > #include <linux/iopoll.h> > > #include <linux/kernel.h> > > -#include <linux/init.h> > > +#include <linux/module.h> > > #include <linux/of_device.h> > > #include <linux/of_gpio.h> > > #include <linux/pci.h> > > @@ -1518,6 +1518,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) > > return ret; > > } > > > > +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie) > > +{ > > + qcom_ep_reset_assert(pcie); > > + if (pcie->cfg->ops->post_deinit) > > + pcie->cfg->ops->post_deinit(pcie); > > + phy_power_off(pcie->phy); > > + pcie->cfg->ops->deinit(pcie); > > +} > > + > > static const struct dw_pcie_host_ops qcom_pcie_dw_ops = { > > .host_init = qcom_pcie_host_init, > > }; > > @@ -1752,6 +1761,22 @@ static int qcom_pcie_probe(struct platform_device *pdev) > > return ret; > > } > > > > +static int qcom_pcie_remove(struct platform_device *pdev) > > +{ > > + struct qcom_pcie *pcie = platform_get_drvdata(pdev); > > + struct device *dev = &pdev->dev; > > + > > + dw_pcie_host_deinit(&pcie->pci->pp); > > + qcom_pcie_host_deinit(pcie); > > + > > + phy_exit(pcie->phy); > > + > > + pm_runtime_put_sync(dev); > > + pm_runtime_disable(dev); > > + > > + return 0; > > +} > > + > > static const struct of_device_id qcom_pcie_match[] = { > > { .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg }, > > { .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg }, > > @@ -1771,6 +1796,7 @@ static const struct of_device_id qcom_pcie_match[] = { > > { .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg }, > > { } > > }; > > +MODULE_DEVICE_TABLE(of, qcom_pcie_match); > > > > static void qcom_fixup_class(struct pci_dev *dev) > > { > > @@ -1786,10 +1812,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class); > > > > static struct platform_driver qcom_pcie_driver = { > > .probe = qcom_pcie_probe, > > + .remove = qcom_pcie_remove, > > .driver = { > > .name = "qcom-pcie", > > - .suppress_bind_attrs = true, > > .of_match_table = qcom_pcie_match, > > }, > > }; > > -builtin_platform_driver(qcom_pcie_driver); > > +module_platform_driver(qcom_pcie_driver); > > + > > +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>"); > > +MODULE_DESCRIPTION("Qualcomm PCIe root complex driver"); > > +MODULE_LICENSE("GPL"); > > -- > > 2.35.1 > >
On Wed, Jul 27, 2022 at 03:02:57PM -0500, Bjorn Helgaas wrote: > On Thu, Jul 21, 2022 at 02:35:13PM -0500, Bjorn Helgaas wrote: > > On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > > > Allow the Qualcomm PCIe controller driver to be built as a module, which > > > is useful for multi-platform kernels as well as during development. > > > > > > Reviewed-by: Rob Herring <robh@kernel.org> > > > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > > > > Applied to pci/ctrl/qcom for v5.20, thanks! > > I'm going to drop this one for now, since the module vs remove > discussion [1] is still ongoing. > > This patch actually makes it both *modular* and *removable*. I think > the modular part is uncontroversial and valuable by itself. > > If you want to just make it modular and *non*-removable, I think that > would be fine and we can add removability next cycle if we think it's > safe. > > [1] https://lore.kernel.org/r/20220721195433.GA1747571@bhelgaas Nah, I prefer we conclude that discussion so that hopefully this can be merged as is. Johan
Hi Lorenzo, On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > Allow the Qualcomm PCIe controller driver to be built as a module, which > is useful for multi-platform kernels as well as during development. > > Reviewed-by: Rob Herring <robh@kernel.org> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > --- > > Changes in v2 > - rebase on next-20220720 (adjust context) > - add Rob and Mani's reviewed-by tags Have you had a change to look at this one since you got back from vacation? I believe this should be uncontroversial as we already have other modular dwc drivers and there's no mapping of legacy INTx interrupts involved. > drivers/pci/controller/dwc/Kconfig | 2 +- > drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++--- > 2 files