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iommu: OMAP: device detach on domain destroy

PATCH New Omar Ramirez Luna 2 participants 2 messages Apr 18, 2012 – Apr 19, 2012 IOMMU

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Omar Ramirez Luna

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PATCH v2 1/1 iommu: OMAP: device detach on domain destroy

'domain_destroy with devices attached' case isn't yet handled, instead code assumes that the device was already detached.

If the domain is destroyed the hardware still has access to invalid pointers to its page table and internal iommu object. In order to detach the users we need to track devices using the iommu, current use cases only have one user of iommu per instance. When required this can evolve to a list with the devices using the iommu_dev.

Reported-by Joerg Roedel <[email protected]>
Reviewed-by Ohad Ben-Cohen <[email protected]>
Signed-off-by Omar Ramirez Luna <[email protected]>

---

v2: rebased onto v3.4-rc2

 drivers/iommu/omap-iommu.c |   32 +++++++++++++++++++++++---------
 1 files changed, 23 insertions(+), 9 deletions(-)
drivers/iommu/omap-iommu.c +23 -9
index 6899dcd..e70ee2b 100644
@@ -41,11 +41,13 @@
  * @pgtable:	the page table
  * @iommu_dev:	an omap iommu device attached to this domain. only a single
  *		iommu device can be attached for now.
+ * @dev:	Device using this domain.
  * @lock:	domain lock, should be taken when attaching/detaching
  */
 struct omap_iommu_domain {
 	u32 *pgtable;
 	struct omap_iommu *iommu_dev;
+	struct device *dev;
 	spinlock_t lock;
 };
 

@@ -1081,6 +1083,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	}
 
 	omap_domain->iommu_dev = arch_data->iommu_dev = oiommu;
+	omap_domain->dev = dev;
 	oiommu->domain = domain;
 
 out:

@@ -1088,19 +1091,16 @@ out:
 	return ret;
 }
 
-static void omap_iommu_detach_dev(struct iommu_domain *domain,
-				 struct device *dev)
+static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
+			struct device *dev)
 {
-	struct omap_iommu_domain *omap_domain = domain->priv;
-	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
 	struct omap_iommu *oiommu = dev_to_omap_iommu(dev);
-
-	spin_lock(&omap_domain->lock);
+	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
 
 	/* only a single device is supported per domain for now */
 	if (omap_domain->iommu_dev != oiommu) {
 		dev_err(dev, "invalid iommu device\n");
-		goto out;
+		return;
 	}
 
 	iopgtable_clear_entry_all(oiommu);

@@ -1108,8 +1108,16 @@ static void omap_iommu_detach_dev(struct iommu_domain *domain,
 	omap_iommu_detach(oiommu);
 
 	omap_domain->iommu_dev = arch_data->iommu_dev = NULL;
+	omap_domain->dev = NULL;
+}
 
-out:
+static void omap_iommu_detach_dev(struct iommu_domain *domain,
+				 struct device *dev)
+{
+	struct omap_iommu_domain *omap_domain = domain->priv;
+
+	spin_lock(&omap_domain->lock);
+	_omap_iommu_detach_dev(omap_domain, dev);
 	spin_unlock(&omap_domain->lock);
 }
 

@@ -1148,13 +1156,19 @@ out:
 	return -ENOMEM;
 }
 
-/* assume device was already detached */
 static void omap_iommu_domain_destroy(struct iommu_domain *domain)
 {
 	struct omap_iommu_domain *omap_domain = domain->priv;
 
 	domain->priv = NULL;
 
+	/*
+	 * An iommu device is still attached
+	 * (currently, only one device can be attached) ?
+	 */
+	if (omap_domain->iommu_dev)
+		_omap_iommu_detach_dev(omap_domain, omap_domain->dev);
+
 	kfree(omap_domain->pgtable);
 	kfree(omap_domain);
 }
Signature · 1 line
1.7.4.1
Applied
#1 lore raw

PATCH v2 1/1 iommu: OMAP: device detach on domain destroy

Quoted 9 lines · Omar Ramirez Luna

'domain_destroy with devices attached' case isn't yet handled, instead code assumes that the device was already detached.

If the domain is destroyed the hardware still has access to invalid pointers to its page table and internal iommu object. In order to detach the users we need to track devices using the iommu, current use cases only have one user of iommu per instance. When required this can evolve to a list with the devices using the iommu_dev.

Quoted 6 lines
Reported-by Joerg Roedel <[email protected]>
Reviewed-by Ohad Ben-Cohen <[email protected]>
Signed-off-by Omar Ramirez Luna <[email protected]>

---

v2: rebased onto v3.4-rc2

Applied, thanks.

Signature · 5 lines
AMD Operating System Research Center

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General Managers: Alberto Bozzo
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