[PATCH v8 4/9] pci: OF: Fix the conversion of IO ranges into IO resources.

Rob Herring
2014-07-05T19:25:52Z

On Tue, Jul 1, 2014 at 1:43 PM, 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 IO_SPACE_LIMIT.
> The conversion from pci ranges to resources failed to take that into account.

I don't think this change is right. There are 2 resources: the PCI bus
addresses and cpu addresses. This function deals with the cpu
addresses. Returning pci addresses for i/o and cpu addresses for
memory is going to be error prone. We probably need both cpu and pci
resources exposed to host controllers.

Making the new function only deal with i/o bus resources and naming it
of_pci_range_to_io_resource would be better.

Rob

> In the process move the function into drivers/of/address.c as it now
> depends on pci_address_to_pio() code and make it return an error message.
>
> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
> Tested-by: Tanmay Inamdar <tinamdar@apm.com>
> ---
> drivers/of/address.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/of_address.h | 13 ++-----------
> 2 files changed, 49 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 1345733..cbbaed2 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -872,3 +872,50 @@ bool of_dma_is_coherent(struct device_node *np)
> return false;
> }
> EXPORT_SYMBOL_GPL(of_dma_is_coherent);
> +
> +/*
> + * 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.
> + *
> + * Returns EINVAL if the range cannot be converted to resource.
> + *
> + * 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 too early or
> + * if the range cannot be matched to any host bridge IO space (our case here).
> + * To guard against that we try to register the IO range first.
> + * If that fails we know that pci_address_to_pio() will do too.
> + */
> +int of_pci_range_to_resource(struct of_pci_range *range,
> + struct device_node *np, struct resource *res)
> +{
> + int err;
> + res->flags = range->flags;
> + res->parent = res->child = res->sibling = NULL;
> + res->name = np->full_name;
> +
> + if (res->flags & IORESOURCE_IO) {
> + unsigned long port = -1;
> + err = pci_register_io_range(range->cpu_addr, range->size);
> + if (err)
> + goto invalid_range;
> + port = pci_address_to_pio(range->cpu_addr);
> + if (port == (unsigned long)-1) {
> + err = -EINVAL;
> + goto invalid_range;
> + }
> + res->start = port;
> + } else {
> + res->start = range->cpu_addr;
> + }
> + res->end = res->start + range->size - 1;
> + return 0;
> +
> +invalid_range:
> + res->start = (resource_size_t)OF_BAD_ADDR;
> + res->end = (resource_size_t)OF_BAD_ADDR;
> + return err;
> +}
> +
> diff --git a/include/linux/of_address.h b/include/linux/of_address.h
> index ac4aac4..33c0420 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 int 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);
> --
> 2.0.0
>
>
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