drm/amdgpu: add parameter to disable kernel queues

On chips that support user queues, setting this option
will disable kernel queues to be used to validate
user queues without kernel queues.

Reviewed-by: Prike Liang <Prike.Liang@amd.com>
Reviewed-by: Sunil Khatri <sunil.khatri@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -271,6 +271,7 @@ extern int amdgpu_agp;
 extern int amdgpu_rebar;
 
 extern int amdgpu_wbrf;
+extern int amdgpu_disable_kq;
 
 #define AMDGPU_VM_MAX_NUM_CTX			4096
 #define AMDGPU_SG_THRESHOLD			(256*1024*1024)

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -242,6 +242,7 @@ int amdgpu_wbrf = -1;
 int amdgpu_damage_clips = -1; /* auto */
 int amdgpu_umsch_mm_fwlog;
 int amdgpu_rebar = -1; /* auto */
+int amdgpu_disable_kq = -1;
 
 DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
 			"DRM_UT_CORE",
@@ -1110,6 +1111,14 @@ module_param_named(wbrf, amdgpu_wbrf, int, 0444);
 MODULE_PARM_DESC(rebar, "Resizable BAR (-1 = auto (default), 0 = disable, 1 = enable)");
 module_param_named(rebar, amdgpu_rebar, int, 0444);
 
+/**
+ * DOC: disable_kq (int)
+ * Disable kernel queues on systems that support user queues.
+ * (0 = kernel queues enabled, 1 = kernel queues disabled, -1 = auto (default setting))
+ */
+MODULE_PARM_DESC(disable_kq, "Disable kernel queues (-1 = auto (default), 0 = enable KQ, 1 = disable KQ)");
+module_param_named(disable_kq, amdgpu_disable_kq, int, 0444);
+
 /* These devices are not supported by amdgpu.
  * They are supported by the mach64, r128, radeon drivers
  */