drm/i915: set "ret" correctly on error paths
[linux-2.6/btrfs-unstable.git] / drivers / gpu / drm / i915 / intel_gvt.c
blobe1ab6432a91464d1ed19c4fee4336c780532ac68
1 /*
2 * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
24 #include "i915_drv.h"
25 #include "intel_gvt.h"
27 /**
28 * DOC: Intel GVT-g host support
30 * Intel GVT-g is a graphics virtualization technology which shares the
31 * GPU among multiple virtual machines on a time-sharing basis. Each
32 * virtual machine is presented a virtual GPU (vGPU), which has equivalent
33 * features as the underlying physical GPU (pGPU), so i915 driver can run
34 * seamlessly in a virtual machine.
36 * To virtualize GPU resources GVT-g driver depends on hypervisor technology
37 * e.g KVM/VFIO/mdev, Xen, etc. to provide resource access trapping capability
38 * and be virtualized within GVT-g device module. More architectural design
39 * doc is available on https://01.org/group/2230/documentation-list.
42 static bool is_supported_device(struct drm_i915_private *dev_priv)
44 if (IS_BROADWELL(dev_priv))
45 return true;
46 if (IS_SKYLAKE(dev_priv))
47 return true;
48 if (IS_KABYLAKE(dev_priv) && INTEL_DEVID(dev_priv) == 0x591D)
49 return true;
50 return false;
53 /**
54 * intel_gvt_init - initialize GVT components
55 * @dev_priv: drm i915 private data
57 * This function is called at the initialization stage to create a GVT device.
59 * Returns:
60 * Zero on success, negative error code if failed.
63 int intel_gvt_init(struct drm_i915_private *dev_priv)
65 int ret;
67 if (!i915.enable_gvt) {
68 DRM_DEBUG_DRIVER("GVT-g is disabled by kernel params\n");
69 return 0;
72 if (intel_vgpu_active(dev_priv)) {
73 DRM_DEBUG_DRIVER("GVT-g is disabled for guest\n");
74 goto bail;
77 if (!is_supported_device(dev_priv)) {
78 DRM_DEBUG_DRIVER("Unsupported device. GVT-g is disabled\n");
79 goto bail;
82 if (!i915.enable_execlists) {
83 DRM_INFO("GPU guest virtualisation [GVT-g] disabled due to disabled execlist submission [i915.enable_execlists module parameter]\n");
84 goto bail;
88 * We're not in host or fail to find a MPT module, disable GVT-g
90 ret = intel_gvt_init_host();
91 if (ret) {
92 DRM_DEBUG_DRIVER("Not in host or MPT modules not found\n");
93 goto bail;
96 ret = intel_gvt_init_device(dev_priv);
97 if (ret) {
98 DRM_DEBUG_DRIVER("Fail to init GVT device\n");
99 goto bail;
102 return 0;
104 bail:
105 i915.enable_gvt = 0;
106 return 0;
110 * intel_gvt_cleanup - cleanup GVT components when i915 driver is unloading
111 * @dev_priv: drm i915 private *
113 * This function is called at the i915 driver unloading stage, to shutdown
114 * GVT components and release the related resources.
116 void intel_gvt_cleanup(struct drm_i915_private *dev_priv)
118 if (!intel_gvt_active(dev_priv))
119 return;
121 intel_gvt_clean_device(dev_priv);