[PATCH 7/7] drm/amdgpu: prefer VM page tables over normal BOs

[Christian König]

From: Christian König <christian.koenig at amd.com>

Keep VM page tables behind normal BOs on the LRU.

Signed-off-by: Christian König <christian.koenig at amd.com>
Acked-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h     |  4 +++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 53 +++++++++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index c4a21c6..1b5e7db 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -408,6 +408,10 @@ struct amdgpu_mman {
 	struct amdgpu_ring			*buffer_funcs_ring;
 	/* Scheduler entity for buffer moves */
 	struct amd_sched_entity			entity;
+
+	/* custom LRU management */
+	struct list_head			*lru[TTM_NUM_MEM_TYPES];
+	struct list_head			*swap_lru;
 };
 
 int amdgpu_copy_buffer(struct amdgpu_ring *ring,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index fefaa9b..f3d118b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -910,6 +910,49 @@ uint32_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
 	return flags;
 }
 
+static void amdgpu_ttm_lru_removal(struct ttm_buffer_object *tbo)
+{
+	struct amdgpu_device *adev = amdgpu_get_adev(tbo->bdev);
+
+	if (&tbo->lru == adev->mman.lru[tbo->mem.mem_type])
+		adev->mman.lru[tbo->mem.mem_type] = tbo->lru.prev;
+
+	if (&tbo->swap == adev->mman.swap_lru)
+		adev->mman.swap_lru = tbo->swap.prev;
+}
+
+static struct list_head *amdgpu_ttm_lru_tail(struct ttm_buffer_object *tbo)
+{
+	struct amdgpu_bo *bo = container_of(tbo, struct amdgpu_bo, tbo);
+	struct amdgpu_device *adev = amdgpu_get_adev(tbo->bdev);
+	struct list_head *res;
+
+	/* only VM BOs have a parent set */
+	if (bo->parent)
+		return ttm_bo_default_lru_tail(tbo);
+
+	res = adev->mman.lru[tbo->mem.mem_type];
+	adev->mman.lru[tbo->mem.mem_type] = &tbo->lru;
+
+	return res;
+}
+
+static struct list_head *amdgpu_ttm_swap_lru_tail(struct ttm_buffer_object *tbo)
+{
+	struct amdgpu_bo *bo = container_of(tbo, struct amdgpu_bo, tbo);
+	struct amdgpu_device *adev = amdgpu_get_adev(tbo->bdev);
+	struct list_head *res;
+
+	/* only VM BOs have a parent set */
+	if (bo->parent)
+		return ttm_bo_default_swap_lru_tail(tbo);
+
+	res = adev->mman.swap_lru;
+	adev->mman.swap_lru = &tbo->swap;
+
+	return res;
+}
+
 static struct ttm_bo_driver amdgpu_bo_driver = {
 	.ttm_tt_create = &amdgpu_ttm_tt_create,
 	.ttm_tt_populate = &amdgpu_ttm_tt_populate,
@@ -923,12 +966,14 @@ static struct ttm_bo_driver amdgpu_bo_driver = {
 	.fault_reserve_notify = &amdgpu_bo_fault_reserve_notify,
 	.io_mem_reserve = &amdgpu_ttm_io_mem_reserve,
 	.io_mem_free = &amdgpu_ttm_io_mem_free,
-	.lru_tail = &ttm_bo_default_lru_tail,
-	.swap_lru_tail = &ttm_bo_default_swap_lru_tail,
+	.lru_removal = &amdgpu_ttm_lru_removal,
+	.lru_tail = &amdgpu_ttm_lru_tail,
+	.swap_lru_tail = &amdgpu_ttm_swap_lru_tail,
 };
 
 int amdgpu_ttm_init(struct amdgpu_device *adev)
 {
+	unsigned i;
 	int r;
 
 	r = amdgpu_ttm_global_init(adev);
@@ -946,6 +991,10 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 		DRM_ERROR("failed initializing buffer object driver(%d).\n", r);
 		return r;
 	}
+	for (i = 0; i < TTM_NUM_MEM_TYPES; ++i)
+		adev->mman.lru[i] = &adev->mman.bdev.man[i].lru;
+	adev->mman.swap_lru = &adev->mman.bdev.glob->swap_lru;
+
 	adev->mman.initialized = true;
 	r = ttm_bo_init_mm(&adev->mman.bdev, TTM_PL_VRAM,
 				adev->mc.real_vram_size >> PAGE_SHIFT);
-- 
2.5.0