[PATCH v8 2/3] drm/fence: add fence timeline to drm_crtc

Gustavo Padovan
2016-11-11T05:16:32Z

From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

Create one timeline context for each CRTC to be able to handle out-fences
and signal them. It adds a few members to struct drm_crtc: fence_context,
where we store the context we get from fence_context_alloc(), the
fence seqno and the fence lock, that we pass in fence_init() to be
used by the fence.

v2: Comment by Daniel Stone:
- add BUG_ON() to fence_to_crtc() macro

v3: Comment by Ville Syrjälä
- Use more meaningful name as crtc timeline name

v4: Comments by Brian Starkey
- Use even more meaninful name for the crtc timeline
- add doc for timeline_name
Comment by Daniel Vetter
- use in-line style for comments

- rebase after fence -> dma_fence rename

v5: Comment by Daniel Vetter
- Add doc for drm_crtc_fence_ops

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
drivers/gpu/drm/drm_crtc.c | 31 +++++++++++++++++++++++++++++++
include/drm/drm_crtc.h | 45 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 76 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 154e040..9b9881b 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -165,6 +165,32 @@ static void drm_crtc_crc_fini(struct drm_crtc *crtc)
#endif
}

+static const char *drm_crtc_fence_get_driver_name(struct dma_fence *fence)
+{
+ struct drm_crtc *crtc = fence_to_crtc(fence);
+
+ return crtc->dev->driver->name;
+}
+
+static const char *drm_crtc_fence_get_timeline_name(struct dma_fence *fence)
+{
+ struct drm_crtc *crtc = fence_to_crtc(fence);
+
+ return crtc->timeline_name;
+}
+
+static bool drm_crtc_fence_enable_signaling(struct dma_fence *fence)
+{
+ return true;
+}
+
+const struct dma_fence_ops drm_crtc_fence_ops = {
+ .get_driver_name = drm_crtc_fence_get_driver_name,
+ .get_timeline_name = drm_crtc_fence_get_timeline_name,
+ .enable_signaling = drm_crtc_fence_enable_signaling,
+ .wait = dma_fence_default_wait,
+};
+
/**
* drm_crtc_init_with_planes - Initialise a new CRTC object with
* specified primary and cursor planes.
@@ -222,6 +248,11 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
return -ENOMEM;
}

+ crtc->fence_context = dma_fence_context_alloc(1);
+ spin_lock_init(&crtc->fence_lock);
+ snprintf(crtc->timeline_name, sizeof(crtc->timeline_name),
+ "CRTC:%d-%s", crtc->base.id, crtc->name);
+
crtc->base.properties = &crtc->properties;

list_add_tail(&crtc->head, &config->crtc_list);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 11780a9..0870de1 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -32,6 +32,8 @@
#include <linux/fb.h>
#include <linux/hdmi.h>
#include <linux/media-bus-format.h>
+#include <linux/srcu.h>
+#include <linux/dma-fence.h>
#include <uapi/drm/drm_mode.h>
#include <uapi/drm/drm_fourcc.h>
#include <drm/drm_modeset_lock.h>
@@ -739,9 +741,52 @@ struct drm_crtc {
*/
struct drm_crtc_crc crc;
#endif
+
+ /**
+ * @fence_context:
+ *
+ * timeline context used for fence operations.
+ */
+ unsigned int fence_context;
+
+ /**
+ * @fence_lock:
+ *
+ * spinlock to protect the fences in the fence_context.
+ */
+
+ spinlock_t fence_lock;
+ /**
+ * @fence_seqno:
+ *
+ * Seqno variable used as monotonic counter for the fences
+ * created on the CRTC's timeline.
+ */
+ unsigned long fence_seqno;
+
+ /**
+ * @timeline_name:
+ *
+ * The name of the CRTC's fence timeline.
+ */
+ char timeline_name[32];
};

/**
+ * dma_crtc_fence_ops - fence ops for the drm_crtc timeline
+ *
+ * It contains the dma_fence_ops that should be called by the dma_fence
+ * code. CRTC core should use this ops when initializing fences.
+ */
+extern const struct dma_fence_ops drm_crtc_fence_ops;
+
+static inline struct drm_crtc *fence_to_crtc(struct dma_fence *fence)
+{
+ BUG_ON(fence->ops != &drm_crtc_fence_ops);
+ return container_of(fence->lock, struct drm_crtc, fence_lock);
+}
+
+/**
* struct drm_mode_set - new values for a CRTC config change
* @fb: framebuffer to use for new config
* @crtc: CRTC whose configuration we're about to change
--
2.5.5