drm/tegra: Use u64_to_user_ptr helper

Use the u64_to_user_ptr helper macro to cast IOCTL argument u64 values
to user pointers instead of writing out the cast manually. Also do
some other cleanup with user pointers to make them stand out more
and look cleaner.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/drm.c

@@ -386,12 +386,10 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 	unsigned int num_cmdbufs = args->num_cmdbufs;
 	unsigned int num_relocs = args->num_relocs;
 	unsigned int num_waitchks = args->num_waitchks;
-	struct drm_tegra_cmdbuf __user *cmdbufs =
-		(void __user *)(uintptr_t)args->cmdbufs;
-	struct drm_tegra_reloc __user *relocs =
-		(void __user *)(uintptr_t)args->relocs;
-	struct drm_tegra_waitchk __user *waitchks =
-		(void __user *)(uintptr_t)args->waitchks;
+	struct drm_tegra_cmdbuf __user *user_cmdbufs;
+	struct drm_tegra_reloc __user *user_relocs;
+	struct drm_tegra_waitchk __user *user_waitchks;
+	struct drm_tegra_syncpt __user *user_syncpt;
 	struct drm_tegra_syncpt syncpt;
 	struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
 	struct drm_gem_object **refs;
@@ -400,6 +398,11 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 	unsigned int num_refs;
 	int err;
 
+	user_cmdbufs = u64_to_user_ptr(args->cmdbufs);
+	user_relocs = u64_to_user_ptr(args->relocs);
+	user_waitchks = u64_to_user_ptr(args->waitchks);
+	user_syncpt = u64_to_user_ptr(args->syncpts);
+
 	/* We don't yet support other than one syncpt_incr struct per submit */
 	if (args->num_syncpts != 1)
 		return -EINVAL;
@@ -440,7 +443,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 		struct tegra_bo *obj;
 		u64 offset;
 
-		if (copy_from_user(&cmdbuf, cmdbufs, sizeof(cmdbuf))) {
+		if (copy_from_user(&cmdbuf, user_cmdbufs, sizeof(cmdbuf))) {
 			err = -EFAULT;
 			goto fail;
 		}
@@ -476,7 +479,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 
 		host1x_job_add_gather(job, bo, cmdbuf.words, cmdbuf.offset);
 		num_cmdbufs--;
-		cmdbufs++;
+		user_cmdbufs++;
 	}
 
 	/* copy and resolve relocations from submit */
@@ -485,7 +488,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 		struct tegra_bo *obj;
 
 		err = host1x_reloc_copy_from_user(&job->relocarray[num_relocs],
-						  &relocs[num_relocs], drm,
+						  &user_relocs[num_relocs], drm,
 						  file);
 		if (err < 0)
 			goto fail;
@@ -519,9 +522,8 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 		struct host1x_waitchk *wait = &job->waitchk[num_waitchks];
 		struct tegra_bo *obj;
 
-		err = host1x_waitchk_copy_from_user(wait,
-						    &waitchks[num_waitchks],
-						    file);
+		err = host1x_waitchk_copy_from_user(
+			wait, &user_waitchks[num_waitchks], file);
 		if (err < 0)
 			goto fail;
 
@@ -539,8 +541,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 		}
 	}
 
-	if (copy_from_user(&syncpt, (void __user *)(uintptr_t)args->syncpts,
-			   sizeof(syncpt))) {
+	if (copy_from_user(&syncpt, user_syncpt, sizeof(syncpt))) {
 		err = -EFAULT;
 		goto fail;
 	}