changed, 34 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig > index 62ce3abf0f19..230f56d1a268 100644 > --- a/drivers/pci/controller/dwc/Kconfig > +++ b/drivers/pci/controller/dwc/Kconfig > @@ -168,7 +168,7 @@ config PCI_HISI > Hip05 and Hip06 SoCs > > config PCIE_QCOM > - bool "Qualcomm PCIe controller" > + tristate "Qualcomm PCIe controller" > depends on OF && (ARCH_QCOM || COMPILE_TEST) > depends on PCI_MSI_IRQ_DOMAIN > select PCIE_DW_HOST > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > index 5ed164c2afa3..d176c635016b 100644 > --- a/drivers/pci/controller/dwc/pcie-qcom.c > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > @@ -16,7 +16,7 @@ > #include <linux/io.h> > #include <linux/iopoll.h> > #include <linux/kernel.h> > -#include <linux/init.h> > +#include <linux/module.h> > #include <linux/of_device.h> > #include <linux/of_gpio.h> > #include <linux/pci.h> > @@ -1518,6 +1518,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) > return ret; > } > > +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie) > +{ > + qcom_ep_reset_assert(pcie); > + if (pcie->cfg->ops->post_deinit) > + pcie->cfg->ops->post_deinit(pcie); > + phy_power_off(pcie->phy); > + pcie->cfg->ops->deinit(pcie); > +} > + > static const struct dw_pcie_host_ops qcom_pcie_dw_ops = { > .host_init = qcom_pcie_host_init, > }; > @@ -1752,6 +1761,22 @@ static int qcom_pcie_probe(struct platform_device *pdev) > return ret; > } > > +static int qcom_pcie_remove(struct platform_device *pdev) > +{ > + struct qcom_pcie *pcie = platform_get_drvdata(pdev); > + struct device *dev = &pdev->dev; > + > + dw_pcie_host_deinit(&pcie->pci->pp); > + qcom_pcie_host_deinit(pcie); > + > + phy_exit(pcie->phy); > + > + pm_runtime_put_sync(dev); > + pm_runtime_disable(dev); > + > + return 0; > +} > + > static const struct of_device_id qcom_pcie_match[] = { > { .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg }, > { .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg }, > @@ -1771,6 +1796,7 @@ static const struct of_device_id qcom_pcie_match[] = { > { .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg }, > { } > }; > +MODULE_DEVICE_TABLE(of, qcom_pcie_match); > > static void qcom_fixup_class(struct pci_dev *dev) > { > @@ -1786,10 +1812,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class); > > static struct platform_driver qcom_pcie_driver = { > .probe = qcom_pcie_probe, > + .remove = qcom_pcie_remove, > .driver = { > .name = "qcom-pcie", > - .suppress_bind_attrs = true, > .of_match_table = qcom_pcie_match, > }, > }; > -builtin_platform_driver(qcom_pcie_driver); > +module_platform_driver(qcom_pcie_driver); > + > +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>"); > +MODULE_DESCRIPTION("Qualcomm PCIe root complex driver"); > +MODULE_LICENSE("GPL"); Johan
Hi Johan, Thanks for the patch. On 7/21/22 09:47, Johan Hovold wrote: > Allow the Qualcomm PCIe controller driver to be built as a module, which > is useful for multi-platform kernels as well as during development. > > Reviewed-by: Rob Herring <robh@kernel.org> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > --- > > Changes in v2 > - rebase on next-20220720 (adjust context) > - add Rob and Mani's reviewed-by tags > > > drivers/pci/controller/dwc/Kconfig | 2 +- > drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++--- > 2 files changed, 34 insertions(+), 4 deletions(-) Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>
On Tue, Sep 20, 2022 at 10:47:56AM +0200, Johan Hovold wrote: > Hi Lorenzo, > > On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > > Allow the Qualcomm PCIe controller driver to be built as a module, which > > is useful for multi-platform kernels as well as during development. > > > > Reviewed-by: Rob Herring <robh@kernel.org> > > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > > --- > > > > Changes in v2 > > - rebase on next-20220720 (adjust context) > > - add Rob and Mani's reviewed-by tags > > Have you had a change to look at this one since you got back from > vacation? > > I believe this should be uncontroversial as we