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 <mutex>
32 #include <hardware/hwvulkan.h>
33 #include <log/log.h>
34 #include "stubhal.h"
35
36 namespace vulkan {
37 namespace stubhal {
38
39 namespace {
40
41 const size_t kMaxInstances = 32;
42 static std::mutex g_instance_mutex;
43 static std::bitset<kMaxInstances> g_instance_used(false);
44 static std::array<hwvulkan_dispatch_t, kMaxInstances> g_instances;
45
NoOp()46 [[noreturn]] void NoOp() {
47 LOG_ALWAYS_FATAL("invalid stub function called");
48 }
49
50 VKAPI_ATTR VkResult
EnumerateInstanceExtensionProperties(const char *,uint32_t * count,VkExtensionProperties *)51 EnumerateInstanceExtensionProperties(const char* /*layer_name*/,
52 uint32_t* count,
53 VkExtensionProperties* /*properties*/) {
54 *count = 0;
55 return VK_SUCCESS;
56 }
57
58 VKAPI_ATTR VkResult
EnumerateInstanceLayerProperties(uint32_t * count,VkLayerProperties *)59 EnumerateInstanceLayerProperties(uint32_t* count,
60 VkLayerProperties* /*properties*/) {
61 *count = 0;
62 return VK_SUCCESS;
63 }
64
CreateInstance(const VkInstanceCreateInfo *,const VkAllocationCallbacks *,VkInstance * instance)65 VKAPI_ATTR VkResult CreateInstance(const VkInstanceCreateInfo* /*create_info*/,
66 const VkAllocationCallbacks* /*allocator*/,
67 VkInstance* instance) {
68 std::lock_guard<std::mutex> lock(g_instance_mutex);
69 for (size_t i = 0; i < kMaxInstances; i++) {
70 if (!g_instance_used[i]) {
71 g_instance_used[i] = true;
72 g_instances[i].magic = HWVULKAN_DISPATCH_MAGIC;
73 *instance = reinterpret_cast<VkInstance>(&g_instances[i]);
74 return VK_SUCCESS;
75 }
76 }
77 ALOGE("no more instances available (max=%zu)", kMaxInstances);
78 return VK_ERROR_INITIALIZATION_FAILED;
79 }
80
DestroyInstance(VkInstance instance,const VkAllocationCallbacks *)81 VKAPI_ATTR void DestroyInstance(VkInstance instance,
82 const VkAllocationCallbacks* /*allocator*/) {
83 std::lock_guard<std::mutex> lock(g_instance_mutex);
84 ssize_t idx =
85 reinterpret_cast<hwvulkan_dispatch_t*>(instance) - &g_instances[0];
86 ALOG_ASSERT(idx >= 0 && static_cast<size_t>(idx) < g_instance_used.size(),
87 "DestroyInstance: invalid instance handle");
88 g_instance_used[static_cast<size_t>(idx)] = false;
89 }
90
EnumeratePhysicalDevices(VkInstance,uint32_t * count,VkPhysicalDevice *)91 VKAPI_ATTR VkResult EnumeratePhysicalDevices(VkInstance /*instance*/,
92 uint32_t* count,
93 VkPhysicalDevice* /*gpus*/) {
94 *count = 0;
95 return VK_SUCCESS;
96 }
97
GetInstanceProcAddr(VkInstance,const char * name)98 VKAPI_ATTR PFN_vkVoidFunction GetInstanceProcAddr(VkInstance /*instance*/,
99 const char* name) {
100 if (strcmp(name, "vkCreateInstance") == 0)
101 return reinterpret_cast<PFN_vkVoidFunction>(CreateInstance);
102 if (strcmp(name, "vkDestroyInstance") == 0)
103 return reinterpret_cast<PFN_vkVoidFunction>(DestroyInstance);
104 if (strcmp(name, "vkEnumerateInstanceExtensionProperties") == 0)
105 return reinterpret_cast<PFN_vkVoidFunction>(
106 EnumerateInstanceExtensionProperties);
107 if (strcmp(name, "vkEnumeratePhysicalDevices") == 0)
108 return reinterpret_cast<PFN_vkVoidFunction>(EnumeratePhysicalDevices);
109 if (strcmp(name, "vkGetInstanceProcAddr") == 0)
110 return reinterpret_cast<PFN_vkVoidFunction>(GetInstanceProcAddr);
111
112 // None of the other Vulkan functions should ever be called, as they all
113 // take a VkPhysicalDevice or other object obtained from a physical device.
114 return reinterpret_cast<PFN_vkVoidFunction>(NoOp);
115 }
116
117 } // anonymous namespace
118
119 const hwvulkan_device_t kDevice = {
120 .common =
121 {
122 .tag = HARDWARE_DEVICE_TAG,
123 .version = HWVULKAN_DEVICE_API_VERSION_0_1,
124 .module = nullptr,
125 .close = nullptr,
126 },
127 .EnumerateInstanceExtensionProperties =
128 EnumerateInstanceExtensionProperties,
129 .CreateInstance = CreateInstance,
130 .GetInstanceProcAddr = GetInstanceProcAddr,
131 };
132
133 } // namespace stubhal
134 } // namespace vulkan
135