diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_ringbuffer.h')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ringbuffer.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 64850293559c..73db3ae8f237 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -106,6 +106,9 @@ struct intel_ringbuffer { int space; int size; int effective_size; + int reserved_size; + int reserved_tail; + bool reserved_in_use; /** We track the position of the requests in the ring buffer, and * when each is retired we increment last_retired_head as the GPU @@ -472,4 +475,26 @@ intel_ring_get_request(struct intel_engine_cs *ring) return ring->outstanding_lazy_request; } +/* + * Arbitrary size for largest possible 'add request' sequence. The code paths + * are complex and variable. Empirical measurement shows that the worst case + * is ILK at 136 words. Reserving too much is better than reserving too little + * as that allows for corner cases that might have been missed. So the figure + * has been rounded up to 160 words. + */ +#define MIN_SPACE_FOR_ADD_REQUEST 160 + +/* + * Reserve space in the ring to guarantee that the i915_add_request() call + * will always have sufficient room to do its stuff. The request creation + * code calls this automatically. + */ +void intel_ring_reserved_space_reserve(struct intel_ringbuffer *ringbuf, int size); +/* Cancel the reservation, e.g. because the request is being discarded. */ +void intel_ring_reserved_space_cancel(struct intel_ringbuffer *ringbuf); +/* Use the reserved space - for use by i915_add_request() only. */ +void intel_ring_reserved_space_use(struct intel_ringbuffer *ringbuf); +/* Finish with the reserved space - for use by i915_add_request() only. */ +void intel_ring_reserved_space_end(struct intel_ringbuffer *ringbuf); + #endif /* _INTEL_RINGBUFFER_H_ */ |