[RFC PATCH 01/18] drm/ttm: Add tracking for evicted memory

[Friedrich Vock <friedrich.vock@xxxxxx>]

These utilities will be used to keep track of what buffers have been
evicted from any particular place, to try and decide when to try undoing
the eviction.

Signed-off-by: Friedrich Vock <friedrich.vock@xxxxxx>
---
 drivers/gpu/drm/ttm/ttm_device.c   |  1 +
 drivers/gpu/drm/ttm/ttm_resource.c | 14 ++++++++++++++
 include/drm/ttm/ttm_device.h       |  5 +++++
 include/drm/ttm/ttm_resource.h     |  9 +++++++++
 4 files changed, 29 insertions(+)

diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
index f5187b384ae9a..969d627ba06c0 100644
--- a/drivers/gpu/drm/ttm/ttm_device.c
+++ b/drivers/gpu/drm/ttm/ttm_device.c
@@ -219,6 +219,7 @@ int ttm_device_init(struct ttm_device *bdev, const struct ttm_device_funcs *func

 	bdev->vma_manager = vma_manager;
 	spin_lock_init(&bdev->lru_lock);
+	spin_lock_init(&bdev->unevict_lock);
 	INIT_LIST_HEAD(&bdev->pinned);
 	bdev->dev_mapping = mapping;
 	mutex_lock(&ttm_global_mutex);
diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index 46ff9c75bb124..1d6755a1153b1 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -25,6 +25,7 @@
 #include <linux/iosys-map.h>
 #include <linux/io-mapping.h>
 #include <linux/scatterlist.h>
+#include <linux/list.h>

 #include <drm/ttm/ttm_bo.h>
 #include <drm/ttm/ttm_placement.h>
@@ -392,9 +393,11 @@ void ttm_resource_manager_init(struct ttm_resource_manager *man,
 	man->bdev = bdev;
 	man->size = size;
 	man->usage = 0;
+	man->evicted_bytes = 0;

 	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
 		INIT_LIST_HEAD(&man->lru[i]);
+	INIT_LIST_HEAD(&man->evicted);
 	man->move = NULL;
 }
 EXPORT_SYMBOL(ttm_resource_manager_init);
@@ -470,6 +473,17 @@ uint64_t ttm_resource_manager_usage(struct ttm_resource_manager *man)
 }
 EXPORT_SYMBOL(ttm_resource_manager_usage);

+uint64_t ttm_resource_manager_evicted_bytes(struct ttm_resource_manager *man)
+{
+	uint64_t evicted;
+
+	spin_lock(&man->bdev->unevict_lock);
+	evicted = man->evicted_bytes;
+	spin_unlock(&man->bdev->unevict_lock);
+	return evicted;
+}
+EXPORT_SYMBOL(ttm_resource_manager_evicted_bytes);
+
 /**
  * ttm_resource_manager_debug
  *
diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
index c22f30535c848..baa264efe483d 100644
--- a/include/drm/ttm/ttm_device.h
+++ b/include/drm/ttm/ttm_device.h
@@ -251,6 +251,11 @@ struct ttm_device {
 	 */
 	spinlock_t lru_lock;

+	/**
+	 * @unevict_lock: Protection for per-manager uneviction tracking
+	 */
+	spinlock_t unevict_lock;
+
 	/**
 	 * @pinned: Buffer objects which are pinned and so not on any LRU list.
 	 */
diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
index 78a226eba953c..7d1ce059c8805 100644
--- a/include/drm/ttm/ttm_resource.h
+++ b/include/drm/ttm/ttm_resource.h
@@ -145,6 +145,7 @@ struct ttm_resource_manager_func {
  * @move_lock: lock for move fence
  * @move: The fence of the last pipelined move operation.
  * @lru: The lru list for this memory type.
+ * @evicted: List of bos evicted from this memory type
  *
  * This structure is used to identify and manage memory types for a device.
  */
@@ -163,6 +164,7 @@ struct ttm_resource_manager {
 	 * Protected by @move_lock.
 	 */
 	struct dma_fence *move;
+	struct list_head evicted;

 	/*
 	 * Protected by the bdev->lru_lock.
@@ -174,6 +176,12 @@ struct ttm_resource_manager {
 	 * bdev->lru_lock.
 	 */
 	uint64_t usage;
+
+	/**
+	 * @evicted_bytes: How many bytes are evicted from this manager,
+	 * protexted by bdev->unevict_lock
+	 */
+	uint64_t evicted_bytes;
 };

 /**
@@ -382,6 +390,7 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
 				   struct ttm_resource_manager *man);

 uint64_t ttm_resource_manager_usage(struct ttm_resource_manager *man);
+uint64_t ttm_resource_manager_evicted_bytes(struct ttm_resource_manager *man);
 void ttm_resource_manager_debug(struct ttm_resource_manager *man,
 				struct drm_printer *p);

--
2.44.0