drm/amdkfd: validate vram svm range from TTM

If svm range perfetch location is not zero, use TTM to alloc
amdgpu_bo vram nodes to validate svm range, then map vram nodes to GPUs.

Use offset to sub allocate from the same amdgpu_bo to handle overlap
vram range while adding new range or unmapping range.

svm_bo has ref count to trace the shared ranges. If all ranges of shared
amdgpu_bo are migrated to ram, ref count becomes 0, then amdgpu_bo is
released, all ranges svm_bo is set to NULL.

To migrate range from ram back to vram, allocate the same amdgpu_bo
with previous offset if the range has svm_bo.

If prange migrate to VRAM, no CPU mapping exist, then process exit will
not have unmap callback for this prange to free prange and svm bo. Free
outstanding pranges from svms list before process is freed in
svm_range_list_fini.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_svm.h

@@ -33,6 +33,13 @@
 #include "amdgpu.h"
 #include "kfd_priv.h"
 
+struct svm_range_bo {
+	struct amdgpu_bo	*bo;
+	struct kref		kref;
+	struct list_head	range_list; /* all svm ranges shared this bo */
+	spinlock_t		list_lock;
+};
+
 enum svm_work_list_ops {
 	SVM_OP_NULL,
 	SVM_OP_UNMAP_RANGE,
@@ -60,6 +67,10 @@ struct svm_work_list_item {
  * @mapping:    bo_va mapping structure to create and update GPU page table
  * @npages:     number of pages
  * @dma_addr:   dma mapping address on each GPU for system memory physical page
+ * @ttm_res:    vram ttm resource map
+ * @offset:     range start offset within mm_nodes
+ * @svm_bo:     struct to manage splited amdgpu_bo
+ * @svm_bo_list:link list node, to scan all ranges which share same svm_bo
  * @lock:       protect prange start, last, child_list, svm_bo_list
  * @saved_flags:save/restore current PF_MEMALLOC flags
  * @flags:      flags defined as KFD_IOCTL_SVM_FLAG_*
@@ -91,6 +102,10 @@ struct svm_range {
 	struct amdgpu_bo_va_mapping	mapping;
 	uint64_t			npages;
 	dma_addr_t			*dma_addr[MAX_GPU_INSTANCE];
+	struct ttm_resource		*ttm_res;
+	uint64_t			offset;
+	struct svm_range_bo		*svm_bo;
+	struct list_head		svm_bo_list;
 	struct mutex                    lock;
 	unsigned int                    saved_flags;
 	uint32_t			flags;
@@ -124,5 +139,10 @@ void svm_range_list_fini(struct kfd_process *p);
 int svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
 	      uint64_t size, uint32_t nattrs,
 	      struct kfd_ioctl_svm_attribute *attrs);
+struct amdgpu_device *svm_range_get_adev_by_id(struct svm_range *prange,
+					       uint32_t id);
+int svm_range_vram_node_new(struct amdgpu_device *adev,
+			    struct svm_range *prange, bool clear);
+void svm_range_vram_node_free(struct svm_range *prange);
 
 #endif /* KFD_SVM_H_ */