From mboxrd@z Thu Jan  1 00:00:00 1970
From: Robert Richter <rric@kernel.org>
Subject: Re: [PATCH v11 10/10] PCI: Introduce pci_remap_iospace() for
 remapping PCI I/O bus resources into CPU space
Date: Mon, 22 Sep 2014 17:29:48 +0200
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To: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>, Liviu Dudau <Liviu.Dudau@arm.com>, Rob Herring <robh+dt@kernel.org>, Jason Gunthorpe <jgunthorpe@obsidianresearch.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <Will.Deacon@arm.com>, Russell King <linux@arm.linux.org.uk>, linux-pci <linux-pci@vger.kernel.org>, Linus Walleij <linus.walleij@linaro.org>, Tanmay Inamdar <tinamdar@apm.com>, Grant Likely <grant.likely@secretlab.ca>, Sinan Kaya <okaya@codeaurora.org>, Jingoo Han <jg1.han@samsung.com>, Kukjin Kim <kgene.kim@samsung.com>, Suravee Suthikulanit <suravee.suthikulpanit@amd.com>, linux-arch <linux-arch@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>, Device Tree ML <devicetree@vger.kernel.org>, LAKML <linux-arm-kernel@lists.infradead.org>

On 20.09.14 04:20:31, Arnd Bergmann wrote:
> On Friday 19 September 2014, Bjorn Helgaas wrote:
> > On Thu, Sep 18, 2014 at 02:30:25AM +0100, Liviu Dudau wrote:
>=20
> > PCI_IOBASE is a virtual address.  So PCI_IOBASE + res->start is als=
o a
> > virtual address (only for IORESOURCE_IO).
> >=20
> > Since res->start is normally a *physical* address, I think it would=
 be less
> > confusing to do something like this:
> >=20
> >     vaddr =3D PCI_IOBASE + res->start;
> >     ioremap_page_range(vaddr, vaddr + resource_size(res), ...);
> >=20
> > so we have a hint that the first two ioremap_page_range() parameter=
s are
> > virtual addresses.  It's also confusing that it uses "unsigned long=
" for
> > the virtual addresses, when we usually use "void *".  But that's ou=
t of
> > scope for this patch.
>=20
> 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.

Right, I see this warning here:

drivers/pci/pci.c: In function =E2=80=98pci_remap_iospace=E2=80=99:
drivers/pci/pci.c:2728:8: warning: assignment makes integer from pointe=
r without a cast [enabled by default]

-Robert