already have other > modular dwc drivers and there's no mapping of legacy INTx interrupts > involved. I'm not Lorenzo, but was there a conclusive outcome to the thread at [1]? The last thing I remember was that a buggy endpoint driver that failed to unmap all its interrupts could cause crashes if the PCIe controller driver was removed. Making the driver modular is essential so distros can build all the drivers and users can load the one needed by their platform. Making the driver removable is useful for developers but not for users, so I don't see it as essential. Developers are in the business of developing and can easily carry a trivial out-of-tree patch to add removability if needed. If removability is actually safe even if endpoint drivers aren't perfect, then I don't object to it. But if it's not always safe, I don't think the argument that "other drivers do it" is strong. I'd rather make all the drivers safe even if that means making them non-removable. [1] https://lore.kernel.org/r/20220721195433.GA1747571@bhelgaas > > drivers/pci/controller/dwc/Kconfig | 2 +- > > drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++--- > > 2 files changed, 34 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig > > index 62ce3abf0f19..230f56d1a268 100644 > > --- a/drivers/pci/controller/dwc/Kconfig > > +++ b/drivers/pci/controller/dwc/Kconfig > > @@ -168,7 +168,7 @@ config PCI_HISI > > Hip05 and Hip06 SoCs > > > > config PCIE_QCOM > > - bool "Qualcomm PCIe controller" > > + tristate "Qualcomm PCIe controller" > > depends on OF && (ARCH_QCOM || COMPILE_TEST) > > depends on PCI_MSI_IRQ_DOMAIN > > select PCIE_DW_HOST > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > > index 5ed164c2afa3..d176c635016b 100644 > > --- a/drivers/pci/controller/dwc/pcie-qcom.c > > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > > @@ -16,7 +16,7 @@ > > #include <linux/io.h> > > #include <linux/iopoll.h> > > #include <linux/kernel.h> > > -#include <linux/init.h> > > +#include <linux/module.h> > > #include <linux/of_device.h> > > #include <linux/of_gpio.h> > > #include <linux/pci.h> > > @@ -1518,6 +1518,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) > > return ret; > > } > > > > +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie) > > +{ > > + qcom_ep_reset_assert(pcie); > > + if (pcie->cfg->ops->post_deinit) > > + pcie->cfg->ops->post_deinit(pcie); > > + phy_power_off(pcie->phy); > > + pcie->cfg->ops->deinit(pcie); > > +} > > + > > static const struct dw_pcie_host_ops qcom_pcie_dw_ops = { > > .host_init = qcom_pcie_host_init, > > }; > > @@ -1752,6 +1761,22 @@ static int qcom_pcie_probe(struct platform_device *pdev) > > return ret; > > } > > > > +static int qcom_pcie_remove(struct platform_device *pdev) > > +{ > > + struct qcom_pcie *pcie = platform_get_drvdata(pdev); > > + struct device *dev = &pdev->dev; > > + > > + dw_pcie_host_deinit(&pcie->pci->pp); > > + qcom_pcie_host_deinit(pcie); > > + > > + phy_exit(pcie->phy); > > + > > + pm_runtime_put_sync(dev); > > + pm_runtime_disable(dev); > > + > > + return 0; > > +} > > + > > static const struct of_device_id qcom_pcie_match[] = { > > { .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg }, > > { .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg }, > > @@ -1771,6 +1796,7 @@ static const struct of_device_id qcom_pcie_match[] = { > > { .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg }, > > { } > > }; > > +MODULE_DEVICE_TABLE(of, qcom_pcie_match); > > > > static void qcom_fixup_class(struct pci_dev *dev) > > { > > @@ -1786,10 +1812,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class); > > > > static struct platform_driver qcom_pcie_driver = { > > .probe = qcom_pcie_probe, > > + .remove = qcom_pcie_remove, > > .driver = { > > .name = "qcom-pcie", > > - .suppress_bind_attrs = true, > > .of_match_table = qcom_pcie_match, > > }, > > }; > > -builtin_platform_driver(qcom_pcie_driver); > > +module_platform_driver(qcom_pcie_driver); > > + > > +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>"); > > +MODULE_DESCRIPTION("Qualcomm PCIe root complex driver"); > > +MODULE_LICENSE("GPL"); > > Johan
