From: Jason Gunthorpe <jgg@nvidia.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: iommu@lists.linux-foundation.org,
LKML <linux-kernel@vger.kernel.org>,
Joerg Roedel <joro@8bytes.org>,
Christoph Hellwig <hch@infradead.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Jean-Philippe Brucker <jean-philippe@linaro.com>,
Jacob Pan <jacob.jun.pan@intel.com>,
Raj Ashok <ashok.raj@intel.com>,
"Kumar, Sanjay K" <sanjay.k.kumar@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Tony Luck <tony.luck@intel.com>,
"Zanussi, Tom" <tom.zanussi@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
"Tian, Kevin" <kevin.tian@intel.com>, Yi Liu <yi.l.liu@intel.com>
Subject: Re: [PATCH v2 5/8] iommu: Add PASID support for DMA mapping API users
Date: Tue, 15 Mar 2022 11:35:35 -0300 [thread overview]
Message-ID: <20220315143535.GX11336@nvidia.com> (raw)
In-Reply-To: <20220315050713.2000518-6-jacob.jun.pan@linux.intel.com>
On Mon, Mar 14, 2022 at 10:07:09PM -0700, Jacob Pan wrote:
> DMA mapping API is the de facto standard for in-kernel DMA. It operates
> on a per device/RID basis which is not PASID-aware.
>
> Some modern devices such as Intel Data Streaming Accelerator, PASID is
> required for certain work submissions. To allow such devices use DMA
> mapping API, we need the following functionalities:
> 1. Provide device a way to retrieve a PASID for work submission within
> the kernel
> 2. Enable the kernel PASID on the IOMMU for the device
> 3. Attach the kernel PASID to the device's default DMA domain, let it
> be IOVA or physical address in case of pass-through.
>
> This patch introduces a driver facing API that enables DMA API
> PASID usage. Once enabled, device drivers can continue to use DMA APIs as
> is. There is no difference in dma_handle between without PASID and with
> PASID.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> drivers/iommu/dma-iommu.c | 65 +++++++++++++++++++++++++++++++++++++++
> include/linux/dma-iommu.h | 7 +++++
> include/linux/iommu.h | 9 ++++++
> 3 files changed, 81 insertions(+)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index b22034975301..d0ff1a34b1b6 100644
> +++ b/drivers/iommu/dma-iommu.c
> @@ -39,6 +39,8 @@ enum iommu_dma_cookie_type {
> IOMMU_DMA_MSI_COOKIE,
> };
>
> +static DECLARE_IOASID_SET(iommu_dma_pasid);
> +
> struct iommu_dma_cookie {
> enum iommu_dma_cookie_type type;
> union {
> @@ -370,6 +372,69 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
> domain->iova_cookie = NULL;
> }
>
> +/**
> + * iommu_enable_pasid_dma --Enable in-kernel DMA request with PASID
> + * @dev: Device to be enabled
> + *
> + * DMA request with PASID will be mapped the same way as the legacy DMA.
> + * If the device is in pass-through, PASID will also pass-through. If the
> + * device is in IOVA map, the supervisor PASID will point to the same IOVA
> + * page table.
> + *
> + * @return the kernel PASID to be used for DMA or INVALID_IOASID on failure
> + */
> +int iommu_enable_pasid_dma(struct device *dev, ioasid_t *pasid)
> +{
> + struct iommu_domain *dom;
> + ioasid_t id, max;
> + int ret;
> +
> + dom = iommu_get_domain_for_dev(dev);
> + if (!dom || !dom->ops || !dom->ops->attach_dev_pasid)
> + return -ENODEV;
Given the purpose of this API I think it should assert that the device
has the DMA API in-use using the machinery from the other series.
ie this should not be used to clone non-DMA API iommu_domains..
> diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
> index 24607dc3c2ac..e6cb9b52a420 100644
> +++ b/include/linux/dma-iommu.h
> @@ -18,6 +18,13 @@ int iommu_get_dma_cookie(struct iommu_domain *domain);
> int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
> void iommu_put_dma_cookie(struct iommu_domain *domain);
>
> +/*
> + * For devices that can do DMA request with PASID, setup a system PASID.
> + * Address modes (IOVA, PA) are selected by the platform code.
> + */
> +int iommu_enable_pasid_dma(struct device *dev, ioasid_t *pasid);
> +void iommu_disable_pasid_dma(struct device *dev, ioasid_t pasid);
The functions already have a kdoc, don't need two..
