[PATCH] drm/msm/gem: Add some cleanup.h

[Rob Clark <robin.clark@oss.qualcomm.com>]

Convert (most of) the msm_gem_lock() and friends over to scope based
cleanup.

Other than fixing a lock leak in msm_ioctl_gem_info_set_metadata() there
should be no functional change.

Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/msm_drv.c        | 38 ++++++++------------------
 drivers/gpu/drm/msm/msm_gem.c        | 41 +++++++---------------------
 drivers/gpu/drm/msm/msm_gem.h        |  3 ++
 drivers/gpu/drm/msm/msm_gem_submit.c |  6 ++--
 drivers/gpu/drm/msm/msm_gpu.c        |  3 +-
 5 files changed, 29 insertions(+), 62 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 5e8f3ce26b32..42381db0c468 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -550,7 +550,6 @@ static int msm_ioctl_gem_info_set_metadata(struct drm_gem_object *obj,
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	void *new_metadata;
-	void *buf;
 	int ret;
 
 	/* Impose a moderate upper bound on metadata size: */
@@ -559,31 +558,25 @@ static int msm_ioctl_gem_info_set_metadata(struct drm_gem_object *obj,
 	}
 
 	/* Use a temporary buf to keep copy_from_user() outside of gem obj lock: */
-	buf = memdup_user(metadata, metadata_size);
+	void *buf __free(kfree) = memdup_user(metadata, metadata_size);
 	if (IS_ERR(buf))
 		return PTR_ERR(buf);
 
-	ret = msm_gem_lock_interruptible(obj);
-	if (ret)
-		goto out;
+	ACQUIRE(gem_lock_intr, lock)(obj);
+	if ((ret = ACQUIRE_ERR(gem_lock_intr, &lock)))
+		return ret;
 
 	new_metadata =
 		krealloc(msm_obj->metadata, metadata_size, GFP_KERNEL);
 	if (!new_metadata) {
-		ret = -ENOMEM;
-		goto out;
+		return -ENOMEM;
 	}
 
 	msm_obj->metadata = new_metadata;
 	msm_obj->metadata_size = metadata_size;
 	memcpy(msm_obj->metadata, buf, metadata_size);
 
-	msm_gem_unlock(obj);
-
-out:
-	kfree(buf);
-
-	return ret;
+	return 0;
 }
 
 static int msm_ioctl_gem_info_get_metadata(struct drm_gem_object *obj,
@@ -607,21 +600,14 @@ static int msm_ioctl_gem_info_get_metadata(struct drm_gem_object *obj,
 		return 0;
 	}
 
-	ret = msm_gem_lock_interruptible(obj);
-	if (ret)
-		return ret;
-
-	/* Avoid copy_to_user() under gem obj lock: */
-	len = msm_obj->metadata_size;
-	buf = kmemdup(msm_obj->metadata, len, GFP_KERNEL);
-
-	if (!buf) {
-		msm_gem_unlock(obj);
-		return -ENOMEM;
+	scoped_cond_guard (gem_lock_intr, return -EINTR, obj) {
+		/* Avoid copy_to_user() under gem obj lock by making a copy: */
+		len = msm_obj->metadata_size;
+		buf = kmemdup(msm_obj->metadata, len, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
 	}
 
-	msm_gem_unlock(obj);
-
 	if (*metadata_size < len) {
 		ret = -ETOOSMALL;
 	} else if (copy_to_user(metadata, buf, len)) {
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 72e3cd8bb1e7..9abcc7beb268 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -376,8 +376,6 @@ static vm_fault_t msm_gem_fault(struct vm_fault *vmf)
 	struct page **pages;
 	unsigned long pfn;
 	pgoff_t pgoff;
-	int err;
-	vm_fault_t ret;
 
 	if (drm_WARN_ON_ONCE(obj->dev, drm_gem_is_imported(obj)))
 		return VM_FAULT_SIGBUS;
@@ -386,22 +384,19 @@ static vm_fault_t msm_gem_fault(struct vm_fault *vmf)
 	 * vm_ops.open/drm_gem_mmap_obj and close get and put
 	 * a reference on obj. So, we dont need to hold one here.
 	 */
-	err = msm_gem_lock_interruptible(obj);
-	if (err) {
-		ret = VM_FAULT_NOPAGE;
-		goto out;
+	ACQUIRE(gem_lock_intr, lock)(obj);
+	if (ACQUIRE_ERR(gem_lock_intr, &lock)) {
+		return VM_FAULT_NOPAGE;
 	}
 
 	if (GEM_WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
-		msm_gem_unlock(obj);
 		return VM_FAULT_SIGBUS;
 	}
 
