| Message ID | 20130819195917.9062.43580.stgit@bling.home (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Mon, Aug 19, 2013 at 2:04 PM, Alex Williamson <alex.williamson@redhat.com> wrote: > We have a pci_walk_bus() interface, but it's exceptionally cumbersome > for the callback function to figure out if the device is relevant if > the caller is trying to walk all the devices in or below a slot. Add > a variant to walk only slot devices. Is it really exceptionally cumbersome? You can supply the top-level slot in the userdata. Can you then use something like this in the callback? bool dev_below_slot(struct pci_dev *dev, struct pci_slot *slot) { if (!dev) return false; if (dev->slot == slot) return true; return dev_below_slot(dev->bus->self, slot); } Bjorn > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > > This allows me to use pci_walk_bus() and pci_walk_slot() instead of > rolling my own for iterating devices for bus/slot reset. Please > consider for 3.12 to go with the rest of the bus/slot infrastructure. > > drivers/pci/bus.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/pci.h | 2 ++ > 2 files changed, 58 insertions(+) > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > index b1ff02a..316579a 100644 > --- a/drivers/pci/bus.c > +++ b/drivers/pci/bus.c > @@ -283,6 +283,62 @@ void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), > } > EXPORT_SYMBOL_GPL(pci_walk_bus); > > +/** pci_walk_slot - walk devices in/under slot, calling callback. > + * @slot slot whose devices should be walked > + * @cb callback to be called for each device found > + * @userdata arbitrary pointer to be passed to callback. > + * > + * Walk the given slot, including any bridged devices > + * on buses under this slot. Call the provided callback > + * on each device found. > + * > + * We check the return of @cb each time. If it returns anything > + * other than 0, we break out. > + * > + */ > +void pci_walk_slot(struct pci_slot *slot, int (*cb)(struct pci_dev *, void *), > + void *userdata) > +{ > + struct pci_dev *dev; > + struct pci_bus *bus; > + struct list_head *next; > + int retval; > + > + bus = slot->bus; > + down_read(&pci_bus_sem); > + next = slot->bus->devices.next; > + for (;;) { > + if (next == &bus->devices) { > + /* end of this bus, go up or finish */ > + if (bus == slot->bus) > + break; > + next = bus->self->bus_list.next; > + bus = bus->self->bus; > + continue; > + } > + dev = list_entry(next, struct pci_dev, bus_list); > + > + /* skip anything on the top level bus not in our slot */ > + if (dev->bus == slot->bus && dev->slot != slot) { > + next = dev->bus_list.next; > + continue; > + } > + > + if (dev->subordinate) { > + /* this is a pci-pci bridge, do its devices next */ > + next = dev->subordinate->devices.next; > + bus = dev->subordinate; > + } else > + next = dev->bus_list.next; > + > + retval = cb(dev, userdata); > + if (retval) > + break; > + } > + up_read(&pci_bus_sem); > +} > +EXPORT_SYMBOL_GPL(pci_walk_slot); > + > struct pci_bus *pci_bus_get(struct pci_bus *bus) > { > if (bus) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index daf40cd..cbb291b 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1087,6 +1087,8 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, > > void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), > void *userdata); > +void pci_walk_slot(struct pci_slot *slot, int (*cb)(struct pci_dev *, void *), > + void *userdata); > int pci_cfg_space_size_ext(struct pci_dev *dev); > int pci_cfg_space_size(struct pci_dev *dev); > unsigned char pci_bus_max_busnr(struct pci_bus *bus); > -- 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 Thu, 2013-08-22 at 15:34 -0600, Bjorn Helgaas wrote: > On Mon, Aug 19, 2013 at 2:04 PM, Alex Williamson > <alex.williamson@redhat.com> wrote: > > We have a pci_walk_bus() interface, but it's exceptionally cumbersome > > for the callback function to figure out if the device is relevant if > > the caller is trying to walk all the devices in or below a slot. Add > > a variant to walk only slot devices. > > Is it really exceptionally cumbersome? You can supply the top-level > slot in the userdata. Can you then use something like this in the > callback? > > bool dev_below_slot(struct pci_dev *dev, struct pci_slot *slot) > { > if (!dev) > return false; > if (dev->slot == slot) > return true; > return dev_below_slot(dev->bus->self, slot); > } Maybe I should have said it's ugly and inefficient rather than cumbersome. This feels like a backwards way to do it, but if you don't want a walk_slot interface, then it looks like this would work. Thanks, Alex > > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > > --- > > > > This allows me to use pci_walk_bus() and pci_walk_slot() instead of > > rolling my own for iterating devices for bus/slot reset. Please > > consider for 3.12 to go with the rest of the bus/slot infrastructure. > > > > drivers/pci/bus.