[PATCH] drm/amdgpu: take back kvmalloc_array for entries alloc because of kzalloc memory limit

[Changfeng]

From: changzhu <Changfeng.Zhu at amd.com>

From: Changfeng <Changfeng.Zhu at amd.com>

It will cause error when alloc memory larger than 128KB in
amdgpu_bo_create->kzalloc.

Call Trace:
   alloc_pages_current+0x6a/0xe0
   kmalloc_order+0x32/0xb0
   kmalloc_order_trace+0x1e/0x80
   __kmalloc+0x249/0x2d0
   amdgpu_bo_create+0x102/0x500 [amdgpu]
   ? xas_create+0x264/0x3e0
   amdgpu_bo_create_vm+0x32/0x60 [amdgpu]
   amdgpu_vm_pt_create+0xf5/0x260 [amdgpu]
   amdgpu_vm_init+0x1fd/0x4d0 [amdgpu]

Change-Id: I29e479db45ead37c39449e856599fd4f6a0e34ce
Signed-off-by: Changfeng <Changfeng.Zhu at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 27 +++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 1923f035713a..714d613d020b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -894,6 +894,10 @@ static int amdgpu_vm_pt_create(struct amdgpu_device *adev,
 		num_entries = 0;
 
 	bp.bo_ptr_size = struct_size((*vmbo), entries, num_entries);
+	if (bp.bo_ptr_size > 32*AMDGPU_GPU_PAGE_SIZE) {
+		DRM_INFO("Can't alloc memory larger than 128KB by using kzalloc in amdgpu_bo_create\n");
+		bp.bo_ptr_size = sizeof(struct amdgpu_bo_vm);
+	}
 
 	if (vm->use_cpu_for_update)
 		bp.flags |= AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
@@ -965,15 +969,19 @@ static int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
 	struct amdgpu_bo_vm *pt;
 	int r;
 
-	if (entry->base.bo) {
-		if (cursor->level < AMDGPU_VM_PTB)
-			entry->entries =
-				to_amdgpu_bo_vm(entry->base.bo)->entries;
-		else
-			entry->entries = NULL;
-		return 0;
+	if (cursor->level < AMDGPU_VM_PTB && !entry->entries) {
+		unsigned num_entries;
+		num_entries = amdgpu_vm_num_entries(adev, cursor->level);
+		entry->entries = kvmalloc_array(num_entries,
+						sizeof(*entry->entries),
+						GFP_KERNEL | __GFP_ZERO);
+		if (!entry->entries)
+			return -ENOMEM;
 	}
 
+	if (entry->base.bo)
+		return 0;
+
 	r = amdgpu_vm_pt_create(adev, vm, cursor->level, immediate, &pt);
 	if (r)
 		return r;
@@ -984,10 +992,6 @@ static int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
 	pt_bo = &pt->bo;
 	pt_bo->parent = amdgpu_bo_ref(cursor->parent->base.bo);
 	amdgpu_vm_bo_base_init(&entry->base, vm, pt_bo);
-	if (cursor->level < AMDGPU_VM_PTB)
-		entry->entries = pt->entries;
-	else
-		entry->entries = NULL;
 
 	r = amdgpu_vm_clear_bo(adev, vm, pt, immediate);
 	if (r)
@@ -1017,6 +1021,7 @@ static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry)
 		amdgpu_bo_unref(&shadow);
 		amdgpu_bo_unref(&entry->base.bo);
 	}
+	kvfree(entry->entries);
 	entry->entries = NULL;
 }
 
-- 
2.17.1