[PATCH 1/3] drm/amdgpu: move GTT to SHM after eviction for hibernation

[Samuel Zhang]

When hibernate with data center dGPUs, huge number of VRAM BOs evicted
to GTT and takes too much system memory. This will cause hibernation
fail due to insufficient memory for creating the hibernation image.

Move GTT BOs to shmem in KMD, then shmem to swap disk in kernel
hibernation code to make room for hibernation image.

Signed-off-by: Samuel Zhang <guoqing.zhang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 13 ++++++++++++-
 drivers/gpu/drm/ttm/ttm_resource.c      | 18 ++++++++++++++++++
 include/drm/ttm/ttm_resource.h          |  1 +
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 4d57269c9ca8..5aede907a591 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2889,6 +2889,7 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
 int amdgpu_ttm_evict_resources(struct amdgpu_device *adev, int mem_type)
 {
 	struct ttm_resource_manager *man;
+	int r;
 
 	switch (mem_type) {
 	case TTM_PL_VRAM:
@@ -2903,7 +2904,17 @@ int amdgpu_ttm_evict_resources(struct amdgpu_device *adev, int mem_type)
 		return -EINVAL;
 	}
 
-	return ttm_resource_manager_evict_all(&adev->mman.bdev, man);
+	r = ttm_resource_manager_evict_all(&adev->mman.bdev, man);
+	if (r) {
+		DRM_ERROR("Failed to evict memory type %d\n", mem_type);
+		return r;
+	}
+	if (adev->in_s4 && mem_type == TTM_PL_VRAM) {
+		r = ttm_resource_manager_swapout();
+		if (r)
+			DRM_ERROR("Failed to swap out, %d\n", r);
+	}
+	return r;
 }
 
 #if defined(CONFIG_DEBUG_FS)
diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index fd41b56e2c66..07b1f5a5afc2 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -534,6 +534,24 @@ void ttm_resource_manager_init(struct ttm_resource_manager *man,
 }
 EXPORT_SYMBOL(ttm_resource_manager_init);
 
+int ttm_resource_manager_swapout(void)
+{
+	struct ttm_operation_ctx ctx = {
+		.interruptible = false,
+		.no_wait_gpu = false,
+		.force_alloc = true
+	};
+	int ret;
+
+	while (true) {
+		ret = ttm_global_swapout(&ctx, GFP_KERNEL);
+		if (ret <= 0)
+			break;
+	}
+	return ret;
+}
+EXPORT_SYMBOL(ttm_resource_manager_swapout);
+
 /*
  * ttm_resource_manager_evict_all
  *
diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
index b873be9597e2..46181758068e 100644
--- a/include/drm/ttm/ttm_resource.h
+++ b/include/drm/ttm/ttm_resource.h
@@ -463,6 +463,7 @@ void ttm_resource_manager_init(struct ttm_resource_manager *man,
 
 int ttm_resource_manager_evict_all(struct ttm_device *bdev,
 				   struct ttm_resource_manager *man);
+int ttm_resource_manager_swapout(void);
 
 uint64_t ttm_resource_manager_usage(struct ttm_resource_manager *man);
 void ttm_resource_manager_debug(struct ttm_resource_manager *man,
-- 
2.43.5