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35 #ifndef GMX_GPU_UTILS_DEVICEBUFFER_CUH
36 #define GMX_GPU_UTILS_DEVICEBUFFER_CUH
38 /*! \libinternal \file
39 * \brief Implements the DeviceBuffer type and routines for CUDA.
40 * Should only be included directly by the main DeviceBuffer file devicebuffer.h.
41 * TODO: the intent is for DeviceBuffer to become a class.
43 * \author Aleksei Iupinov <a.yupinov@gmail.com>
48 #include "gromacs/gpu_utils/cuda_arch_utils.cuh"
49 #include "gromacs/gpu_utils/cudautils.cuh"
50 #include "gromacs/gpu_utils/device_context.h"
51 #include "gromacs/gpu_utils/device_stream.h"
52 #include "gromacs/gpu_utils/devicebuffer_datatype.h"
53 #include "gromacs/gpu_utils/gpu_utils.h" //only for GpuApiCallBehavior
54 #include "gromacs/gpu_utils/gputraits.cuh"
55 #include "gromacs/utility/gmxassert.h"
56 #include "gromacs/utility/stringutil.h"
59 * Allocates a device-side buffer.
60 * It is currently a caller's responsibility to call it only on not-yet allocated buffers.
62 * \tparam ValueType Raw value type of the \p buffer.
63 * \param[in,out] buffer Pointer to the device-side buffer.
64 * \param[in] numValues Number of values to accommodate.
65 * \param[in] deviceContext The buffer's dummy device context - not managed explicitly in CUDA RT.
67 template<typename ValueType>
68 void allocateDeviceBuffer(DeviceBuffer<ValueType>* buffer, size_t numValues, const DeviceContext& /* deviceContext */)
70 GMX_ASSERT(buffer, "needs a buffer pointer");
71 cudaError_t stat = cudaMalloc((void**)buffer, numValues * sizeof(ValueType));
74 ("Allocation of the device buffer failed. " + gmx::getDeviceErrorString(stat)).c_str());
78 * Frees a device-side buffer.
79 * This does not reset separately stored size/capacity integers,
80 * as this is planned to be a destructor of DeviceBuffer as a proper class,
81 * and no calls on \p buffer should be made afterwards.
83 * \param[in] buffer Pointer to the buffer to free.
85 template<typename DeviceBuffer>
86 void freeDeviceBuffer(DeviceBuffer* buffer)
88 GMX_ASSERT(buffer, "needs a buffer pointer");
91 cudaError_t stat = cudaFree(*buffer);
94 ("Freeing of the device buffer failed. " + gmx::getDeviceErrorString(stat)).c_str());
99 * Performs the host-to-device data copy, synchronous or asynchronously on request.
101 * \tparam ValueType Raw value type of the \p buffer.
102 * \param[in,out] buffer Pointer to the device-side buffer
103 * \param[in] hostBuffer Pointer to the raw host-side memory, also typed \p ValueType
104 * \param[in] startingOffset Offset (in values) at the device-side buffer to copy into.
105 * \param[in] numValues Number of values to copy.
106 * \param[in] deviceStream GPU stream to perform asynchronous copy in.
107 * \param[in] transferKind Copy type: synchronous or asynchronous.
108 * \param[out] timingEvent A dummy pointer to the H2D copy timing event to be filled in.
109 * Not used in CUDA implementation.
111 template<typename ValueType>
112 void copyToDeviceBuffer(DeviceBuffer<ValueType>* buffer,
113 const ValueType* hostBuffer,
114 size_t startingOffset,
116 const DeviceStream& deviceStream,
117 GpuApiCallBehavior transferKind,
118 CommandEvent* /*timingEvent*/)
124 GMX_ASSERT(buffer, "needs a buffer pointer");
125 GMX_ASSERT(hostBuffer, "needs a host buffer pointer");
127 const size_t bytes = numValues * sizeof(ValueType);
129 switch (transferKind)
131 case GpuApiCallBehavior::Async:
132 GMX_ASSERT(isHostMemoryPinned(hostBuffer),
133 "Source host buffer was not pinned for CUDA");
134 stat = cudaMemcpyAsync(*((ValueType**)buffer) + startingOffset, hostBuffer, bytes,
135 cudaMemcpyHostToDevice, deviceStream.stream());
138 ("Asynchronous H2D copy failed. " + gmx::getDeviceErrorString(stat)).c_str());
141 case GpuApiCallBehavior::Sync:
142 stat = cudaMemcpy(*((ValueType**)buffer) + startingOffset, hostBuffer, bytes,
143 cudaMemcpyHostToDevice);
146 ("Synchronous H2D copy failed. " + gmx::getDeviceErrorString(stat)).c_str());
154 * Performs the device-to-host data copy, synchronous or asynchronously on request.
156 * \tparam ValueType Raw value type of the \p buffer.
157 * \param[in,out] hostBuffer Pointer to the raw host-side memory, also typed \p ValueType
158 * \param[in] buffer Pointer to the device-side buffer
159 * \param[in] startingOffset Offset (in values) at the device-side buffer to copy from.
160 * \param[in] numValues Number of values to copy.
161 * \param[in] deviceStream GPU stream to perform asynchronous copy in.
162 * \param[in] transferKind Copy type: synchronous or asynchronous.
163 * \param[out] timingEvent A dummy pointer to the H2D copy timing event to be filled in.
164 * Not used in CUDA implementation.
