[RFC PATCH 10/16] drm/ttm: Remove pinned bos from shrinkable accounting

[Thomas Hellström]

Pinned bos aren't shinkable and needs to be removed from the shrinkable
accounting. Do that, and in the process constify the tt argument to
ttm_tt_is_populated.

Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c |  7 +++++++
 drivers/gpu/drm/ttm/ttm_tt.c | 22 ++++++++++++++++++++++
 include/drm/ttm/ttm_tt.h     |  6 +++++-
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index e5c0970564c0..e59e2a4605d0 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -650,6 +650,10 @@ void ttm_bo_pin(struct ttm_buffer_object *bo)
 {
 	dma_resv_assert_held(bo->base.resv);
 	WARN_ON_ONCE(!kref_read(&bo->kref));
+
+	if (!bo->pin_count && bo->ttm)
+		ttm_tt_set_pinned(bo->bdev, bo->ttm);
+
 	spin_lock(&bo->bdev->lru_lock);
 	if (bo->resource)
 		ttm_resource_del_bulk_move(bo->resource, bo);
@@ -671,6 +675,9 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo)
 	if (WARN_ON_ONCE(!bo->pin_count))
 		return;
 
+	if (bo->pin_count == 1 && bo->ttm)
+		ttm_tt_set_unpinned(bo->bdev, bo->ttm);
+
 	spin_lock(&bo->bdev->lru_lock);
 	--bo->pin_count;
 	if (bo->resource)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 848adf2a623e..a39c617c7a8e 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -83,6 +83,28 @@ static void ttm_tt_mod_shrinkable_pages(long shrinkable, long purgeable)
 	write_unlock(&shrinkable_lock);
 }
 
+/**
+ * ttm_tt_set_pinned() - Modify the shinkable accounting when pinning a bo.
+ * @bdev: The TTM device.
+ * @tt: The struct tt_tt used by the pinned bo.
+ */
+void ttm_tt_set_pinned(const struct ttm_device *bdev, const struct ttm_tt *tt)
+{
+	if (ttm_tt_shrinkable(bdev, tt) && ttm_tt_is_populated(tt))
+		ttm_tt_mod_shrinkable_pages(-(long)tt->num_pages, 0);
+}
+
+/**
+ * ttm_tt_set_unpinned() - Modify the shinkable accounting when unpinning a bo.
+ * @bdev: The TTM device.
+ * @tt: The struct tt_tt used by the no longer pinned bo.
+ */
+void ttm_tt_set_unpinned(const struct ttm_device *bdev, const struct ttm_tt *tt)
+{
+	if (ttm_tt_shrinkable(bdev, tt) && ttm_tt_is_populated(tt))
+		ttm_tt_mod_shrinkable_pages(tt->num_pages, 0);
+}
+
 /*
  * Allocates a ttm structure for the given BO.
  */
diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h
index 3f99787e2b93..69467671c2dd 100644
--- a/include/drm/ttm/ttm_tt.h
+++ b/include/drm/ttm/ttm_tt.h
@@ -118,7 +118,7 @@ struct ttm_kmap_iter_tt {
 	pgprot_t prot;
 };
 
-static inline bool ttm_tt_is_populated(struct ttm_tt *tt)
+static inline bool ttm_tt_is_populated(const struct ttm_tt *tt)
 {
 	return tt->page_flags & TTM_TT_FLAG_PRIV_POPULATED;
 }
@@ -238,6 +238,10 @@ static inline bool ttm_tt_purgeable(struct ttm_tt *tt)
 	return tt->page_flags & TTM_TT_FLAG_DONTNEED;
 }
 
+void ttm_tt_set_pinned(const struct ttm_device *bdev, const struct ttm_tt *tt);
+
+void ttm_tt_set_unpinned(const struct ttm_device *bdev, const struct ttm_tt *tt);
+
 #if IS_ENABLED(CONFIG_AGP)
 #include <linux/agp_backend.h>
 
-- 
2.34.1