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/pci.h | 2 ++ > > 2 files changed, 58 insertions(+) > > > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > > index b1ff02a..316579a 100644 > > --- a/drivers/pci/bus.c > > +++ b/drivers/pci/bus.c > > @@ -283,6 +283,62 @@ void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), > > } > > EXPORT_SYMBOL_GPL(pci_walk_bus); > > > > +/** pci_walk_slot - walk devices in/under slot, calling callback. > > + * @slot slot whose devices should be walked > > + * @cb callback to be called for each device found > > + * @userdata arbitrary pointer to be passed to callback. > > + * > > + * Walk the given slot, including any bridged devices > > + * on buses under this slot. Call the provided callback > > + * on each device found. > > + * > > + * We check the return of @cb each time. If it returns anything > > + * other than 0, we break out. > > + * > > + */ > > +void pci_walk_slot(struct pci_slot *slot, int (*cb)(struct pci_dev *, void *), > > + void *userdata) > > +{ > > + struct pci_dev *dev; > > + struct pci_bus *bus; > > + struct list_head *next; > > + int retval; > > + > > + bus = slot->bus; > > + down_read(&pci_bus_sem); > > + next = slot->bus->devices.next; > > + for (;;) { > > + if (next == &bus->devices) { > > + /* end of this bus, go up or finish */ > > + if (bus == slot->bus) > > + break; > > + next = bus->self->bus_list.next; > > + bus = bus->self->bus; > > + continue; > > + } > > + dev = list_entry(next, struct pci_dev, bus_list); > > + > > + /* skip anything on the top level bus not in our slot */ > > + if (dev->bus == slot->bus && dev->slot != slot) { > > + next = dev->bus_list.next; > > + continue; > > + } > > + > > + if (dev->subordinate) { > > + /* this is a pci-pci bridge, do its devices next */ > > + next = dev->subordinate->devices.next; > > + bus = dev->subordinate; > > + } else > > + next = dev->bus_list.next; > > + > > + retval = cb(dev, userdata); > > + if (retval) > > + break; > > + } > > + up_read(&pci_bus_sem); > > +} > > +EXPORT_SYMBOL_GPL(pci_walk_slot); > > + > > struct pci_bus *pci_bus_get(struct pci_bus *bus) > > { > > if (bus) > > diff --git a/include/linux/pci.h b/include/linux/pci.h > > index daf40cd..cbb291b 100644 > > --- a/include/linux/pci.h > > +++ b/include/linux/pci.h > > @@ -1087,6 +1087,8 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, > > > > void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), > > void *userdata); > > +void pci_walk_slot(struct pci_slot *slot, int (*cb)(struct pci_dev *, void *), > > + void *userdata); > > int pci_cfg_space_size_ext(struct pci_dev *dev); > > int pci_cfg_space_size(struct pci_dev *dev); > > unsigned char pci_bus_max_busnr(struct pci_bus *bus); > > > -- > 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 -- 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
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index b1ff02a..316579a 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -283,6 +283,62 @@ void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), } EXPORT_SYMBOL_GPL(pci_walk_bus); +/** pci_walk_slot - walk devices in/under slot, calling callback. + * @slot slot whose devices should be walked + * @cb callback to be called for each device found + * @userdata arbitrary pointer to be passed to callback. + * + * Walk the given slot, including any bridged devices + * on buses under this slot. Call the provided callback + * on each device found. + * + * We check the return of @cb each time. If it returns anything + * other than 0, we break out. + * + */ +void pci_walk_slot(struct pci_slot *slot, int (*cb)(struct pci_dev *, void *), + void *userdata) +{ + struct pci_dev *dev; + struct pci_bus *bus; + struct list_head *next; + int retval; + + bus = slot->bus; + down_read(&pci_bus_sem); + next = slot->bus->devices.next; + for (;;) { + if (next == &bus->devices) { + /* end of this bus, go up or finish */ + if (bus == slot->bus) + break; + next = bus->self->bus_list.next; + bus = bus->self->bus; + continue; + } + dev = list_entry(next, struct pci_dev, bus_list); + + /* skip anything on the top level bus not in our slot */ + if (dev->bus == slot->bus && dev->slot != slot) { + next = dev->bus_list.next; + continue; + } + + if (dev->subordinate) { + /* this is a pci-pci bridge, do its devices next */ + next = dev->subordinate->devices.next; + bus = dev->subordinate; + } else + next = dev->bus_list.next; + + retval = cb(dev, userdata); + if (retval) + break; + } + up_read(&pci_bus_sem); +} +EXPORT_SYMBOL_GPL(pci_walk_slot); + struct pci_bus *pci_bus_get(struct pci_bus *bus) { if (bus) diff --git a/include/linux/pci.h b/include/linux/pci.h index daf40cd..cbb291b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1087,6 +1087,8 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), void *userdata); +void pci_walk_slot(struct pci_slot *slot, int (*cb)(struct pci_dev *, void *), + void *userdata); int pci_cfg_space_size_ext(struct pci_dev *dev); int pci_cfg_space_size(struct pci_dev *dev); unsigned char pci_bus_max_busnr(struct pci_bus *bus);
We have a pci_walk_bus() interface, but it's exceptionally cumbersome for the callback function to figure out if the device is relevant if the caller is trying to walk all the devices in or below a slot. Add a variant to walk only slot devices. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- This allows me to use pci_walk_bus() and pci_walk_slot() instead of rolling my own for iterating devices for bus/slot reset. Please consider for 3.12 to go with the rest of the bus/slot infrastructure. drivers/pci/bus.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 2 ++ 2 files changed, 58 insertions(+) -- 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