1 //===-- omptargetplugin.h - Target dependent OpenMP Plugin API --*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines an interface between target independent OpenMP offload
10 // runtime library libomptarget and target dependent plugin.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef _OMPTARGETPLUGIN_H_
15 #define _OMPTARGETPLUGIN_H_
16 
17 #include <omptarget.h>
18 
19 #ifdef __cplusplus
20 extern "C" {
21 #endif
22 
23 // First method called on the plugin
24 int32_t __tgt_rtl_init_plugin();
25 
26 // Last method called on the plugin
27 int32_t __tgt_rtl_deinit_plugin();
28 
29 // Return the number of available devices of the type supported by the
30 // target RTL.
31 int32_t __tgt_rtl_number_of_devices(void);
32 
33 // Return an integer different from zero if the provided device image can be
34 // supported by the runtime. The functionality is similar to comparing the
35 // result of __tgt__rtl__load__binary to NULL. However, this is meant to be a
36 // lightweight query to determine if the RTL is suitable for an image without
37 // having to load the library, which can be expensive.
38 int32_t __tgt_rtl_is_valid_binary(__tgt_device_image *Image);
39 
40 // This provides the same functionality as __tgt_rtl_is_valid_binary except we
41 // also use additional information to determine if the image is valid. This
42 // allows us to determine if an image has a compatible architecture.
43 int32_t __tgt_rtl_is_valid_binary_info(__tgt_device_image *Image,
44                                        __tgt_image_info *Info);
45 
46 // Return an integer other than zero if the data can be exchaned from SrcDevId
47 // to DstDevId. If it is data exchangable, the device plugin should provide
48 // function to move data from source device to destination device directly.
49 int32_t __tgt_rtl_is_data_exchangable(int32_t SrcDevId, int32_t DstDevId);
50 
51 // Return an integer other than zero if the plugin can handle images which do
52 // not contain target regions and global variables (but can contain other
53 // functions)
54 int32_t __tgt_rtl_supports_empty_images();
55 
56 // Initialize the requires flags for the device.
57 int64_t __tgt_rtl_init_requires(int64_t RequiresFlags);
58 
59 // Initialize the specified device. In case of success return 0; otherwise
60 // return an error code.
61 int32_t __tgt_rtl_init_device(int32_t ID);
62 
63 // Deinitialize the specified device. In case of success return 0; otherwise
64 // return an error code.
65 int32_t __tgt_rtl_deinit_device(int32_t ID);
66 
67 // Pass an executable image section described by image to the specified
68 // device and prepare an address table of target entities. In case of error,
69 // return NULL. Otherwise, return a pointer to the built address table.
70 // Individual entries in the table may also be NULL, when the corresponding
71 // offload region is not supported on the target device.
72 __tgt_target_table *__tgt_rtl_load_binary(int32_t ID,
73                                           __tgt_device_image *Image);
74 
75 // Allocate data on the particular target device, of the specified size.
76 // HostPtr is a address of the host data the allocated target data
77 // will be associated with (HostPtr may be NULL if it is not known at
78 // allocation time, like for example it would be for target data that
79 // is allocated by omp_target_alloc() API). Return address of the
80 // allocated data on the target that will be used by libomptarget.so to
81 // initialize the target data mapping structures. These addresses are
82 // used to generate a table of target variables to pass to
83 // __tgt_rtl_run_region(). The __tgt_rtl_data_alloc() returns NULL in
84 // case an error occurred on the target device. Kind dictates what allocator
85 // to use (e.g. shared, host, device).
86 void *__tgt_rtl_data_alloc(int32_t ID, int64_t Size, void *HostPtr,
87                            int32_t Kind);
88 
89 // Pass the data content to the target device using the target address. In case
90 // of success, return zero. Otherwise, return an error code.
91 int32_t __tgt_rtl_data_submit(int32_t ID, void *TargetPtr, void *HostPtr,
92                               int64_t Size);
93 
94 int32_t __tgt_rtl_data_submit_async(int32_t ID, void *TargetPtr, void *HostPtr,
95                                     int64_t Size, __tgt_async_info *AsyncInfo);
96 
97 // Retrieve the data content from the target device using its address. In case
98 // of success, return zero. Otherwise, return an error code.
99 int32_t __tgt_rtl_data_retrieve(int32_t ID, void *HostPtr, void *TargetPtr,
100                                 int64_t Size);
101 
102 // Asynchronous version of __tgt_rtl_data_retrieve
103 int32_t __tgt_rtl_data_retrieve_async(int32_t ID, void *HostPtr,
104                                       void *TargetPtr, int64_t Size,
105                                       __tgt_async_info *AsyncInfo);
106 
107 // Copy the data content from one target device to another target device using
108 // its address. This operation does not need to copy data back to host and then
109 // from host to another device. In case of success, return zero. Otherwise,
110 // return an error code.
