We need the entire downstream bus range, not just the base bus number, to
support _CBA. See the PCI Firmware spec, rev 3.0, sec 4.1.3. It's clear
that the bus range is supposed to be in _CRS, but if we don't find it there,
we'll assume [_BBN - 0xFF].
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx>
---
drivers/acpi/pci_root.c | 19 +++++++++++++------
include/acpi/acpi_bus.h | 1 +
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index aa9eeee..a3e6f0e 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -485,16 +485,22 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
/* Check _CRS first, then _BBN. If no _BBN, default to zero. */
secondary.start = 0;
+ secondary.end = 0xFF;
status = try_get_root_bridge_busnr(device->handle, &secondary);
- if (ACPI_SUCCESS(status)) {
- bus = secondary.start;
- } else {
+ if (ACPI_FAILURE(status)) {
+ /*
+ * We need both the start and end of the downstream bus range
+ * to interpret _CBA (MMCONFIG base address), so it really is
+ * supposed to be in _CRS.
+ */
+ printk(KERN_WARNING FW_BUG PREFIX
+ "no secondary bus range in _CRS\n");
status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL, &bus);
if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
- printk(KERN_ERR PREFIX
- "no bus number in _CRS and can't evaluate _BBN\n");
+ printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
return -ENODEV;
}
+ secondary.start = bus;
}
root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
@@ -504,7 +510,8 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
INIT_LIST_HEAD(&root->node);
root->device = device;
root->segment = segment & 0xFFFF;
- root->bus_nr = bus & 0xFF;
+ root->bus_nr = secondary.start & 0xFF;
+ root->subordinate_bus_nr = secondary.end & 0xFF;
strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
device->driver_data = root;
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 3cd9ccd..3d6e6e8 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -371,6 +371,7 @@ struct acpi_pci_root {
struct pci_bus *bus;
u16 segment;
u8 bus_nr;
+ u8 subordinate_bus_nr;
u32 osc_support_set; /* _OSC state of support bits */
u32 osc_control_set; /* _OSC state of control bits */
--
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