From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: <joro@8bytes.org>, <will@kernel.org>, <lorenzo.pieralisi@arm.com>,
<robh+dt@kernel.org>, <guohanjun@huawei.com>,
<sudeep.holla@arm.com>, <rjw@rjwysocki.net>, <lenb@kernel.org>,
<robin.murphy@arm.com>, <eric.auger@redhat.com>,
<iommu@lists.linux-foundation.org>, <devicetree@vger.kernel.org>,
<linux-acpi@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-accelerators@lists.ozlabs.org>, <baolu.lu@linux.intel.com>,
<vdumpa@nvidia.com>, <zhangfei.gao@linaro.org>,
<shameerali.kolothum.thodi@huawei.com>, <vivek.gautam@arm.com>,
"Arnd Bergmann" <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Zhou Wang <wangzhou1@hisilicon.com>
Subject: Re: [PATCH v9 05/10] uacce: Enable IOMMU_DEV_FEAT_IOPF
Date: Tue, 19 Jan 2021 12:27:59 +0000 [thread overview]
Message-ID: <20210119122759.000048f9@Huawei.com> (raw)
In-Reply-To: <20210108145217.2254447-6-jean-philippe@linaro.org>
On Fri, 8 Jan 2021 15:52:13 +0100
Jean-Philippe Brucker <jean-philippe@linaro.org> wrote:
> The IOPF (I/O Page Fault) feature is now enabled independently from the
> SVA feature, because some IOPF implementations are device-specific and
> do not require IOMMU support for PCIe PRI or Arm SMMU stall.
>
> Enable IOPF unconditionally when enabling SVA for now. In the future, if
> a device driver implementing a uacce interface doesn't need IOPF
> support, it will need to tell the uacce module, for example with a new
> flag.
>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Hi Jean-Philippe,
A minor suggestion inline but I'm not that bothered so either way
looks good to me.
> ---
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
> Cc: Zhou Wang <wangzhou1@hisilicon.com>
> ---
> drivers/misc/uacce/uacce.c | 32 +++++++++++++++++++++++++-------
> 1 file changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
> index d07af4edfcac..41ef1eb62a14 100644
> --- a/drivers/misc/uacce/uacce.c
> +++ b/drivers/misc/uacce/uacce.c
> @@ -385,6 +385,24 @@ static void uacce_release(struct device *dev)
> kfree(uacce);
> }
>
> +static unsigned int uacce_enable_sva(struct device *parent, unsigned int flags)
> +{
> + if (!(flags & UACCE_DEV_SVA))
> + return flags;
> +
> + flags &= ~UACCE_DEV_SVA;
> +
> + if (iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_IOPF))
> + return flags;
> +
> + if (iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA)) {
> + iommu_dev_disable_feature(parent, IOMMU_DEV_FEAT_IOPF);
> + return flags;
> + }
> +
> + return flags | UACCE_DEV_SVA;
> +}
I'm a great fan of paired enable / disable functions.
Whilst it would be trivial, maybe it is worth introducing
uacce_disable_sva()?
Also make that do the flags check internally to make it match
up with the enable path.