On Tue, Sep 20, 2022 at 08:37:54AM -0500, Bjorn Helgaas wrote: > On Tue, Sep 20, 2022 at 10:47:56AM +0200, Johan Hovold wrote: > > Hi Lorenzo, > > > > On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > > > Allow the Qualcomm PCIe controller driver to be built as a module, which > > > is useful for multi-platform kernels as well as during development. > > > > > > Reviewed-by: Rob Herring <robh@kernel.org> > > > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > > > --- > > > > > > Changes in v2 > > > - rebase on next-20220720 (adjust context) > > > - add Rob and Mani's reviewed-by tags > > > > Have you had a change to look at this one since you got back from > > vacation? > > > > I believe this should be uncontroversial as we already have other > > modular dwc drivers and there's no mapping of legacy INTx interrupts > > involved. > > I'm not Lorenzo, but was there a conclusive outcome to the thread at > [1]? The last thing I remember was that a buggy endpoint driver that > failed to unmap all its interrupts could cause crashes if the PCIe > controller driver was removed. That's not so much an argument against allowing the PCIe controller driver to be unbound as it is an argument for preventing endpoint drivers from being unbound. And they generally need to be able to unbind due to hotplugging, right? > Making the driver modular is essential so distros can build all the > drivers and users can load the one needed by their platform. > > Making the driver removable is useful for developers but not for > users, so I don't see it as essential. Developers are in the business > of developing and can easily carry a trivial out-of-tree patch to add > removability if needed. Having modular drivers that can be unloaded is a debugging feature. I believe I already posted this quote from Linus: The proper thing to do (and what we _have_ done) is to say "unloading of modules is not supported". It's a debugging feature, and you literally shouldn't do it unless you are actively developing that module. https://lore.kernel.org/all/Pine.LNX.4.58.0401251054340.18932@home.osdl.org/ And no, keeping such patches out-of-tree is not an option as it prevents sharing them with others and they will quickly bit rot. > If removability is actually safe even if endpoint drivers aren't > perfect, then I don't object to it. But if it's not always safe, I > don't think the argument that "other drivers do it" is strong. I'd > rather make all the drivers safe even if that means making them > non-removable. If we have buggy endpoint drivers we need fix them regardless. Allowing this fundamental debugging feature will even allow developers to catch those bugs sooner. And this is really no different from any other type of bug in endpoint drivers; a failure to deregister a class device on unbind would lead to crashes due to use-after-free, etc. > [1] https://lore.kernel.org/r/20220721195433.GA1747571@bhelgaas Johan
On Tue, Sep 20, 2022 at 08:37:54AM -0500, Bjorn Helgaas wrote: > On Tue, Sep 20, 2022 at 10:47:56AM +0200, Johan Hovold wrote: > > Hi Lorenzo, > > > > On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > > > Allow the Qualcomm PCIe controller driver to be built as a module, which > > > is useful for multi-platform kernels as well as during development. > > > > > > Reviewed-by: Rob Herring <robh@kernel.org> > > > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > > > --- > > > > > > Changes in v2 > > > - rebase on next-20220720 (adjust context) > > > - add Rob and Mani's reviewed-by tags > > > > Have you had a change to look at this one since you got back from > > vacation? > > > > I believe this should be uncontroversial as we already have other > > modular dwc drivers and there's no mapping of legacy INTx interrupts > > involved. > > I'm not Lorenzo, but was there a conclusive outcome to the thread at > [1]? The last thing I remember was that a buggy endpoint driver that > failed to unmap all its interrupts could cause crashes if the PCIe > controller