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If the kernel fails to allocate resources for the initial value of a BAR

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for a PCI device during the boot-time probe of the parent PCI bus, then
zero the BAR and clear the resource list entry for that BAR.  This forces
the PCI bus driver to request a valid resource range from the parent bridge
driver when the device driver tries to allocate the BAR.  Similarly, if the
initial value of a BAR is a valid range but it is > 4GB and the current OS
only has 32-bit longs, then do a full teardown of the initial value of the
BAR to force a reallocation.

Reviewed by:	imp
MFC after:	1 week
This commit is contained in:
John Baldwin 2008-08-05 18:24:41 +00:00
parent 9e58d59f41
commit e29bfa9ed9
1 changed files with 33 additions and 13 deletions
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46
sys/dev/pci/pci.c
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@ -2379,7 +2379,7 @@ pci_add_map(device_t pcib, device_t bus, device_t dev,
count = 1 << ln2size;
if (base == 0 || base == pci_mapbase(testval)) {
start = 0; /* Let the parent deside */
start = 0; /* Let the parent decide. */
end = ~0ULL;
} else {
start = base;
@ -2388,21 +2388,41 @@ pci_add_map(device_t pcib, device_t bus, device_t dev,
resource_list_add(rl, type, reg, start, end, count);
/*
* Not quite sure what to do on failure of allocating the resource
* since I can postulate several right answers.
* Try to allocate the resource for this BAR from our parent
* so that this resource range is already reserved. The
* driver for this device will later inherit this resource in
* pci_alloc_resource().
*/
res = resource_list_alloc(rl, bus, dev, type, &reg, start, end, count,
prefetch ? RF_PREFETCHABLE : 0);
if (res == NULL)
return (barlen);
start = rman_get_start(res);
if ((u_long)start != start) {
/* Wait a minute! this platform can't do this address. */
device_printf(bus,
"pci%d:%d.%d.%x bar %#x start %#jx, too many bits.",
pci_get_domain(dev), b, s, f, reg, (uintmax_t)start);
resource_list_release(rl, bus, dev, type, reg, res);
return (barlen);
if (res == NULL) {
/*
* If the allocation fails, clear the BAR and delete
* the resource list entry to force
* pci_alloc_resource() to allocate resources from the
* parent.
*/
resource_list_delete(rl, type, reg);
start = 0;
} else {
start = rman_get_start(res);
if ((u_long)start != start) {
/*
* Wait a minute! This platform can't do this
* address.
*/
device_printf(bus,
"pci%d:%d.%d.%x bar %#x start %#jx, too many bits.",
pci_get_domain(dev), b, s, f, reg,
(uintmax_t)start);
/*
* Delete this resource and zero the BAR.
*/
resource_list_release(rl, bus, dev, type, reg, res);
resource_list_delete(rl, type, reg);
start = 0;
}
}
pci_write_config(dev, reg, start, 4);
if (ln2range == 64)