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| author | Bjorn Helgaas <bhelgaas@google.com> | 2011-06-14 19:04:29 (GMT) |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2011-07-22 16:06:58 (GMT) |
| commit | 8d6a6a47636648754dc371b01228520a2adaf430 (patch) | |
| tree | 5bab37b155798d9db8549fe6ee28499b1a5633c5 /drivers/pci | |
| parent | c9b378c7cbf623649e4ca64f955f2afd12ef01b2 (diff) | |
| download | linux-8d6a6a47636648754dc371b01228520a2adaf430.tar.xz | |
PCI: treat mem BAR type "11" (reserved) as 32-bit, not 64-bit, BAR
This fixes a minor regression where broken PCI devices that use the
reserved "11" memory BAR type worked before e354597cce but not after.
The low four bits of a memory BAR are "PTT0" where P=1 for prefetchable
BARs, and TT is as follows:
00 32-bit BAR, anywhere in lower 4GB
01 anywhere below 1MB (reserved as of PCI 2.2)
10 64-bit BAR
11 reserved
Prior to e354597cce, we treated "0100" as a 64-bit BAR and all others,
including prefetchable 64-bit BARs ("1100") as 32-bit BARs. The e354597cce
fix, which appeared in 2.6.28, treats "x1x0" as 64-bit BARs, so the
reserved "x110" types are treated as 64-bit instead of 32-bit.
This patch returns to treating the reserved "11" type as a 32-bit BAR and
adds a warning if we see it.
It also logs a note if we see a 1M BAR. This is not a warning, because
such hardware conforms to pre-PCI 2.2 spec, but I think it's worth noting
because Linux ignores the 1M restriction if it ever has to assign the BAR.
CC: Peter Chubb <peterc@gelato.unsw.edu.au>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=35952
Reported-by: Jan Zwiegers <jan@radicalsystems.co.za>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/probe.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index f03ed96..3e7a00a 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -100,8 +100,11 @@ static u64 pci_size(u64 base, u64 maxbase, u64 mask) return size; } -static inline enum pci_bar_type decode_bar(struct resource *res, u32 bar) +static inline enum pci_bar_type decode_bar(struct pci_dev *dev, + struct resource *res, u32 bar) { + u32 mem_type; + if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) { res->flags = bar & ~PCI_BASE_ADDRESS_IO_MASK; return pci_bar_io; @@ -109,8 +112,21 @@ static inline enum pci_bar_type decode_bar(struct resource *res, u32 bar) res->flags = bar & ~PCI_BASE_ADDRESS_MEM_MASK; - if (res->flags & PCI_BASE_ADDRESS_MEM_TYPE_64) + mem_type = bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK; + switch (mem_type) { + case PCI_BASE_ADDRESS_MEM_TYPE_32: + break; + case PCI_BASE_ADDRESS_MEM_TYPE_1M: + dev_info(&dev->dev, "1M mem BAR treated as 32-bit BAR\n"); + break; + case PCI_BASE_ADDRESS_MEM_TYPE_64: return pci_bar_mem64; + default: + dev_warn(&dev->dev, + "mem unknown type %x treated as 32-bit BAR\n", + mem_type); + break; + } return pci_bar_mem32; } @@ -164,7 +180,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, l = 0; if (type == pci_bar_unknown) { - type = decode_bar(res, l); + type = decode_bar(dev, res, l); res->flags |= pci_calc_resource_flags(l) | IORESOURCE_SIZEALIGN; if (type == pci_bar_io) { l &= PCI_BASE_ADDRESS_IO_MASK; |