[PATCH 3/4] drm/amdkfd: avoid svm conflicting with userptr address

[Philip Yang]

For ioctl_alloc_memory_of_gpu to alloc userptr bo, check userptr address
does not exist in svm->objects.

For svm range allocation, look for address in the userptr range of
interval tree VA nodes.

Change helper svm_range_check_vm to return amdgpu_bo, which will be used
to avoid creating new svm range overlap with bo later.

Signed-off-by: Philip Yang <Philip.Yang at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 17 +++++---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c     | 55 +++++++++++++++++++-----
 2 files changed, 57 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index f1e7edeb4e6b..34dfa6a938bf 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1255,6 +1255,7 @@ static int kfd_ioctl_alloc_memory_of_gpu(struct file *filep,
 	long err;
 	uint64_t offset = args->mmap_offset;
 	uint32_t flags = args->flags;
+	unsigned long start, last;
 
 	if (args->size == 0)
 		return -EINVAL;
@@ -1266,11 +1267,17 @@ static int kfd_ioctl_alloc_memory_of_gpu(struct file *filep,
 	svm_range_list_lock_and_flush_work(&p->svms, current->mm);
 	mutex_lock(&p->svms.lock);
 	mmap_write_unlock(current->mm);
-	if (interval_tree_iter_first(&p->svms.objects,
-				     args->va_addr >> PAGE_SHIFT,
-				     (args->va_addr + args->size - 1) >> PAGE_SHIFT)) {
-		pr_err("Address: 0x%llx already allocated by SVM\n",
-			args->va_addr);
+
+	if (flags & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {
+		start = args->mmap_offset >> PAGE_SHIFT;
+		last = (args->mmap_offset + args->size - 1) >> PAGE_SHIFT;
+	} else {
+		start = args->va_addr >> PAGE_SHIFT;
+		last = (args->va_addr + args->size - 1) >> PAGE_SHIFT;
+	}
+
+	if (interval_tree_iter_first(&p->svms.objects, start, last)) {
+		pr_err("[0x%lx 0x%lx] already allocated by SVM\n", start, last);
 		mutex_unlock(&p->svms.lock);
 		return -EADDRINUSE;
 	}
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 7f0743fcfcc3..d49c08618714 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2679,15 +2679,18 @@ int svm_range_list_init(struct kfd_process *p)
  *
  * Context: Process context
  *
- * Return 0 - OK, if the range is not mapped.
+ * Return NULL - if the range is not mapped.
+ * amdgpu_bo - if the range is mapped by old API
  * Otherwise error code:
- * -EADDRINUSE - if address is mapped already by kfd_ioctl_alloc_memory_of_gpu
  * -ERESTARTSYS - A wait for the buffer to become unreserved was interrupted by
  * a signal. Release all buffer reservations and return to user-space.
  */
-static int
+static struct amdgpu_bo *
 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last)
 {
+	struct amdgpu_bo_va_mapping *mapping;
+	struct interval_tree_node *node;
+	struct amdgpu_bo *bo = NULL;
 	uint32_t i;
 	int r;
 
@@ -2700,16 +2703,42 @@ svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last)
 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
 		r = amdgpu_bo_reserve(vm->root.bo, false);
 		if (r)
-			return r;
-		if (interval_tree_iter_first(&vm->va, start, last)) {
-			pr_debug("Range [0x%llx 0x%llx] already mapped\n", start, last);
-			amdgpu_bo_unreserve(vm->root.bo);
-			return -EADDRINUSE;
+			return ERR_PTR(r);
+		node = interval_tree_iter_first(&vm->va, start, last);
+		if (node) {
+			pr_debug("range [0x%llx 0x%llx] already TTM mapped\n",
+				 start, last);
+			mapping = container_of((struct rb_node *)node,
+					       struct amdgpu_bo_va_mapping, rb);
+			bo = mapping->bo_va->base.bo;
+			goto out_unreserve;
+		}
+
+		/* Check userptr by searching entire vm->va interval tree */
+		node = interval_tree_iter_first(&vm->va, 0, ~0ULL);
+		while (node) {
+			mapping = container_of((struct rb_node *)node,
+					       struct amdgpu_bo_va_mapping, rb);
+			bo = mapping->bo_va->base.bo;
+
+			if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
+							 start << PAGE_SHIFT,
+							 last << PAGE_SHIFT)) {
+				pr_debug("[0x%llx 0x%llx] userptr mapped\n",
+					 start, last);
+				goto out_unreserve;
+			}
+			bo = NULL;
+			node = interval_tree_iter_next(node, 0, ~0ULL);
 		}
+
+out_unreserve:
 		amdgpu_bo_unreserve(vm->root.bo);
+		if (bo)
+			break;
 	}
 
-	return 0;
+	return bo;
 }
 
 /**
@@ -2732,6 +2761,7 @@ svm_range_is_valid(struct kfd_process *p, uint64_t start, uint64_t size)
 	struct vm_area_struct *vma;
 	unsigned long end;
 	unsigned long start_unchg = start;
+	struct amdgpu_bo *bo;
 
 	start <<= PAGE_SHIFT;
 	end = start + (size << PAGE_SHIFT);
@@ -2743,7 +2773,12 @@ svm_range_is_valid(struct kfd_process *p, uint64_t start, uint64_t size)
 		start = min(end, vma->vm_end);
 	} while (start < end);
 
-	return svm_range_check_vm(p, start_unchg, (end - 1) >> PAGE_SHIFT);
+	bo = svm_range_check_vm(p, start_unchg, (end - 1) >> PAGE_SHIFT);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+	if (bo)
+		return -EADDRINUSE;
+	return 0;
 }
 
 /**
-- 
2.17.1