Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Lu Baolu <baolu.lu@linux.intel.com>
To:     Joerg Roedel <joro@8bytes.org>,
        David Woodhouse <dwmw2@infradead.org>
Cc:     ashok.raj@intel.com, sanjay.k.kumar@intel.com,
        jacob.jun.pan@intel.com, kevin.tian@intel.com, yi.l.liu@intel.com,
        yi.y.sun@intel.com, peterx@redhat.com,
        Jean-Philippe Brucker <jean-philippe.brucker@arm.com>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH v2 05/12] iommu/vt-d: Reserve a domain id for FL and PT modes
Date:   Thu, 30 Aug 2018 09:35:17 +0800
Message-Id: <20180830013524.28743-6-baolu.lu@linux.intel.com>
In-Reply-To: <20180830013524.28743-1-baolu.lu@linux.intel.com>
References: <20180830013524.28743-1-baolu.lu@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Vt-d spec rev3.0 (section 6.2.3.1) requires that each pasid
entry for first-level or pass-through translation should be
programmed with a domain id different from those used for
second-level or nested translation. It is recommended that
software could use a same domain id for all first-only and
pass-through translations.

This reserves a domain id for first-level and pass-through
translations.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Cc: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel-iommu.c | 10 ++++++++++
 drivers/iommu/intel-pasid.h |  6 ++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 93cde957adc7..562da10bf93e 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1643,6 +1643,16 @@ static int iommu_init_domains(struct intel_iommu *iommu)
 	 */
 	set_bit(0, iommu->domain_ids);
 
+	/*
+	 * Vt-d spec rev3.0 (section 6.2.3.1) requires that each pasid
+	 * entry for first-level or pass-through translation modes should
+	 * be programmed with a domain id different from those used for
+	 * second-level or nested translation. We reserve a domain id for
+	 * this purpose.
+	 */
+	if (sm_supported(iommu))
+		set_bit(FLPT_DEFAULT_DID, iommu->domain_ids);
+
 	return 0;
 }
 
diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h
index 12f480c2bb8b..03c1612d173c 100644
--- a/drivers/iommu/intel-pasid.h
+++ b/drivers/iommu/intel-pasid.h
@@ -17,6 +17,12 @@
 #define PDE_PFN_MASK			PAGE_MASK
 #define PASID_PDE_SHIFT			6
 
+/*
+ * Domain ID reserved for pasid entries programmed for first-level
+ * only and pass-through transfer modes.
+ */
+#define FLPT_DEFAULT_DID		1
+
 struct pasid_dir_entry {
 	u64 val;
 };
-- 
2.17.1