diff mbox series

drm/i915: Drop stealing of bits from i915_sw_fence function pointer

Message ID 20210922154713.1109-1-matthew.brost@intel.com (mailing list archive)
State New, archived
Headers show
Series drm/i915: Drop stealing of bits from i915_sw_fence function pointer | expand

Commit Message

Matthew Brost Sept. 22, 2021, 3:47 p.m. UTC 
Rather than stealing bits from i915_sw_fence function pointer use
seperate fields for function pointer and flags. If using two different
fields, the 4 byte alignment for the i915_sw_fence function pointer can
also be dropped.

v2:
 (CI)
  - Set new function field rather than flags in __i915_sw_fence_init
v3:
 (Tvrtko)
  - Remove BUG_ON(!fence->flags) in reinit as that will now blow up
  - Only define fence->flags if CONFIG_DRM_I915_SW_FENCE_CHECK_DAG is
    defined

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c  |  2 +-
 drivers/gpu/drm/i915/gem/i915_gem_context.c   |  2 +-
 drivers/gpu/drm/i915/i915_request.c           |  4 +--
 drivers/gpu/drm/i915/i915_sw_fence.c          | 28 +++++++++++--------
 drivers/gpu/drm/i915/i915_sw_fence.h          | 23 +++++++--------
 drivers/gpu/drm/i915/i915_sw_fence_work.c     |  2 +-
 .../gpu/drm/i915/selftests/i915_sw_fence.c    |  2 +-
 drivers/gpu/drm/i915/selftests/lib_sw_fence.c |  8 +++---
 8 files changed, 39 insertions(+), 32 deletions(-)

Comments

Alan Previn Nov. 11, 2021, 8:18 p.m. UTC | #1 
Hey Matt, apologies for the delay, went thru all the code, LGTM.

Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>

P.S. - As a side note, would be interesting to replay the original reason behind the overloading of the
func ptr bits to begin with... to see what the initial intention was.


...alan

On Wed, 2021-09-22 at 08:47 -0700, Matthew Brost wrote:
> Rather than stealing bits from i915_sw_fence function pointer use
> seperate fields for function pointer and flags. If using two different
> fields, the 4 byte alignment for the i915_sw_fence function pointer can
> also be dropped.
> 
> v2:
>  (CI)
>   - Set new function field rather than flags in __i915_sw_fence_init
> v3:
>  (Tvrtko)
>   - Remove BUG_ON(!fence->flags) in reinit as that will now blow up
>   - Only define fence->flags if CONFIG_DRM_I915_SW_FENCE_CHECK_DAG is
>     defined
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> Acked-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c  |  2 +-
>  drivers/gpu/drm/i915/gem/i915_gem_context.c   |  2 +-
>  drivers/gpu/drm/i915/i915_request.c           |  4 +--
>  drivers/gpu/drm/i915/i915_sw_fence.c          | 28 +++++++++++--------
>  drivers/gpu/drm/i915/i915_sw_fence.h          | 23 +++++++--------
>  drivers/gpu/drm/i915/i915_sw_fence_work.c     |  2 +-
>  .../gpu/drm/i915/selftests/i915_sw_fence.c    |  2 +-
>  drivers/gpu/drm/i915/selftests/lib_sw_fence.c |  8 +++---
>  8 files changed, 39 insertions(+), 32 deletions(-)
> 
>  
> -- 
> 2.32.0
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index a7ca38613f89..6d5bb55ffc82 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -10323,7 +10323,7 @@  static void intel_atomic_commit_work(struct work_struct *work)
 	intel_atomic_commit_tail(state);
 }
 
-static int __i915_sw_fence_call
+static int
 intel_atomic_commit_ready(struct i915_sw_fence *fence,
 			  enum i915_sw_fence_notify notify)
 {
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index c2ab0e22db0a..df5fec5c3da8 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -800,7 +800,7 @@  static void free_engines_rcu(struct rcu_head *rcu)
 	free_engines(engines);
 }
 
