diff mbox

[v2] iommu: OMAP: device detach on domain destroy

Message ID 1334772581-32015-1-git-send-email-omar.luna@linaro.org
State Accepted
Headers show

Commit Message

Omar Ramirez Luna April 18, 2012, 6:09 p.m. UTC 
'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 <joro@8bytes.org>
Reviewed-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Omar Ramirez Luna <omar.luna@linaro.org>
---

v2: rebased onto v3.4-rc2

 drivers/iommu/omap-iommu.c |   32 +++++++++++++++++++++++---------
 1 files changed, 23 insertions(+), 9 deletions(-)

Comments

Joerg Roedel April 19, 2012, 1:09 p.m. UTC | #1 
On Wed, Apr 18, 2012 at 01:09:41PM -0500, Omar Ramirez Luna wrote:
> '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 <joro@8bytes.org>
> Reviewed-by: Ohad Ben-Cohen <ohad@wizery.com>
> Signed-off-by: Omar Ramirez Luna <omar.luna@linaro.org>
> ---
> 
> v2: rebased onto v3.4-rc2

Applied, thanks.
diff mbox

Patch

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 6899dcd..e70ee2b 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -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);
 }