PCI: Don't enable decoding if BAR hasn't been assigned an address

Don't enable memory or I/O decoding if we haven't assigned or claimed the
BAR's resource.

If we enable decoding for a BAR that hasn't been assigned an address, we'll
likely cause bus conflicts.  This declines to enable decoding for resources
with IORESOURCE_UNSET.

Note that drivers can use pci_enable_device_io() or pci_enable_device_mem()
if they only care about specific types of BARs.  In that case, we don't
bother checking whether the corresponding resources are assigned or
claimed.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 6e443135ba24..7eed671d5586 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -343,9 +343,15 @@ int pci_enable_resources(struct pci_dev *dev, int mask)
                                 (!(r->flags & IORESOURCE_ROM_ENABLE)))
                         continue;
 
+                if (r->flags & IORESOURCE_UNSET) {
+                        dev_err(&dev->dev, "can't enable device: BAR %d %pR not assigned\n",
+                                i, r);
+                        return -EINVAL;
+                }
+
                 if (!r->parent) {
-                        dev_err(&dev->dev, "device not available "
-                                "(can't reserve %pR)\n", r);
+                        dev_err(&dev->dev, "can't enable device: BAR %d %pR not claimed\n",
+                                i, r);
                         return -EINVAL;
                 }