drm/msm: Separate locking of buffer resources from struct_mutex

Buffer object specific resources like pages, domains, sg list
need not be protected with struct_mutex. They can be protected
with a buffer object level lock. This simplifies locking and
makes it easier to avoid potential recursive locking scenarios
for SVM involving mmap_sem and struct_mutex. This also removes
unnecessary serialization when creating buffer objects, and also
between buffer object creation and GPU command submission.

Signed-off-by: Sushmita Susheelendra <ssusheel@codeaurora.org>
[robclark: squash in handling new locking for shrinker]
Signed-off-by: Rob Clark <robdclark@gmail.com>

1 files changed, 169 insertions, 105 deletions

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 9951c78ee215..65f35544c1ec 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -26,6 +26,9 @@
 #include "msm_gpu.h"
 #include "msm_mmu.h"
 
+static void msm_gem_vunmap_locked(struct drm_gem_object *obj);
+
+
 static dma_addr_t physaddr(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -41,8 +44,7 @@ static bool use_pages(struct drm_gem_object *obj)
 }
 
 /* allocate pages from VRAM carveout, used when no IOMMU: */
-static struct page **get_pages_vram(struct drm_gem_object *obj,
-		int npages)
+static struct page **get_pages_vram(struct drm_gem_object *obj, int npages)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct msm_drm_private *priv = obj->dev->dev_private;
@@ -54,7 +56,9 @@ static struct page **get_pages_vram(struct drm_gem_object *obj,
 	if (!p)
 		return ERR_PTR(-ENOMEM);
 
+	spin_lock(&priv->vram.lock);
 	ret = drm_mm_insert_node(&priv->vram.mm, msm_obj->vram_node, npages);
+	spin_unlock(&priv->vram.lock);
 	if (ret) {
 		kvfree(p);
 		return ERR_PTR(ret);
@@ -69,7 +73,6 @@ static struct page **get_pages_vram(struct drm_gem_object *obj,
 	return p;
 }
 
-/* called with dev->struct_mutex held */
 static struct page **get_pages(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -109,6 +112,18 @@ static struct page **get_pages(struct drm_gem_object *obj)
 	return msm_obj->pages;
 }
 
+static void put_pages_vram(struct drm_gem_object *obj)
+{
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
+	struct msm_drm_private *priv = obj->dev->dev_private;
+
+	spin_lock(&priv->vram.lock);
+	drm_mm_remove_node(msm_obj->vram_node);
+	spin_unlock(&priv->vram.lock);
+
+	kvfree(msm_obj->pages);
+}
+
 static void put_pages(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -125,10 +140,8 @@ static void put_pages(struct drm_gem_object *obj)
 
 		if (use_pages(obj))
 			drm_gem_put_pages(obj, msm_obj->pages, true, false);
-		else {
-			drm_mm_remove_node(msm_obj->vram_node);
-			kvfree(msm_obj->pages);
-		}
+		else
+			put_pages_vram(obj);
 
 		msm_obj->pages = NULL;
 	}
@@ -136,11 +149,18 @@ static void put_pages(struct drm_gem_object *obj)
 
 struct page **msm_gem_get_pages(struct drm_gem_object *obj)
 {
-	struct drm_device *dev = obj->dev;
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct page **p;
-	mutex_lock(&dev->struct_mutex);
+
+	mutex_lock(&msm_obj->lock);
+
+	if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
+		mutex_unlock(&msm_obj->lock);
+		return ERR_PTR(-EBUSY);
+	}
+
 	p = get_pages(obj);
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&msm_obj->lock);
 	return p;
 }
 
@@ -195,28 +215,25 @@ int msm_gem_fault(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
 	struct drm_gem_object *obj = vma->vm_private_data;
-	struct drm_device *dev = obj->dev;
-	struct msm_drm_private *priv = dev->dev_private;
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct page **pages;
 	unsigned long pfn;
 	pgoff_t pgoff;
 	int ret;
 