driver was removed. > > Making the driver modular is essential so distros can build all the > drivers and users can load the one needed by their platform. > > Making the driver removable is useful for developers but not for > users, so I don't see it as essential. Developers are in the business > of developing and can easily carry a trivial out-of-tree patch to add > removability if needed. > > If removability is actually safe even if endpoint drivers aren't > perfect, then I don't object to it. But if it's not always safe, I > don't think the argument that "other drivers do it" is strong. I'd > rather make all the drivers safe even if that means making them > non-removable. > If the problem is with the endpoint drivers, then those need to be fixed for properly disposing the IRQ mappings. I don't see any real issue with the remove() handler of this controller driver. Thanks, Mani > [1] https://lore.kernel.org/r/20220721195433.GA1747571@bhelgaas > > > > drivers/pci/controller/dwc/Kconfig | 2 +- > > > drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++--- > > > 2 files changed, 34 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig > > > index 62ce3abf0f19..230f56d1a268 100644 > > > --- a/drivers/pci/controller/dwc/Kconfig > > > +++ b/drivers/pci/controller/dwc/Kconfig > > > @@ -168,7 +168,7 @@ config PCI_HISI > > > Hip05 and Hip06 SoCs > > > > > > config PCIE_QCOM > > > - bool "Qualcomm PCIe controller" > > > + tristate "Qualcomm PCIe controller" > > > depends on OF && (ARCH_QCOM || COMPILE_TEST) > > > depends on PCI_MSI_IRQ_DOMAIN > > > select PCIE_DW_HOST > > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > > > index 5ed164c2afa3..d176c635016b 100644 > > > --- a/drivers/pci/controller/dwc/pcie-qcom.c > > > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > > > @@ -16,7 +16,7 @@ > > > #include <linux/io.h> > > > #include <linux/iopoll.h> > > > #include <linux/kernel.h> > > > -#include <linux/init.h> > > > +#include <linux/module.h> > > > #include <linux/of_device.h> > > > #include <linux/of_gpio.h> > > > #include <linux/pci.h> > > > @@ -1518,6 +1518,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) > > > return ret; > > > } > > > > > > +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie) > > > +{ > > > + qcom_ep_reset_assert(pcie); > > > + if (pcie->cfg->ops->post_deinit) > > > + pcie->cfg->ops->post_deinit(pcie); > > > + phy_power_off(pcie->phy); > > > + pcie->cfg->ops->deinit(pcie); > > > +} > > > + > > > static const struct dw_pcie_host_ops qcom_pcie_dw_ops = { > > > .host_init = qcom_pcie_host_init, > > > }; > > > @@ -1752,6 +1761,22 @@ static int qcom_pcie_probe(struct platform_device *pdev) > > > return ret; > > > } > > > > > > +static int qcom_pcie_remove(struct platform_device *pdev) > > > +{ > > > + struct qcom_pcie *pcie = platform_get_drvdata(pdev); > > > + struct device *dev = &pdev->dev; > > > + > > > + dw_pcie_host_deinit(&pcie->pci->pp); > > > + qcom_pcie_host_deinit(pcie); > > > + > > > + phy_exit(pcie->phy); > > > + > > > + pm_runtime_put_sync(dev); > > > + pm_runtime_disable(dev); > > > + > > > + return 0; > > > +} > > > + > > > static const struct of_device_id qcom_pcie_match[] = { > > > { .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg }, > > > { .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg }, > > > @@ -1771,6 +1796,7 @@ static const struct of_device_id qcom_pcie_match[] = { > > > { .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg }, > > > { } > > > }; > > > +MODULE_DEVICE_TABLE(of, qcom_pcie_match); > > > > > > static void qcom_fixup_class(struct pci_dev *dev) > > > { > > > @@ -1786,10 +1812,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class); > > > > > > static struct platform_driver qcom_pcie_driver = { > > > .probe = qcom_pcie_probe, > > > + .remove = qcom_pcie_remove, > > > .driver = { > > > .name = "qcom-pcie", > > > - .suppress_bind_attrs = true, > > > .of_match_table = qcom_pcie_match, > > > }, > > > }; > > > -builtin_platform_driver(qcom_pcie_driver); > > > +module_platform_driver(qcom_pcie_driver); > > > + > > > +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>"); > > > +MODULE_DESCRIPTION("Qualcomm PCIe root complex driver"); > > > +MODULE_LICENSE("GPL"); > > > > Johan
