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[3/8] PCI: Update BARs using property bits appropriate for type

Message ID 1484343099-26786-4-git-send-email-tim.gardner@canonical.com
State New
Headers show

Commit Message

Tim Gardner Jan. 13, 2017, 9:31 p.m. UTC 
From: Bjorn Helgaas <bhelgaas@google.com>

BugLink: http://bugs.launchpad.net/bugs/1625318

The BAR property bits (0-3 for memory BARs, 0-1 for I/O BARs) are supposed
to be read-only, but we do save them in res->flags and include them when
updating the BAR.

Mask the I/O property bits with ~PCI_BASE_ADDRESS_IO_MASK (0x3) instead of
PCI_REGION_FLAG_MASK (0xf) to make it obvious that we can't corrupt bits
2-3 of I/O addresses.

Use PCI_ROM_ADDRESS_MASK for ROM BARs.  This means we'll only check the top
21 bits (instead of the 28 bits we used to check) of a ROM BAR to see if
the update was successful.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
(cherry picked from commit 45d004f4afefdd8d79916ee6d97a9ecd94bb1ffe)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
 drivers/pci/setup-res.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)
diff mbox

Patch

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 8f32dac..98c17b4 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -59,12 +59,17 @@  void pci_update_resource(struct pci_dev *dev, int resno)
 		return;
 
 	pcibios_resource_to_bus(dev->bus, &region, res);
+	new = region.start;
 
-	new = region.start | (res->flags & PCI_REGION_FLAG_MASK);
-	if (res->flags & IORESOURCE_IO)
+	if (res->flags & IORESOURCE_IO) {
 		mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
-	else
+		new |= res->flags & ~PCI_BASE_ADDRESS_IO_MASK;
+	} else if (resno == PCI_ROM_RESOURCE) {
+		mask = (u32)PCI_ROM_ADDRESS_MASK;
+	} else {
 		mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
+		new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
+	}
 
 	reg = pci_resource_bar(dev, resno, &type);
 	if (!reg)