1 files changed, 69 insertions, 25 deletions

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index bd2d4d2764dd..2fb2963df553 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
+#include <linux/device.h>
+#include <linux/kernel.h>
 #include <linux/bug.h>
 #include <linux/types.h>
 #include <linux/module.h>
@@ -23,21 +25,42 @@
 #include <linux/errno.h>
 #include <linux/iommu.h>
 
-static struct iommu_ops *iommu_ops;
+static void iommu_bus_init(struct bus_type *bus, struct iommu_ops *ops)
+{
+}
 
-void register_iommu(struct iommu_ops *ops)
+/**
+ * bus_set_iommu - set iommu-callbacks for the bus
+ * @bus: bus.
+ * @ops: the callbacks provided by the iommu-driver
+ *
+ * This function is called by an iommu driver to set the iommu methods
+ * used for a particular bus. Drivers for devices on that bus can use
+ * the iommu-api after these ops are registered.
+ * This special function is needed because IOMMUs are usually devices on
+ * the bus itself, so the iommu drivers are not initialized when the bus
+ * is set up. With this function the iommu-driver can set the iommu-ops
+ * afterwards.
+ */
+int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops)
 {
-	if (iommu_ops)
-		BUG();
+	if (bus->iommu_ops != NULL)
+		return -EBUSY;
 
-	iommu_ops = ops;
+	bus->iommu_ops = ops;
+
+	/* Do IOMMU specific setup for this bus-type */
+	iommu_bus_init(bus, ops);
+
+	return 0;
 }
+EXPORT_SYMBOL_GPL(bus_set_iommu);
 
-bool iommu_found(void)
+bool iommu_present(struct bus_type *bus)
 {
-	return iommu_ops != NULL;
+	return bus->iommu_ops != NULL;
 }
-EXPORT_SYMBOL_GPL(iommu_found);
+EXPORT_SYMBOL_GPL(iommu_present);
 
 /**
  * iommu_set_fault_handler() - set a fault handler for an iommu domain
@@ -59,16 +82,21 @@ void iommu_set_fault_handler(struct iommu_domain *domain,
 }
 EXPORT_SYMBOL_GPL(iommu_set_fault_handler);
 
-struct iommu_domain *iommu_domain_alloc(void)
+struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
 {
 	struct iommu_domain *domain;
 	int ret;
 
+	if (bus == NULL || bus->iommu_ops == NULL)
+		return NULL;
+
 	domain = kmalloc(sizeof(*domain), GFP_KERNEL);
 	if (!domain)
 		return NULL;
 
-	ret = iommu_ops->domain_init(domain);
+	domain->ops = bus->iommu_ops;
+
+	ret = domain->ops->domain_init(domain);
 	if (ret)
 		goto out_free;
 
@@ -83,62 +111,78 @@ EXPORT_SYMBOL_GPL(iommu_domain_alloc);
 
 void iommu_domain_free(struct iommu_domain *domain)
 {
-	iommu_ops->domain_destroy(domain);
+	if (likely(domain->ops->domain_destroy != NULL))
+		domain->ops->domain_destroy(domain);
+
 	kfree(domain);
 }
 EXPORT_SYMBOL_GPL(iommu_domain_free);
 
 int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
 {
-	return iommu_ops->attach_dev(domain, dev);
+	if (unlikely(domain->ops->attach_dev == NULL))
+		return -ENODEV;
+
+	return domain->ops->attach_dev(domain, dev);
 }
 EXPORT_SYMBOL_GPL(iommu_attach_device);
 
 void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
 {
-	iommu_ops->detach_dev(domain, dev);
+	if (unlikely(domain->ops->detach_dev == NULL))
+		return;
+
+	domain->ops->detach_dev(domain, dev);
 }
 EXPORT_SYMBOL_GPL(iommu_detach_device);
 
 phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
 			       unsigned long iova)
 {
-	return iommu_ops->iova_to_phys(domain, iova);
+	if (unlikely(domain->ops->iova_to_phys == NULL))
+		return 0;
+
+	return domain->ops->iova_to_phys(domain, iova);
 }
 EXPORT_SYMBOL_GPL(iommu_iova_to_phys);
 
 int iommu_domain_has_cap(struct iommu_domain *domain,
 			 unsigned long cap)
 {
-	return iommu_ops->domain_has_cap(domain, cap);
+	if (unlikely(domain->ops->domain_has_cap == NULL))
+		return 0;
+
+	return domain->ops->domain_has_cap(domain, cap);
 }
 EXPORT_SYMBOL_GPL(iommu_domain_has_cap);
 
 int iommu_map(struct iommu_domain *domain, unsigned long iova,
 	      phys_addr_t paddr, int gfp_order, int prot)
 {
-	unsigned long invalid_mask;
 	size_t size;
 
-	size         = 0x1000UL << gfp_order;
-	invalid_mask = size - 1;
+	if (unlikely(domain->ops->map == NULL))
+		return -ENODEV;
 
-	BUG_ON((iova | paddr) & invalid_mask);
+	size         = PAGE_SIZE << gfp_order;
 
-	return iommu_ops->map(domain, iova, paddr, gfp_order, prot);
+	BUG_ON(!IS_ALIGNED(iova | paddr, size));
+
+	return domain->ops->map(domain, iova, paddr, gfp_order, prot);
 }
 EXPORT_SYMBOL_GPL(iommu_map);
 
 int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order)
 {
-	unsigned long invalid_mask;
 	size_t size;
 
-	size         = 0x1000UL << gfp_order;
-	invalid_mask = size - 1;
+	if (unlikely(domain->ops->unmap == NULL))
+		return -ENODEV;
+
+	size         = PAGE_SIZE << gfp_order;
 
-	BUG_ON(iova & invalid_mask);
+	BUG_ON(!IS_ALIGNED(iova, size));
 
-	return iommu_ops->unmap(domain, iova, gfp_order);
+	return domain->ops->unmap(domain, iova, gfp_order);
 }
 EXPORT_SYMBOL_GPL(iommu_unmap);