KVM: arm64: vgic-its: Add collection allocator/destructor

Instead of spreading random allocations all over the place,
consolidate allocation/init/freeing of collections in a pair
of constructor/destructor.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 54 insertions, 38 deletions

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 2faf1f458e8a..d6f68e9c946d 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -581,14 +581,45 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
         return 0;
 }
 
-static void vgic_its_init_collection(struct vgic_its *its,
-                                     struct its_collection *collection,
+static int vgic_its_alloc_collection(struct vgic_its *its,
+                                     struct its_collection **colp,
                                      u32 coll_id)
 {
+        struct its_collection *collection;
+
+        collection = kzalloc(sizeof(*collection), GFP_KERNEL);
+
         collection->collection_id = coll_id;
         collection->target_addr = COLLECTION_NOT_MAPPED;
 
         list_add_tail(&collection->coll_list, &its->collection_list);
+        *colp = collection;
+
+        return 0;
+}
+
+static void vgic_its_free_collection(struct vgic_its *its, u32 coll_id)
+{
+        struct its_collection *collection;
+        struct its_device *device;
+        struct its_itte *itte;
+
+        /*
+         * Clearing the mapping for that collection ID removes the
+         * entry from the list. If there wasn't any before, we can
+         * go home early.
+         */
+        collection = find_collection(its, coll_id);
+        if (!collection)
+                return;
+
+        for_each_lpi_its(device, itte, its)
+                if (itte->collection &&
+                    itte->collection->collection_id == coll_id)
+                        itte->collection = NULL;
+
+        list_del(&collection->coll_list);
+        kfree(collection);
 }
 
 /*
@@ -605,6 +636,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
         struct its_device *device;
         struct its_collection *collection, *new_coll = NULL;
         int lpi_nr;
+        int ret;
 
         device = find_its_device(its, device_id);
         if (!device)
@@ -612,9 +644,10 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
 
         collection = find_collection(its, coll_id);
         if (!collection) {
-                new_coll = kzalloc(sizeof(struct its_collection), GFP_KERNEL);
-                if (!new_coll)
-                        return -ENOMEM;
+                ret = vgic_its_alloc_collection(its, &collection, coll_id);
+                if (ret)
+                        return ret;
+                new_coll = collection;
         }
 
         if (subcmd == GITS_CMD_MAPTI)
@@ -623,27 +656,22 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
                 lpi_nr = event_id;
         if (lpi_nr < GIC_LPI_OFFSET ||
             lpi_nr >= max_lpis_propbaser(kvm->arch.vgic.propbaser)) {
-                kfree(new_coll);
-                return E_ITS_MAPTI_PHYSICALID_OOR;
+                ret = E_ITS_MAPTI_PHYSICALID_OOR;
+                goto err;
         }
 
         itte = find_itte(its, device_id, event_id);
         if (!itte) {
                 itte = kzalloc(sizeof(struct its_itte), GFP_KERNEL);
                 if (!itte) {
-                        kfree(new_coll);
-                        return -ENOMEM;
+                        ret = -ENOMEM;
+                        goto err;
                 }
 
                 itte->event_id  = event_id;
                 list_add_tail(&itte->itte_list, &device->itt_head);
         }
 
-        if (!collection) {
-                collection = new_coll;
-                vgic_its_init_collection(its, collection, coll_id);
-        }
-
         itte->collection = collection;
         itte->lpi = lpi_nr;
         itte->irq = vgic_add_lpi(kvm, lpi_nr);
@@ -657,6 +685,10 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
         update_lpi_config(kvm, itte->irq, NULL);
 
         return 0;
+err:
+        if (new_coll)
+                vgic_its_free_collection(its, coll_id);
+        return ret;
 }
 
 /* Requires the its_lock to be held. */
@@ -809,34 +841,18 @@ static int vgic_its_cmd_handle_mapc(struct kvm *kvm, struct vgic_its *its,
         if (coll_id >= vgic_its_nr_collection_ids(its))
                 return E_ITS_MAPC_COLLECTION_OOR;
 
-        collection = find_collection(its, coll_id);
-
         if (!valid) {
-                struct its_device *device;
-                struct its_itte *itte;
-                /*
-                 * Clearing the mapping for that collection ID removes the
-                 * entry from the list. If there wasn't any before, we can
-                 * go home early.
-                 */
-                if (!collection)
-                        return 0;
-
-                for_each_lpi_its(device, itte, its)
-                        if (itte->collection &&
-                            itte->collection->collection_id == coll_id)
-                                itte->collection = NULL;
-
-                list_del(&collection->coll_list);
-                kfree(collection);
+                vgic_its_free_collection(its, coll_id);
         } else {
+                collection = find_collection(its, coll_id);
+
                 if (!collection) {
-                        collection = kzalloc(sizeof(struct its_collection),
-                                             GFP_KERNEL);
-                        if (!collection)
-                                return -ENOMEM;
+                        int ret;
 
-                        vgic_its_init_collection(its, collection, coll_id);
+                        ret = vgic_its_alloc_collection(its, &collection,
+                                                        coll_id);
+                        if (ret)
+                                return ret;
                         collection->target_addr = target_addr;
                 } else {
                         collection->target_addr = target_addr;