Re: [PATCH 1/3] ARM: hackup pcibios support for commmon bridge code

[Bjorn Helgaas <bhelgaas@google.com>]

On Thu, Mar 27, 2014 at 05:46:36PM -0500, Rob Herring wrote:
> From: Rob Herring <robh@kernel.org>
> 
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
>  arch/arm/kernel/bios32.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 63 insertions(+)
> 
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index 317da88..31ec14a 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -11,6 +11,7 @@
>  #include <linux/slab.h>
>  #include <linux/init.h>
>  #include <linux/io.h>
> +#include <linux/of_pci.h>
>  
>  #include <asm/mach-types.h>
>  #include <asm/mach/map.h>
> @@ -337,6 +338,15 @@ void pcibios_fixup_bus(struct pci_bus *bus)
>  	list_for_each_entry(dev, &bus->devices, bus_list) {
>  		u16 cmd;
>  
> +		/* Ignore fully discovered devices */
> +		if (dev->is_added)
> +			continue;
> +
> +		set_dev_node(&dev->dev, pcibus_to_node(dev->bus));

We already do this in pci_device_add(); why do we need it here, too?

> +		/* Read default IRQs and fixup if necessary */
> +		dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);

Could this be done in pcibios_enable_device() or some other per-device
interface()?  I'd like to get rid of pcibios_fixup_bus() eventually.

>  		pci_read_config_word(dev, PCI_COMMAND, &cmd);
>  		cmd |= features;
>  		pci_write_config_word(dev, PCI_COMMAND, cmd);
> @@ -681,3 +691,56 @@ void __init pci_map_io_early(unsigned long pfn)
>  	pci_io_desc.pfn = pfn;
>  	iotable_init(&pci_io_desc, 1);
>  }
> +
> +struct ioresource {
> +	struct list_head list;
> +	phys_addr_t start;
> +	resource_size_t size;
> +};
> +
> +static LIST_HEAD(io_list);
> +
> +int pci_register_io_range(phys_addr_t address, resource_size_t size)
> +{
> +	struct ioresource *res;
> +	resource_size_t allocated_size = 0;
> +
> +	/* find if the range has not been already allocated */
> +	list_for_each_entry(res, &io_list, list) {
> +		if (address >= res->start &&
> +			address + size <= res->start + size)
> +			return 0;
> +		allocated_size += res->size;
> +	}
> +
> +	/* range not already registered, check for space */
> +	if (allocated_size + size > IO_SPACE_LIMIT)
> +		return -E2BIG;
> +
> +	/* add the range in the list */
> +	res = kzalloc(sizeof(*res), GFP_KERNEL);
> +	if (!res)
> +		return -ENOMEM;
> +	res->start = address;
> +	res->size = size;
> +
> +	list_add_tail(&res->list, &io_list);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(pci_register_io_range);
> +
> +unsigned long pci_address_to_pio(phys_addr_t address)
> +{
> +	struct ioresource *res;
> +
> +	list_for_each_entry(res, &io_list, list) {
> +		if (address >= res->start &&
> +			address < res->start + res->size) {
> +			return res->start - address;
> +		}
> +	}
> +
> +	return (unsigned long)-1;
> +}
> +EXPORT_SYMBOL_GPL(pci_address_to_pio);

ISTR some discussion about this, so maybe this has already been addressed,
but it doesn't seem right to export generically-named symbols like these
from the ARM arch code.  And they don't look very ARM-specific.

Bjorn