diff mbox

[RFC,1/6] omap: iommu: generic iommu api migration

Message ID 1307053663-24572-2-git-send-email-ohad@wizery.com (mailing list archive)
State Awaiting Upstream, archived
Delegated to: Tony Lindgren
Headers show

Commit Message

Ohad Ben Cohen June 2, 2011, 10:27 p.m. UTC
Migrate OMAP's iommu to the generic iommu api, so users can stay
generic, and non-omap-specific code can be removed and eventually
consolidated into a generic framework.

Tested on both OMAP3 and OMAP4.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
---
 arch/arm/plat-omap/Kconfig              |    7 +-
 arch/arm/plat-omap/include/plat/iommu.h |    3 +-
 arch/arm/plat-omap/iommu.c              |  288 +++++++++++++++++++++++++++----
 arch/arm/plat-omap/iopgtable.h          |   18 ++
 4 files changed, 278 insertions(+), 38 deletions(-)

Comments

Laurent Pinchart June 7, 2011, 9:22 a.m. UTC | #1
Hi Ohad,

Thanks for the patch.

On Friday 03 June 2011 00:27:38 Ohad Ben-Cohen wrote:
> Migrate OMAP's iommu to the generic iommu api, so users can stay
> generic, and non-omap-specific code can be removed and eventually
> consolidated into a generic framework.
> 
> Tested on both OMAP3 and OMAP4.
> 
> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

[snip]

> diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
> index 34fc31e..f06e99c 100644
> --- a/arch/arm/plat-omap/iommu.c
> +++ b/arch/arm/plat-omap/iommu.c

[snip]

> +static int omap_iommu_domain_init(struct iommu_domain *domain)
> +{
> +	struct omap_iommu_domain *omap_domain;
> +
> +	omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
> +	if (!omap_domain) {
> +		pr_err("kzalloc failed\n");
> +		goto fail_nomem;
> +	}
> +
> +	omap_domain->pgtable = (u32 *)__get_free_pages(GFP_KERNEL,
> +					get_order(IOPGD_TABLE_SIZE));
> +	if (!omap_domain->pgtable) {
> +		pr_err("__get_free_pages failed\n");
> +		goto fail_nomem;
> +	}
> +
> +	BUG_ON(!IS_ALIGNED((long)omap_domain->pgtable, IOPGD_TABLE_SIZE));

Either __get_free_pages() guarantees that the allocated memory will be aligned 
on an IOPGD_TABLE_SIZE boundary, in which case the BUG_ON() is unnecessary, or 
doesn't offer such guarantee, in which case the BUG_ON() will oops randomly. 
In both cases BUG_ON() should probably be avoided.

> +	memset(omap_domain->pgtable, 0, IOPGD_TABLE_SIZE);
> +	clean_dcache_area(omap_domain->pgtable, IOPGD_TABLE_SIZE);
> +	mutex_init(&omap_domain->lock);
> +
> +	domain->priv = omap_domain;
> +
> +	return 0;
> +
> +fail_nomem:
> +	kfree(omap_domain);
> +	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;
> +
> +	kfree(omap_domain);

This leaks omap_domain->pgtable.

The free_pages() call in omap_iommu_remove() should be removed, as 
omap_iommu_probe() doesn't allocate the pages table anymore. You can also 
remove the the struct iommu::iopgd field.

> +}


> +
> +static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,
> +					  unsigned long da)
> +{
> +	struct omap_iommu_domain *omap_domain = domain->priv;
> +	struct iommu *oiommu = omap_domain->iommu_dev;
> +	struct device *dev = oiommu->dev;
> +	u32 *pgd, *pte;
> +	phys_addr_t ret = 0;
> +
> +	iopgtable_lookup_entry(oiommu, da, &pgd, &pte);
> +
> +	if (pte) {
> +		if (iopte_is_small(*pte))
> +			ret = omap_iommu_translate(*pte, da, IOPTE_MASK);
> +		else if (iopte_is_large(*pte))
> +			ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);
> +		else
> +			dev_err(dev, "bogus pte 0x%x", *pte);
> +	} else {
> +		if (iopgd_is_section(*pgd))
> +			ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);
> +		else if (iopgd_is_super(*pgd))
> +			ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);
> +		else
> +			dev_err(dev, "bogus pgd 0x%x", *pgd);
> +	}
> +
> +	return ret;

You return 0 in the bogus pte/pgd cases. Is that intentional ?

