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| author | Myron Stowe <myron.stowe@redhat.com> | 2014-10-30 20:54:37 +0300 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2015-01-05 16:48:41 +0300 |
| commit | 587764b042c0b7723ea381cd650ce2773ece93e8 (patch) | |
| tree | 8a3e1b3ef982494d9ef576150ba8fca5f0fba107 | |
| parent | 518206ca234906f9fe7278f64dcf39a5ea00425e (diff) | |
| download | linux-587764b042c0b7723ea381cd650ce2773ece93e8.tar.xz | |
PCI: Restore detection of read-only BARs
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 <unruh@physics.ubc.ca>
Reported-by: Martin Lucina <martin@lucina.net>
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
| -rw-r--r-- | drivers/pci/probe.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 9cce960029aa..f096079d1fa3 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -215,14 +215,17 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, 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; } |