On 26/10/10 02:10, Emilio G. Cota wrote: > From: Emilio G. Cota <[email protected]> > > In a configuration with several bridges, each bridge is > assigned a certain bus number depending on the order in which > vme_register_bridge is called. This can complicate multi-bridge > installations because the eventual bus numbers will depend > on the order the bridges were loaded. > > The appended allows bridges to register with a bus number of > their choice, while keeping the previous 'first come, first > served' behaviour as the default. >
I can't see where this is being used. I assume this is a part of future changes you wish to make? Martyn > Signed-off-by: Emilio G. Cota <[email protected]> > --- > drivers/staging/vme/bridges/vme_ca91cx42.c | 1 + > drivers/staging/vme/bridges/vme_tsi148.c | 1 + > drivers/staging/vme/vme.c | 46 > +++++++++++++++++++++------- > drivers/staging/vme/vme.h | 1 + > 4 files changed, 38 insertions(+), 11 deletions(-) > > diff --git a/drivers/staging/vme/bridges/vme_ca91cx42.c > b/drivers/staging/vme/bridges/vme_ca91cx42.c > index 1f2089f..14e10a6 100644 > --- a/drivers/staging/vme/bridges/vme_ca91cx42.c > +++ b/drivers/staging/vme/bridges/vme_ca91cx42.c > @@ -1600,6 +1600,7 @@ static int ca91cx42_probe(struct pci_dev *pdev, const > struct pci_device_id *id) > } > > ca91cx42_bridge->driver_priv = ca91cx42_device; > + ca91cx42_bridge->num = -1; > > /* Enable the device */ > retval = pci_enable_device(pdev); > diff --git a/drivers/staging/vme/bridges/vme_tsi148.c > b/drivers/staging/vme/bridges/vme_tsi148.c > index 1cba1fa..e341122 100644 > --- a/drivers/staging/vme/bridges/vme_tsi148.c > +++ b/drivers/staging/vme/bridges/vme_tsi148.c > @@ -2247,6 +2247,7 @@ static int tsi148_probe(struct pci_dev *pdev, const > struct pci_device_id *id) > } > > tsi148_bridge->driver_priv = tsi148_device; > + tsi148_bridge->num = -1; > > /* Enable the device */ > retval = pci_enable_device(pdev); > diff --git a/drivers/staging/vme/vme.c b/drivers/staging/vme/vme.c > index 47e9d5c..9fa0609 100644 > --- a/drivers/staging/vme/vme.c > +++ b/drivers/staging/vme/vme.c > @@ -1307,20 +1307,42 @@ EXPORT_SYMBOL(vme_slot_get); > > /* - Bridge Registration --------------------------------------------------- > */ > > -static int vme_alloc_bus_num(void) > +/* call with vme_bus_num_mtx held */ > +static int __vme_alloc_bus_num(int *bus) > { > - int i; > - > - mutex_lock(&vme_bus_num_mtx); > - for (i = 0; i < sizeof(vme_bus_numbers) * 8; i++) { > - if (((vme_bus_numbers >> i) & 0x1) == 0) { > - vme_bus_numbers |= (0x1 << i); > - break; > + int index; > + > + if (*bus == -1) { > + /* try to find a free bus number */ > + for (index = 0; index < VME_MAX_BRIDGES; index++) { > + if (~vme_bus_numbers & 1 << index) { > + *bus = index; > + break; > + } > + } > + if (index == VME_MAX_BRIDGES) { > + pr_warn("vme: No bus numbers left\n"); > + return -ENODEV; > + } > + } else { > + /* check if the given bus number is already in use */ > + if (vme_bus_numbers & (1 << *bus)) { > + pr_warn("vme: bus number %d already in use\n", *bus); > + return -EBUSY; > } > } > - mutex_unlock(&vme_bus_num_mtx); > + vme_bus_numbers |= 1 << *bus; > + return 0; > +} > + > +static int vme_alloc_bus_num(int *bus) > +{ > + int ret; > > - return i; > + mutex_lock(&vme_bus_num_mtx); > + ret = __vme_alloc_bus_num(bus); > + mutex_unlock(&vme_bus_num_mtx); > + return ret; > } > > static void vme_free_bus_num(int bus) > @@ -1336,7 +1358,9 @@ int vme_register_bridge(struct vme_bridge *bridge) > int retval; > int i; > > - bridge->num = vme_alloc_bus_num(); > + retval = vme_alloc_bus_num(&bridge->num); > + 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 > diff --git a/drivers/staging/vme/vme.h b/drivers/staging/vme/vme.h > index 48768ca..5cdfa52 100644 > --- a/drivers/staging/vme/vme.h > +++ b/drivers/staging/vme/vme.h > @@ -88,6 +88,7 @@ struct vme_resource { > > extern struct bus_type vme_bus_type; > > +#define VME_MAX_BRIDGES 32 > #define VME_SLOT_CURRENT -1 > #define VME_SLOT_ALL -2 > -- 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
