drm/radeon/kms: manage r300 CMASK RAM access and allow CMASK clear

The CMASK RAM is for colorbuffer compression (used in conjunction
with MSAA). Only one user (filp) can access it.

The CMASK RAM access is managed in the same way as Hyper-Z, but there is
a separate ioctl, because an app that uses MSAA does not necessarily
have to use zbuffering.

Signed-off-by: Marek Olšák <maraeo@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 27 insertions, 12 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index b2686334d46b..28a53e4a925f 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -96,9 +96,27 @@ out:
 	return r;
 }
 
+static void radeon_set_filp_rights(struct drm_device *dev,
+				   struct drm_file **owner,
+				   struct drm_file *applier,
+				   uint32_t *value)
+{
+	mutex_lock(&dev->struct_mutex);
+	if (*value == 1) {
+		/* wants rights */
+		if (!*owner)
+			*owner = applier;
+	} else if (*value == 0) {
+		/* revokes rights */
+		if (*owner == applier)
+			*owner = NULL;
+	}
+	*value = *owner == applier ? 1 : 0;
+	mutex_unlock(&dev->struct_mutex);
+}
 
 /*
- * Userspace get informations ioctl
+ * Userspace get information ioctl
  */
 int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 {
@@ -173,18 +191,15 @@ int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 			DRM_DEBUG_KMS("WANT_HYPERZ: invalid value %d\n", value);
 			return -EINVAL;
 		}
-		mutex_lock(&dev->struct_mutex);
-		if (value == 1) {
-			/* wants hyper-z */
-			if (!rdev->hyperz_filp)
-				rdev->hyperz_filp = filp;
-		} else if (value == 0) {
-			/* revokes hyper-z */
-			if (rdev->hyperz_filp == filp)
-				rdev->hyperz_filp = NULL;
+		radeon_set_filp_rights(dev, &rdev->hyperz_filp, filp, &value);
+		break;
+	case RADEON_INFO_WANT_CMASK:
+		/* The same logic as Hyper-Z. */
+		if (value >= 2) {
+			DRM_DEBUG_KMS("WANT_CMASK: invalid value %d\n", value);
+			return -EINVAL;
 		}
-		value = rdev->hyperz_filp == filp ?  1 : 0;
-		mutex_unlock(&dev->struct_mutex);
+		radeon_set_filp_rights(dev, &rdev->cmask_filp, filp, &value);
 		break;
 	default:
 		DRM_DEBUG_KMS("Invalid request %d\n", info->request);