> +}
Ohad Ben Cohen June 7, 2011, 11:19 a.m. UTC | #2
Hi Laurent,

On Tue, Jun 7, 2011 at 12:22 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>> +     BUG_ON(!IS_ALIGNED((long)omap_domain->pgtable, IOPGD_TABLE_SIZE));
>
> Either __get_free_pages() guarantees that the allocated memory will be aligned
> on an IOPGD_TABLE_SIZE boundary, in which case the BUG_ON() is unnecessary, or
> doesn't offer such guarantee, in which case the BUG_ON() will oops randomly.

Curious, does it oops randomly today ?
(i just copied this from omap_iommu_probe, where it always existed).

It is a bit ugly though, and thinking on it again, 16KB is not that
big. We can just use kmalloc here, which does ensure the alignment
(or, better yet, kzalloc, and then ditch the memset).

> In both cases BUG_ON() should probably be avoided.

I disagree; we must check this so user data won't be harmed (hardware
requirement), and if a memory allocation API fails to meet its
requirements - that's really bad and user data is again at stake (much
more will break, not only the iommu driver).

> This leaks omap_domain->pgtable.
>
> The free_pages() call in omap_iommu_remove() should be removed, as
> omap_iommu_probe() doesn't allocate the pages table anymore.

thanks !

> You can also remove the the struct iommu::iopgd field.

No, I can't; it's used when the device is attached to an address space domain.

> You return 0 in the bogus pte/pgd cases. Is that intentional ?

Yes, that's probably the most (if any) reasonable value to return here
(all other iommu implementations are doing so too).

Thanks,
Ohad.
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Laurent Pinchart June 7, 2011, 11:40 a.m. UTC | #3
Hi Ohad,

On Tuesday 07 June 2011 13:19:05 Ohad Ben-Cohen wrote:
> On Tue, Jun 7, 2011 at 12:22 PM, Laurent Pinchart wrote:
> >> +     BUG_ON(!IS_ALIGNED((long)omap_domain->pgtable, IOPGD_TABLE_SIZE));
> > 
> > Either __get_free_pages() guarantees that the allocated memory will be
> > aligned on an IOPGD_TABLE_SIZE boundary, in which case the BUG_ON() is
> > unnecessary, or doesn't offer such guarantee, in which case the BUG_ON()
> > will oops randomly.
> 
> Curious, does it oops randomly today ?
> (i just copied this from omap_iommu_probe, where it always existed).

No that I know of :-)

> It is a bit ugly though, and thinking on it again, 16KB is not that
> big. We can just use kmalloc here, which does ensure the alignment
> (or, better yet, kzalloc, and then ditch the memset).
> 
> > In both cases BUG_ON() should probably be avoided.
> 
> I disagree; we must check this so user data won't be harmed (hardware
> requirement), and if a memory allocation API fails to meet its
> requirements - that's really bad and user data is again at stake (much
> more will break, not only the iommu driver).

My point is that if the allocator guarantees the alignment (not as a side 
effect of the implementation, but per its API) there's no need to check it 
again. As the alignement is required, we need an allocator that guarantees it 
anyway.

> > This leaks omap_domain->pgtable.
> > 
> > The free_pages() call in omap_iommu_remove() should be removed, as
> > omap_iommu_probe() doesn't allocate the pages table anymore.
> 
> thanks !
> 
> > You can also remove the the struct iommu::iopgd field.
> 
> No, I can't; it's used when the device is attached to an address space
> domain.

Right, my bad.

> > You return 0 in the bogus pte/pgd cases. Is that intentional ?
> 
> Yes, that's probably the most (if any) reasonable value to return here
> (all other iommu implementations are doing so too).
Ohad Ben Cohen June 7, 2011, 12:27 p.m. UTC | #4
On Tue, Jun 7, 2011 at 2:40 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> My point is that if the allocator guarantees the alignment (not as a side
> effect of the implementation, but per its API) there's no need to check it
> again. As the alignement is required, we need an allocator that guarantees it
> anyway.

