drm/etnaviv: add 'sync point' support

In order to support performance counters in a sane way we need to provide
a method to sync the GPU with the CPU. The GPU can process multpile command
buffers/events per irq. With the help of a 'sync point' we can trigger an event
and stop the GPU/FE immediately. When the CPU is done with is processing it
simply needs to restart the FE and the GPU will process the command stream.

Changes from v1 -> v2:
- process sync point with a work item to keep irq as fast as possible

Changes from v4 -> v5:
- renamed pmrs_* to sync_point_*
- call event_free(..) in sync_point_worker(..)

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
index 70e6590aacdf..3be5cb53e89f 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
@@ -89,6 +89,8 @@ struct etnaviv_chip_identity {
 
 struct etnaviv_event {
 	struct dma_fence *fence;
+
+	void (*sync_point)(struct etnaviv_gpu *gpu, struct etnaviv_event *event);
 };
 
 struct etnaviv_cmdbuf_suballoc;
@@ -135,6 +137,10 @@ struct etnaviv_gpu {
 	/* worker for handling active-list retiring: */
 	struct work_struct retire_work;
 
+	/* worker for handling 'sync' points: */
+	struct work_struct sync_point_work;
+	int sync_point_event;
+
 	void __iomem *mmio;
 	int irq;