diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_timeline_types.h')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_timeline_types.h | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline_types.h b/drivers/gpu/drm/i915/gt/intel_timeline_types.h index 9a71aea7a338..2b1baf2fcc8e 100644 --- a/drivers/gpu/drm/i915/gt/intel_timeline_types.h +++ b/drivers/gpu/drm/i915/gt/intel_timeline_types.h @@ -25,7 +25,25 @@ struct intel_timeline { struct mutex mutex; /* protects the flow of requests */ - unsigned int pin_count; + /* + * pin_count and active_count track essentially the same thing: + * How many requests are in flight or may be under construction. + * + * We need two distinct counters so that we can assign different + * lifetimes to the events for different use-cases. For example, + * we want to permanently keep the timeline pinned for the kernel + * context so that we can issue requests at any time without having + * to acquire space in the GGTT. However, we want to keep tracking + * the activity (to be able to detect when we become idle) along that + * permanently pinned timeline and so end up requiring two counters. + * + * Note that the active_count is protected by the intel_timeline.mutex, + * but the pin_count is protected by a combination of serialisation + * from the intel_context caller plus internal atomicity. + */ + atomic_t pin_count; + unsigned int active_count; + const u32 *hwsp_seqno; struct i915_vma *hwsp_ggtt; u32 hwsp_offset; |