1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pool.c b/drivers/gpu/drm/i915/gt/intel_engine_pool.c
new file mode 100644
index 000000000000..4cd54c569911
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pool.c
@@ -0,0 +1,177 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2014-2018 Intel Corporation
+ */
+
+#include "gem/i915_gem_object.h"
+
+#include "i915_drv.h"
+#include "intel_engine_pm.h"
+#include "intel_engine_pool.h"
+
+static struct intel_engine_cs *to_engine(struct intel_engine_pool *pool)
+{
+	return container_of(pool, struct intel_engine_cs, pool);
+}
+
+static struct list_head *
+bucket_for_size(struct intel_engine_pool *pool, size_t sz)
+{
+	int n;
+
+	/*
+	 * Compute a power-of-two bucket, but throw everything greater than
+	 * 16KiB into the same bucket: i.e. the buckets hold objects of
+	 * (1 page, 2 pages, 4 pages, 8+ pages).
+	 */
+	n = fls(sz >> PAGE_SHIFT) - 1;
+	if (n >= ARRAY_SIZE(pool->cache_list))
+		n = ARRAY_SIZE(pool->cache_list) - 1;
+
+	return &pool->cache_list[n];
+}
+
+static void node_free(struct intel_engine_pool_node *node)
+{
+	i915_gem_object_put(node->obj);
+	i915_active_fini(&node->active);
+	kfree(node);
+}
+
+static int pool_active(struct i915_active *ref)
+{
+	struct intel_engine_pool_node *node =
+		container_of(ref, typeof(*node), active);
+	struct dma_resv *resv = node->obj->base.resv;
+	int err;
+
+	if (dma_resv_trylock(resv)) {
+		dma_resv_add_excl_fence(resv, NULL);
+		dma_resv_unlock(resv);
+	}
+
+	err = i915_gem_object_pin_pages(node->obj);
+	if (err)
+		return err;
+
+	/* Hide this pinned object from the shrinker until retired */
+	i915_gem_object_make_unshrinkable(node->obj);
+
+	return 0;
+}
+
+static void pool_retire(struct i915_active *ref)
+{
+	struct intel_engine_pool_node *node =
+		container_of(ref, typeof(*node), active);
+	struct intel_engine_pool *pool = node->pool;
+	struct list_head *list = bucket_for_size(pool, node->obj->base.size);
+	unsigned long flags;
+
+	GEM_BUG_ON(!intel_engine_pm_is_awake(to_engine(pool)));
+
+	i915_gem_object_unpin_pages(node->obj);
+
+	/* Return this object to the shrinker pool */
+	i915_gem_object_make_purgeable(node->obj);
+
+	spin_lock_irqsave(&pool->lock, flags);
+	list_add(&node->link, list);
+	spin_unlock_irqrestore(&pool->lock, flags);
+}
+
+static struct intel_engine_pool_node *
+node_create(struct intel_engine_pool *pool, size_t sz)
+{
+	struct intel_engine_cs *engine = to_engine(pool);
+	struct intel_engine_pool_node *node;
+	struct drm_i915_gem_object *obj;
+
+	node = kmalloc(sizeof(*node),
+		       GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+	if (!node)
+		return ERR_PTR(-ENOMEM);
+
+	node->pool = pool;
+	i915_active_init(engine->i915, &node->active, pool_active, pool_retire);
+
+	obj = i915_gem_object_create_internal(engine->i915, sz);
+	if (IS_ERR(obj)) {
+		i915_active_fini(&node->active);
+		kfree(node);
+		return ERR_CAST(obj);
+	}
+
+	node->obj = obj;
+	return node;
+}
+
+struct intel_engine_pool_node *
+intel_engine_pool_get(struct intel_engine_pool *pool, size_t size)
+{
+	struct intel_engine_pool_node *node;
+	struct list_head *list;
+	unsigned long flags;
+	int ret;
+
+	GEM_BUG_ON(!intel_engine_pm_is_awake(to_engine(pool)));
+
+	size = PAGE_ALIGN(size);
+	list = bucket_for_size(pool, size);
+
+	spin_lock_irqsave(&pool->lock, flags);
+	list_for_each_entry(node, list, link) {
+		if (node->obj->base.size < size)
+			continue;
+		list_del(&node->link);
+		break;
+	}
+	spin_unlock_irqrestore(&pool->lock, flags);
+
+	if (&node->link == list) {
+		node = node_create(pool, size);
+		if (IS_ERR(node))
+			return node;
+	}
+
+	ret = i915_active_acquire(&node->active);
+	if (ret) {
+		node_free(node);
+		return ERR_PTR(ret);
+	}
+
+	return node;
+}
+
+void intel_engine_pool_init(struct intel_engine_pool *pool)
+{
+	int n;
+
+	spin_lock_init(&pool->lock);
+	for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++)
+		INIT_LIST_HEAD(&pool->cache_list[n]);
+}
+
+void intel_engine_pool_park(struct intel_engine_pool *pool)
+{
+	int n;
+
+	for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++) {
+		struct list_head *list = &pool->cache_list[n];
+		struct intel_engine_pool_node *node, *nn;
+
+		list_for_each_entry_safe(node, nn, list, link)
+			node_free(node);
+
+		INIT_LIST_HEAD(list);
+	}
+}
+
+void intel_engine_pool_fini(struct intel_engine_pool *pool)
+{
+	int n;
+
+	for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++)
+		GEM_BUG_ON(!list_empty(&pool->cache_list[n]));
+}