[PATCH 3/4] drm/amdgpu: drm/amdgpu: Handle IOMMU enabled case

[Andrey Grodzovsky]

Handle all DMA IOMMU group related dependencies before the
group is removed and we try to access it after free.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    | 50 ++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h    |  1 +
 3 files changed, 53 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 0b5764aa98a4..288a465b8101 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3860,6 +3860,8 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
 
 	amdgpu_device_ip_fini_early(adev);
 
+	amdgpu_ttm_clear_dma_mappings(adev);
+
 	amdgpu_gart_dummy_page_fini(adev);
 
 	amdgpu_device_unmap_mmio(adev);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 446943e32e3e..f73d807db3b0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -64,6 +64,7 @@
 static int amdgpu_ttm_backend_bind(struct ttm_device *bdev,
 				   struct ttm_tt *ttm,
 				   struct ttm_resource *bo_mem);
+
 static void amdgpu_ttm_backend_unbind(struct ttm_device *bdev,
 				      struct ttm_tt *ttm);
 
@@ -2293,6 +2294,55 @@ static ssize_t amdgpu_iomem_write(struct file *f, const char __user *buf,
 	return result;
 }
 
+void amdgpu_ttm_clear_dma_mappings(struct amdgpu_device *adev)
+{
+	struct ttm_device *bdev = &adev->mman.bdev;
+	struct ttm_resource_manager *man;
+	struct ttm_buffer_object *bo;
+	unsigned int i, j;
+
+	spin_lock(&bdev->lru_lock);
+	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
+		man = ttm_manager_type(bdev, i);
+		if (!man || !man->use_tt)
+			continue;
+
+		while (!list_empty(&man->pinned)) {
+			bo = list_first_entry(&man->pinned, struct ttm_buffer_object, lru);
+			/* Take ref against racing releases once lru_lock is unlocked */
+			ttm_bo_get(bo);
+			list_del_init(&bo->lru);
+			spin_unlock(&bdev->lru_lock);
+
+			if (bo->ttm) {
+				amdgpu_ttm_backend_unbind(bo->bdev, bo->ttm);
+				ttm_tt_destroy_common(bo->bdev, bo->ttm);
+			}
+
+			ttm_bo_put(bo);
+			spin_lock(&bdev->lru_lock);
+		}
+
+		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j) {
+			while (!list_empty(&man->lru[j])) {
+				bo = list_first_entry(&man->lru[j], struct ttm_buffer_object, lru);
+				ttm_bo_get(bo);
+				list_del_init(&bo->lru);
+				spin_unlock(&bdev->lru_lock);
+
+				if (bo->ttm) {
+					amdgpu_ttm_backend_unbind(bo->bdev, bo->ttm);
+					ttm_tt_destroy_common(bo->bdev, bo->ttm);
+				}
+				ttm_bo_put(bo);
+				spin_lock(&bdev->lru_lock);
+			}
+		}
+	}
+	spin_unlock(&bdev->lru_lock);
+
+}
+
 static const struct file_operations amdgpu_ttm_iomem_fops = {
 	.owner = THIS_MODULE,
 	.read = amdgpu_iomem_read,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index e69f3e8e06e5..02c8eac48a64 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -190,6 +190,7 @@ bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm);
 uint64_t amdgpu_ttm_tt_pde_flags(struct ttm_tt *ttm, struct ttm_resource *mem);
 uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
 				 struct ttm_resource *mem);
+void amdgpu_ttm_clear_dma_mappings(struct amdgpu_device *adev);
 
 void amdgpu_ttm_debugfs_init(struct amdgpu_device *adev);
 
-- 
2.25.1