-	/* This should only happen if userspace tries to pass a mmap'd
-	 * but unfaulted gem bo vaddr into submit ioctl, triggering
-	 * a page fault while struct_mutex is already held.  This is
-	 * not a valid use-case so just bail.
-	 */
-	if (priv->struct_mutex_task == current)
-		return VM_FAULT_SIGBUS;
-
-	/* Make sure we don't parallel update on a fault, nor move or remove
-	 * something from beneath our feet
+	/*
+	 * vm_ops.open/drm_gem_mmap_obj and close get and put
+	 * a reference on obj. So, we dont need to hold one here.
 	 */
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
+	ret = mutex_lock_interruptible(&msm_obj->lock);
 	if (ret)
 		goto out;
 
+	if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
+		mutex_unlock(&msm_obj->lock);
+		return VM_FAULT_SIGBUS;
+	}
+
 	/* make sure we have pages attached now */
 	pages = get_pages(obj);
 	if (IS_ERR(pages)) {
@@ -235,7 +252,7 @@ int msm_gem_fault(struct vm_fault *vmf)
 	ret = vm_insert_mixed(vma, vmf->address, __pfn_to_pfn_t(pfn, PFN_DEV));
 
 out_unlock:
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&msm_obj->lock);
 out:
 	switch (ret) {
 	case -EAGAIN:
@@ -259,9 +276,10 @@ out:
 static uint64_t mmap_offset(struct drm_gem_object *obj)
 {
 	struct drm_device *dev = obj->dev;
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	int ret;
 
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+	WARN_ON(!mutex_is_locked(&msm_obj->lock));
 
 	/* Make it mmapable */
 	ret = drm_gem_create_mmap_offset(obj);
@@ -277,9 +295,11 @@ static uint64_t mmap_offset(struct drm_gem_object *obj)
 uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj)
 {
 	uint64_t offset;
-	mutex_lock(&obj->dev->struct_mutex);
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
+
+	mutex_lock(&msm_obj->lock);
 	offset = mmap_offset(obj);
-	mutex_unlock(&obj->dev->struct_mutex);
+	mutex_unlock(&msm_obj->lock);
 	return offset;
 }
 
@@ -289,6 +309,8 @@ static struct msm_gem_vma *add_vma(struct drm_gem_object *obj,
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct msm_gem_vma *vma;
 
+	WARN_ON(!mutex_is_locked(&msm_obj->lock));
+
 	vma = kzalloc(sizeof(*vma), GFP_KERNEL);
 	if (!vma)
 		return ERR_PTR(-ENOMEM);
@@ -306,7 +328,7 @@ static struct msm_gem_vma *lookup_vma(struct drm_gem_object *obj,
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct msm_gem_vma *vma;
 
-	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+	WARN_ON(!mutex_is_locked(&msm_obj->lock));
 
 	list_for_each_entry(vma, &msm_obj->vmas, list) {
 		if (vma->aspace == aspace)
@@ -325,13 +347,14 @@ static void del_vma(struct msm_gem_vma *vma)
 	kfree(vma);
 }
 
+/* Called with msm_obj->lock locked */
 static void
 put_iova(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct msm_gem_vma *vma, *tmp;
 
-	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+	WARN_ON(!mutex_is_locked(&msm_obj->lock));
 
 	list_for_each_entry_safe(vma, tmp, &msm_obj->vmas, list) {
 		msm_gem_unmap_vma(vma->aspace, vma, msm_obj->sgt);
@@ -339,21 +362,20 @@ put_iova(struct drm_gem_object *obj)
 	}
 }
 
-/* should be called under struct_mutex.. although it can be called
- * from atomic context without struct_mutex to acquire an extra
- * iova ref if you know one is already held.
- *
- * That means when I do eventually need to add support for unpinning
- * the refcnt counter needs to be atomic_t.
- */
-int msm_gem_get_iova_locked(struct drm_gem_object *obj,
+/* get iova, taking a reference.  Should have a matching put */
+int msm_gem_get_iova(struct drm_gem_object *obj,
 		struct msm_gem_address_space *aspace, uint64_t *iova)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct msm_gem_vma *vma;
 	int ret = 0;
 
-	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+	mutex_lock(&msm_obj->lock);
+
+	if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
+		mutex_unlock(&msm_obj->lock);
+		return -EBUSY;
+	}
 
 	vma = lookup_vma(obj, aspace);
 
@@ -377,24 +399,14 @@ int msm_gem_get_iova_locked(struct drm_gem_object *obj,
 	}
 
