From: Dmitry Osipenko <dmitry.osipenko@collabora.com>
To: Robin Murphy <robin.murphy@arm.com>, thierry.reding@gmail.com
Cc: jonathanh@nvidia.com, dri-devel@lists.freedesktop.org,
linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org
Subject: Re: [PATCH v2] drm/tegra: Stop using iommu_present()
Date: Wed, 4 May 2022 03:52:21 +0300 [thread overview]
Message-ID: <add31812-50d5-6cb0-3908-143c523abd37@collabora.com> (raw)
In-Reply-To: <1f7c304a79b8b8dd5d4716786cae7502a0cc31f5.1649684782.git.robin.murphy@arm.com>
On 4/11/22 16:46, Robin Murphy wrote:
> @@ -1092,6 +1092,19 @@ static bool host1x_drm_wants_iommu(struct host1x_device *dev)
> struct host1x *host1x = dev_get_drvdata(dev->dev.parent);
> struct iommu_domain *domain;
>
> + /* For starters, this is moot if no IOMMU is available */
> + if (!device_iommu_mapped(&dev->dev))
> + return false;
Unfortunately this returns false on T30 with enabled IOMMU because we
don't use IOMMU for Host1x on T30 [1] to optimize performance. We can't
change it until we will update drivers to support Host1x-dedicated buffers.
[1]
https://elixir.bootlin.com/linux/latest/source/drivers/gpu/host1x/dev.c#L258
--
Best regards,
Dmitry
WARNING: multiple messages have this Message-ID (diff)
From: Dmitry Osipenko <dmitry.osipenko@collabora.com>
To: Robin Murphy <robin.murphy@arm.com>, thierry.reding@gmail.com
Cc: linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org,
dri-devel@lists.freedesktop.org, jonathanh@nvidia.com
Subject: Re: [PATCH v2] drm/tegra: Stop using iommu_present()
Date: Wed, 4 May 2022 03:52:21 +0300 [thread overview]
Message-ID: <add31812-50d5-6cb0-3908-143c523abd37@collabora.com> (raw)
In-Reply-To: <1f7c304a79b8b8dd5d4716786cae7502a0cc31f5.1649684782.git.robin.murphy@arm.com>
On 4/11/22 16:46, Robin Murphy wrote:
> @@ -1092,6 +1092,19 @@ static bool host1x_drm_wants_iommu(struct host1x_device *dev)
> struct host1x *host1x = dev_get_drvdata(dev->dev.parent);
> struct iommu_domain *domain;
>
> + /* For starters, this is moot if no IOMMU is available */
> + if (!device_iommu_mapped(&dev->dev))
> + return false;
Unfortunately this returns false on T30 with enabled IOMMU because we
don't use IOMMU for Host1x on T30 [1] to optimize performance. We can't
change it until we will update drivers to support Host1x-dedicated buffers.
[1]
https://elixir.bootlin.com/linux/latest/source/drivers/gpu/host1x/dev.c#L258
--
Best regards,
Dmitry
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Dmitry Osipenko <dmitry.osipenko@collabora.com>
To: Robin Murphy <robin.murphy@arm.com>, thierry.reding@gmail.com
Cc: linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org,
dri-devel@lists.freedesktop.org, jonathanh@nvidia.com
Subject: Re: [PATCH v2] drm/tegra: Stop using iommu_present()
Date: Wed, 4 May 2022 03:52:21 +0300 [thread overview]
Message-ID: <add31812-50d5-6cb0-3908-143c523abd37@collabora.com> (raw)
In-Reply-To: <1f7c304a79b8b8dd5d4716786cae7502a0cc31f5.1649684782.git.robin.murphy@arm.com>
On 4/11/22 16:46, Robin Murphy wrote:
> @@ -1092,6 +1092,19 @@ static bool host1x_drm_wants_iommu(struct host1x_device *dev)
> struct host1x *host1x = dev_get_drvdata(dev->dev.parent);
> struct iommu_domain *domain;
>
> + /* For starters, this is moot if no IOMMU is available */
> + if (!device_iommu_mapped(&dev->dev))
> + return false;
Unfortunately this returns false on T30 with enabled IOMMU because we
don't use IOMMU for Host1x on T30 [1] to optimize performance. We can't
change it until we will update drivers to support Host1x-dedicated buffers.
[1]
https://elixir.bootlin.com/linux/latest/source/drivers/gpu/host1x/dev.c#L258
--
Best regards,
Dmitry
next prev parent reply other threads:[~2022-05-04 0:52 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-11 13:46 [PATCH v2] drm/tegra: Stop using iommu_present() Robin Murphy
2022-04-11 13:46 ` Robin Murphy
2022-04-11 13:46 ` Robin Murphy
2022-04-13 22:34 ` Dmitry Osipenko
2022-04-13 22:34 ` Dmitry Osipenko
2022-04-13 22:34 ` Dmitry Osipenko
2022-05-04 0:52 ` Dmitry Osipenko [this message]
2022-05-04 0:52 ` Dmitry Osipenko
2022-05-04 0:52 ` Dmitry Osipenko
2022-05-04 11:52 ` Robin Murphy
2022-05-04 11:52 ` Robin Murphy
2022-05-04 11:52 ` Robin Murphy
2022-05-11 11:08 ` Dmitry Osipenko
2022-05-11 11:08 ` Dmitry Osipenko
2022-05-11 11:08 ` Dmitry Osipenko
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