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    SubjectRe: [PATCH v2 1/4] pci: OF: Fix the conversion of IO ranges into IO resources.
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    On 27 February 2014 13:06, Liviu Dudau <Liviu.Dudau@arm.com> wrote:
    >
    > The ranges property for a host bridge controller in DT describes
    > the mapping between the PCI bus address and the CPU physical address.
    > The resources framework however expects that the IO resources start
    > at a pseudo "port" address 0 (zero) and have a maximum size of 64kb.

    Is this just in the case of ARM? (I've tried to keep up with the
    conversation, but apologies if I've misunderstood).

    > The conversion from pci ranges to resources failed to take that into
    > account.
    >
    > In the process move the function into drivers/of/address.c as it
    > now depends on pci_address_to_pio() code.
    >
    > Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
    >
    > diff --git a/drivers/of/address.c b/drivers/of/address.c
    > index 1a54f1f..7cf2b16 100644
    > --- a/drivers/of/address.c
    > +++ b/drivers/of/address.c
    > @@ -719,3 +719,34 @@ void __iomem *of_iomap(struct device_node *np, int index)
    > return ioremap(res.start, resource_size(&res));
    > }
    > EXPORT_SYMBOL(of_iomap);
    > +
    > +/**
    > + * of_pci_range_to_resource - Create a resource from an of_pci_range
    > + * @range: the PCI range that describes the resource
    > + * @np: device node where the range belongs to
    > + * @res: pointer to a valid resource that will be updated to
    > + * reflect the values contained in the range.
    > + * Note that if the range is an IO range, the resource will be converted
    > + * using pci_address_to_pio() which can fail if it is called to early or
    > + * if the range cannot be matched to any host bridge IO space.
    > + */
    > +void of_pci_range_to_resource(struct of_pci_range *range,
    > + struct device_node *np, struct resource *res)
    > +{
    > + res->flags = range->flags;
    > + if (res->flags & IORESOURCE_IO) {
    > + unsigned long port;
    > + port = pci_address_to_pio(range->pci_addr);

    Is this likely to break existing users of of_pci_range_to_resource?

    For example arch/mips: IO_SPACE_LIMIT defaults to 0xffff and there is
    no overridden implementation for pci_address_to_pio, therefore this
    will set res->start to OF_BAD_ADDR whereas previously it would have
    been the CPU address for I/O (assuming the cpu_addr was previously >
    64K).

    I have no idea if I/O previously worked for mips, but this patch seems
    to change that behavior. It may be a similar story for microblaze and
    powerpc.

    Andrew Murray

    > + if (port == (unsigned long)-1) {
    > + res->start = (resource_size_t)OF_BAD_ADDR;
    > + res->end = (resource_size_t)OF_BAD_ADDR;
    > + return;
    > + }
    > + res->start = port;
    > + } else {
    > + res->start = range->cpu_addr;
    > + }
    > + res->end = res->start + range->size - 1;
    > + res->parent = res->child = res->sibling = NULL;
    > + res->name = np->full_name;
    > +}
    > diff --git a/include/linux/of_address.h b/include/linux/of_address.h
    > index 5f6ed6b..a667762 100644
    > --- a/include/linux/of_address.h
    > +++ b/include/linux/of_address.h
    > @@ -23,17 +23,8 @@ struct of_pci_range {
    > #define for_each_of_pci_range(parser, range) \
    > for (; of_pci_range_parser_one(parser, range);)
    >
    > -static inline void of_pci_range_to_resource(struct of_pci_range *range,
    > - struct device_node *np,
    > - struct resource *res)
    > -{
    > - res->flags = range->flags;
    > - res->start = range->cpu_addr;
    > - res->end = range->cpu_addr + range->size - 1;
    > - res->parent = res->child = res->sibling = NULL;
    > - res->name = np->full_name;
    > -}
    > -
    > +extern void of_pci_range_to_resource(struct of_pci_range *range,
    > + struct device_node *np, struct resource *res);
    > /* Translate a DMA address from device space to CPU space */
    > extern u64 of_translate_dma_address(struct device_node *dev,
    > const __be32 *in_addr);
    > --
    > 1.9.0
    >
    > --
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