 	*iova = vma->iova;
+
+	mutex_unlock(&msm_obj->lock);
 	return 0;
 
 fail:
 	del_vma(vma);
 
-	return ret;
-}
-
-/* get iova, taking a reference.  Should have a matching put */
-int msm_gem_get_iova(struct drm_gem_object *obj,
-		struct msm_gem_address_space *aspace, uint64_t *iova)
-{
-	int ret;
-
-	mutex_lock(&obj->dev->struct_mutex);
-	ret = msm_gem_get_iova_locked(obj, aspace, iova);
-	mutex_unlock(&obj->dev->struct_mutex);
-
+	mutex_unlock(&msm_obj->lock);
 	return ret;
 }
 
@@ -404,11 +416,12 @@ int msm_gem_get_iova(struct drm_gem_object *obj,
 uint64_t msm_gem_iova(struct drm_gem_object *obj,
 		struct msm_gem_address_space *aspace)
 {
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct msm_gem_vma *vma;
 
-	mutex_lock(&obj->dev->struct_mutex);
+	mutex_lock(&msm_obj->lock);
 	vma = lookup_vma(obj, aspace);
-	mutex_unlock(&obj->dev->struct_mutex);
+	mutex_unlock(&msm_obj->lock);
 	WARN_ON(!vma);
 
 	return vma ? vma->iova : 0;
@@ -455,45 +468,57 @@ fail:
 	return ret;
 }
 
-void *msm_gem_get_vaddr_locked(struct drm_gem_object *obj)
+void *msm_gem_get_vaddr(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
-	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+	int ret = 0;
+
+	mutex_lock(&msm_obj->lock);
+
+	if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
+		mutex_unlock(&msm_obj->lock);
+		return ERR_PTR(-EBUSY);
+	}
+
+	/* increment vmap_count *before* vmap() call, so shrinker can
+	 * check vmap_count (is_vunmapable()) outside of msm_obj->lock.
+	 * This guarantees that we won't try to msm_gem_vunmap() this
+	 * same object from within the vmap() call (while we already
+	 * hold msm_obj->lock)
+	 */
+	msm_obj->vmap_count++;
+
 	if (!msm_obj->vaddr) {
 		struct page **pages = get_pages(obj);
-		if (IS_ERR(pages))
-			return ERR_CAST(pages);
+		if (IS_ERR(pages)) {
+			ret = PTR_ERR(pages);
+			goto fail;
+		}
 		msm_obj->vaddr = vmap(pages, obj->size >> PAGE_SHIFT,
 				VM_MAP, pgprot_writecombine(PAGE_KERNEL));
-		if (msm_obj->vaddr == NULL)
-			return ERR_PTR(-ENOMEM);
+		if (msm_obj->vaddr == NULL) {
+			ret = -ENOMEM;
+			goto fail;
+		}
 	}
-	msm_obj->vmap_count++;
+
+	mutex_unlock(&msm_obj->lock);
 	return msm_obj->vaddr;
-}
 
-void *msm_gem_get_vaddr(struct drm_gem_object *obj)
-{
-	void *ret;
-	mutex_lock(&obj->dev->struct_mutex);
-	ret = msm_gem_get_vaddr_locked(obj);
-	mutex_unlock(&obj->dev->struct_mutex);
-	return ret;
+fail:
+	msm_obj->vmap_count--;
+	mutex_unlock(&msm_obj->lock);
+	return ERR_PTR(ret);
 }
 
-void msm_gem_put_vaddr_locked(struct drm_gem_object *obj)
+void msm_gem_put_vaddr(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
-	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+
+	mutex_lock(&msm_obj->lock);
 	WARN_ON(msm_obj->vmap_count < 1);
 	msm_obj->vmap_count--;
-}
-
-void msm_gem_put_vaddr(struct drm_gem_object *obj)
-{
-	mutex_lock(&obj->dev->struct_mutex);
-	msm_gem_put_vaddr_locked(obj);
-	mutex_unlock(&obj->dev->struct_mutex);
+	mutex_unlock(&msm_obj->lock);
 }
 
 /* Update madvise status, returns true if not purged, else
@@ -503,15 +528,21 @@ int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 
+	mutex_lock(&msm_obj->lock);
+
 	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
 
 	if (msm_obj->madv != __MSM_MADV_PURGED)
 		msm_obj->madv = madv;
 
