[PATCH] drm/amdgpu: add module parameter to enable/disable bulk move

[Huang Rui]

The bulk moving mechanism still has bug on some corner cases. So disable it by
default till it is fixed. We can use the module parameter to enable it for
debugging.

Signed-off-by: Huang Rui <ray.huang at amd.com>
Cc: Christian König <christian.koenig at amd.com>
Cc: Tom StDenis <Tom.StDenis at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h     |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 11 +++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c  | 11 +++++++++--
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index e992e0f..75fd7be 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -134,6 +134,7 @@ extern int amdgpu_compute_multipipe;
 extern int amdgpu_gpu_recovery;
 extern int amdgpu_emu_mode;
 extern uint amdgpu_smu_memory_pool_size;
+extern int amdgpu_bulk_move_enabled;
 
 #ifdef CONFIG_DRM_AMDGPU_SI
 extern int amdgpu_si_support;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index b5c2ccb..d57d16e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -127,6 +127,7 @@ int amdgpu_compute_multipipe = -1;
 int amdgpu_gpu_recovery = -1; /* auto */
 int amdgpu_emu_mode = 0;
 uint amdgpu_smu_memory_pool_size = 0;
+int amdgpu_bulk_move_enabled = 0;
 
 /**
  * DOC: vramlimit (int)
@@ -532,6 +533,16 @@ MODULE_PARM_DESC(smu_memory_pool_size,
 		"0x1 = 256Mbyte, 0x2 = 512Mbyte, 0x4 = 1 Gbyte, 0x8 = 2GByte");
 module_param_named(smu_memory_pool_size, amdgpu_smu_memory_pool_size, uint, 0444);
 
+/**
+ * DOC: bulk_move_enabled (int)
+ * It is used to enable/disable bulk moving on LRU list mechanism for debugging
+ * and testing. The default is false (disabled).  It will be enabled by default
+ * till all corner cases are hammered out.
+ */
+MODULE_PARM_DESC(bulk_move_enabled,
+		 "Enable bulk moving on LRU list mechanism (1 = enabled, 0 = disabled (default)");
+module_param_named(bulk_move_enabled, amdgpu_bulk_move_enabled, uint, 0444);
+
 #ifdef CONFIG_HSA_AMD
 /**
  * DOC: sched_policy (int)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 9a5b1bb..ab95a9c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -397,7 +397,8 @@ void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
 	}
 	spin_unlock(&glob->lru_lock);
 
-	vm->bulk_moveable = true;
+	if (amdgpu_bulk_move_enabled)
+		vm->bulk_moveable = true;
 }
 
 /**
@@ -1213,7 +1214,13 @@ int amdgpu_vm_update_directories(struct amdgpu_device *adev,
 		bo_base = list_first_entry(&vm->relocated,
 					   struct amdgpu_vm_bo_base,
 					   vm_status);
-		amdgpu_vm_bo_idle(bo_base);
+		if (amdgpu_bulk_move_enabled)
+			amdgpu_vm_bo_idle(bo_base);
+		else {
+			/* workaround: don't move PD/PT bos on LRU */
+			list_del_init(&bo_base->vm_status);
+			bo_base->moved = false;
+		}
 
 		bo = bo_base->bo->parent;
 		if (!bo)
-- 
2.7.4