[PATCH v2 02/11] drm/i915: Apply lockdep annotations to i915_gem_context.c

Chris Wilson
2016-05-23T11:34:28Z

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>
---
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem_context.c | 16 ++++++++++++++--
2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ff35e36599de..a0f5f00f552f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3429,6 +3429,7 @@ 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 8484da26b5d4..af747f14522e 100644
--- 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;
@@ -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) {