 	/* make sure we have pages attached now */
 	pages = get_pages(obj);
 	if (IS_ERR(pages)) {
-		ret = vmf_error(PTR_ERR(pages));
-		goto out_unlock;
+		return vmf_error(PTR_ERR(pages));
 	}
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
@@ -412,12 +407,7 @@ static vm_fault_t msm_gem_fault(struct vm_fault *vmf)
 	VERB("Inserting %p pfn %lx, pa %lx", (void *)vmf->address,
 			pfn, pfn << PAGE_SHIFT);
 
-	ret = vmf_insert_pfn(vma, vmf->address, pfn);
-
-out_unlock:
-	msm_gem_unlock(obj);
-out:
-	return ret;
+	return vmf_insert_pfn(vma, vmf->address, pfn);
 }
 
 
@@ -803,13 +793,8 @@ void *msm_gem_get_vaddr_locked(struct drm_gem_object *obj)
 
 void *msm_gem_get_vaddr(struct drm_gem_object *obj)
 {
-	void *ret;
-
-	msm_gem_lock(obj);
-	ret = msm_gem_get_vaddr_locked(obj);
-	msm_gem_unlock(obj);
-
-	return ret;
+	guard(gem_lock)(obj);
+	return msm_gem_get_vaddr_locked(obj);
 }
 
 /*
@@ -836,9 +821,8 @@ void msm_gem_put_vaddr_locked(struct drm_gem_object *obj)
 
 void msm_gem_put_vaddr(struct drm_gem_object *obj)
 {
-	msm_gem_lock(obj);
+	guard(gem_lock)(obj);
 	msm_gem_put_vaddr_locked(obj);
-	msm_gem_unlock(obj);
 }
 
 /* Update madvise status, returns true if not purged, else
@@ -849,9 +833,8 @@ int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv)
 	struct drm_device *dev = obj->dev;
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 
-	msm_gem_lock(obj);
-
-	mutex_lock(&dev->gem_lru_mutex);
+	guard(gem_lock)(obj);
+	guard(mutex)(&dev->gem_lru_mutex);
 
 	if (msm_obj->madv != __MSM_MADV_PURGED)
 		msm_obj->madv = madv;
@@ -863,10 +846,6 @@ int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv)
 	 */
 	update_lru_locked(obj);
 
-	mutex_unlock(&dev->gem_lru_mutex);
-
-	msm_gem_unlock(obj);
-
 	return (madv != __MSM_MADV_PURGED);
 }
 
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index d8ec696d89d7..bd7968232d73 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -347,6 +347,9 @@ msm_gem_unlock(struct drm_gem_object *obj)
 	dma_resv_unlock(obj->resv);
 }
 
+DEFINE_LOCK_GUARD_1(gem_lock, struct drm_gem_object, msm_gem_lock(_T->lock), msm_gem_unlock(_T->lock));
+DEFINE_LOCK_GUARD_1_COND(gem_lock, _intr, msm_gem_lock_interruptible(_T->lock), _RET == 0);
+
 /**
  * msm_gem_lock_vm_and_obj() - Helper to lock an obj + VM
  * @exec: the exec context helper which will be initalized
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 5862db05297a..ff6cf39587c9 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -536,9 +536,9 @@ void msm_submit_retire(struct msm_gem_submit *submit)
 		struct drm_gem_object *obj = submit->bos[i].obj;
 		struct drm_gpuvm_bo *vm_bo = submit->bos[i].vm_bo;
 
-		msm_gem_lock(obj);
-		drm_gpuvm_bo_put(vm_bo);
-		msm_gem_unlock(obj);
+		scoped_guard (gem_lock, obj)
+			drm_gpuvm_bo_put(vm_bo);
+
 		drm_gem_object_put(obj);
 	}
 }
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 0c2c35636251..fb07803f5aba 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -308,10 +308,9 @@ static void crashstate_get_bos(struct msm_gpu_state *state, struct msm_gem_submi
 			struct drm_gem_object *obj = submit->bos[i].obj;
 			bool dump = rd_full || (submit->bos[i].flags & MSM_SUBMIT_BO_DUMP);
 
-			msm_gem_lock(obj);
+			guard(gem_lock)(obj);
 			msm_gpu_crashstate_get_bo(state, obj, submit->bos[i].iova,
 						  dump, 0, obj->size);
-			msm_gem_unlock(obj);
 		}
 	}
 }
-- 
2.56.0