| Message ID | 20140602194258.5135925bf3c71b9c010fb409@freescale.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jun 02, 2014 at 07:42:58PM -0500, Kim Phillips wrote: > Needed by platform device drivers, such as the upcoming > vfio-platform driver, in order to bypass the existing OF, ACPI, > id_table and name string matches, and successfully be able to be > bound to any device, like so: > > echo vfio-platform > /sys/bus/platform/devices/fff51000.ethernet/driver_override > echo fff51000.ethernet > /sys/bus/platform/devices/fff51000.ethernet/driver/unbind > echo fff51000.ethernet > /sys/bus/platform/drivers_probe > > This mimics "PCI: Introduce new device binding path using > pci_dev.driver_override", which is an interface enhancement > for more deterministic PCI device binding, e.g., when in the > presence of hotplug. > > Reviewed-by: Alex Williamson <alex.williamson@redhat.com> > Reviewed-by: Alexander Graf <agraf@suse.de> > Reviewed-by: Stuart Yoder <stuart.yoder@freescale.com> > Signed-off-by: Kim Phillips <kim.phillips@freescale.com> > --- > Greg, > > This is largely identical to the PCI version of the same that has > been accepted for v3.16 and ack'd by you: > > https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009674.html > > and applied to Bjorn Helgaas' PCI tree: > > https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/commit/?h=pci/virtualization&id=782a985d7af26db39e86070d28f987cad21313c0 > > You are the platform driver core maintainer: can you apply this to > your driver-core tree now? Yes, I will after this merge window ends, it's too late for 3.16-rc1 with the window opening up a week early, sorry. greg k-h -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2 Jun 2014 21:28:42 -0700 Greg KH <gregkh@linuxfoundation.org> wrote: > On Mon, Jun 02, 2014 at 07:42:58PM -0500, Kim Phillips wrote: > > You are the platform driver core maintainer: can you apply this to > > your driver-core tree now? > > Yes, I will after this merge window ends, it's too late for 3.16-rc1 > with the window opening up a week early, sorry. How about now? fwiw, I just checked: it still applies cleanly. Thanks, Kim -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2 Jun 2014 21:28:42 -0700 Greg KH <gregkh@linuxfoundation.org> wrote: > On Mon, Jun 02, 2014 at 07:42:58PM -0500, Kim Phillips wrote: > > You are the platform driver core maintainer: can you apply this to > > your driver-core tree now? > > Yes, I will after this merge window ends, it's too late for 3.16-rc1 > with the window opening up a week early, sorry. Hi Greg, The merge window has ended, and I see commit activity on your driver-core tree's driver-core-next branch, but this patch is still missing: Do you think you can get around to applying it before the next merge window? Thanks, Kim -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jun 02, 2014 at 07:42:58PM -0500, Kim Phillips wrote: > Needed by platform device drivers, such as the upcoming > vfio-platform driver, in order to bypass the existing OF, ACPI, > id_table and name string matches, and successfully be able to be > bound to any device, like so: > > echo vfio-platform > /sys/bus/platform/devices/fff51000.ethernet/driver_override > echo fff51000.ethernet > /sys/bus/platform/devices/fff51000.ethernet/driver/unbind > echo fff51000.ethernet > /sys/bus/platform/drivers_probe > > This mimics "PCI: Introduce new device binding path using > pci_dev.driver_override", which is an interface enhancement > for more deterministic PCI device binding, e.g., when in the > presence of hotplug. > > Reviewed-by: Alex Williamson <alex.williamson@redhat.com> > Reviewed-by: Alexander Graf <agraf@suse.de> > Reviewed-by: Stuart Yoder <stuart.yoder@freescale.com> > Signed-off-by: Kim Phillips <kim.phillips@freescale.com> > --- > Greg, > > This is largely identical to the PCI version of the same that has > been accepted for v3.16 and ack'd by you: > > https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009674.html > > and applied to Bjorn Helgaas' PCI tree: > > https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/commit/?h=pci/virtualization&id=782a985d7af26db39e86070d28f987cad21313c0 > > You are the platform driver core maintainer: can you apply this to > your driver-core tree now? Sorry for the very long delay, it's now merged in my tree. Thanks for being persistant. greg k-h -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/ABI/testing/sysfs-bus-platform b/Documentation/ABI/testing/sysfs-bus-platform new file mode 100644 index 0000000..5172a61 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-platform @@ -0,0 +1,20 @@ +What: /sys/bus/platform/devices/.../driver_override +Date: April 2014 +Contact: Kim Phillips <kim.phillips@freescale.com> +Description: + This file allows the driver for a device to be specified which + will override standard OF, ACPI, ID table, and name matching. + When specified, only a driver with a name matching the value + written to driver_override will have an opportunity to bind + to the device. The override is specified by writing a string + to the driver_override file (echo vfio-platform > \ + driver_override) and may be cleared with an empty string + (echo > driver_override). This returns the device to standard + matching rules binding. Writing to driver_override does not + automatically unbind the device from its current driver or make + any attempt to automatically load the specified driver. If no + driver with a matching name is currently loaded in the kernel, + the device will not bind to any driver. This also allows + devices to opt-out of driver binding using a driver_override + name such as "none". Only a single driver may be specified in + the override, there is no support for parsing delimiters. diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 5b47210..4f47563 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -23,6 +23,7 @@ #include <linux/pm_runtime.h> #include <linux/idr.h> #include <linux/acpi.h> +#include <linux/limits.h> #include "base.h" #include "power/power.h" @@ -188,6 +189,7 @@ static void platform_device_release(struct device *dev) kfree(pa->pdev.dev.platform_data); kfree(pa->pdev.mfd_cell); kfree(pa->pdev.resource); + kfree(pa->pdev.driver_override); kfree(pa); } @@ -695,8 +697,49 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *a, } static DEVICE_ATTR_RO(modalias); +static ssize_t driver_override_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct platform_device *pdev = to_platform_device(dev); + char *driver_override, *old = pdev->driver_override, *cp; + + if (count > PATH_MAX) + return -EINVAL; + + driver_override = kstrndup(buf, count, GFP_KERNEL); + if (!driver_override) + return -ENOMEM; + + cp = strchr(driver_override, '\n'); + if (cp) + *cp = '\0'; + + if (strlen(driver_override)) { + pdev->driver_override = driver_override; + } else { + kfree(driver_override); + pdev->driver_override = NULL; + } + + kfree(old); + + return count; +} + +static ssize_t driver_override_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + + return sprintf(buf, "%s\n", pdev->driver_override); +} +static DEVICE_ATTR_RW(driver_override); + + static struct attribute *platform_dev_attrs[] = { &dev_attr_modalias.attr, + &dev_attr_driver_override.attr, NULL, }; ATTRIBUTE_GROUPS(platform_dev); @@ -752,6 +795,10 @@ static int platform_match(struct device *dev, struct device_driver *drv) struct platform_device *pdev = to_platform_device(dev); struct platform_driver *pdrv = to_platform_driver(drv); + /* When driver_override is set, only bind to the matching driver */ + if (pdev->driver_override) + return !strcmp(pdev->driver_override, drv->name); + /* Attempt an OF style match first */ if (of_driver_match_device(dev, drv)) return 1; diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 16f6654..153d303 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -28,6 +28,7 @@ struct platform_device { struct resource *resource; const struct platform_device_id *id_entry; + char *driver_override; /* Driver name to force a match */ /* MFD cell pointer */ struct mfd_cell *mfd_cell;