> +
> /**
> * uacce_alloc() - alloc an accelerator
> * @parent: pointer of uacce parent device
> @@ -404,11 +422,7 @@ struct uacce_device *uacce_alloc(struct device *parent,
> if (!uacce)
> return ERR_PTR(-ENOMEM);
>
> - if (flags & UACCE_DEV_SVA) {
> - ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA);
> - if (ret)
> - flags &= ~UACCE_DEV_SVA;
> - }
> + flags = uacce_enable_sva(parent, flags);
>
> uacce->parent = parent;
> uacce->flags = flags;
> @@ -432,8 +446,10 @@ struct uacce_device *uacce_alloc(struct device *parent,
> return uacce;
>
> err_with_uacce:
> - if (flags & UACCE_DEV_SVA)
> + if (flags & UACCE_DEV_SVA) {
> iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_SVA);
> + iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_IOPF);
> + }
> kfree(uacce);
> return ERR_PTR(ret);
> }
> @@ -487,8 +503,10 @@ void uacce_remove(struct uacce_device *uacce)
> mutex_unlock(&uacce->queues_lock);
>
> /* disable sva now since no opened queues */
> - if (uacce->flags & UACCE_DEV_SVA)
> + if (uacce->flags & UACCE_DEV_SVA) {
> iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_SVA);
> + iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_IOPF);
> + }
>
> if (uacce->cdev)
> cdev_device_del(uacce->cdev, &uacce->dev);
next prev parent reply other threads:[~2021-01-19 14:26 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-08 14:52 [PATCH v9 00/10] iommu: I/O page faults for SMMUv3 Jean-Philippe Brucker
2021-01-08 14:52 ` [PATCH v9 01/10] iommu: Remove obsolete comment Jean-Philippe Brucker
2021-01-19 11:11 ` Jonathan Cameron
2021-01-20 17:41 ` Jean-Philippe Brucker
2021-01-08 14:52 ` [PATCH v9 02/10] iommu/arm-smmu-v3: Use device properties for pasid-num-bits Jean-Philippe Brucker
2021-01-19 11:22 ` Jonathan Cameron
2021-01-08 14:52 ` [PATCH v9 03/10] iommu: Separate IOMMU_DEV_FEAT_IOPF from IOMMU_DEV_FEAT_SVA Jean-Philippe Brucker
2021-01-12 4:31 ` Lu Baolu
2021-01-12 9:16 ` Jean-Philippe Brucker
2021-01-13 2:49 ` Lu Baolu
2021-01-13 8:10 ` Tian, Kevin
2021-01-14 16:41 ` Jean-Philippe Brucker
2021-01-16 3:54 ` Lu Baolu
2021-01-18 6:54 ` Tian, Kevin
2021-01-19 10:16 ` Jean-Philippe Brucker
2021-01-20 1:57 ` Lu Baolu
2021-01-08 14:52 ` [PATCH v9 04/10] iommu/vt-d: Support IOMMU_DEV_FEAT_IOPF Jean-Philippe Brucker
2021-01-08 14:52 ` [PATCH v9 05/10] uacce: Enable IOMMU_DEV_FEAT_IOPF Jean-Philippe Brucker
2021-01-11 3:29 ` Zhangfei Gao
2021-01-19 12:27 ` Jonathan Cameron [this message]
2021-01-20 17:42 ` Jean-Philippe Brucker
2021-01-20 20:47 ` Dave Jiang
2021-01-22 11:53 ` Zhou Wang
2021-01-22 15:43 ` Dave Jiang
2021-01-08 14:52 ` [PATCH v9 06/10] iommu: Add a page fault handler Jean-Philippe Brucker
2021-01-19 13:38 ` Jonathan Cameron
2021-01-20 17:43 ` Jean-Philippe Brucker
2021-01-08 14:52 ` [PATCH v9 07/10] iommu/arm-smmu-v3: Maintain a SID->device structure Jean-Philippe Brucker
2021-01-19 13:51 ` Jonathan Cameron
2021-01-08 14:52 ` [PATCH v9 08/10] dt-bindings: document stall property for IOMMU masters Jean-Philippe Brucker
2021-01-08 14:52 ` [PATCH v9 09/10] ACPI/IORT: Enable stall support for platform devices Jean-Philippe Brucker
2021-01-08 14:52 ` [PATCH v9 10/10] iommu/arm-smmu-v3: Add " Jean-Philippe Brucker
2021-01-19 17:28 ` Robin Murphy
2021-01-20 17:55 ` Jean-Philippe Brucker
2021-01-11 3:26 ` [PATCH v9 00/10] iommu: I/O page faults for SMMUv3 Zhangfei Gao
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