I understand, but I'd still prefer to have an explicit check that the
hardware alignment requirement is met.

There's no cost in doing that (it's a cold path), and even if it would
only fail once and with an extremely broken kernel - it's worth it.
Will save huge amount of debugging pain (think of the poor guy that
will have to debug this...).

Thanks,
Ohad.
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index 49a4c75..1c3acb5 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -131,8 +131,13 @@  config OMAP_MBOX_KFIFO_SIZE
 	  This can also be changed at runtime (via the mbox_kfifo_size
 	  module parameter).
 
+config IOMMU_API
+	bool
+
+#can't be tristate; iommu api doesn't support un-registration
 config OMAP_IOMMU
-	tristate
+	bool
+	select IOMMU_API
 
 config OMAP_IOMMU_DEBUG
        tristate "Export OMAP IOMMU internals in DebugFS"
diff --git a/arch/arm/plat-omap/include/plat/iommu.h b/arch/arm/plat-omap/include/plat/iommu.h
index 174f1b9..db1c492 100644
--- a/arch/arm/plat-omap/include/plat/iommu.h
+++ b/arch/arm/plat-omap/include/plat/iommu.h
@@ -167,8 +167,6 @@  extern void iopgtable_lookup_entry(struct iommu *obj, u32 da, u32 **ppgd,
 extern size_t iopgtable_clear_entry(struct iommu *obj, u32 iova);
 
 extern int iommu_set_da_range(struct iommu *obj, u32 start, u32 end);
-extern struct iommu *iommu_get(const char *name);
-extern void iommu_put(struct iommu *obj);
 extern int iommu_set_isr(const char *name,
 			 int (*isr)(struct iommu *obj, u32 da, u32 iommu_errs,
 				    void *priv),
@@ -185,5 +183,6 @@  extern int foreach_iommu_device(void *data,
 
 extern ssize_t iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t len);
 extern size_t dump_tlb_entries(struct iommu *obj, char *buf, ssize_t len);
+struct device *omap_find_iommu_device(const char *name);
 
 #endif /* __MACH_IOMMU_H */
diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
index 34fc31e..f06e99c 100644
--- a/arch/arm/plat-omap/iommu.c
+++ b/arch/arm/plat-omap/iommu.c
@@ -18,6 +18,8 @@ 
 #include <linux/ioport.h>
 #include <linux/clk.h>
 #include <linux/platform_device.h>
+#include <linux/iommu.h>
+#include <linux/mutex.h>
 
 #include <asm/cacheflush.h>
 
@@ -30,6 +32,19 @@ 
 	     (__i < (n)) && (cr = __iotlb_read_cr((obj), __i), true);	\
 	     __i++)
 
+/**
+ * struct omap_iommu_domain - omap iommu domain
+ * @pgtable:	the page table
+ * @iommu_dev:	an omap iommu device attached to this domain. only a single
+ *		iommu device can be attached for now.
+ * @lock:	domain lock, should be taken when attaching/detaching
+ */
+struct omap_iommu_domain {
+	u32 *pgtable;
+	struct iommu *iommu_dev;
+	struct mutex lock;
+};
+
 /* accommodate the difference between omap1 and omap2/3 */
 static const struct iommu_functions *arch_iommu;
 
@@ -852,31 +867,50 @@  int iommu_set_da_range(struct iommu *obj, u32 start, u32 end)
 EXPORT_SYMBOL_GPL(iommu_set_da_range);
 
