xref: /libCEED/backends/cuda-gen/ceed-cuda-gen-qfunction.c (revision 5f67fade47e323fa44018f277580acfe24400ad4)
1 // Copyright (c) 2017-2018, Lawrence Livermore National Security, LLC.
2 // Produced at the Lawrence Livermore National Laboratory. LLNL-CODE-734707.
3 // All Rights reserved. See files LICENSE and NOTICE for details.
4 //
5 // This file is part of CEED, a collection of benchmarks, miniapps, software
6 // libraries and APIs for efficient high-order finite element and spectral
7 // element discretizations for exascale applications. For more information and
8 // source code availability see http://github.com/ceed.
9 //
10 // The CEED research is supported by the Exascale Computing Project 17-SC-20-SC,
11 // a collaborative effort of two U.S. Department of Energy organizations (Office
12 // of Science and the National Nuclear Security Administration) responsible for
13 // the planning and preparation of a capable exascale ecosystem, including
14 // software, applications, hardware, advanced system engineering and early
15 // testbed platforms, in support of the nation's exascale computing imperative.
16 
17 #include <string.h>
18 #include <stdio.h>
19 #include "ceed-cuda-gen.h"
20 
21 //------------------------------------------------------------------------------
22 // Apply QFunction
23 //------------------------------------------------------------------------------
24 static int CeedQFunctionApply_Cuda_gen(CeedQFunction qf, CeedInt Q,
25                                        CeedVector *U, CeedVector *V) {
26   int ierr;
27   Ceed ceed;
28   ierr = CeedQFunctionGetCeed(qf, &ceed); CeedChk(ierr);
29   return CeedError(ceed, 1, "Backend does not implement QFunctionApply");
30 }
31 
32 //------------------------------------------------------------------------------
33 // Destroy QFunction
34 //------------------------------------------------------------------------------
35 static int CeedQFunctionDestroy_Cuda_gen(CeedQFunction qf) {
36   int ierr;
37   CeedQFunction_Cuda_gen *data;
38   ierr = CeedQFunctionGetData(qf, (void *)&data); CeedChk(ierr);
39   Ceed ceed;
40   ierr = CeedQFunctionGetCeed(qf, &ceed); CeedChk(ierr);
41   ierr = cudaFree(data->d_c); CeedChk_Cu(ceed, ierr);
42   ierr = CeedFree(&data->qFunctionSource); CeedChk(ierr);
43   ierr = CeedFree(&data); CeedChk(ierr);
44   return 0;
45 }
46 
47 //------------------------------------------------------------------------------
48 // Load QFunction
49 //------------------------------------------------------------------------------
50 static int loadCudaFunction(CeedQFunction qf, char *c_src_file) {
51   int ierr;
52   Ceed ceed;
53   CeedQFunctionGetCeed(qf, &ceed);
54   CeedQFunction_Cuda_gen *data;
55   ierr = CeedQFunctionGetData(qf, (void *)&data); CeedChk(ierr);
56 
57   // Find source file
58   char *cuda_file;
59   ierr = CeedCalloc(CUDA_MAX_PATH, &cuda_file); CeedChk(ierr);
60   memcpy(cuda_file, c_src_file, strlen(c_src_file));
61   const char *last_dot = strrchr(cuda_file, '.');
62   if (!last_dot)
63     return CeedError(ceed, 1, "Cannot find file's extension!");
64   const size_t cuda_path_len = last_dot - cuda_file;
65   strncpy(&cuda_file[cuda_path_len], ".h", 3);
66 
67   // Open source file
68   FILE *fp;
69   long lSize;
70   char *buffer;
71   fp = fopen (cuda_file, "rb");
72   if (!fp)
73     CeedError(ceed, 1, "Couldn't open the Cuda file for the QFunction.");
74 
75   // Compute size of source file
76   fseek(fp, 0L, SEEK_END);
77   lSize = ftell(fp);
78   rewind(fp);
79 
80   // Allocate memory for entire content
81   ierr = CeedCalloc(lSize+1, &buffer); CeedChk(ierr);
82 
83   // Copy the file into the buffer
84   if (1 != fread(buffer, lSize, 1, fp)) {
85     fclose(fp);
86     ierr = CeedFree(&buffer); CeedChk(ierr);
87     CeedError(ceed, 1, "Couldn't read the Cuda file for the QFunction.");
88   }
89 
90   // Append typedef and save source string
91   // FIXME: the magic number 16 should be defined somewhere...
92   char *fields_string =
93     "typedef struct { const CeedScalar* inputs[16]; CeedScalar* outputs[16]; } Fields_Cuda_gen;";
94   ierr = CeedMalloc(1 + strlen(fields_string) + strlen(buffer),
95                     &data->qFunctionSource); CeedChk(ierr);
96   memcpy(data->qFunctionSource, fields_string, strlen(fields_string));
97   memcpy(data->qFunctionSource + strlen(fields_string), buffer,
98          strlen(buffer) + 1);
99 
100   // Cleanup
101   ierr = CeedFree(&buffer); CeedChk(ierr);
102   fclose(fp);
103   ierr = CeedFree(&cuda_file); CeedChk(ierr);
104   return 0;
105 }
106 
107 //------------------------------------------------------------------------------
108 // Create QFunction
109 //------------------------------------------------------------------------------
110 int CeedQFunctionCreate_Cuda_gen(CeedQFunction qf) {
111   int ierr;
112   Ceed ceed;
113   CeedQFunctionGetCeed(qf, &ceed);
114   CeedQFunction_Cuda_gen *data;
115   ierr = CeedCalloc(1,&data); CeedChk(ierr);
116   ierr = CeedQFunctionSetData(qf, (void *)&data); CeedChk(ierr);
117   size_t ctxsize;
118   ierr = CeedQFunctionGetContextSize(qf, &ctxsize); CeedChk(ierr);
119   ierr = cudaMalloc(&data->d_c, ctxsize); CeedChk_Cu(ceed, ierr);
120 
121   char *source;
122   ierr = CeedQFunctionGetSourcePath(qf, &source); CeedChk(ierr);
123   const char *funname = strrchr(source, ':') + 1;
124   data->qFunctionName = (char *)funname;
125   const int filenamelen = funname - source;
126   char filename[filenamelen];
127   memcpy(filename, source, filenamelen - 1);
128   filename[filenamelen - 1] = '\0';
129   ierr = loadCudaFunction(qf, filename); CeedChk(ierr);
130 
131   ierr = CeedSetBackendFunction(ceed, "QFunction", qf, "Apply",
132                                 CeedQFunctionApply_Cuda_gen); CeedChk(ierr);
133   ierr = CeedSetBackendFunction(ceed, "QFunction", qf, "Destroy",
134                                 CeedQFunctionDestroy_Cuda_gen); CeedChk(ierr);
135   return 0;
136 }
137 //------------------------------------------------------------------------------
138