[PATCH v4 1/6] iommu: Add a per domain PASID for DMA API

From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: iommu@lists.linux-foundation.org,
	LKML <linux-kernel@vger.kernel.org>,
	dmaengine@vger.kernel.org, Joerg Roedel <joro@8bytes.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>,
	"Lu Baolu" <baolu.lu@linux.intel.com>,
	Jason Gunthorpe <jgg@nvidia.com>,
	"Christoph Hellwig" <hch@infradead.org>,
	vkoul@kernel.org, robin.murphy@arm.com, will@kernel.org
Cc: Yi Liu <yi.l.liu@intel.com>, Dave Jiang <dave.jiang@intel.com>,
	"Tian, Kevin" <kevin.tian@intel.com>,
	Raj Ashok <ashok.raj@intel.com>,
	Eric Auger <eric.auger@redhat.com>,
	Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH v4 1/6] iommu: Add a per domain PASID for DMA API
Date: Wed, 18 May 2022 11:21:15 -0700	[thread overview]
Message-ID: <20220518182120.1136715-2-jacob.jun.pan@linux.intel.com> (raw)
In-Reply-To: <20220518182120.1136715-1-jacob.jun.pan@linux.intel.com>

DMA requests tagged with PASID can target individual IOMMU domains.
Introduce a domain-wide PASID for DMA API, it will be used on the same
mapping as legacy DMA without PASID. Let it be IOVA or PA in case of
identity domain.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 include/linux/iommu.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 9405034e3013..36ad007084cc 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -106,6 +106,8 @@ struct iommu_domain {
 	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
 						      void *data);
 	void *fault_data;
+	ioasid_t dma_pasid;		/* Used for DMA requests with PASID */
+	atomic_t dma_pasid_users;
 };
 
 static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
-- 
2.25.1

