+int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request)
+{
+ int ret;
+
+ if (request->ctx != request->ring->default_context) {
+ ret = intel_lr_context_pin(request->ring, request->ctx);
+ if (ret)
+ return ret;
+ }
+
+ request->ringbuf = request->ctx->engine[request->ring->id].ringbuf;
+
+ return 0;
+}
+
+static int logical_ring_wait_for_space(struct intel_ringbuffer *ringbuf,
+ struct intel_context *ctx,
+ int bytes)
+{
+ struct intel_engine_cs *ring = ringbuf->ring;
+ struct drm_i915_gem_request *request;
+ unsigned space;
+ int ret;
+
+ /* The whole point of reserving space is to not wait! */
+ WARN_ON(ringbuf->reserved_in_use);
+
+ if (intel_ring_space(ringbuf) >= bytes)
+ return 0;
+
+ list_for_each_entry(request, &ring->request_list, list) {
+ /*
+ * The request queue is per-engine, so can contain requests
+ * from multiple ringbuffers. Here, we must ignore any that
+ * aren't from the ringbuffer we're considering.
+ */
+ if (request->ringbuf != ringbuf)
+ continue;
+
+ /* Would completion of this request free enough space? */
+ space = __intel_ring_space(request->postfix, ringbuf->tail,
+ ringbuf->size);
+ if (space >= bytes)
+ break;
+ }
+
+ if (WARN_ON(&request->list == &ring->request_list))
+ return -ENOSPC;
+
+ ret = i915_wait_request(request);
+ if (ret)
+ return ret;
+
+ ringbuf->space = space;
+ return 0;
+}
+
+/*
+ * intel_logical_ring_advance_and_submit() - advance the tail and submit the workload
+ * @ringbuf: Logical Ringbuffer to advance.
+ *
+ * The tail is updated in our logical ringbuffer struct, not in the actual context. What
+ * really happens during submission is that the context and current tail will be placed
+ * on a queue waiting for the ELSP to be ready to accept a new context submission. At that
+ * point, the tail *inside* the context is updated and the ELSP written to.
+ */
+static void
+intel_logical_ring_advance_and_submit(struct intel_ringbuffer *ringbuf,
+ struct intel_context *ctx,
+ struct drm_i915_gem_request *request)
+{
+ struct intel_engine_cs *ring = ringbuf->ring;
+
+ intel_logical_ring_advance(ringbuf);
+
+ if (intel_ring_stopped(ring))
+ return;
+
+ execlists_context_queue(ring, ctx, ringbuf->tail, request);
+}
+
+static int logical_ring_wrap_buffer(struct intel_ringbuffer *ringbuf,
+ struct intel_context *ctx)
+{
+ uint32_t __iomem *virt;
+ int rem = ringbuf->size - ringbuf->tail;
+
+ /* Can't wrap if space has already been reserved! */
+ WARN_ON(ringbuf->reserved_in_use);
+
+ if (ringbuf->space < rem) {
+ int ret = logical_ring_wait_for_space(ringbuf, ctx, rem);
+
+ if (ret)
+ return ret;
+ }
+
+ virt = ringbuf->virtual_start + ringbuf->tail;
+ rem /= 4;
+ while (rem--)
+ iowrite32(MI_NOOP, virt++);
+
+ ringbuf->tail = 0;
+ intel_ring_update_space(ringbuf);
+
+ return 0;
+}
+
+static int logical_ring_prepare(struct intel_ringbuffer *ringbuf,
+ struct intel_context *ctx, int bytes)
+{
+ int ret;
+
+ /*
+ * Add on the reserved size to the request to make sure that after
+ * the intended commands have been emitted, there is guaranteed to
+ * still be enough free space to send them to the hardware.
+ */
+ if (!ringbuf->reserved_in_use)
+ bytes += ringbuf->reserved_size;
+
+ if (unlikely(ringbuf->tail + bytes > ringbuf->effective_size)) {
+ ret = logical_ring_wrap_buffer(ringbuf, ctx);
+ if (unlikely(ret))
+ return ret;
+
+ if(ringbuf->reserved_size) {
+ uint32_t size = ringbuf->reserved_size;
+
+ intel_ring_reserved_space_cancel(ringbuf);
+ intel_ring_reserved_space_reserve(ringbuf, size);
+ }
+ }
+
+ if (unlikely(ringbuf->space < bytes)) {
+ ret = logical_ring_wait_for_space(ringbuf, ctx, bytes);
+ if (unlikely(ret))
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * intel_logical_ring_begin() - prepare the logical ringbuffer to accept some commands
+ *
+ * @ringbuf: Logical ringbuffer.
+ * @num_dwords: number of DWORDs that we plan to write to the ringbuffer.
+ *
+ * The ringbuffer might not be ready to accept the commands right away (maybe it needs to
+ * be wrapped, or wait a bit for the tail to be updated). This function takes care of that
+ * and also preallocates a request (every workload submission is still mediated through
+ * requests, same as it did with legacy ringbuffer submission).
+ *
+ * Return: non-zero if the ringbuffer is not ready to be written to.
+ */
+static int intel_logical_ring_begin(struct intel_ringbuffer *ringbuf,
+ struct intel_context *ctx, int num_dwords)
+{
+ struct intel_engine_cs *ring = ringbuf->ring;
+ struct drm_device *dev = ring->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int ret;
+
+ ret = i915_gem_check_wedge(&dev_priv->gpu_error,
+ dev_priv->mm.interruptible);
+ if (ret)
+ return ret;
+
+ ret = logical_ring_prepare(ringbuf, ctx, num_dwords * sizeof(uint32_t));
+ if (ret)
+ return ret;
+
+ /* Preallocate the olr before touching the ring */
+ ret = i915_gem_request_alloc(ring, ctx);
+ if (ret)
+ return ret;
+
+ ringbuf->space -= num_dwords * sizeof(uint32_t);
+ return 0;
+}
+