On Thu, May 5, 2016 at 3:02 PM, Benjamin Herrenschmidt
<b...@kernel.crashing.org> wrote:
> On Thu, 2016-05-05 at 08:53 -0700, Yinghai Lu wrote:
>> For powerpc io port, we still need extra offset from resource address
>> to final address.
>>
>> resource_size_t offset =
>> ((resource_size_t)vma->vm_pgoff) << PAGE_SHIFT;
>>
>> + if (mmap_state == pci_mmap_io) {
>> + struct pci_controller *hose = pci_bus_to_host(dev->bus);
>> +
>> + /* hose should never be NULL */
>> + offset += hose->io_base_phys -
>> + ((unsigned long)hose->io_base_virt - _IO_BASE);
>> + }
>>
>> vma->vm_pgoff = offset >> PAGE_SHIFT;
>>
>> but sparc does not need that trick.
>
> I'm not sure how sparc handles IO space but on powerpc, the IO resource
> is not a physical address, it's a virtual address (coming from
> ioremap).
That is interesting. Any reason for that ?
why just cpu_addr in resource directly ?
Thanks
Yinghai