Jason
next prev parent reply other threads:[~2022-03-15 14:35 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 5:07 [PATCH v2 0/8] Enable PASID for DMA API users Jacob Pan
2022-03-15 5:07 ` [PATCH v2 1/8] iommu: Assign per device max PASID Jacob Pan
2022-03-15 5:07 ` [PATCH v2 2/8] iommu: Add attach/detach_dev_pasid domain ops Jacob Pan
2022-03-15 10:24 ` Tian, Kevin
2022-03-15 11:26 ` Jean-Philippe Brucker
2022-03-15 11:49 ` Tian, Kevin
2022-03-15 16:11 ` Jacob Pan
2022-03-18 12:01 ` Lu Baolu
2022-03-18 13:50 ` Jason Gunthorpe
2022-03-18 11:52 ` Lu Baolu
2022-03-18 13:48 ` Jason Gunthorpe
2022-03-15 5:07 ` [PATCH v2 3/8] iommu/vt-d: Implement device_pasid domain attach ops Jacob Pan
2022-03-15 10:33 ` Tian, Kevin
2022-03-15 22:23 ` Jacob Pan
2022-03-15 14:33 ` Jason Gunthorpe
2022-03-15 22:36 ` Jacob Pan
2022-03-15 23:04 ` Jason Gunthorpe
2022-03-16 20:50 ` Jacob Pan
2022-03-16 22:15 ` Jason Gunthorpe
2022-03-16 22:23 ` Luck, Tony
2022-03-17 0:04 ` Jason Gunthorpe
2022-03-18 5:47 ` Tian, Kevin
2022-03-18 13:47 ` Jason Gunthorpe
2022-03-17 0:49 ` Jacob Pan
2022-03-17 13:23 ` Jason Gunthorpe
2022-03-17 18:23 ` Jacob Pan
2022-03-16 7:41 ` Tian, Kevin
2022-03-16 21:01 ` Jacob Pan
2022-03-18 5:33 ` Tian, Kevin
2022-03-28 21:41 ` Jacob Pan
2022-03-16 7:39 ` Tian, Kevin
2022-03-16 20:51 ` Jacob Pan
2022-03-15 5:07 ` [PATCH v2 4/8] iommu/vt-d: Use device_pasid attach op for RID2PASID Jacob Pan
2022-03-16 7:54 ` Tian, Kevin
2022-03-17 20:45 ` Jacob Pan
2022-03-15 5:07 ` [PATCH v2 5/8] iommu: Add PASID support for DMA mapping API users Jacob Pan
2022-03-15 11:16 ` Robin Murphy
2022-03-15 14:22 ` Jason Gunthorpe
2022-03-15 16:31 ` Jacob Pan
2022-03-15 17:05 ` Jason Gunthorpe
2022-03-15 21:24 ` Jacob Pan
2022-03-16 10:32 ` Tian, Kevin
2022-03-16 8:41 ` Tian, Kevin
2022-03-16 14:07 ` Jason Gunthorpe
2022-03-15 14:35 ` Jason Gunthorpe [this message]
2022-03-15 16:38 ` Jacob Pan
2022-03-15 23:05 ` Jason Gunthorpe
2022-03-18 12:43 ` Lu Baolu
2022-03-28 21:44 ` Jacob Pan
2022-03-15 5:07 ` [PATCH v2 6/8] dmaengine: idxd: Use DMA API for in-kernel DMA with PASID Jacob Pan
2022-03-18 6:10 ` Tian, Kevin
2022-03-29 17:39 ` Jacob Pan
2022-03-15 5:07 ` [PATCH v2 7/8] iommu/vt-d: Delete supervisor/kernel SVA Jacob Pan
2022-03-18 6:16 ` Tian, Kevin
2022-03-29 17:42 ` Jacob Pan
2022-03-15 5:07 ` [PATCH v2 8/8] iommu: Remove unused driver data in sva_bind_device Jacob Pan
2022-03-15 11:37 ` Jean-Philippe Brucker
2022-03-15 5:07 ` [PATCH v2 9/9] dmaengine: idxd: separate user and kernel pasid enabling Jacob Pan
2022-03-18 6:28 ` Tian, Kevin
2022-03-15 8:16 ` [PATCH v2 0/8] Enable PASID for DMA API users Tian, Kevin
2022-03-15 15:49 ` Jacob Pan
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=20220315143535.GX11336@nvidia.com \
--to=jgg@nvidia.com \
--cc=ashok.raj@intel.com \
--cc=baolu.lu@linux.intel.com \
--cc=dan.j.williams@intel.com \
--cc=dave.jiang@intel.com \
--cc=hch@infradead.org \
--cc=iommu@lists.linux-foundation.org \
--cc=jacob.jun.pan@intel.com \
--cc=jacob.jun.pan@linux.intel.com \
--cc=jean-philippe@linaro.com \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=sanjay.k.kumar@intel.com \
--cc=tom.zanussi@intel.com \
--cc=tony.luck@intel.com \
--cc=yi.l.liu@intel.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).