 /**
- * iommu_get - Get iommu handler
- * @name:	target iommu name
+ * omap_find_iommu_device() - find an omap iommu device by name
+ * @name:	name of the iommu device
+ *
+ * The generic iommu API requires the caller to provide the device
+ * he wishes to attach to a certain iommu domain. Users of that API
+ * may look up the device using PCI credentials when relevent, and when
+ * not, this helper should be used to find a specific iommu device by name.
+ *
+ * This may be relevant to other platforms as well (msm ?) so consider
+ * moving this to the generic iommu framework.
+ */
+struct device *omap_find_iommu_device(const char *name)
+{
+	return driver_find_device(&omap_iommu_driver.driver, NULL,
+				(void *)name,
+				device_match_by_alias);
+}
+EXPORT_SYMBOL_GPL(omap_find_iommu_device);
+
+/**
+ * omap_iommu_attach() - attach iommu device to an iommu domain
+ * @dev:	target omap iommu device
+ * @iopgd:	page table
  **/
-struct iommu *iommu_get(const char *name)
+static struct iommu *omap_iommu_attach(struct device *dev, u32 *iopgd)
 {
 	int err = -ENOMEM;
-	struct device *dev;
-	struct iommu *obj;
-
-	dev = driver_find_device(&omap_iommu_driver.driver, NULL, (void *)name,
-				 device_match_by_alias);
-	if (!dev)
-		return ERR_PTR(-ENODEV);
-
-	obj = to_iommu(dev);
+	struct iommu *obj = to_iommu(dev);
 
 	mutex_lock(&obj->iommu_lock);
 
-	if (obj->refcount++ == 0) {
-		err = iommu_enable(obj);
-		if (err)
-			goto err_enable;
-		flush_iotlb_all(obj);
+	/* an iommu device can only be attached once */
+	if (++obj->refcount > 1) {
+		dev_err(dev, "%s: already attached!\n", obj->name);
+		err = -EBUSY;
+		goto err_enable;
 	}
 
+	obj->iopgd = iopgd;
+	err = iommu_enable(obj);
+	if (err)
+		goto err_enable;
+	flush_iotlb_all(obj);
+
 	if (!try_module_get(obj->owner))
 		goto err_module;
 
@@ -893,13 +927,12 @@  err_enable:
 	mutex_unlock(&obj->iommu_lock);
 	return ERR_PTR(err);
 }
-EXPORT_SYMBOL_GPL(iommu_get);
 
 /**
- * iommu_put - Put back iommu handler
+ * omap_iommu_detach - release iommu device
  * @obj:	target iommu
  **/
-void iommu_put(struct iommu *obj)
+static void omap_iommu_detach(struct iommu *obj)
 {
 	if (!obj || IS_ERR(obj))
 		return;
@@ -911,11 +944,12 @@  void iommu_put(struct iommu *obj)
 
 	module_put(obj->owner);
 
+	obj->iopgd = NULL;
+
 	mutex_unlock(&obj->iommu_lock);
 
 	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
 }
-EXPORT_SYMBOL_GPL(iommu_put);
 
 int iommu_set_isr(const char *name,
 		  int (*isr)(struct iommu *obj, u32 da, u32 iommu_errs,
@@ -950,7 +984,6 @@  EXPORT_SYMBOL_GPL(iommu_set_isr);
 static int __devinit omap_iommu_probe(struct platform_device *pdev)
 {
 	int err = -ENODEV;
-	void *p;
 	int irq;
 	struct iommu *obj;
 	struct resource *res;
@@ -1009,22 +1042,9 @@  static int __devinit omap_iommu_probe(struct platform_device *pdev)
 		goto err_irq;
 	platform_set_drvdata(pdev, obj);
 
-	p = (void *)__get_free_pages(GFP_KERNEL, get_order(IOPGD_TABLE_SIZE));
-	if (!p) {
-		err = -ENOMEM;
-		goto err_pgd;
-	}
-	memset(p, 0, IOPGD_TABLE_SIZE);
-	clean_dcache_area(p, IOPGD_TABLE_SIZE);
-	obj->iopgd = p;
-
-	BUG_ON(!IS_ALIGNED((unsigned long)obj->iopgd, IOPGD_TABLE_SIZE));
-
 	dev_info(&pdev->dev, "%s registered\n", obj->name);
 	return 0;
 
-err_pgd:
-	free_irq(irq, obj);
 err_irq:
 	iounmap(obj->regbase);
 err_ioremap:
@@ -1072,6 +1092,202 @@  static void iopte_cachep_ctor(void *iopte)
 	clean_dcache_area(iopte, IOPTE_TABLE_SIZE);
 }
 
