Messages in this thread | | | Date | Mon, 4 Aug 2008 00:38:33 -0600 | From | Grant Grundler <> | Subject | Re: [PATCH 3/3] PCI: Add pci_read_base() API |
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On Mon, Jul 28, 2008 at 01:39:01PM -0400, Matthew Wilcox wrote: > Some devices have a BAR at a non-standard address. The pci_read_base() > API allows us to probe these BARs and fill in a resource for it as if > they were standard BARs.
Willy, Can you add a comment to the code listing the offending device? That way we know how to test next time this code changes.
thanks, grant
> > Signed-off-by: Matthew Wilcox <willy@linux.intel.com> > --- > drivers/pci/probe.c | 47 ++++++++++++++++++++++++++++++++++++++++------- > include/linux/pci.h | 10 ++++++++++ > 2 files changed, 50 insertions(+), 7 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 2036300..a977d07 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -181,13 +181,6 @@ static u64 pci_size(u64 base, u64 maxbase, u64 mask) > return size; > } > > -enum pci_bar_type { > - pci_bar_unknown, /* Standard PCI BAR probe */ > - pci_bar_io, /* An io port BAR */ > - pci_bar_mem32, /* A 32-bit memory BAR */ > - pci_bar_mem64, /* A 64-bit memory BAR */ > -}; > - > static inline enum pci_bar_type decode_bar(struct resource *res, u32 bar) > { > if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) { > @@ -300,6 +293,46 @@ static int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > goto out; > } > > +/** > + * pci_read_base - Read a BAR from a specified location > + * @dev: The PCI device to read > + * @type: The type of BAR to read > + * @res: A struct resource to be filled in > + * @reg: The address in PCI config space to read the BAR from. > + * > + * Some devices have BARs in unusual places. This function lets a driver ask > + * the PCI subsystem to read it and place it in the resource tree. If it is > + * like a ROM BAR with an enable in bit 0, the caller should specify a @type > + * of io, mem32 or mem64. If it's like a normal BAR with memory type in the > + * low bits, specify unknown, even if the caller knows what kind of BAR it is. > + * > + * Returns -ENXIO if the BAR was not successfully read. If the BAR is read, > + * but no suitable parent resource can be found for the BAR, this function > + * returns -ENODEV. If the resource cannot be inserted into the resource tree, > + * it will return -EBUSY. Note that the resource is still 'live' for these > + * last two cases; the caller should set res->flags to 0 if this is not wanted. > + */ > +int pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > + struct resource *res, unsigned int reg) > +{ > + struct pci_bus_region region; > + struct resource *parent; > + > + __pci_read_base(dev, type, res, reg); > + if (!res->flags) > + return -ENXIO; > + > + region.start = res->start; > + region.end = res->end; > + pcibios_bus_to_resource(dev, res, ®ion); > + > + parent = pci_find_parent_resource(dev, res); > + if (!parent) > + return -ENODEV; > + return request_resource(parent, res); > +} > +EXPORT_SYMBOL_GPL(pci_read_base); > + > static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) > { > unsigned int pos, reg; > diff --git a/include/linux/pci.h b/include/linux/pci.h > index a6a088e..f6ad5e8 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -310,6 +310,16 @@ struct pci_bus { > #define pci_bus_b(n) list_entry(n, struct pci_bus, node) > #define to_pci_bus(n) container_of(n, struct pci_bus, dev) > > +enum pci_bar_type { > + pci_bar_unknown, /* Standard PCI BAR probe */ > + pci_bar_io, /* An io port BAR */ > + pci_bar_mem32, /* A 32-bit memory BAR */ > + pci_bar_mem64, /* A 64-bit memory BAR */ > +}; > + > +int pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > + struct resource *res, unsigned int reg); > + > /* > * Error values that may be returned by PCI functions. > */ > -- > 1.5.5.4 > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
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