1 /*
2 * Copyright 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 /* NOTE:
18 * This stub HAL is only used internally by the loader when a real HAL
19 * implementation is not present, in order to avoid needing "null HAL" checks
20 * throughout the loader. It does not enumerate any physical devices, and is
21 * only as conformant to the Vulkan and Android HAL interfaces as the loader
22 * needs it to be. Do not use it as an example of a correct implementation; the
23 * code in ../null_driver is better for that.
24 */
25
26 #undef LOG_TAG
27 #define LOG_TAG "vkstub"
28
29 #include <array>
30 #include <bitset>
31 #include <cstring>
32 #include <mutex>
33
34 #include <log/log.h>
35 #include <hardware/hwvulkan.h>
36
37 #include "stubhal.h"
38
39 namespace vulkan {
40 namespace stubhal {
41
42 namespace {
43
44 const size_t kMaxInstances = 32;
45 static std::mutex g_instance_mutex;
46 static std::bitset<kMaxInstances> g_instance_used(false);
47 static std::array<hwvulkan_dispatch_t, kMaxInstances> g_instances;
48
NoOp()49 [[noreturn]] VKAPI_ATTR void NoOp() {
50 LOG_ALWAYS_FATAL("invalid stub function called");
51 }
52
53 VKAPI_ATTR VkResult
EnumerateInstanceExtensionProperties(const char *,uint32_t * count,VkExtensionProperties *)54 EnumerateInstanceExtensionProperties(const char* /*layer_name*/,
55 uint32_t* count,
56 VkExtensionProperties* /*properties*/) {
57 *count = 0;
58 return VK_SUCCESS;
59 }
60
61 VKAPI_ATTR VkResult
EnumerateInstanceLayerProperties(uint32_t * count,VkLayerProperties *)62 EnumerateInstanceLayerProperties(uint32_t* count,
63 VkLayerProperties* /*properties*/) {
64 *count = 0;
65 return VK_SUCCESS;
66 }
67
CreateInstance(const VkInstanceCreateInfo *,const VkAllocationCallbacks *,VkInstance * instance)68 VKAPI_ATTR VkResult CreateInstance(const VkInstanceCreateInfo* /*create_info*/,
69 const VkAllocationCallbacks* /*allocator*/,
70 VkInstance* instance) {
71 std::lock_guard<std::mutex> lock(g_instance_mutex);
72 for (size_t i = 0; i < kMaxInstances; i++) {
73 if (!g_instance_used[i]) {
74 g_instance_used[i] = true;
75 g_instances[i].magic = HWVULKAN_DISPATCH_MAGIC;
76 *instance = reinterpret_cast<VkInstance>(&g_instances[i]);
77 return VK_SUCCESS;
78 }
79 }
80 ALOGE("no more instances available (max=%zu)", kMaxInstances);
81 return VK_ERROR_INITIALIZATION_FAILED;
82 }
83
DestroyInstance(VkInstance instance,const VkAllocationCallbacks *)84 VKAPI_ATTR void DestroyInstance(VkInstance instance,
85 const VkAllocationCallbacks* /*allocator*/) {
86 std::lock_guard<std::mutex> lock(g_instance_mutex);
87 ssize_t idx =
88 reinterpret_cast<hwvulkan_dispatch_t*>(instance) - &g_instances[0];
89 ALOG_ASSERT(idx >= 0 && static_cast<size_t>(idx) < g_instance_used.size(),
90 "DestroyInstance: invalid instance handle");
91 g_instance_used[static_cast<size_t>(idx)] = false;
92 }
93
EnumeratePhysicalDevices(VkInstance,uint32_t * count,VkPhysicalDevice *)94 VKAPI_ATTR VkResult EnumeratePhysicalDevices(VkInstance /*instance*/,
95 uint32_t* count,
96 VkPhysicalDevice* /*gpus*/) {
97 *count = 0;
98 return VK_SUCCESS;
99 }
100
101 VKAPI_ATTR VkResult
EnumeratePhysicalDeviceGroups(VkInstance,uint32_t * count,VkPhysicalDeviceGroupProperties *)102 EnumeratePhysicalDeviceGroups(VkInstance /*instance*/,
103 uint32_t* count,
104 VkPhysicalDeviceGroupProperties* /*properties*/) {
105 *count = 0;
106 return VK_SUCCESS;
107 }
108
GetInstanceProcAddr(VkInstance instance,const char * name)109 VKAPI_ATTR PFN_vkVoidFunction GetInstanceProcAddr(VkInstance instance,
110 const char* name) {
111 if (strcmp(name, "vkCreateInstance") == 0)
112 return reinterpret_cast<PFN_vkVoidFunction>(CreateInstance);
113 if (strcmp(name, "vkDestroyInstance") == 0)
114 return reinterpret_cast<PFN_vkVoidFunction>(DestroyInstance);
115 if (strcmp(name, "vkEnumerateInstanceExtensionProperties") == 0)
116 return reinterpret_cast<PFN_vkVoidFunction>(
117 EnumerateInstanceExtensionProperties);
118 if (strcmp(name, "vkEnumeratePhysicalDevices") == 0)
119 return reinterpret_cast<PFN_vkVoidFunction>(EnumeratePhysicalDevices);
120 if (strcmp(name, "vkEnumeratePhysicalDeviceGroups") == 0)
121 return reinterpret_cast<PFN_vkVoidFunction>(
122 EnumeratePhysicalDeviceGroups);
123 if (strcmp(name, "vkGetInstanceProcAddr") == 0)
124 return reinterpret_cast<PFN_vkVoidFunction>(GetInstanceProcAddr);
125 // Per the spec, return NULL if instance is NULL.
126 if (!instance)
127 return nullptr;
128 // None of the other Vulkan functions should ever be called, as they all
129 // take a VkPhysicalDevice or other object obtained from a physical device.
130 return reinterpret_cast<PFN_vkVoidFunction>(NoOp);
131 }
132
133 } // anonymous namespace
134
135 const hwvulkan_device_t kDevice = {
136 .common =
137 {
138 .tag = HARDWARE_DEVICE_TAG,
139 .version = HWVULKAN_DEVICE_API_VERSION_0_1,
140 .module = nullptr,
141 .close = nullptr,
142 },
143 .EnumerateInstanceExtensionProperties =
144 EnumerateInstanceExtensionProperties,
145 .CreateInstance = CreateInstance,
146 .GetInstanceProcAddr = GetInstanceProcAddr,
147 };
148
149 } // namespace stubhal
150 } // namespace vulkan
151