-static int __i915_sw_fence_call
+static int
 engines_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 {
 	struct i915_gem_engines *engines =
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index ce446716d092..945d3025a0b6 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -719,7 +719,7 @@  void i915_request_cancel(struct i915_request *rq, int error)
 	intel_context_cancel_request(rq->context, rq);
 }
 
-static int __i915_sw_fence_call
+static int
 submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 {
 	struct i915_request *request =
@@ -755,7 +755,7 @@  submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 	return NOTIFY_DONE;
 }
 
-static int __i915_sw_fence_call
+static int
 semaphore_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 {
 	struct i915_request *rq = container_of(fence, typeof(*rq), semaphore);
diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c
index c589a681da77..f10d31818ecc 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence.c
+++ b/drivers/gpu/drm/i915/i915_sw_fence.c
@@ -18,7 +18,9 @@ 
 #define I915_SW_FENCE_BUG_ON(expr) BUILD_BUG_ON_INVALID(expr)
 #endif
 
+#ifdef CONFIG_DRM_I915_SW_FENCE_CHECK_DAG
 static DEFINE_SPINLOCK(i915_sw_fence_lock);
+#endif
 
 #define WQ_FLAG_BITS \
 	BITS_PER_TYPE(typeof_member(struct wait_queue_entry, flags))
@@ -34,7 +36,7 @@  enum {
 
 static void *i915_sw_fence_debug_hint(void *addr)
 {
-	return (void *)(((struct i915_sw_fence *)addr)->flags & I915_SW_FENCE_MASK);
+	return (void *)(((struct i915_sw_fence *)addr)->fn);
 }
 
 #ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
@@ -126,10 +128,7 @@  static inline void debug_fence_assert(struct i915_sw_fence *fence)
 static int __i915_sw_fence_notify(struct i915_sw_fence *fence,
 				  enum i915_sw_fence_notify state)
 {
-	i915_sw_fence_notify_t fn;
-
-	fn = (i915_sw_fence_notify_t)(fence->flags & I915_SW_FENCE_MASK);
-	return fn(fence, state);
+	return fence->fn(fence, state);
 }
 
 #ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
@@ -242,10 +241,13 @@  void __i915_sw_fence_init(struct i915_sw_fence *fence,
 			  const char *name,
 			  struct lock_class_key *key)
 {
-	BUG_ON(!fn || (unsigned long)fn & ~I915_SW_FENCE_MASK);
+	BUG_ON(!fn);
 
 	__init_waitqueue_head(&fence->wait, name, key);
-	fence->flags = (unsigned long)fn;
+	fence->fn = fn;
+#ifdef CONFIG_DRM_I915_SW_FENCE_CHECK_DAG
+	fence->flags = 0;
+#endif
 
 	i915_sw_fence_reinit(fence);
 }
@@ -257,7 +259,6 @@  void i915_sw_fence_reinit(struct i915_sw_fence *fence)
 	atomic_set(&fence->pending, 1);
 	fence->error = 0;
 
-	I915_SW_FENCE_BUG_ON(!fence->flags);
 	I915_SW_FENCE_BUG_ON(!list_empty(&fence->wait.head));
 }
 
@@ -279,6 +280,7 @@  static int i915_sw_fence_wake(wait_queue_entry_t *wq, unsigned mode, int flags,
 	return 0;
 }
 
+#ifdef CONFIG_DRM_I915_SW_FENCE_CHECK_DAG
 static bool __i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
 				    const struct i915_sw_fence * const signaler)
 {
@@ -322,9 +324,6 @@  static bool i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
 	unsigned long flags;
 	bool err;
 
