On 12/08/11 11:30, Manohar Vanga wrote: > This patch adds a list which keeps track of all registered VME > buses. This is required for adding refcounting later to bridge > modules, something that is not currently implemented. > > This is based on the changes introduced by Emilio G. Cota in the > patch: > > https://lkml.org/lkml/2010/10/25/486 > > Signed-off-by: Manohar Vanga <[email protected]>
Acked-by: Martyn Welch <[email protected]> > --- > drivers/staging/vme/vme.c | 38 > +++++++++++++++++++++++--------------- > drivers/staging/vme/vme_bridge.h | 1 + > 2 files changed, 24 insertions(+), 15 deletions(-) > > diff --git a/drivers/staging/vme/vme.c b/drivers/staging/vme/vme.c > index d243a4a..feb2d00 100644 > --- a/drivers/staging/vme/vme.c > +++ b/drivers/staging/vme/vme.c > @@ -34,9 +34,10 @@ > #include "vme.h" > #include "vme_bridge.h" > > -/* Bitmask and mutex to keep track of bridge numbers */ > +/* Bitmask and list of registered buses both protected by common mutex */ > static unsigned int vme_bus_numbers; > -static DEFINE_MUTEX(vme_bus_num_mtx); > +static LIST_HEAD(vme_bus_list); > +static DEFINE_MUTEX(vme_buses_lock); > > static void __exit vme_exit(void); > static int __init vme_init(void); > @@ -1309,27 +1310,32 @@ EXPORT_SYMBOL(vme_slot_get); > > /* - Bridge Registration --------------------------------------------------- > */ > > -static int vme_alloc_bus_num(void) > +static int vme_add_bus(struct vme_bridge *bridge) > { > int i; > + int ret = -1; > > - mutex_lock(&vme_bus_num_mtx); > + mutex_lock(&vme_buses_lock); > for (i = 0; i < sizeof(vme_bus_numbers) * 8; i++) { > - if (((vme_bus_numbers >> i) & 0x1) == 0) { > - vme_bus_numbers |= (0x1 << i); > + if ((vme_bus_numbers & (1 << i)) == 0) { > + vme_bus_numbers |= (1 << i); > + bridge->num = i; > + list_add_tail(&bridge->bus_list, &vme_bus_list); > + ret = 0; > break; > } > } > - mutex_unlock(&vme_bus_num_mtx); > + mutex_unlock(&vme_buses_lock); > > - return i; > + return ret; > } > > -static void vme_free_bus_num(int bus) > +static void vme_remove_bus(struct vme_bridge *bridge) > { > - mutex_lock(&vme_bus_num_mtx); > - vme_bus_numbers &= ~(0x1 << bus); > - mutex_unlock(&vme_bus_num_mtx); > + mutex_lock(&vme_buses_lock); > + vme_bus_numbers &= ~(1 << bridge->num); > + list_del(&bridge->bus_list); > + mutex_unlock(&vme_buses_lock); > } > > int vme_register_bridge(struct vme_bridge *bridge) > @@ -1338,7 +1344,9 @@ int vme_register_bridge(struct vme_bridge *bridge) > int retval; > int i; > > - bridge->num = vme_alloc_bus_num(); > + retval = vme_add_bus(bridge); > + if (retval) > + return retval; > > /* This creates 32 vme "slot" devices. This equates to a slot for each > * ID available in a system conforming to the ANSI/VITA 1-1994 > @@ -1370,7 +1378,7 @@ err_reg: > dev = &bridge->dev[i]; > device_unregister(dev); > } > - vme_free_bus_num(bridge->num); > + vme_remove_bus(bridge); > return retval; > } > EXPORT_SYMBOL(vme_register_bridge); > @@ -1385,7 +1393,7 @@ void vme_unregister_bridge(struct vme_bridge *bridge) > dev = &bridge->dev[i]; > device_unregister(dev); > } > - vme_free_bus_num(bridge->num); > + vme_remove_bus(bridge); > } > EXPORT_SYMBOL(vme_unregister_bridge); > > diff --git a/drivers/staging/vme/vme_bridge.h > b/drivers/staging/vme/vme_bridge.h > index a9084f0..8959670 100644 > --- a/drivers/staging/vme/vme_bridge.h > +++ b/drivers/staging/vme/vme_bridge.h > @@ -112,6 +112,7 @@ struct vme_bridge { > /* Bridge Info - XXX Move to private structure? */ > struct device *parent; /* Parent device (eg. pdev->dev for PCI) */ > void *driver_priv; /* Private pointer for the bridge driver */ > + struct list_head bus_list; /* list of VME buses */ > > struct device dev[VME_SLOTS_MAX]; /* Device registered with > * device model on VME bus -- Martyn Welch (Principal Software Engineer) | Registered in England and GE Intelligent Platforms | Wales (3828642) at 100 T +44(0)127322748 | Barbirolli Square, Manchester, E [email protected] | M2 3AB VAT:GB 927559189 _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
