Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: Arnd Bergmann <arnd@arndb.de>
To: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: DTML <devicetree@vger.kernel.org>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Will Deacon <will@kernel.org>,
	Neil Armstrong <narmstrong@baylibre.com>,
	David Woodhouse <dwmw2@infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Russell King - ARM Linux <linux@armlinux.org.uk>,
	Christoph Hellwig <hch@infradead.org>,
	Rob Herring <robh+dt@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Ard Biesheuvel <ardb@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [RFC 09/13] iommu/arm-smmu: Make use of dev_64bit_mmio_supported()
Date: Tue, 2 Mar 2021 10:32:06 +0100
Message-ID: <CAK8P3a1t3yCD4vXF803nL=n3Y3hD1MOPOAEZwZA+782N64PXTA@mail.gmail.com> (raw)
In-Reply-To: <20210226140305.26356-10-nsaenzjulienne@suse.de>

On Fri, Feb 26, 2021 at 3:03 PM Nicolas Saenz Julienne
<nsaenzjulienne@suse.de> wrote:

>         if (smmu->impl && unlikely(smmu->impl->write_reg))
>                 smmu->impl->write_reg(smmu, page, offset, val);
> -       else
> +       else if (dev_64bit_mmio_supported(smmu->dev))
>                 writel_relaxed(val, arm_smmu_page(smmu, page) + offset);
> +       else
> +               hi_lo_writeq_relaxed(val, arm_smmu_page(smmu, page) + offset);
>  }

This is a writel_relaxed(), not a writeq_relaxed(), so I suppose you don't
have to change it at all.

> +       else if (dev_64bit_mmio_supported(smmu->dev))
> +               return readq_relaxed(arm_smmu_page(smmu, page) + offset);
> +       else
> +               return hi_lo_readq_relaxed(arm_smmu_page(smmu, page) + offset);
> }


I see this pattern repeat across multiple drivers. I think Christoph
had originally
suggested folding the if/else logic into the writel_relaxed() that is defined in
include/linux/io-64-nonatomic-hi-lo.h, but of course that doesn't work if you
need to pass a device pointer.

It might still make sense to have another wrapper in that same file though,
something like

static inline hi_lo_writeq_relaxed_if_possible(struct device *dev, __u64 val,
                    volatile void __iomem *addr)
{
       if (dev_64bit_mmio_supported(smmu->dev)) {
              readq_relaxed(arm_smmu_page(smmu, page) + offset);
       } else {
               writel_relaxed(val >> 32, addr + 4);
               writel_relaxed(val, addr);
       }
}

         Arnd

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply index

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-26 14:02 [RFC 00/13] Generic way of dealing with broken 64-bit buses Nicolas Saenz Julienne
2021-02-26 14:02 ` [RFC 01/13] dt-bindings: Introduce 64bit-mmio-broken Nicolas Saenz Julienne
2021-02-26 14:02 ` [RFC 02/13] driver core: Introduce MMIO configuration Nicolas Saenz Julienne
2021-03-02 11:29   ` Robin Murphy
2021-03-02 14:09     ` Nicolas Saenz Julienne
2021-02-26 14:02 ` [RFC 03/13] of: device: Introduce of_mmio_configure() Nicolas Saenz Julienne
2021-02-26 14:02 ` [RFC 04/13] driver core: plafrom: Introduce platform_mmio_configure() Nicolas Saenz Julienne
2021-02-26 14:02 ` [RFC 05/13] pci: Introduce pci_mmio_configure() Nicolas Saenz Julienne
2021-02-26 14:02 ` [RFC 06/13] device core: Introduce dev_64bit_mmio_supported() Nicolas Saenz Julienne
2021-02-26 14:02 ` [RFC 07/13] arm64: Mark ARCH_MVEBU as needing broken 64bit MMIO support Nicolas Saenz Julienne
2021-02-26 14:03 ` [RFC 08/13] arm64: dts: marvell: armada-ap80x: Mark config-space bus as 64bit-mmio-broken Nicolas Saenz Julienne
2021-02-26 14:03 ` [RFC 09/13] iommu/arm-smmu: Make use of dev_64bit_mmio_supported() Nicolas Saenz Julienne
2021-03-02  9:32   ` Arnd Bergmann [this message]
2021-03-02 12:42     ` Nicolas Saenz Julienne
2021-03-02 11:07   ` Robin Murphy
2021-03-02 13:38     ` Nicolas Saenz Julienne
2021-03-03  8:44     ` Arnd Bergmann
2021-02-26 14:03 ` [RFC 10/13] iommu/arm-smmu-impl: Get rid of Marvell's implementation details Nicolas Saenz Julienne
2021-03-02 11:40   ` Robin Murphy
2021-03-02 14:06     ` Nicolas Saenz Julienne
2021-02-26 14:03 ` [RFC 11/13] arm64: Mark ARCH_BCM2835 as needing broken 64bit MMIO support Nicolas Saenz Julienne
2021-02-26 14:03 ` [RFC 12/13] ARM: dts: bcm2711: Mark PCIe bus as 64bit-mmio-broken Nicolas Saenz Julienne
2021-02-26 14:03 ` [RFC 13/13] scsi: megaraid: Make use of dev_64bit_mmio_supported() Nicolas Saenz Julienne
2021-02-26 14:30   ` Arnd Bergmann
2021-02-26 18:06     ` Arnd Bergmann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAK8P3a1t3yCD4vXF803nL=n3Y3hD1MOPOAEZwZA+782N64PXTA@mail.gmail.com' \
    --to=arnd@arndb.de \
    --cc=ardb@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=devicetree@vger.kernel.org \
    --cc=dwmw2@infradead.org \
    --cc=f.fainelli@gmail.com \
    --cc=hch@infradead.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=narmstrong@baylibre.com \
    --cc=nsaenzjulienne@suse.de \
    --cc=robh+dt@kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org
	public-inbox-index linux-arm-kernel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git