From 8d6a6a47636648754dc371b01228520a2adaf430 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 14 Jun 2011 13:04:29 -0600 Subject: [PATCH] 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 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=35952 Reported-by: Jan Zwiegers Signed-off-by: Bjorn Helgaas Signed-off-by: Jesse Barnes --- drivers/pci/probe.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index f03ed96533d5..3e7a00a3fc81 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;