Revert "drm: mark context support as a legacy subsystem"

This reverts commit 7c510133.

Well looks like not enough digging was done, libdrm_nouveau before 2.4.33
used contexts,

292da616fe1f936ca78a3fa8e1b1b19883e343b6 nouveau: pull in major libdrm rewrite

got rid of them,
Reported-by: Paul Zimmerman <Paul.Zimmerman@synopsys.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_context.c

@@ -42,6 +42,10 @@
 
 #include <drm/drmP.h>
 
+/******************************************************************/
+/** \name Context bitmap support */
+/*@{*/
+
 /**
  * Free a handle from the context bitmap.
  *
@@ -52,48 +56,13 @@
  * in drm_device::ctx_idr, while holding the drm_device::struct_mutex
  * lock.
  */
-static void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
+void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
 {
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return;
-
 	mutex_lock(&dev->struct_mutex);
 	idr_remove(&dev->ctx_idr, ctx_handle);
 	mutex_unlock(&dev->struct_mutex);
 }
 
-/******************************************************************/
-/** \name Context bitmap support */
-/*@{*/
-
-void drm_legacy_ctxbitmap_release(struct drm_device *dev,
-				  struct drm_file *file_priv)
-{
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return;
-
-	mutex_lock(&dev->ctxlist_mutex);
-	if (!list_empty(&dev->ctxlist)) {
-		struct drm_ctx_list *pos, *n;
-
-		list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
-			if (pos->tag == file_priv &&
-			    pos->handle != DRM_KERNEL_CONTEXT) {
-				if (dev->driver->context_dtor)
-					dev->driver->context_dtor(dev,
-								  pos->handle);
-
-				drm_ctxbitmap_free(dev, pos->handle);
-
-				list_del(&pos->head);
-				kfree(pos);
-				--dev->ctx_count;
-			}
-		}
-	}
-	mutex_unlock(&dev->ctxlist_mutex);
-}
-
 /**
  * Context bitmap allocation.
  *
@@ -121,12 +90,10 @@ static int drm_ctxbitmap_next(struct drm_device * dev)
  *
  * Initialise the drm_device::ctx_idr
  */
-void drm_legacy_ctxbitmap_init(struct drm_device * dev)
+int drm_ctxbitmap_init(struct drm_device * dev)
 {
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return;
-
 	idr_init(&dev->ctx_idr);
+	return 0;
 }
 
 /**
@@ -137,7 +104,7 @@ void drm_legacy_ctxbitmap_init(struct drm_device * dev)
  * Free all idr members using drm_ctx_sarea_free helper function
  * while holding the drm_device::struct_mutex lock.
  */
-void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)
+void drm_ctxbitmap_cleanup(struct drm_device * dev)
 {
 	mutex_lock(&dev->struct_mutex);
 	idr_destroy(&dev->ctx_idr);
@@ -169,9 +136,6 @@ int drm_getsareactx(struct drm_device *dev, void *data,
 	struct drm_local_map *map;
 	struct drm_map_list *_entry;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
 	mutex_lock(&dev->struct_mutex);
 
 	map = idr_find(&dev->ctx_idr, request->ctx_id);
@@ -216,9 +180,6 @@ int drm_setsareactx(struct drm_device *dev, void *data,
 	struct drm_local_map *map = NULL;
 	struct drm_map_list *r_list = NULL;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
 	mutex_lock(&dev->struct_mutex);
 	list_for_each_entry(r_list, &dev->maplist, head) {
 		if (r_list->map
@@ -319,9 +280,6 @@ int drm_resctx(struct drm_device *dev, void *data,
 	struct drm_ctx ctx;
 	int i;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
 	if (res->count >= DRM_RESERVED_CONTEXTS) {
 		memset(&ctx, 0, sizeof(ctx));
 		for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
@@ -352,9 +310,6 @@ int drm_addctx(struct drm_device *dev, void *data,
 	struct drm_ctx_list *ctx_entry;
 	struct drm_ctx *ctx = data;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
 	ctx->handle = drm_ctxbitmap_next(dev);
 	if (ctx->handle == DRM_KERNEL_CONTEXT) {
 		/* Skip kernel's context and get a new one. */
@@ -398,9 +353,6 @@ int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 {
 	struct drm_ctx *ctx = data;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
 	/* This is 0, because we don't handle any context flags */
 	ctx->flags = 0;
 
