On Wednesday 31 October 2012, Pratyush Anand wrote:

Sorry, I could not find pci_ioremap_io function. May be you wanted to 
refer something else.

$ git grep pci_ioremap_io
arch/arm/include/asm/io.h:extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr);
arch/arm/mach-dove/pcie.c:              pci_ioremap_io(sys->busnr * SZ_64K, DOVE_PCIE0_IO_PHYS_BASE);
...
arch/arm/mach-versatile/pci.c:  ret = pci_ioremap_io(0, VERSATILE_PCI_MEM_BASE0);
arch/arm/mm/ioremap.c:int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
arch/arm/mm/ioremap.c:EXPORT_SYMBOL_GPL(pci_ioremap_io);

In case of SPEAr too , we can reserve first 32Kb per controller as PCIe 
IO space. So, lets say I fixed address 0x80000000--0x80007FFF for IO 
transaction. I need to register address range of this window somehow.

But, issue which faced was that I was not able to successfully 
request_resource(&ioport_resource, &res]) with res.start = 0x80000000 
and res.end = 0x80007fff.

That cannot work properly, because the ioport_resource lists ports between
0 and 0x10000 normally, or possibly a little bit higher. You certainly
don't want to waste 2 GB of virtual address space for having a PCI I/O window
that you don't use.

So, I though first to change IO_SPACE_LIMIT. But I found it not a 
correct way.

May be I am missing something and not able to get how can I use 
pci_ioremap_io or something else to register 0x80000000--0x80007FFF 
window. A reference will help.

Calling pci_ioremap_io will do the right thing, you just have to decide
how you partition the I/O space between the root complexes you have.

	Arnd