iommu: Introduce domain_alloc and domain_free iommu_ops

These new call-backs defer the allocation and destruction of
'struct iommu_domain' to the iommu driver. This allows
drivers to embed this struct into their private domain
structures and to get rid of the domain_init and
domain_destroy call-backs when all drivers have been
converted.

Tested-by: Thierry Reding <treding@nvidia.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 72e683df0731727bd46d17c8bb21a2d53554804f..11de2620bbf4194f9f897b165f44bf3e39e62bcf 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -900,26 +900,34 @@ EXPORT_SYMBOL_GPL(iommu_set_fault_handler);
 
 struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
 {
+       const struct iommu_ops *ops;
        struct iommu_domain *domain;
-       int ret;
 
        if (bus == NULL || bus->iommu_ops == NULL)
                return NULL;
 
-       domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+       ops = bus->iommu_ops;
+
+       if (ops->domain_alloc)
+               domain = ops->domain_alloc();
+       else
+               domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+
        if (!domain)
                return NULL;
 
        domain->ops = bus->iommu_ops;
 
-       ret = domain->ops->domain_init(domain);
-       if (ret)
+       if (ops->domain_init && domain->ops->domain_init(domain))
                goto out_free;
 
        return domain;
 
 out_free:
-       kfree(domain);
+       if (ops->domain_free)
+               ops->domain_free(domain);
+       else
+               kfree(domain);
 
        return NULL;
 }
@@ -927,10 +935,15 @@ EXPORT_SYMBOL_GPL(iommu_domain_alloc);
 
 void iommu_domain_free(struct iommu_domain *domain)
 {
-       if (likely(domain->ops->domain_destroy != NULL))
-               domain->ops->domain_destroy(domain);
+       const struct iommu_ops *ops = domain->ops;
 
-       kfree(domain);
+       if (likely(ops->domain_destroy != NULL))
+               ops->domain_destroy(domain);
+
+       if (ops->domain_free)
+               ops->domain_free(domain);
+       else
+               kfree(domain);
 }
 EXPORT_SYMBOL_GPL(iommu_domain_free);
 

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 38daa453f2e532f0c36d7ba81b10860ccc28b478..69d1d120c0a34fd46162f5eaa6416825b475e948 100644 (file)
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -115,6 +115,11 @@ struct iommu_ops {
        bool (*capable)(enum iommu_cap);
        int (*domain_init)(struct iommu_domain *domain);
        void (*domain_destroy)(struct iommu_domain *domain);
+
+       /* Domain allocation and freeing by the iommu driver */
+       struct iommu_domain *(*domain_alloc)(void);
+       void (*domain_free)(struct iommu_domain *);
+
        int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
        void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
        int (*map)(struct iommu_domain *domain, unsigned long iova,