drm/amdkfd: Separate dma unmap and free of dma address array operations

We do not need free dma address array of svm_range each time we do dma unmap
for pages in svm_range as we can reuse the same array. Only free it when free
svm_range. Separate these two operations and use them accordingly.
Signed-off-by: Xiaogang Chen <xiaogang.chen@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_migrate.c

@@ -460,7 +460,7 @@ svm_migrate_vma_to_vram(struct kfd_node *node, struct svm_range *prange,
 				    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
 				    0, node->id, trigger);
 
-	svm_range_dma_unmap(adev->dev, scratch, 0, npages);
+	svm_range_dma_unmap_dev(adev->dev, scratch, 0, npages);
 
 out_free:
 	kvfree(buf);
@@ -544,7 +544,7 @@ svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t best_loc,
 
 	if (cpages) {
 		prange->actual_loc = best_loc;
-		svm_range_free_dma_mappings(prange, true);
+		svm_range_dma_unmap(prange);
 	} else {
 		svm_range_vram_node_free(prange);
 	}
@@ -745,7 +745,7 @@ svm_migrate_vma_to_ram(struct kfd_node *node, struct svm_range *prange,
 				    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
 				    node->id, 0, trigger);
 
-	svm_range_dma_unmap(adev->dev, scratch, 0, npages);
+	svm_range_dma_unmap_dev(adev->dev, scratch, 0, npages);
 
 out_free:
 	kvfree(buf);

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

@@ -231,7 +231,7 @@ svm_range_dma_map(struct svm_range *prange, unsigned long *bitmap,
 	return r;
 }
 
-void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
+void svm_range_dma_unmap_dev(struct device *dev, dma_addr_t *dma_addr,
 			 unsigned long offset, unsigned long npages)
 {
 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
@@ -249,7 +249,7 @@ void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
 	}
 }
 
-void svm_range_free_dma_mappings(struct svm_range *prange, bool unmap_dma)
+void svm_range_dma_unmap(struct svm_range *prange)
 {
 	struct kfd_process_device *pdd;
 	dma_addr_t *dma_addr;
@@ -270,10 +270,8 @@ void svm_range_free_dma_mappings(struct svm_range *prange, bool unmap_dma)
 			continue;
 		}
 		dev = &pdd->dev->adev->pdev->dev;
-		if (unmap_dma)
-			svm_range_dma_unmap(dev, dma_addr, 0, prange->npages);
-		kvfree(dma_addr);
-		prange->dma_addr[gpuidx] = NULL;
+
+		svm_range_dma_unmap_dev(dev, dma_addr, 0, prange->npages);
 	}
 }
 
@@ -281,18 +279,29 @@ static void svm_range_free(struct svm_range *prange, bool do_unmap)
 {
 	uint64_t size = (prange->last - prange->start + 1) << PAGE_SHIFT;
 	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
+	uint32_t gpuidx;
 
 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms, prange,
 		 prange->start, prange->last);
 
 	svm_range_vram_node_free(prange);
-	svm_range_free_dma_mappings(prange, do_unmap);
+	if (do_unmap)
+		svm_range_dma_unmap(prange);
 
 	if (do_unmap && !p->xnack_enabled) {
 		pr_debug("unreserve prange 0x%p size: 0x%llx\n", prange, size);
 		amdgpu_amdkfd_unreserve_mem_limit(NULL, size,
 					KFD_IOC_ALLOC_MEM_FLAGS_USERPTR, 0);
 	}
+
+	/* free dma_addr array for each gpu */
+	for (gpuidx = 0; gpuidx < MAX_GPU_INSTANCE; gpuidx++) {
+		if (prange->dma_addr[gpuidx]) {
+			kvfree(prange->dma_addr[gpuidx]);
+				prange->dma_addr[gpuidx] = NULL;
+		}
+	}
+
 	mutex_destroy(&prange->lock);
 	mutex_destroy(&prange->migrate_mutex);
 	kfree(prange);

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

@@ -181,9 +181,9 @@ void svm_range_add_list_work(struct svm_range_list *svms,
 			     struct svm_range *prange, struct mm_struct *mm,
 			     enum svm_work_list_ops op);
 void schedule_deferred_list_work(struct svm_range_list *svms);
-void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
+void svm_range_dma_unmap_dev(struct device *dev, dma_addr_t *dma_addr,
 			 unsigned long offset, unsigned long npages);
-void svm_range_free_dma_mappings(struct svm_range *prange, bool unmap_dma);
+void svm_range_dma_unmap(struct svm_range *prange);
 int svm_range_get_info(struct kfd_process *p, uint32_t *num_svm_ranges,
 		       uint64_t *svm_priv_data_size);
 int kfd_criu_checkpoint_svm(struct kfd_process *p,