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Allow direct children of PCI-ISA bridges to allocate resources from

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the parent PCI bus.

Heavily inspired by jhb@ and a similar implementation present in
sys/dev/pci/vga_pci.c.

Reviewed by:	jhb
Approved by:	jhb
This commit is contained in:
Henrik Brix Andersen 2011-05-13 15:06:35 +00:00
parent 4342b6100b
commit adc38bf22f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=221839
1 changed files with 111 additions and 7 deletions
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118
sys/dev/pci/isa_pci.c
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@ -45,12 +45,22 @@ __FBSDID("$FreeBSD$");
#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
static int isab_probe(device_t dev);
#include <machine/bus.h>
#include <sys/rman.h>
#include <machine/resource.h>
static int isab_pci_probe(device_t dev);
static int isab_pci_attach(device_t dev);
static struct resource * isab_pci_alloc_resource(device_t dev,
device_t child, int type, int *rid, u_long start, u_long end, u_long count,
u_int flags);
static int isab_pci_release_resource(device_t dev, device_t child,
int type, int rid, struct resource *r);
static device_method_t isab_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, isab_probe),
DEVMETHOD(device_attach, isab_attach),
DEVMETHOD(device_probe, isab_pci_probe),
DEVMETHOD(device_attach, isab_pci_attach),
DEVMETHOD(device_detach, bus_generic_detach),
DEVMETHOD(device_shutdown, bus_generic_shutdown),
DEVMETHOD(device_suspend, bus_generic_suspend),
@ -58,8 +68,8 @@ static device_method_t isab_methods[] = {
/* Bus interface */
DEVMETHOD(bus_print_child, bus_generic_print_child),
DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource),
DEVMETHOD(bus_release_resource, bus_generic_release_resource),
DEVMETHOD(bus_alloc_resource, isab_pci_alloc_resource),
DEVMETHOD(bus_release_resource, isab_pci_release_resource),
DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
DEVMETHOD(bus_setup_intr, bus_generic_setup_intr),
@ -68,10 +78,19 @@ static device_method_t isab_methods[] = {
{ 0, 0 }
};
struct isab_pci_resource {
struct resource *ip_res;
int ip_refs;
};
struct isab_pci_softc {
struct isab_pci_resource isab_pci_res[PCIR_MAX_BAR_0 + 1];
};
static driver_t isab_driver = {
"isab",
isab_methods,
0,
sizeof(struct isab_pci_softc),
};
DRIVER_MODULE(isab, pci, isab_driver, isab_devclass, 0, 0);
@ -81,7 +100,7 @@ DRIVER_MODULE(isab, pci, isab_driver, isab_devclass, 0, 0);
* report themselves.
*/
static int
isab_probe(device_t dev)
isab_pci_probe(device_t dev)
{
int matched = 0;
@ -139,3 +158,88 @@ isab_probe(device_t dev)
}
return(ENXIO);
}
static int
isab_pci_attach(device_t dev)
{
bus_generic_probe(dev);
return (isab_attach(dev));
}
static struct resource *
isab_pci_alloc_resource(device_t dev, device_t child, int type, int *rid,
u_long start, u_long end, u_long count, u_int flags)
{
struct isab_pci_softc *sc;
int bar;
if (device_get_parent(child) != dev)
return bus_generic_alloc_resource(dev, child, type, rid, start,
end, count, flags);
switch (type) {
case SYS_RES_MEMORY:
case SYS_RES_IOPORT:
/*
* For BARs, we cache the resource so that we only allocate it
* from the PCI bus once.
*/
bar = PCI_RID2BAR(*rid);
if (bar < 0 || bar > PCIR_MAX_BAR_0)
return (NULL);
sc = device_get_softc(dev);
if (sc->isab_pci_res[bar].ip_res == NULL)
sc->isab_pci_res[bar].ip_res = bus_alloc_resource(dev, type,
rid, start, end, count, flags);
if (sc->isab_pci_res[bar].ip_res != NULL)
sc->isab_pci_res[bar].ip_refs++;
return (sc->isab_pci_res[bar].ip_res);
}
return (BUS_ALLOC_RESOURCE(device_get_parent(dev), child, type, rid,
start, end, count, flags));
}
static int
isab_pci_release_resource(device_t dev, device_t child, int type, int rid,
struct resource *r)
{
struct isab_pci_softc *sc;
int bar, error;
if (device_get_parent(child) != dev)
return bus_generic_release_resource(dev, child, type, rid, r);
switch (type) {
case SYS_RES_MEMORY:
case SYS_RES_IOPORT:
/*
* For BARs, we release the resource from the PCI bus
* when the last child reference goes away.
*/
bar = PCI_RID2BAR(rid);
if (bar < 0 || bar > PCIR_MAX_BAR_0)
return (EINVAL);
sc = device_get_softc(dev);
if (sc->isab_pci_res[bar].ip_res == NULL)
return (EINVAL);
KASSERT(sc->isab_pci_res[bar].ip_res == r,
("isa_pci resource mismatch"));
if (sc->isab_pci_res[bar].ip_refs > 1) {
sc->isab_pci_res[bar].ip_refs--;
return (0);
}
KASSERT(sc->isab_pci_res[bar].ip_refs > 0,
("isa_pci resource reference count underflow"));
error = bus_release_resource(dev, type, rid, r);
if (error == 0) {
sc->isab_pci_res[bar].ip_res = NULL;
sc->isab_pci_res[bar].ip_refs = 0;
}
return (error);
}
return (BUS_RELEASE_RESOURCE(device_get_parent(dev), child, type,
rid, r));
}