@@ -423,9 +375,6 @@ int drm_switchctx(struct drm_device *dev, void *data,
 {
 	struct drm_ctx *ctx = data;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
 	DRM_DEBUG("%d\n", ctx->handle);
 	return drm_context_switch(dev, dev->last_context, ctx->handle);
 }
@@ -446,9 +395,6 @@ int drm_newctx(struct drm_device *dev, void *data,
 {
 	struct drm_ctx *ctx = data;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
 	DRM_DEBUG("%d\n", ctx->handle);
 	drm_context_switch_complete(dev, file_priv, ctx->handle);
 
@@ -471,9 +417,6 @@ int drm_rmctx(struct drm_device *dev, void *data,
 {
 	struct drm_ctx *ctx = data;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
 	DRM_DEBUG("%d\n", ctx->handle);
 	if (ctx->handle != DRM_KERNEL_CONTEXT) {
 		if (dev->driver->context_dtor)

drivers/gpu/drm/drm_fops.c

@@ -439,7 +439,26 @@ int drm_release(struct inode *inode, struct file *filp)
 	if (dev->driver->driver_features & DRIVER_GEM)
 		drm_gem_release(dev, file_priv);
 
-	drm_legacy_ctxbitmap_release(dev, file_priv);
+	mutex_lock(&dev->ctxlist_mutex);
+	if (!list_empty(&dev->ctxlist)) {
+		struct drm_ctx_list *pos, *n;
+
+		list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
+			if (pos->tag == file_priv &&
+			    pos->handle != DRM_KERNEL_CONTEXT) {
+				if (dev->driver->context_dtor)
+					dev->driver->context_dtor(dev,
+								  pos->handle);
+
+				drm_ctxbitmap_free(dev, pos->handle);
+
+				list_del(&pos->head);
+				kfree(pos);
+				--dev->ctx_count;
+			}
+		}
+	}
+	mutex_unlock(&dev->ctxlist_mutex);
 
 	mutex_lock(&dev->struct_mutex);
 

drivers/gpu/drm/drm_stub.c

@@ -292,7 +292,13 @@ int drm_fill_in_dev(struct drm_device *dev,
 			goto error_out_unreg;
 	}
 
-	drm_legacy_ctxbitmap_init(dev);
+
+
+	retcode = drm_ctxbitmap_init(dev);
+	if (retcode) {
+		DRM_ERROR("Cannot allocate memory for context bitmap.\n");
+		goto error_out_unreg;
+	}
 
 	if (driver->driver_features & DRIVER_GEM) {
 		retcode = drm_gem_init(dev);
@@ -446,7 +452,7 @@ void drm_put_dev(struct drm_device *dev)
 		drm_rmmap(dev, r_list->map);
 	drm_ht_remove(&dev->map_hash);
 
-	drm_legacy_ctxbitmap_cleanup(dev);
+	drm_ctxbitmap_cleanup(dev);
 
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		drm_put_minor(&dev->control);

include/drm/drmP.h

@@ -1322,10 +1322,9 @@ extern int drm_newctx(struct drm_device *dev, void *data,
 extern int drm_rmctx(struct drm_device *dev, void *data,
 		     struct drm_file *file_priv);
 
-extern void drm_legacy_ctxbitmap_init(struct drm_device *dev);
-extern void drm_legacy_ctxbitmap_cleanup(struct drm_device *dev);
-extern void drm_legacy_ctxbitmap_release(struct drm_device *dev,
-					 struct drm_file *file_priv);
+extern int drm_ctxbitmap_init(struct drm_device *dev);
+extern void drm_ctxbitmap_cleanup(struct drm_device *dev);
+extern void drm_ctxbitmap_free(struct drm_device *dev, int ctx_handle);
 
 extern int drm_setsareactx(struct drm_device *dev, void *data,
 			   struct drm_file *file_priv);