+static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
+			 phys_addr_t pa, int order, int prot)
+{
+	struct omap_iommu_domain *omap_domain = domain->priv;
+	struct iommu *oiommu = omap_domain->iommu_dev;
+	struct device *dev = oiommu->dev;
+	size_t bytes = PAGE_SIZE << order;
+	struct iotlb_entry e;
+	int omap_pgsz;
+	u32 ret, flags;
+
+	/* we only support mapping a single iommu page for now */
+	omap_pgsz = bytes_to_iopgsz(bytes);
+	if (omap_pgsz < 0) {
+		dev_err(dev, "invalid size to map: %d\n", bytes);
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "mapping da 0x%lx to pa 0x%x size 0x%x\n", da, pa, bytes);
+
+	flags = omap_pgsz | prot;
+
+	iotlb_init_entry(&e, da, pa, flags);
+
+	ret = iopgtable_store_entry(oiommu, &e);
+	if (ret) {
+		dev_err(dev, "iopgtable_store_entry failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
+			    int order)
+{
+	struct omap_iommu_domain *omap_domain = domain->priv;
+	struct iommu *oiommu = omap_domain->iommu_dev;
+	struct device *dev = oiommu->dev;
+	size_t bytes = PAGE_SIZE << order;
+	size_t ret;
+
+	dev_dbg(dev, "unmapping da 0x%lx size 0x%x\n", da, bytes);
+
+	ret = iopgtable_clear_entry(oiommu, da);
+	if (ret != bytes) {
+		dev_err(dev, "entry @ 0x%lx was %d; not %d\n", da, ret, bytes);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
+{
+	struct omap_iommu_domain *omap_domain = domain->priv;
+	struct iommu *oiommu;
+	int ret = 0;
+
+	mutex_lock(&omap_domain->lock);
+
+	/* only a single device is supported per domain for now */
+	if (omap_domain->iommu_dev) {
+		dev_err(dev, "iommu domain is already attached\n");
+		ret = -EBUSY;
+		goto out;
+	}
+
+	/* get a handle to and enable the omap iommu */
+	oiommu = omap_iommu_attach(dev, omap_domain->pgtable);
+	if (IS_ERR(oiommu)) {
+		ret = PTR_ERR(oiommu);
+		dev_err(dev, "can't get omap iommu: %d\n", ret);
+		goto out;
+	}
+
+	omap_domain->iommu_dev = oiommu;
+
+out:
+	mutex_unlock(&omap_domain->lock);
+	return ret;
+}
+
+static void omap_iommu_detach_dev(struct iommu_domain *domain,
+				 struct device *dev)
+{
+	struct omap_iommu_domain *omap_domain = domain->priv;
+	struct iommu *oiommu = to_iommu(dev);
+
+	mutex_lock(&omap_domain->lock);
+
+	/* 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;
+	}
+
+	iopgtable_clear_entry_all(oiommu);
+
+	omap_iommu_detach(oiommu);
+
+	omap_domain->iommu_dev = NULL;
+
+out:
+	mutex_unlock(&omap_domain->lock);
+}
+
+static int omap_iommu_domain_init(struct iommu_domain *domain)
+{
+	struct omap_iommu_domain *omap_domain;
+
+	omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
+	if (!omap_domain) {
+		pr_err("kzalloc failed\n");
+		goto fail_nomem;
+	}
+
+	omap_domain->pgtable = (u32 *)__get_free_pages(GFP_KERNEL,
+					get_order(IOPGD_TABLE_SIZE));
+	if (!omap_domain->pgtable) {
+		pr_err("__get_free_pages failed\n");
+		goto fail_nomem;
+	}
+
+	BUG_ON(!IS_ALIGNED((long)omap_domain->pgtable, IOPGD_TABLE_SIZE));
+	memset(omap_domain->pgtable, 0, IOPGD_TABLE_SIZE);
+	clean_dcache_area(omap_domain->pgtable, IOPGD_TABLE_SIZE);
+	mutex_init(&omap_domain->lock);
+
+	domain->priv = omap_domain;
+
+	return 0;
+
+fail_nomem:
+	kfree(omap_domain);
+	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;
+
+	kfree(omap_domain);
+}
+
+static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,
+					  unsigned long da)
+{
+	struct omap_iommu_domain *omap_domain = domain->priv;
+	struct iommu *oiommu = omap_domain->iommu_dev;
+	struct device *dev = oiommu->dev;
+	u32 *pgd, *pte;
+	phys_addr_t ret = 0;
+
+	iopgtable_lookup_entry(oiommu, da, &pgd, &pte);
+
+	if (pte) {
+		if (iopte_is_small(*pte))
+			ret = omap_iommu_translate(*pte, da, IOPTE_MASK);
+		else if (iopte_is_large(*pte))
+			ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);
+		else
+			dev_err(dev, "bogus pte 0x%x", *pte);
+	} else {
+		if (iopgd_is_section(*pgd))
+			ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);
+		else if (iopgd_is_super(*pgd))
+			ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);
+		else
+			dev_err(dev, "bogus pgd 0x%x", *pgd);
+	}
+
+	return ret;
+}
+
+static int omap_iommu_domain_has_cap(struct iommu_domain *domain,
+				    unsigned long cap)
+{
+	return 0;
+}
+
+static struct iommu_ops omap_iommu_ops = {
+	.domain_init	= omap_iommu_domain_init,
+	.domain_destroy	= omap_iommu_domain_destroy,
+	.attach_dev	= omap_iommu_attach_dev,
+	.detach_dev	= omap_iommu_detach_dev,
+	.map		= omap_iommu_map,
+	.unmap		= omap_iommu_unmap,
+	.iova_to_phys	= omap_iommu_iova_to_phys,
+	.domain_has_cap	= omap_iommu_domain_has_cap,
+};
+
 static int __init omap_iommu_init(void)
 {
 	struct kmem_cache *p;
@@ -1084,6 +1300,8 @@  static int __init omap_iommu_init(void)
 		return -ENOMEM;
 	iopte_cachep = p;
 
