Commit 81699d8a authored by Anthony Liguori's avatar Anthony Liguori Committed by Michael S. Tsirkin
Browse files

qbus: add functions to walk both devices and busses 



There are some cases where you want to walk the busses, in particular, when
searching for a bus either by name or DeviceInfo.
Paolo suggested that we model the return values on how GCC's walkers work which
allows an actor to skip child transversal, or terminate walking with a positive
value that's returned as the qbus_walk_children's result.

Signed-off-by: default avatarIsaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 0389ced4

hw/qdev.c

+46 −0
Original line number Diff line number Diff line
@@ -449,6 +449,52 @@ BusState *qdev_get_child_bus(DeviceState *dev, const char *name) 
    return NULL;

}



int qbus_walk_children(BusState *bus, qdev_walkerfn *devfn,

                       qbus_walkerfn *busfn, void *opaque)

{

    DeviceState *dev;

    int err;



    if (busfn) {

        err = busfn(bus, opaque);

        if (err) {

            return err;

        }

    }



    QLIST_FOREACH(dev, &bus->children, sibling) {

        err = qdev_walk_children(dev, devfn, busfn, opaque);

        if (err < 0) {

            return err;

        }

    }



    return 0;

}



int qdev_walk_children(DeviceState *dev, qdev_walkerfn *devfn,

                       qbus_walkerfn *busfn, void *opaque)

{

    BusState *bus;

    int err;



    if (devfn) {

        err = devfn(dev, opaque);

        if (err) {

            return err;

        }

    }



    QLIST_FOREACH(bus, &dev->child_bus, sibling) {

        err = qbus_walk_children(bus, devfn, busfn, opaque);

        if (err < 0) {

            return err;

        }

    }



    return 0;

}



static BusState *qbus_find_recursive(BusState *bus, const char *name,

                                     const BusInfo *info)

{

hw/qdev.h

+11 −0
Original line number Diff line number Diff line
@@ -173,9 +173,20 @@ BusState *qdev_get_parent_bus(DeviceState *dev); 


/*** BUS API. ***/



/* Returns 0 to walk children, > 0 to skip walk, < 0 to terminate walk. */

typedef int (qbus_walkerfn)(BusState *bus, void *opaque);

typedef int (qdev_walkerfn)(DeviceState *dev, void *opaque);



void qbus_create_inplace(BusState *bus, BusInfo *info,

                         DeviceState *parent, const char *name);

BusState *qbus_create(BusInfo *info, DeviceState *parent, const char *name);

/* Returns > 0 if either devfn or busfn skip walk somewhere in cursion,

 *         < 0 if either devfn or busfn terminate walk somewhere in cursion,

 *           0 otherwise. */

int qbus_walk_children(BusState *bus, qdev_walkerfn *devfn,

                       qbus_walkerfn *busfn, void *opaque);

int qdev_walk_children(DeviceState *dev, qdev_walkerfn *devfn,

                       qbus_walkerfn *busfn, void *opaque);

void qbus_free(BusState *bus);



#define FROM_QBUS(type, dev) DO_UPCAST(type, qbus, dev)