Some BIOSes incorrectly use standard memory resource ranges to list

the memory ranges that they decode for downstream devices rather than
creating ResourceProducer range resource entries.  The result is that
we allocate the full range to the PCI root bridge device causing
allocations in child devices to all fail.

As a workaround, ignore any standard memory resources on a PCI root
bridge device.  It is normal for a PCI root bridge to allocate an I/O
resource for the I/O ports used for PCI config access, but I have not
seen any PCI root bridges that legitimately allocate a memory resource.

Reviewed by:	jkim
MFC after:	1 week

1 files changed, 16 insertions, 0 deletions

diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index d17245e..dee0c46 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -1190,12 +1190,28 @@ acpi_set_resource(device_t dev, device_t child, int type, int rid,
     struct acpi_softc *sc = device_get_softc(dev);
     struct acpi_device *ad = device_get_ivars(child);
     struct resource_list *rl = &ad->ad_rl;
+    ACPI_DEVICE_INFO *devinfo;
     u_long end;
     
     /* Ignore IRQ resources for PCI link devices. */
     if (type == SYS_RES_IRQ && ACPI_ID_PROBE(dev, child, pcilink_ids) != NULL)
 	return (0);
 
+    /*
+     * Ignore memory resources for PCI root bridges.  Some BIOSes
+     * incorrectly enumerate the memory ranges they decode as plain
+     * memory resources instead of as a ResourceProducer range.
+     */
+    if (type == SYS_RES_MEMORY) {
+	if (ACPI_SUCCESS(AcpiGetObjectInfo(ad->ad_handle, &devinfo))) {
+	    if ((devinfo->Flags & ACPI_PCI_ROOT_BRIDGE) != 0) {
+		AcpiOsFree(devinfo);
+		return (0);
+	    }
+	    AcpiOsFree(devinfo);
+	}
+    }
+
     /* If the resource is already allocated, fail. */
     if (resource_list_busy(rl, type, rid))
 	return (EBUSY);