[PATCH 9/9] PCI: Don't enable decoding if BAR hasn't been assigned an address

From: Bjorn Helgaas
Date: Wed Feb 26 2014 - 14:38:18 EST


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@xxxxxxxxxx>
---
drivers/pci/setup-res.c | 10 ++++++++--
1 file 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;
}


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