166 template<typename ValueType>
167 void copyFromDeviceBuffer(ValueType* hostBuffer,
168 DeviceBuffer<ValueType>* buffer,
169 size_t startingOffset,
171 const DeviceStream& deviceStream,
172 GpuApiCallBehavior transferKind,
173 CommandEvent* /*timingEvent*/)
179 GMX_ASSERT(buffer, "needs a buffer pointer");
180 GMX_ASSERT(hostBuffer, "needs a host buffer pointer");
183 const size_t bytes = numValues * sizeof(ValueType);
184 switch (transferKind)
186 case GpuApiCallBehavior::Async:
187 GMX_ASSERT(isHostMemoryPinned(hostBuffer),
188 "Destination host buffer was not pinned for CUDA");
189 stat = cudaMemcpyAsync(hostBuffer, *((ValueType**)buffer) + startingOffset, bytes,
190 cudaMemcpyDeviceToHost, deviceStream.stream());
193 ("Asynchronous D2H copy failed. " + gmx::getDeviceErrorString(stat)).c_str());
196 case GpuApiCallBehavior::Sync:
197 stat = cudaMemcpy(hostBuffer, *((ValueType**)buffer) + startingOffset, bytes,
198 cudaMemcpyDeviceToHost);
201 ("Synchronous D2H copy failed. " + gmx::getDeviceErrorString(stat)).c_str());
209 * Clears the device buffer asynchronously.
211 * \tparam ValueType Raw value type of the \p buffer.
212 * \param[in,out] buffer Pointer to the device-side buffer
213 * \param[in] startingOffset Offset (in values) at the device-side buffer to start clearing at.
214 * \param[in] numValues Number of values to clear.
215 * \param[in] deviceStream GPU stream.
217 template<typename ValueType>
218 void clearDeviceBufferAsync(DeviceBuffer<ValueType>* buffer,
219 size_t startingOffset,
221 const DeviceStream& deviceStream)
223 GMX_ASSERT(buffer, "needs a buffer pointer");
224 const size_t bytes = numValues * sizeof(ValueType);
225 const char pattern = 0;
227 cudaError_t stat = cudaMemsetAsync(*((ValueType**)buffer) + startingOffset, pattern, bytes,
228 deviceStream.stream());
229 GMX_RELEASE_ASSERT(stat == cudaSuccess,
230 ("Couldn't clear the device buffer. " + gmx::getDeviceErrorString(stat)).c_str());
233 /*! \brief Check the validity of the device buffer.
235 * Checks if the buffer is not nullptr.
237 * \todo Add checks on the buffer size when it will be possible.
239 * \param[in] buffer Device buffer to be checked.
240 * \param[in] requiredSize Number of elements that the buffer will have to accommodate.
242 * \returns Whether the device buffer can be set.
245 gmx_unused static bool checkDeviceBuffer(DeviceBuffer<T> buffer, gmx_unused int requiredSize)
247 GMX_ASSERT(buffer != nullptr, "The device pointer is nullptr");
248 return buffer != nullptr;
251 //! Device texture wrapper.
252 using DeviceTexture = cudaTextureObject_t;
254 /*! \brief Create a texture object for an array of type ValueType.
256 * Creates the device buffer, copies data and binds texture object for an array of type ValueType.
258 * \todo Test if using textures is still relevant on modern hardware.
260 * \tparam ValueType Raw data type.
262 * \param[out] deviceBuffer Device buffer to store data in.
263 * \param[out] deviceTexture Device texture object to initialize.
264 * \param[in] hostBuffer Host buffer to get date from
265 * \param[in] numValues Number of elements in the buffer.
266 * \param[in] deviceContext GPU device context.
268 template<typename ValueType>
269 void initParamLookupTable(DeviceBuffer<ValueType>* deviceBuffer,
270 DeviceTexture* deviceTexture,
271 const ValueType* hostBuffer,
273 const DeviceContext& deviceContext)
279 GMX_ASSERT(hostBuffer, "Host buffer should be specified.");
281 allocateDeviceBuffer(deviceBuffer, numValues, deviceContext);
283 const size_t sizeInBytes = numValues * sizeof(ValueType);
286 cudaMemcpy(*((ValueType**)deviceBuffer), hostBuffer, sizeInBytes, cudaMemcpyHostToDevice);
288 GMX_RELEASE_ASSERT(stat == cudaSuccess,
289 ("Synchronous H2D copy failed. " + gmx::getDeviceErrorString(stat)).c_str());
291 if (!c_disableCudaTextures)
296 memset(&rd, 0, sizeof(rd));
297 rd.resType = cudaResourceTypeLinear;
298 rd.res.linear.devPtr = *deviceBuffer;
299 rd.res.linear.desc = cudaCreateChannelDesc<ValueType>();
300 rd.res.linear.sizeInBytes = sizeInBytes;
302 memset(&td, 0, sizeof(td));
303 td.readMode = cudaReadModeElementType;
304 stat = cudaCreateTextureObject(deviceTexture, &rd, &td, nullptr);
307 ("Binding of the texture object failed. " + gmx::getDeviceErrorString(stat)).c_str());
311 /*! \brief Unbind the texture and release the CUDA texture object.
313 * \tparam ValueType Raw data type
315 * \param[in,out] deviceBuffer Device buffer to store data in.
316 * \param[in,out] deviceTexture Device texture object to unbind.
318 template<typename ValueType>
319 void destroyParamLookupTable(DeviceBuffer<ValueType>* deviceBuffer, DeviceTexture& deviceTexture)
321 if (!c_disableCudaTextures && deviceTexture && deviceBuffer)
323 cudaError_t stat = cudaDestroyTextureObject(deviceTexture);
326 ("Destruction of the texture object failed. " + gmx::getDeviceErrorString(stat)).c_str());
328 freeDeviceBuffer(deviceBuffer);