iommu: Remove functions that support private domain

After moving iommu_group setup to iommu core code [1][2] and removing
private domain support in vt-d [3], there are no users for functions such
as iommu_request_dm_for_dev(), iommu_request_dma_domain_for_dev() and
request_default_domain_for_dev(). So, remove these functions.

[1] commit dce8d69 ("iommu/amd: Convert to probe/release_device()
    call-backs")
[2] commit e5d1841 ("iommu/vt-d: Convert to probe/release_device()
    call-backs")
[3] commit 327d5b2 ("iommu/vt-d: Allow 32bit devices to uses DMA
    domain")

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200513224721.20504-1-sai.praneeth.prakhya@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/iommu.c

@@ -2536,71 +2536,6 @@ struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start,
 }
 EXPORT_SYMBOL_GPL(iommu_alloc_resv_region);
 
-static int
-request_default_domain_for_dev(struct device *dev, unsigned long type)
-{
-	struct iommu_domain *domain;
-	struct iommu_group *group;
-	int ret;
-
-	/* Device must already be in a group before calling this function */
-	group = iommu_group_get(dev);
-	if (!group)
-		return -EINVAL;
-
-	mutex_lock(&group->mutex);
-
-	ret = 0;
-	if (group->default_domain && group->default_domain->type == type)
-		goto out;
-
-	/* Don't change mappings of existing devices */
-	ret = -EBUSY;
-	if (iommu_group_device_count(group) != 1)
-		goto out;
-
-	ret = -ENOMEM;
-	domain = __iommu_domain_alloc(dev->bus, type);
-	if (!domain)
-		goto out;
-
-	/* Attach the device to the domain */
-	ret = __iommu_attach_group(domain, group);
-	if (ret) {
-		iommu_domain_free(domain);
-		goto out;
-	}
-
-	/* Make the domain the default for this group */
-	if (group->default_domain)
-		iommu_domain_free(group->default_domain);
-	group->default_domain = domain;
-
-	iommu_create_device_direct_mappings(group, dev);
-
-	dev_info(dev, "Using iommu %s mapping\n",
-		 type == IOMMU_DOMAIN_DMA ? "dma" : "direct");
-
-	ret = 0;
-out:
-	mutex_unlock(&group->mutex);
-	iommu_group_put(group);
-
-	return ret;
-}
-
-/* Request that a device is direct mapped by the IOMMU */
-int iommu_request_dm_for_dev(struct device *dev)
-{
-	return request_default_domain_for_dev(dev, IOMMU_DOMAIN_IDENTITY);
-}
-
-/* Request that a device can't be direct mapped by the IOMMU */
-int iommu_request_dma_domain_for_dev(struct device *dev)
-{
-	return request_default_domain_for_dev(dev, IOMMU_DOMAIN_DMA);
-}
-
 void iommu_set_default_passthrough(bool cmd_line)
 {
 	if (cmd_line)

include/linux/iommu.h

@@ -482,8 +482,6 @@ extern void iommu_get_resv_regions(struct device *dev, struct list_head *list);
 extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
 extern void generic_iommu_put_resv_regions(struct device *dev,
 					   struct list_head *list);
-extern int iommu_request_dm_for_dev(struct device *dev);
-extern int iommu_request_dma_domain_for_dev(struct device *dev);
 extern void iommu_set_default_passthrough(bool cmd_line);
 extern void iommu_set_default_translated(bool cmd_line);
 extern bool iommu_default_passthrough(void);
@@ -804,16 +802,6 @@ static inline int iommu_get_group_resv_regions(struct iommu_group *group,
 	return -ENODEV;
 }
 
-static inline int iommu_request_dm_for_dev(struct device *dev)
-{
-	return -ENODEV;
-}
-
-static inline int iommu_request_dma_domain_for_dev(struct device *dev)
-{
-	return -ENODEV;
-}
-
 static inline void iommu_set_default_passthrough(bool cmd_line)
 {
 }