111 int32_t __tgt_rtl_data_exchange(int32_t SrcID, void *SrcPtr, int32_t DstID,
112                                 void *DstPtr, int64_t Size);
113 
114 // Asynchronous version of __tgt_rtl_data_exchange
115 int32_t __tgt_rtl_data_exchange_async(int32_t SrcID, void *SrcPtr,
116                                       int32_t DesID, void *DstPtr, int64_t Size,
117                                       __tgt_async_info *AsyncInfo);
118 
119 // De-allocate the data referenced by target ptr on the device. In case of
120 // success, return zero. Otherwise, return an error code.
121 int32_t __tgt_rtl_data_delete(int32_t ID, void *TargetPtr);
122 
123 // Transfer control to the offloaded entry Entry on the target device.
124 // Args and Offsets are arrays of NumArgs size of target addresses and
125 // offsets. An offset should be added to the target address before passing it
126 // to the outlined function on device side. If AsyncInfo is nullptr, it is
127 // synchronous; otherwise it is asynchronous. However, AsyncInfo may be
128 // ignored on some platforms, like x86_64. In that case, it is synchronous. In
129 // case of success, return zero. Otherwise, return an error code.
130 int32_t __tgt_rtl_run_target_region(int32_t ID, void *Entry, void **Args,
131                                     ptrdiff_t *Offsets, int32_t NumArgs);
132 
133 // Asynchronous version of __tgt_rtl_run_target_region
134 int32_t __tgt_rtl_run_target_region_async(int32_t ID, void *Entry, void **Args,
135                                           ptrdiff_t *Offsets, int32_t NumArgs,
136                                           __tgt_async_info *AsyncInfo);
137 
138 // Similar to __tgt_rtl_run_target_region, but additionally specify the
139 // number of teams to be created and a number of threads in each team. If
140 // AsyncInfo is nullptr, it is synchronous; otherwise it is asynchronous.
141 // However, AsyncInfo may be ignored on some platforms, like x86_64. In that
142 // case, it is synchronous.
143 int32_t __tgt_rtl_run_target_team_region(int32_t ID, void *Entry, void **Args,
144                                          ptrdiff_t *Offsets, int32_t NumArgs,
145                                          int32_t NumTeams, int32_t ThreadLimit,
146                                          uint64_t LoopTripcount);
147 
148 // Asynchronous version of __tgt_rtl_run_target_team_region
149 int32_t __tgt_rtl_run_target_team_region_async(
150     int32_t ID, void *Entry, void **Args, ptrdiff_t *Offsets, int32_t NumArgs,
151     int32_t NumTeams, int32_t ThreadLimit, uint64_t LoopTripcount,
152     __tgt_async_info *AsyncInfo);
153 
154 // Device synchronization. In case of success, return zero. Otherwise, return an
155 // error code.
156 int32_t __tgt_rtl_synchronize(int32_t ID, __tgt_async_info *AsyncInfo);
157 
158 // Set plugin's internal information flag externally.
159 void __tgt_rtl_set_info_flag(uint32_t);
160 
161 // Print the device information
162 void __tgt_rtl_print_device_info(int32_t ID);
163 
164 // Event related interfaces. It is expected to use the interfaces in the
165 // following way:
166 // 1) Create an event on the target device (__tgt_rtl_create_event).
167 // 2) Record the event based on the status of \p AsyncInfo->Queue at the moment
168 // of function call to __tgt_rtl_record_event. An event becomes "meaningful"
169 // once it is recorded, such that others can depend on it.
170 // 3) Call __tgt_rtl_wait_event to set dependence on the event. Whether the
171 // operation is blocking or non-blocking depends on the target. It is expected
172 // to be non-blocking, just set dependence and return.
173 // 4) Call __tgt_rtl_sync_event to sync the event. It is expected to block the
174 // thread calling the function.
175 // 5) Destroy the event (__tgt_rtl_destroy_event).
176 // {
177 int32_t __tgt_rtl_create_event(int32_t ID, void **Event);
178 
179 int32_t __tgt_rtl_record_event(int32_t ID, void *Event,
180                                __tgt_async_info *AsyncInfo);
181 
182 int32_t __tgt_rtl_wait_event(int32_t ID, void *Event,
183                              __tgt_async_info *AsyncInfo);
184 
185 int32_t __tgt_rtl_sync_event(int32_t ID, void *Event);
186 
187 int32_t __tgt_rtl_destroy_event(int32_t ID, void *Event);
188 // }
189 
190 int32_t __tgt_rtl_init_async_info(int32_t ID, __tgt_async_info **AsyncInfoPtr);
191 int32_t __tgt_rtl_init_device_info(int32_t ID, __tgt_device_info *DeviceInfoPtr,
192                                    const char **ErrStr);
193 
194 #ifdef __cplusplus
195 }
196 #endif
197 
198 #endif // _OMPTARGETPLUGIN_H_
199