On Tue, 2014-09-23 at 16:46 +0200, Antonios Motakis wrote: > As already demonstrated with PCI [1] and the platform bus [2], a > driver_override property in sysfs can be used to bypass the id matching > of a device to a AMBA driver. This can be used by VFIO to bind to any AMBA > device requested by the user. > > [1] http://lists-archives.com/linux-kernel/28030441-pci-introduce-new-device-binding-path-using-pci_dev-driver_override.html > [2] https://www.redhat.com/archives/libvir-list/2014-April/msg00382.html > > Signed-off-by: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx> > --- > drivers/amba/bus.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/amba/bus.h | 1 + > 2 files changed, 45 insertions(+) Why are 7 & 8 being dragged into this series? Combine them into a single patch and post it separately. > > diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c > index 3cf61a1..473177c 100644 > --- a/drivers/amba/bus.c > +++ b/drivers/amba/bus.c > @@ -17,6 +17,7 @@ > #include <linux/pm_runtime.h> > #include <linux/amba/bus.h> > #include <linux/sizes.h> > +#include <linux/limits.h> > > #include <asm/irq.h> > > @@ -42,6 +43,10 @@ static int amba_match(struct device *dev, struct device_driver *drv) > struct amba_device *pcdev = to_amba_device(dev); > struct amba_driver *pcdrv = to_amba_driver(drv); > > + /* When driver_override is set, only bind to the matching driver */ > + if (pcdev->driver_override) > + return !strcmp(pcdev->driver_override, drv->name); > + > return amba_lookup(pcdrv->id_table, pcdev) != NULL; > } > > @@ -58,6 +63,44 @@ static int amba_uevent(struct device *dev, struct kobj_uevent_env *env) > return retval; > } > > +static ssize_t driver_override_show(struct device *_dev, > + struct device_attribute *attr, char *buf) > +{ > + struct amba_device *dev = to_amba_device(_dev); > + > + return sprintf(buf, "%s\n", dev->driver_override); > +} > + > +static ssize_t driver_override_store(struct device *_dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct amba_device *dev = to_amba_device(_dev); > + char *driver_override, *old = dev->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)) { > + dev->driver_override = driver_override; > + } else { > + kfree(driver_override); > + dev->driver_override = NULL; > + } > + > + kfree(old); > + > + return count; > +} > + > #define amba_attr_func(name,fmt,arg...) \ > static ssize_t name##_show(struct device *_dev, \ > struct device_attribute *attr, char *buf) \ > @@ -80,6 +123,7 @@ amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n", > static struct device_attribute amba_dev_attrs[] = { > __ATTR_RO(id), > __ATTR_RO(resource), > + __ATTR_RW(driver_override), > __ATTR_NULL, > }; > > diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h > index fdd7e1b..7c011e7 100644 > --- a/include/linux/amba/bus.h > +++ b/include/linux/amba/bus.h > @@ -32,6 +32,7 @@ struct amba_device { > struct clk *pclk; > unsigned int periphid; > unsigned int irq[AMBA_NR_IRQS]; > + char *driver_override; > }; > > struct amba_driver { -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
