This is a note to let you know that I've just added the patch titled
PCI: Restore detection of read-only BARs
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-restore-detection-of-read-only-bars.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 36e8164882ca6d3c41cb91e6f09a3ed236841f80 Mon Sep 17 00:00:00 2001
From: Myron Stowe <[email protected]>
Date: Thu, 30 Oct 2014 11:54:37 -0600
Subject: PCI: Restore detection of read-only BARs
From: Myron Stowe <[email protected]>
commit 36e8164882ca6d3c41cb91e6f09a3ed236841f80 upstream.
Commit 6ac665c63dca ("PCI: rewrite PCI BAR reading code") masked off
low-order bits from 'l', but not from 'sz'. Both are passed to pci_size(),
which compares 'base == maxbase' to check for read-only BARs. The masking
of 'l' means that comparison will never be 'true', so the check for
read-only BARs no longer works.
Resolve this by also masking off the low-order bits of 'sz' before passing
it into pci_size() as 'maxbase'. With this change, pci_size() will once
again catch the problems that have been encountered to date:
- AGP aperture BAR of AMD-7xx host bridges: if the AGP window is
disabled, this BAR is read-only and read as 0x00000008 [1]
- BARs 0-4 of ALi IDE controllers can be non-zero and read-only [1]
- Intel Sandy Bridge - Thermal Management Controller [8086:0103];
BAR 0 returning 0xfed98004 [2]
- Intel Xeon E5 v3/Core i7 Power Control Unit [8086:2fc0];
Bar 0 returning 0x00001a [3]
Link: [1]
https://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/drivers/pci/probe.c?id=1307ef6621991f1c4bc3cec1b5a4ebd6fd3d66b9
("PCI: probing read-only BARs" (pre-git))
Link: [2] https://bugzilla.kernel.org/show_bug.cgi?id=43331
Link: [3] https://bugzilla.kernel.org/show_bug.cgi?id=85991
Reported-by: William Unruh <[email protected]>
Reported-by: Martin Lucina <[email protected]>
Signed-off-by: Myron Stowe <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
CC: Matthew Wilcox <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/pci/probe.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -210,14 +210,17 @@ int __pci_read_base(struct pci_dev *dev,
res->flags |= IORESOURCE_SIZEALIGN;
if (res->flags & IORESOURCE_IO) {
l &= PCI_BASE_ADDRESS_IO_MASK;
+ sz &= PCI_BASE_ADDRESS_IO_MASK;
mask = PCI_BASE_ADDRESS_IO_MASK & (u32) IO_SPACE_LIMIT;
} else {
l &= PCI_BASE_ADDRESS_MEM_MASK;
+ sz &= PCI_BASE_ADDRESS_MEM_MASK;
mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
}
} else {
res->flags |= (l & IORESOURCE_ROM_ENABLE);
l &= PCI_ROM_ADDRESS_MASK;
+ sz &= PCI_ROM_ADDRESS_MASK;
mask = (u32)PCI_ROM_ADDRESS_MASK;
}
Patches currently in stable-queue which might be from [email protected] are
queue-3.10/pci-restore-detection-of-read-only-bars.patch
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