On Tue, Sep 20, 2022 at 10:47:56AM +0200, Johan Hovold wrote: > Hi Lorenzo, > > On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > > Allow the Qualcomm PCIe controller driver to be built as a module, which > > is useful for multi-platform kernels as well as during development. > > > > Reviewed-by: Rob Herring <robh@kernel.org> > > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > > --- > > > > Changes in v2 > > - rebase on next-20220720 (adjust context) > > - add Rob and Mani's reviewed-by tags > > Have you had a change to look at this one since you got back from > vacation? > > I believe this should be uncontroversial as we already have other > modular dwc drivers and there's no mapping of legacy INTx interrupts > involved. Sincere apologies for the delay. I am afraid it does look controversial - I need some time to go through the full discussion and make up my mind, unfortunately we are late in the cycle and I am dealing with the patch backlog, I believe this may end up being a discussion targeting the v6.2 merge window I am afraid. Lorenzo > > drivers/pci/controller/dwc/Kconfig | 2 +- > > drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++--- > > 2 files changed, 34 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig > > index 62ce3abf0f19..230f56d1a268 100644 > > --- a/drivers/pci/controller/dwc/Kconfig > > +++ b/drivers/pci/controller/dwc/Kconfig > > @@ -168,7 +168,7 @@ config PCI_HISI > > Hip05 and Hip06 SoCs > > > > config PCIE_QCOM > > - bool "Qualcomm PCIe controller" > > + tristate "Qualcomm PCIe controller" > > depends on OF && (ARCH_QCOM || COMPILE_TEST) > > depends on PCI_MSI_IRQ_DOMAIN > > select PCIE_DW_HOST > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > > index 5ed164c2afa3..d176c635016b 100644 > > --- a/drivers/pci/controller/dwc/pcie-qcom.c > > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > > @@ -16,7 +16,7 @@ > > #include <linux/io.h> > > #include <linux/iopoll.h> > > #include <linux/kernel.h> > > -#include <linux/init.h> > > +#include <linux/module.h> > > #include <linux/of_device.h> > > #include <linux/of_gpio.h> > > #include <linux/pci.h> > > @@ -1518,6 +1518,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) > > return ret; > > } > > > > +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie) > > +{ > > + qcom_ep_reset_assert(pcie); > > + if (pcie->cfg->ops->post_deinit) > > + pcie->cfg->ops->post_deinit(pcie); > > + phy_power_off(pcie->phy); > > + pcie->cfg->ops->deinit(pcie); > > +} > > + > > static const struct dw_pcie_host_ops qcom_pcie_dw_ops = { > > .host_init = qcom_pcie_host_init, > > }; > > @@ -1752,6 +1761,22 @@ static int qcom_pcie_probe(struct platform_device *pdev) > > return ret; > > } > > > > +static int qcom_pcie_remove(struct platform_device *pdev) > > +{ > > + struct qcom_pcie *pcie = platform_get_drvdata(pdev); > > + struct device *dev = &pdev->dev; > > + > > + dw_pcie_host_deinit(&pcie->pci->pp); > > + qcom_pcie_host_deinit(pcie); > > + > > + phy_exit(pcie->phy); > > + > > + pm_runtime_put_sync(dev); > > + pm_runtime_disable(dev); > > + > > + return 0; > > +} > > + > > static const struct of_device_id qcom_pcie_match[] = { > > { .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg }, > > { .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg }, > > @@ -1771,6 +1796,7 @@ static const struct of_device_id qcom_pcie_match[] = { > > { .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg }, > > { } > > }; > > +MODULE_DEVICE_TABLE(of, qcom_pcie_match); > > > > static void qcom_fixup_class(struct pci_dev *dev) > > { > > @@ -1786,10 +1812,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class); > > > > static struct platform_driver qcom_pcie_driver = { > > .probe = qcom_pcie_probe, > > + .remove = qcom_pcie_remove, > > .driver = { > > .name = "qcom-pcie", > > - .suppress_bind_attrs = true, > > .of_match_table = qcom_pcie_match, > > }, > > }; > > -builtin_platform_driver(qcom_pcie_driver); > > +module_platform_driver(qcom_pcie_driver); > > + > > +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>"); > > +MODULE_DESCRIPTION("Qualcomm PCIe root complex driver"); > > +MODULE_LICENSE("GPL"); > > Johan
