drm/i915/execlists: Split insert_request()

In the next patch we will want to reinsert a request not at the end of
the priority queue, but at the front. Here we split insert_request()
into two, the first function retrieves the priority list (for reuse for
unsubmit later) and a wrapper function to insert at the end of that list
and to schedule the tasklet if we were first.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170916204414.32762-3-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 7c709530b4224ba9f3264d65599edd5c56b10707..be2cba6b36d1bedc55e29461b18538e22c90c22d 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -286,10 +286,10 @@ intel_lr_context_descriptor_update(struct i915_gem_context *ctx,
        ce->lrc_desc = desc;
 }
 
-static bool
-insert_request(struct intel_engine_cs *engine,
-              struct i915_priotree *pt,
-              int prio)
+static struct i915_priolist *
+lookup_priolist(struct intel_engine_cs *engine,
+               struct i915_priotree *pt,
+               int prio)
 {
        struct i915_priolist *p;
        struct rb_node **parent, *rb;
@@ -311,8 +311,7 @@ find_priolist:
                        parent = &rb->rb_right;
                        first = false;
                } else {
-                       list_add_tail(&pt->link, &p->requests);
-                       return false;
+                       return p;
                }
        }
 
@@ -338,16 +337,14 @@ find_priolist:
        }
 
        p->priority = prio;
+       INIT_LIST_HEAD(&p->requests);
        rb_link_node(&p->node, rb, parent);
        rb_insert_color(&p->node, &engine->execlist_queue);
 
-       INIT_LIST_HEAD(&p->requests);
-       list_add_tail(&pt->link, &p->requests);
-
        if (first)
                engine->execlist_first = &p->node;
 
-       return first;
+       return ptr_pack_bits(p, first, 1);
 }
 
 static inline void
@@ -764,6 +761,17 @@ static void intel_lrc_irq_handler(unsigned long data)
        intel_uncore_forcewake_put(dev_priv, engine->fw_domains);
 }
 
+static void insert_request(struct intel_engine_cs *engine,
+                          struct i915_priotree *pt,
+                          int prio)
+{
+       struct i915_priolist *p = lookup_priolist(engine, pt, prio);
+
+       list_add_tail(&pt->link, &ptr_mask_bits(p, 1)->requests);
+       if (ptr_unmask_bits(p, 1) && execlists_elsp_ready(engine))
+               tasklet_hi_schedule(&engine->irq_tasklet);
+}
+
 static void execlists_submit_request(struct drm_i915_gem_request *request)
 {
        struct intel_engine_cs *engine = request->engine;
@@ -772,12 +780,7 @@ static void execlists_submit_request(struct drm_i915_gem_request *request)
        /* Will be called from irq-context when using foreign fences. */
        spin_lock_irqsave(&engine->timeline->lock, flags);
 
-       if (insert_request(engine,
-                          &request->priotree,
-                          request->priotree.priority)) {
-               if (execlists_elsp_ready(engine))
-                       tasklet_hi_schedule(&engine->irq_tasklet);
-       }
+       insert_request(engine, &request->priotree, request->priotree.priority);
 
        GEM_BUG_ON(!engine->execlist_first);
        GEM_BUG_ON(list_empty(&request->priotree.link));