-	return (msm_obj->madv != __MSM_MADV_PURGED);
+	madv = msm_obj->madv;
+
+	mutex_unlock(&msm_obj->lock);
+
+	return (madv != __MSM_MADV_PURGED);
 }
 
-void msm_gem_purge(struct drm_gem_object *obj)
+void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass)
 {
 	struct drm_device *dev = obj->dev;
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -520,9 +551,11 @@ void msm_gem_purge(struct drm_gem_object *obj)
 	WARN_ON(!is_purgeable(msm_obj));
 	WARN_ON(obj->import_attach);
 
+	mutex_lock_nested(&msm_obj->lock, subclass);
+
 	put_iova(obj);
 
-	msm_gem_vunmap(obj);
+	msm_gem_vunmap_locked(obj);
 
 	put_pages(obj);
 
@@ -540,12 +573,16 @@ void msm_gem_purge(struct drm_gem_object *obj)
 
 	invalidate_mapping_pages(file_inode(obj->filp)->i_mapping,
 			0, (loff_t)-1);
+
+	mutex_unlock(&msm_obj->lock);
 }
 
-void msm_gem_vunmap(struct drm_gem_object *obj)
+static void msm_gem_vunmap_locked(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 
+	WARN_ON(!mutex_is_locked(&msm_obj->lock));
+
 	if (!msm_obj->vaddr || WARN_ON(!is_vunmapable(msm_obj)))
 		return;
 
@@ -553,6 +590,15 @@ void msm_gem_vunmap(struct drm_gem_object *obj)
 	msm_obj->vaddr = NULL;
 }
 
+void msm_gem_vunmap(struct drm_gem_object *obj, enum msm_gem_lock subclass)
+{
+	struct msm_gem_object *msm_obj = to_msm_bo(obj);
+
+	mutex_lock_nested(&msm_obj->lock, subclass);
+	msm_gem_vunmap_locked(obj);
+	mutex_unlock(&msm_obj->lock);
+}
+
 /* must be called before _move_to_active().. */
 int msm_gem_sync_object(struct drm_gem_object *obj,
 		struct msm_fence_context *fctx, bool exclusive)
@@ -674,7 +720,7 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 	uint64_t off = drm_vma_node_start(&obj->vma_node);
 	const char *madv;
 
-	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+	mutex_lock(&msm_obj->lock);
 
 	switch (msm_obj->madv) {
 	case __MSM_MADV_PURGED:
@@ -715,6 +761,8 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 	if (fence)
 		describe_fence(fence, "Exclusive", m);
 	rcu_read_unlock();
+
+	mutex_unlock(&msm_obj->lock);
 }
 
 void msm_gem_describe_objects(struct list_head *list, struct seq_file *m)
@@ -747,6 +795,8 @@ void msm_gem_free_object(struct drm_gem_object *obj)
 
 	list_del(&msm_obj->mm_list);
 
+	mutex_lock(&msm_obj->lock);
+
 	put_iova(obj);
 
 	if (obj->import_attach) {
@@ -761,7 +811,7 @@ void msm_gem_free_object(struct drm_gem_object *obj)
 
 		drm_prime_gem_destroy(obj, msm_obj->sgt);
 	} else {
-		msm_gem_vunmap(obj);
+		msm_gem_vunmap_locked(obj);
 		put_pages(obj);
 	}
 
@@ -770,6 +820,7 @@ void msm_gem_free_object(struct drm_gem_object *obj)
 
 	drm_gem_object_release(obj);
 
+	mutex_unlock(&msm_obj->lock);
 	kfree(msm_obj);
 }
 
@@ -780,14 +831,8 @@ int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
 	struct drm_gem_object *obj;
 	int ret;
 
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
-	if (ret)
-		return ret;
-
 	obj = msm_gem_new(dev, size, flags);
 
-	mutex_unlock(&dev->struct_mutex);
-
 	if (IS_ERR(obj))
 		return PTR_ERR(obj);
 
@@ -802,13 +847,12 @@ int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
 static int msm_gem_new_impl(struct drm_device *dev,
 		uint32_t size, uint32_t flags,
 		struct reservation_object *resv,
-		struct drm_gem_object **obj)
+		struct drm_gem_object **obj,
+		bool struct_mutex_locked)
 {
 	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_gem_object *msm_obj;
 
