[PATCH 2/8] drm/xe/oa: Introduce 'struct xe_oa_fence'

[Ashutosh Dixit]

Here we introduce 'struct xe_oa_fence' which will contain the fence used
for signalling xe_syncs (in a later patch). The struct also contains the
work struct used for signalling the fences. Otherwise, this patch is a
simple refactor of the previous patch. In this patch the work function is
executed synchronously.

Signed-off-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
---
 drivers/gpu/drm/xe/xe_oa.c | 73 ++++++++++++++++++++++++++++++--------
 1 file changed, 59 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c
index d842c801fb9f1..f97d64ffb460f 100644
--- a/drivers/gpu/drm/xe/xe_oa.c
+++ b/drivers/gpu/drm/xe/xe_oa.c
@@ -90,6 +90,15 @@ struct xe_oa_config_bo {
 	struct xe_bb *bb;
 };
 
+struct xe_oa_fence {
+	/* @xe: pointer to xe device */
+	struct xe_device *xe;
+	/* @work: work to signal that OA configuration is applied */
+	struct work_struct work;
+	/* @config_fence: dma fence for OA config to be applied */
+	struct dma_fence *config_fence;
+};
+
 #define DRM_FMT(x) DRM_XE_OA_FMT_TYPE_##x
 
 static const struct xe_oa_format oa_formats[] = {
@@ -905,14 +914,51 @@ xe_oa_alloc_config_buffer(struct xe_oa_stream *stream, struct xe_oa_config *oa_c
 	return oa_bo;
 }
 
-static int xe_oa_emit_oa_config(struct xe_oa_stream *stream, struct xe_oa_config *config)
+static void xe_oa_fence_work_fn(struct work_struct *w)
 {
 #define NOA_PROGRAM_ADDITIONAL_DELAY_US 500
-	struct xe_oa_config_bo *oa_bo;
+	struct xe_oa_fence *ofence = container_of(w, typeof(*ofence), work);
 	int err = 0, us = NOA_PROGRAM_ADDITIONAL_DELAY_US;
-	struct dma_fence *fence;
 	long timeout;
 
+	/* Wait till all previous batches have executed */
+	timeout = dma_fence_wait_timeout(ofence->config_fence, false, 5 * HZ);
+	dma_fence_put(ofence->config_fence);
+	if (timeout < 0)
+		err = timeout;
+	else if (!timeout)
+		err = -ETIME;
+	if (err)
+		drm_dbg(&ofence->xe->drm, "dma_fence_wait_timeout err %d\n", err);
+
+	/* Additional empirical delay needed for NOA programming after registers are written */
+	usleep_range(us, 2 * us);
+
+	kfree(ofence);
+}
+
+static struct xe_oa_fence *xe_oa_fence_init(struct xe_device *xe, struct dma_fence *config_fence)
+{
+	struct xe_oa_fence *ofence;
+
+	ofence = kzalloc(sizeof(*ofence), GFP_KERNEL);
+	if (!ofence)
+		return ERR_PTR(-ENOMEM);
+
+	ofence->xe = xe;
+	INIT_WORK(&ofence->work, xe_oa_fence_work_fn);
+	ofence->config_fence = config_fence;
+
+	return ofence;
+}
+
+static int xe_oa_emit_oa_config(struct xe_oa_stream *stream, struct xe_oa_config *config)
+{
+	struct xe_oa_config_bo *oa_bo;
+	struct xe_oa_fence *ofence;
+	struct dma_fence *fence;
+	int err;
+
 	/* Emit OA configuration batch */
 	oa_bo = xe_oa_alloc_config_buffer(stream, config);
 	if (IS_ERR(oa_bo)) {
@@ -924,18 +970,17 @@ static int xe_oa_emit_oa_config(struct xe_oa_stream *stream, struct xe_oa_config
 	if (err)
 		goto exit;
 
-	/* Wait till all previous batches have executed */
-	timeout = dma_fence_wait_timeout(fence, false, 5 * HZ);
-	dma_fence_put(fence);
-	if (timeout < 0)
-		err = timeout;
-	else if (!timeout)
-		err = -ETIME;
-	if (err)
-		drm_dbg(&stream->oa->xe->drm, "dma_fence_wait_timeout err %d\n", err);
+	ofence = xe_oa_fence_init(stream->oa->xe, fence);
+	if (IS_ERR(ofence)) {
+		err = PTR_ERR(ofence);
+		goto put_fence;
+	}
 
-	/* Additional empirical delay needed for NOA programming after registers are written */
-	usleep_range(us, 2 * us);
+	xe_oa_fence_work_fn(&ofence->work);
+
+	return 0;
+put_fence:
+	dma_fence_put(fence);
 exit:
 	return err;
 }
-- 
2.41.0