Re: [PATCH v9 12/12] PCI: Introduce pci_remap_iospace() for remapping PCI I/O bus resources into CPU space

From: Rob Herring <robherring2@gmail.com>
To: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	Catalin Marinas <Catalin.Marinas@arm.com>,
	Will Deacon <Will.Deacon@arm.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Russell King <linux@arm.linux.org.uk>,
	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-pci <linux-pci@vger.kernel.org>,
	linux-arch <linux-arch@vger.kernel.org>,
	Device Tree ML <devicetree@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	LAKML <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v9 12/12] PCI: Introduce pci_remap_iospace() for remapping PCI I/O bus resources into CPU space
Date: Thu, 21 Aug 2014 23:16:16 -0500	[thread overview]
Message-ID: <CAL_JsqK6XiuS7OJ_2F16ySA8oj9AHqP0fAft21AOtJxXP2SqnQ@mail.gmail.com> (raw)
In-Reply-To: <1407860725-25202-13-git-send-email-Liviu.Dudau@arm.com>

On Tue, Aug 12, 2014 at 11:25 AM, Liviu Dudau <Liviu.Dudau@arm.com> wrote:
> Introduce a default implementation for remapping PCI bus I/O resources
> onto the CPU address space. Architectures with special needs may
> provide their own version, but most should be able to use this one.
>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>

Reviewed-by: Rob Herring <robh@kernel.org>

However, I would like to see ARM pci_ioremap_io converted over to this function.

Rob

> ---
>  drivers/pci/pci.c   | 33 +++++++++++++++++++++++++++++++++
>  include/linux/pci.h |  3 +++
>  2 files changed, 36 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 29d1775..76d21b6 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2707,6 +2707,39 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
>  }
>  EXPORT_SYMBOL(pci_request_regions_exclusive);
>
> +/**
> + *     pci_remap_iospace - Remap the memory mapped I/O space
> + *     @res: Resource describing the I/O space
> + *     @phys_addr: physical address where the range will be mapped.
> + *
> + *     Remap the memory mapped I/O space described by the @res
> + *     into the CPU physical address space. Only architectures
> + *     that have memory mapped IO defined (and hence PCI_IOBASE)
> + *     should call this function.
> + */
> +int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
> +{
> +       int err = -ENODEV;
> +
> +#ifdef PCI_IOBASE
> +       if (!(res->flags & IORESOURCE_IO))
> +               return -EINVAL;
> +
> +       if (res->end > IO_SPACE_LIMIT)
> +               return -EINVAL;
> +
> +       err = ioremap_page_range(res->start + (unsigned long)PCI_IOBASE,
> +                               res->end + 1 + (unsigned long)PCI_IOBASE,
> +                               phys_addr, pgprot_device(PAGE_KERNEL));
> +#else
> +       /* this architecture does not have memory mapped I/O space,
> +          so this function should never be called */
> +       WARN_ON(1);
> +#endif
> +
> +       return err;
> +}
> +
>  static void __pci_set_master(struct pci_dev *dev, bool enable)
>  {
>         u16 old_cmd, cmd;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index e1e0d80..988c2f5 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1098,6 +1098,9 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
>                                                   resource_size_t),
>                         void *alignf_data);
>
> +
> +int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
> +
>  static inline dma_addr_t pci_bus_address(struct pci_dev *pdev, int bar)
>  {
>         struct pci_bus_region region;
> --
> 2.0.4
>
>
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