[PATCH v2 07/10] KVM: arm/arm64: vgic-its: new helper functions to free the caches

Eric Auger
2017-09-27T13:30:38Z

From: wanghaibin <wanghaibin.wang@huawei.com>

We create 2 new functions that frees the device and
collection lists. this is currently called by vgic_its_destroy()
and we will add other callers in subsequent patches.

We also remove the check on its->device_list.next as it looks
unnecessary:

The kvm device is removed by kvm_destroy_devices which loops on
all the devices added to kvm->devices. kvm_ioctl_create_device
only adds the device to kvm_devices once the lists have been
initialized (in vgic_create_its).

We also move vgic_its_free_device to prepare for new callers.

Signed-off-by: wanghaibin <wanghaibin.wang@huawei.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
[Eric] removed its->device_list.next which is not needed as
pointed out by Wanghaibin. Reword the commit message
---
virt/kvm/arm/vgic/vgic-its.c | 76 ++++++++++++++++++++++++--------------------
1 file changed, 41 insertions(+), 35 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 9e6b556..0df6d5f 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -611,6 +611,45 @@ static void its_free_ite(struct kvm *kvm, struct its_ite *ite)
kfree(ite);
}

+static void vgic_its_free_device(struct kvm *kvm, struct its_device *dev)
+{
+ struct its_ite *ite, *tmp;
+
+ list_for_each_entry_safe(ite, tmp, &dev->itt_head, ite_list)
+ its_free_ite(kvm, ite);
+ list_del(&dev->dev_list);
+ kfree(dev);
+}
+
+static void vgic_its_free_device_list(struct kvm *kvm, struct vgic_its *its)
+{
+ struct list_head *cur, *temp;
+
+ mutex_lock(&its->its_lock);
+ list_for_each_safe(cur, temp, &its->device_list) {
+ struct its_device *dev;
+
+ dev = list_entry(cur, struct its_device, dev_list);
+ vgic_its_free_device(kvm, dev);
+ }
+ mutex_unlock(&its->its_lock);
+}
+
+static void vgic_its_free_collection_list(struct kvm *kvm, struct vgic_its *its)
+{
+ struct list_head *cur, *temp;
+
+ list_for_each_safe(cur, temp, &its->collection_list) {
+ struct its_collection *coll;
+
+ coll = list_entry(cur, struct its_collection, coll_list);
+ list_del(cur);
+ kfree(coll);
+ }
+ mutex_unlock(&its->its_lock);
+}
+
+
static u64 its_cmd_mask_field(u64 *its_cmd, int word, int shift, int size)
{
return (le64_to_cpu(its_cmd[word]) >> shift) & (BIT_ULL(size) - 1);
@@ -1634,46 +1673,13 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
return vgic_its_set_abi(its, NR_ITS_ABIS - 1);
}

-static void vgic_its_free_device(struct kvm *kvm, struct its_device *dev)
-{
- struct its_ite *ite, *tmp;
-
- list_for_each_entry_safe(ite, tmp, &dev->itt_head, ite_list)
- its_free_ite(kvm, ite);
- list_del(&dev->dev_list);
- kfree(dev);
-}
-
static void vgic_its_destroy(struct kvm_device *kvm_dev)
{
struct kvm *kvm = kvm_dev->kvm;
struct vgic_its *its = kvm_dev->private;
- struct list_head *cur, *temp;
-
- /*
- * We may end up here without the lists ever having been initialized.
- * Check this and bail out early to avoid dereferencing a NULL pointer.
- */
- if (!its->device_list.next)
- return;
-
- mutex_lock(&its->its_lock);
- list_for_each_safe(cur, temp, &its->device_list) {
- struct its_device *dev;
-
- dev = list_entry(cur, struct its_device, dev_list);
- vgic_its_free_device(kvm, dev);
- }
-
- list_for_each_safe(cur, temp, &its->collection_list) {
- struct its_collection *coll;
-
- coll = list_entry(cur, struct its_collection, coll_list);
- list_del(cur);
- kfree(coll);
- }
- mutex_unlock(&its->its_lock);

+ vgic_its_free_device_list(kvm, its);
+ vgic_its_free_collection_list(kvm, its);
kfree(its);
}

--
2.5.5