drm/i915: Apply lockdep annotations to i915_gem_context.c

Markup the functions that require the caller to hold struct_mutex with
lockdep_assert_held(). In the hopefully not-too-distant future we will
split the struct_mutex up, and in doing so we need to be sure that we
know what it protects - here the lockdep annotations are invaluable.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464098023-3294-2-git-send-email-chris@chris-wilson.co.uk
Link: http://patchwork.freedesktop.org/patch/msgid/1464098023-3294-2-git-send-email-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 961ef40..820748d 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3439,6 +3439,7 @@ static inline void i915_gem_context_reference(struct i915_gem_context *ctx)
 
 static inline void i915_gem_context_unreference(struct i915_gem_context *ctx)
 {
+       lockdep_assert_held(&ctx->i915->dev->struct_mutex);
        kref_put(&ctx->ref, i915_gem_context_free);
 }
 

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 8484da2..6b4c5ad 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -153,6 +153,7 @@ void i915_gem_context_free(struct kref *ctx_ref)
 {
        struct i915_gem_context *ctx = container_of(ctx_ref, typeof(*ctx), ref);
 
+       lockdep_assert_held(&ctx->i915->dev->struct_mutex);
        trace_i915_context_free(ctx);
 
        if (i915.enable_execlists)
@@ -181,6 +182,8 @@ i915_gem_alloc_context_obj(struct drm_device *dev, size_t size)
        struct drm_i915_gem_object *obj;
        int ret;
 
+       lockdep_assert_held(&dev->struct_mutex);
+
        obj = i915_gem_object_create(dev, size);
        if (IS_ERR(obj))
                return obj;
@@ -304,7 +307,7 @@ i915_gem_create_context(struct drm_device *dev,
        struct i915_gem_context *ctx;
        int ret = 0;
 
-       BUG_ON(!mutex_is_locked(&dev->struct_mutex));
+       lockdep_assert_held(&dev->struct_mutex);
 
        ctx = __create_hw_context(dev, file_priv);
        if (IS_ERR(ctx))
@@ -368,6 +371,8 @@ void i915_gem_context_reset(struct drm_device *dev)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
 
+       lockdep_assert_held(&dev->struct_mutex);
+
        if (i915.enable_execlists) {
                struct i915_gem_context *ctx;
 
@@ -433,6 +438,8 @@ void i915_gem_context_lost(struct drm_i915_private *dev_priv)
 {
        struct intel_engine_cs *engine;
 
+       lockdep_assert_held(&dev_priv->dev->struct_mutex);
+
        for_each_engine(engine, dev_priv) {
                if (engine->last_context == NULL)
                        continue;
@@ -451,6 +458,8 @@ void i915_gem_context_fini(struct drm_device *dev)
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct i915_gem_context *dctx = dev_priv->kernel_context;
 
+       lockdep_assert_held(&dev->struct_mutex);
+
        if (dctx->legacy_hw_ctx.rcs_state)
                i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
 
@@ -491,6 +500,8 @@ void i915_gem_context_close(struct drm_device *dev, struct drm_file *file)
 {
        struct drm_i915_file_private *file_priv = file->driver_priv;
 
+       lockdep_assert_held(&dev->struct_mutex);
+
        idr_for_each(&file_priv->context_idr, context_idr_cleanup, NULL);
        idr_destroy(&file_priv->context_idr);
 }
@@ -500,6 +511,8 @@ i915_gem_context_get(struct drm_i915_file_private *file_priv, u32 id)
 {
        struct i915_gem_context *ctx;
 
+       lockdep_assert_held(&file_priv->dev_priv->dev->struct_mutex);
+
        ctx = idr_find(&file_priv->context_idr, id);
        if (!ctx)
                return ERR_PTR(-ENOENT);
@@ -852,10 +865,9 @@ unpin_out:
 int i915_switch_context(struct drm_i915_gem_request *req)
 {
        struct intel_engine_cs *engine = req->engine;
-       struct drm_i915_private *dev_priv = req->i915;
 
        WARN_ON(i915.enable_execlists);
-       WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex));
+       lockdep_assert_held(&req->i915->dev->struct_mutex);
 
        if (engine->id != RCS ||
            req->ctx->legacy_hw_ctx.rcs_state == NULL) {