[ ... ]
> > A PCI device driver want to tell the kernel:
> >
> > - Give me some MMIO handle to access this configured PCI BUS address range
> > on that PCI BUS, but I donnot care of how you will proceed for it.
> >
> > Instead of that, you tell the driver:
> >
> > - Provide ioremap() with some right-cooked address value supplied in the
> > pcidev structure and you will get some address-typed value to access the
> > device.
>
> Perhaps, but do not forget the needs of some lesser known programs like
> Xservers too, or propose a new interface for programs who need the
> equivalent of mmap on /dev/mem. And anyway the cooked value is the
> physical address on the processor pins as Martin repeated, it's not that
> artificial and it's the lesser evil we have to live with for 2.2.
Hi Gabriel,
I didn't write that I didn't want MMIO regions to be memory-mapped from
user space, nor I forget this need, and I will probably _never_ write
that. It is its memory-like based design that makes PCI so simple and
pleasant. I already wrote about what I think about hardwares that do not
have a unified memory addressing for all BUSES and host memory that break
the simplicity of PCI and introduced the complexity with addressing we
have to deal with.
I was only speaking about the base_addresses provided by the pci_dev
structure that has been presented as some input parameters for ioremap()
and told that this is _not_, in my opinion, what a PCI device driver
expects as kernel service, or at least _not_ enough.
I like oranges and apples as well, but dislike any mix of both, btw.
Regards,
Gérard.
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