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
 	switch (flags & MSM_BO_CACHE_MASK) {
 	case MSM_BO_UNCACHED:
 	case MSM_BO_CACHED:
@@ -824,6 +868,8 @@ static int msm_gem_new_impl(struct drm_device *dev,
 	if (!msm_obj)
 		return -ENOMEM;
 
+	mutex_init(&msm_obj->lock);
+
 	msm_obj->flags = flags;
 	msm_obj->madv = MSM_MADV_WILLNEED;
 
@@ -837,23 +883,28 @@ static int msm_gem_new_impl(struct drm_device *dev,
 	INIT_LIST_HEAD(&msm_obj->submit_entry);
 	INIT_LIST_HEAD(&msm_obj->vmas);
 
-	list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+	if (struct_mutex_locked) {
+		WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+		list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+	} else {
+		mutex_lock(&dev->struct_mutex);
+		list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+		mutex_unlock(&dev->struct_mutex);
+	}
 
 	*obj = &msm_obj->base;
 
 	return 0;
 }
 
-struct drm_gem_object *msm_gem_new(struct drm_device *dev,
-		uint32_t size, uint32_t flags)
+static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
+		uint32_t size, uint32_t flags, bool struct_mutex_locked)
 {
 	struct msm_drm_private *priv = dev->dev_private;
 	struct drm_gem_object *obj = NULL;
 	bool use_vram = false;
 	int ret;
 
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
 	size = PAGE_ALIGN(size);
 
 	if (!iommu_present(&platform_bus_type))
@@ -870,7 +921,7 @@ struct drm_gem_object *msm_gem_new(struct drm_device *dev,
 	if (size == 0)
 		return ERR_PTR(-EINVAL);
 
-	ret = msm_gem_new_impl(dev, size, flags, NULL, &obj);
+	ret = msm_gem_new_impl(dev, size, flags, NULL, &obj, struct_mutex_locked);
 	if (ret)
 		goto fail;
 
@@ -904,10 +955,22 @@ struct drm_gem_object *msm_gem_new(struct drm_device *dev,
 	return obj;
 
 fail:
-	drm_gem_object_unreference(obj);
+	drm_gem_object_unreference_unlocked(obj);
 	return ERR_PTR(ret);
 }
 
+struct drm_gem_object *msm_gem_new_locked(struct drm_device *dev,
+		uint32_t size, uint32_t flags)
+{
+	return _msm_gem_new(dev, size, flags, true);
+}
+
+struct drm_gem_object *msm_gem_new(struct drm_device *dev,
+		uint32_t size, uint32_t flags)
+{
+	return _msm_gem_new(dev, size, flags, false);
+}
+
 struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 		struct dma_buf *dmabuf, struct sg_table *sgt)
 {
@@ -924,11 +987,7 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 
 	size = PAGE_ALIGN(dmabuf->size);
 
-	/* Take mutex so we can modify the inactive list in msm_gem_new_impl */
-	mutex_lock(&dev->struct_mutex);
-	ret = msm_gem_new_impl(dev, size, MSM_BO_WC, dmabuf->resv, &obj);
-	mutex_unlock(&dev->struct_mutex);
-
+	ret = msm_gem_new_impl(dev, size, MSM_BO_WC, dmabuf->resv, &obj, false);
 	if (ret)
 		goto fail;
 
@@ -937,17 +996,22 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 	npages = size / PAGE_SIZE;
 
 	msm_obj = to_msm_bo(obj);
+	mutex_lock(&msm_obj->lock);
 	msm_obj->sgt = sgt;
 	msm_obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
 	if (!msm_obj->pages) {
+		mutex_unlock(&msm_obj->lock);
 		ret = -ENOMEM;
 		goto fail;
 	}
 
 	ret = drm_prime_sg_to_page_addr_arrays(sgt, msm_obj->pages, NULL, npages);
-	if (ret)
+	if (ret) {
+		mutex_unlock(&msm_obj->lock);
 		goto fail;
+	}
 
+	mutex_unlock(&msm_obj->lock);
 	return obj;
 
 fail: