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
33 #include <log/log.h>
34 #include <hardware/hwvulkan.h>
35
36 #include "stubhal.h"
37
38 namespace vulkan {
39 namespace stubhal {
40
41 namespace {
42
43 const size_t kMaxInstances = 32;
44 static std::mutex g_instance_mutex;
45 static std::bitset<kMaxInstances> g_instance_used(false);
46 static std::array<hwvulkan_dispatch_t, kMaxInstances> g_instances;
47
NoOp()48 [[noreturn]] VKAPI_ATTR void NoOp() {
49 LOG_ALWAYS_FATAL("invalid stub function called");
50 }
51
52 VKAPI_ATTR VkResult
EnumerateInstanceExtensionProperties(const char *,uint32_t * count,VkExtensionProperties *)53 EnumerateInstanceExtensionProperties(const char* /*layer_name*/,
54 uint32_t* count,
55 VkExtensionProperties* /*properties*/) {
56 *count = 0;
57 return VK_SUCCESS;
58 }
59
60 VKAPI_ATTR VkResult
EnumerateInstanceLayerProperties(uint32_t * count,VkLayerProperties *)61 EnumerateInstanceLayerProperties(uint32_t* count,
62 VkLayerProperties* /*properties*/) {
63 *count = 0;
64 return VK_SUCCESS;
65 }
66
CreateInstance(const VkInstanceCreateInfo *,const VkAllocationCallbacks *,VkInstance * instance)67 VKAPI_ATTR VkResult CreateInstance(const VkInstanceCreateInfo* /*create_info*/,
68 const VkAllocationCallbacks* /*allocator*/,
69 VkInstance* instance) {
70 std::lock_guard<std::mutex> lock(g_instance_mutex);
71 for (size_t i = 0; i < kMaxInstances; i++) {
72 if (!g_instance_used[i]) {
73 g_instance_used[i] = true;
74 g_instances[i].magic = HWVULKAN_DISPATCH_MAGIC;
75 *instance = reinterpret_cast<VkInstance>(&g_instances[i]);
76 return VK_SUCCESS;
77 }
78 }
79 ALOGE("no more instances available (max=%zu)", kMaxInstances);
80 return VK_ERROR_INITIALIZATION_FAILED;
81 }
82
DestroyInstance(VkInstance instance,const VkAllocationCallbacks *)83 VKAPI_ATTR void DestroyInstance(VkInstance instance,
84 const VkAllocationCallbacks* /*allocator*/) {
85 std::lock_guard<std::mutex> lock(g_instance_mutex);
86 ssize_t idx =
87 reinterpret_cast<hwvulkan_dispatch_t*>(instance) - &g_instances[0];
88 ALOG_ASSERT(idx >= 0 && static_cast<size_t>(idx) < g_instance_used.size(),
89 "DestroyInstance: invalid instance handle");
90 g_instance_used[static_cast<size_t>(idx)] = false;
91 }
92
EnumeratePhysicalDevices(VkInstance,uint32_t * count,VkPhysicalDevice *)93 VKAPI_ATTR VkResult EnumeratePhysicalDevices(VkInstance /*instance*/,
94 uint32_t* count,
95 VkPhysicalDevice* /*gpus*/) {
96 *count = 0;
97 return VK_SUCCESS;
98 }
99
GetInstanceProcAddr(VkInstance,const char * name)100 VKAPI_ATTR PFN_vkVoidFunction GetInstanceProcAddr(VkInstance /*instance*/,
101 const char* name) {
102 if (strcmp(name, "vkCreateInstance") == 0)
103 return reinterpret_cast<PFN_vkVoidFunction>(CreateInstance);
104 if (strcmp(name, "vkDestroyInstance") == 0)
105 return reinterpret_cast<PFN_vkVoidFunction>(DestroyInstance);
106 if (strcmp(name, "vkEnumerateInstanceExtensionProperties") == 0)
107 return reinterpret_cast<PFN_vkVoidFunction>(
108 EnumerateInstanceExtensionProperties);
109 if (strcmp(name, "vkEnumeratePhysicalDevices") == 0)
110 return reinterpret_cast<PFN_vkVoidFunction>(EnumeratePhysicalDevices);
111 if (strcmp(name, "vkGetInstanceProcAddr") == 0)
112 return reinterpret_cast<PFN_vkVoidFunction>(GetInstanceProcAddr);
113
114 // None of the other Vulkan functions should ever be called, as they all
115 // take a VkPhysicalDevice or other object obtained from a physical device.
116 return reinterpret_cast<PFN_vkVoidFunction>(NoOp);
117 }
118
119 } // anonymous namespace
120
121 const hwvulkan_device_t kDevice = {
122 .common =
123 {
124 .tag = HARDWARE_DEVICE_TAG,
125 .version = HWVULKAN_DEVICE_API_VERSION_0_1,
126 .module = nullptr,
127 .close = nullptr,
128 },
129 .EnumerateInstanceExtensionProperties =
130 EnumerateInstanceExtensionProperties,
131 .CreateInstance = CreateInstance,
132 .GetInstanceProcAddr = GetInstanceProcAddr,
133 };
134
135 } // namespace stubhal
136 } // namespace vulkan
137