+	register_iommu(&omap_iommu_ops);
+
 	return platform_driver_register(&omap_iommu_driver);
 }
 module_init(omap_iommu_init);
diff --git a/arch/arm/plat-omap/iopgtable.h b/arch/arm/plat-omap/iopgtable.h
index c3e93bb..33c7aa9 100644
--- a/arch/arm/plat-omap/iopgtable.h
+++ b/arch/arm/plat-omap/iopgtable.h
@@ -56,6 +56,19 @@ 
 
 #define IOPAGE_MASK		IOPTE_MASK
 
+/**
+ * omap_iommu_translate() - va to pa translation
+ * @d:		omap iommu descriptor
+ * @va:		virtual address
+ * @mask:	omap iommu descriptor mask
+ *
+ * va to pa translation
+ */
+static inline phys_addr_t omap_iommu_translate(u32 d, u32 va, u32 mask)
+{
+	return (d & mask) | (va & (~mask));
+}
+
 /*
  * some descriptor attributes.
  */
@@ -64,10 +77,15 @@ 
 #define IOPGD_SUPER		(1 << 18 | 2 << 0)
 
 #define iopgd_is_table(x)	(((x) & 3) == IOPGD_TABLE)
+#define iopgd_is_section(x)	(((x) & (1 << 18 | 3)) == IOPGD_SECTION)
+#define iopgd_is_super(x)	(((x) & (1 << 18 | 3)) == IOPGD_SUPER)
 
 #define IOPTE_SMALL		(2 << 0)
 #define IOPTE_LARGE		(1 << 0)
 
+#define iopte_is_small(x)	(((x) & 2) == IOPTE_SMALL)
+#define iopte_is_large(x)	(((x) & 3) == IOPTE_LARGE)
+
 /* to find an entry in a page-table-directory */
 #define iopgd_index(da)		(((da) >> IOPGD_SHIFT) & (PTRS_PER_IOPGD - 1))
 #define iopgd_offset(obj, da)	((obj)->iopgd + iopgd_index(da))