On Tue, Sep 27, 2022 at 03:28:09PM +0200, Lorenzo Pieralisi wrote: > On Tue, Sep 20, 2022 at 10:47:56AM +0200, Johan Hovold wrote: > > Hi Lorenzo, > > > > On Thu, Jul 21, 2022 at 08:47:20AM +0200, Johan Hovold wrote: > > > Allow the Qualcomm PCIe controller driver to be built as a module, which > > > is useful for multi-platform kernels as well as during development. > > > > > > Reviewed-by: Rob Herring <robh@kernel.org> > > > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > > > --- > > > > > > Changes in v2 > > > - rebase on next-20220720 (adjust context) > > > - add Rob and Mani's reviewed-by tags > > > > Have you had a change to look at this one since you got back from > > vacation? > > > > I believe this should be uncontroversial as we already have other > > modular dwc drivers and there's no mapping of legacy INTx interrupts > > involved. > > Sincere apologies for the delay. > > I am afraid it does look controversial - I need some time to go through > the full discussion and make up my mind, unfortunately we are late in > the cycle and I am dealing with the patch backlog, I believe this may > end up being a discussion targeting the v6.2 merge window I am afraid. No worries. Thanks for taking a look. Johan
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig index 62ce3abf0f19..230f56d1a268 100644 --- a/drivers/pci/controller/dwc/Kconfig +++ b/drivers/pci/controller/dwc/Kconfig @@ -168,7 +168,7 @@ config PCI_HISI Hip05 and Hip06 SoCs config PCIE_QCOM - bool "Qualcomm PCIe controller" + tristate "Qualcomm PCIe controller" depends on OF && (ARCH_QCOM || COMPILE_TEST) depends on PCI_MSI_IRQ_DOMAIN select PCIE_DW_HOST diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 5ed164c2afa3..d176c635016b 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -16,7 +16,7 @@ #include <linux/io.h> #include <linux/iopoll.h> #include <linux/kernel.h> -#include <linux/init.h> +#include <linux/module.h> #include <linux/of_device.h> #include <linux/of_gpio.h> #include <linux/pci.h> @@ -1518,6 +1518,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) return ret; } +static void qcom_pcie_host_deinit(struct qcom_pcie *pcie) +{ + qcom_ep_reset_assert(pcie); + if (pcie->cfg->ops->post_deinit) + pcie->cfg->ops->post_deinit(pcie); + phy_power_off(pcie->phy); + pcie->cfg->ops->deinit(pcie); +} + static const struct dw_pcie_host_ops qcom_pcie_dw_ops = { .host_init = qcom_pcie_host_init, }; @@ -1752,6 +1761,22 @@ static int qcom_pcie_probe(struct platform_device *pdev) return ret; } +static int qcom_pcie_remove(struct platform_device *pdev) +{ + struct qcom_pcie *pcie = platform_get_drvdata(pdev); + struct device *dev = &pdev->dev; + + dw_pcie_host_deinit(&pcie->pci->pp); + qcom_pcie_host_deinit(pcie); + + phy_exit(pcie->phy); + + pm_runtime_put_sync(dev); + pm_runtime_disable(dev); + + return 0; +} + static const struct of_device_id qcom_pcie_match[] = { { .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg }, { .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg }, @@ -1771,6 +1796,7 @@ static const struct of_device_id qcom_pcie_match[] = { { .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg }, { } }; +MODULE_DEVICE_TABLE(of, qcom_pcie_match); static void qcom_fixup_class(struct pci_dev *dev) { @@ -1786,10 +1812,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_QCOM, 0x1001, qcom_fixup_class); static struct platform_driver qcom_pcie_driver = { .probe = qcom_pcie_probe, + .remove = qcom_pcie_remove, .driver = { .name = "qcom-pcie", - .suppress_bind_attrs = true, .of_match_table = qcom_pcie_match, }, }; -builtin_platform_driver(qcom_pcie_driver); +module_platform_driver(qcom_pcie_driver); + +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>"); +MODULE_DESCRIPTION("Qualcomm PCIe root complex driver"); +MODULE_LICENSE("GPL");