-	if (!IS_ENABLED(CONFIG_DRM_I915_SW_FENCE_CHECK_DAG))
-		return false;
-
 	spin_lock_irqsave(&i915_sw_fence_lock, flags);
 	err = __i915_sw_fence_check_if_after(fence, signaler);
 	__i915_sw_fence_clear_checked_bit(fence);
@@ -332,6 +331,13 @@  static bool i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
 
 	return err;
 }
+#else
+static bool i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
+					 const struct i915_sw_fence * const signaler)
+{
+	return false;
+}
+#endif
 
 static int __i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
 					  struct i915_sw_fence *signaler,
diff --git a/drivers/gpu/drm/i915/i915_sw_fence.h b/drivers/gpu/drm/i915/i915_sw_fence.h
index 30a863353ee6..a7c603bc1b01 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence.h
+++ b/drivers/gpu/drm/i915/i915_sw_fence.h
@@ -17,26 +17,27 @@ 
 
 struct completion;
 struct dma_resv;
+struct i915_sw_fence;
+
+enum i915_sw_fence_notify {
+	FENCE_COMPLETE,
+	FENCE_FREE
+};
+
+typedef int (*i915_sw_fence_notify_t)(struct i915_sw_fence *,
+				      enum i915_sw_fence_notify state);
 
 struct i915_sw_fence {
 	wait_queue_head_t wait;
+	i915_sw_fence_notify_t fn;
+#ifdef CONFIG_DRM_I915_SW_FENCE_CHECK_DAG
 	unsigned long flags;
+#endif
 	atomic_t pending;
 	int error;
 };
 
 #define I915_SW_FENCE_CHECKED_BIT	0 /* used internally for DAG checking */
-#define I915_SW_FENCE_PRIVATE_BIT	1 /* available for use by owner */
-#define I915_SW_FENCE_MASK		(~3)
-
-enum i915_sw_fence_notify {
-	FENCE_COMPLETE,
-	FENCE_FREE
-};
-
-typedef int (*i915_sw_fence_notify_t)(struct i915_sw_fence *,
-				      enum i915_sw_fence_notify state);
-#define __i915_sw_fence_call __aligned(4)
 
 void __i915_sw_fence_init(struct i915_sw_fence *fence,
 			  i915_sw_fence_notify_t fn,
diff --git a/drivers/gpu/drm/i915/i915_sw_fence_work.c b/drivers/gpu/drm/i915/i915_sw_fence_work.c
index 5b33ef23d54c..d2e56b387993 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence_work.c
+++ b/drivers/gpu/drm/i915/i915_sw_fence_work.c
@@ -23,7 +23,7 @@  static void fence_work(struct work_struct *work)
 	dma_fence_put(&f->dma);
 }
 
-static int __i915_sw_fence_call
+static int
 fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 {
 	struct dma_fence_work *f = container_of(fence, typeof(*f), chain);
diff --git a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
index cbf45d85cbff..daa985e5a19b 100644
--- a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
+++ b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
@@ -28,7 +28,7 @@ 
 
 #include "../i915_selftest.h"
 
-static int __i915_sw_fence_call
+static int
 fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 {
 	switch (state) {
diff --git a/drivers/gpu/drm/i915/selftests/lib_sw_fence.c b/drivers/gpu/drm/i915/selftests/lib_sw_fence.c
index 080b90b63d16..bf2752cc1e0b 100644
--- a/drivers/gpu/drm/i915/selftests/lib_sw_fence.c
+++ b/drivers/gpu/drm/i915/selftests/lib_sw_fence.c
@@ -26,7 +26,7 @@ 
 
 /* Small library of different fence types useful for writing tests */
 
-static int __i915_sw_fence_call
+static int
 nop_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 {
 	return NOTIFY_DONE;
@@ -41,12 +41,12 @@  void __onstack_fence_init(struct i915_sw_fence *fence,
 	__init_waitqueue_head(&fence->wait, name, key);
 	atomic_set(&fence->pending, 1);
 	fence->error = 0;
-	fence->flags = (unsigned long)nop_fence_notify;
+	fence->fn = nop_fence_notify;
 }
 
 void onstack_fence_fini(struct i915_sw_fence *fence)
 {
-	if (!fence->flags)
+	if (!fence->fn)
 		return;
 
 	i915_sw_fence_commit(fence);
@@ -89,7 +89,7 @@  struct heap_fence {
 	};
 };
 
-static int __i915_sw_fence_call
+static int
 heap_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 {
 	struct heap_fence *h = container_of(fence, typeof(*h), fence);