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[added,to,the,4.1,stable,tree] PCI: Update BARs using property bits appropriate for type

Message ID 20180118205908.3220-78-alexander.levin@microsoft.com
State New
Headers show
Series [added,to,the,4.1,stable,tree] PCI: Update BARs using property bits appropriate for type | expand

Commit Message

Sasha Levin Jan. 18, 2018, 9 p.m. UTC 
From: Sumit Semwal <sumit.semwal@linaro.org>


This patch has been added to the  stable tree. If you have any
objections, please let us know.

-- 
2.11.0
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Patch

===============

[ Upstream commit 45d004f4afefdd8d79916ee6d97a9ecd94bb1ffe ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/pci/setup-res.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index b1b88bfaddc0..00f32ff6f74e 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -53,12 +53,17 @@  static void pci_std_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;
+	}
 
 	if (resno < PCI_ROM_RESOURCE) {
 		reg = PCI_BASE_ADDRESS_0 + 4 * resno;