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From: Arnd Bergmann <arnd@arndb.de>
To: Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH v11 10/10] PCI: Introduce pci_remap_iospace() for remapping PCI I/O bus resources into CPU space
Date: Sat, 20 Sep 2014 04:20:31 +0200
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Cc: Liviu Dudau <Liviu.Dudau@arm.com>, Rob Herring <robh+dt@kernel.org>,
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On Friday 19 September 2014, Bjorn Helgaas wrote:
> On Thu, Sep 18, 2014 at 02:30:25AM +0100, Liviu Dudau wrote:

> PCI_IOBASE is a virtual address.  So PCI_IOBASE + res->start is also a
> virtual address (only for IORESOURCE_IO).
> 
> Since res->start is normally a *physical* address, I think it would be less
> confusing to do something like this:
> 
>     vaddr = PCI_IOBASE + res->start;
>     ioremap_page_range(vaddr, vaddr + resource_size(res), ...);
> 
> so we have a hint that the first two ioremap_page_range() parameters are
> virtual addresses.  It's also confusing that it uses "unsigned long" for
> the virtual addresses, when we usually use "void *".  But that's out of
> scope for this patch.

Good idea. I think it will have to be (unsigned long)PCI_IOBASE above then,
since ioremap_page_range takes a 'unsigned long' virtual address and PCI_IOBASE
should really remain an __iomem pointer.

	Arnd