diff options
Diffstat (limited to 'trampoline.c')
| -rw-r--r-- | trampoline.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/trampoline.c b/trampoline.c new file mode 100644 index 0000000..6659223 --- /dev/null +++ b/trampoline.c @@ -0,0 +1,406 @@ +#include <stdio.h> +#include <string.h> +#include <opencl.h> + +#include "cl_error.h" +#include "slurp.h" + +static cl_platform_id platform; +static cl_context context; +static cl_device_id* devices; +static cl_uint device_count; +static unsigned int device_in_use; +static cl_command_queue command_queue; +static cl_mem device_buffer; + +static cl_kernel kernel; +static cl_program program; + +static unsigned int size; +static unsigned int iterations; + +/** + * Wrapper to help with fetching string-based information about an OpenCL + * platform. + * + * Returns non-null pointer to a string which will need to be passed to free() + * when finished with. + * On failure, returns NULL + */ +char *get_platform_info(cl_platform_id id, cl_platform_info value_name) +{ + cl_int ret = 0; + char *value = NULL; + size_t value_len = 0; + + ret = clGetPlatformInfo(id, value_name, 0, NULL, &value_len); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get platform info for platform %d: %s\n", id, get_cl_error_string(ret)); + return NULL; + } + + value = malloc(value_len); + if (value == NULL) { + perror("value buffer malloc"); + return NULL; + } + + ret = clGetPlatformInfo(id, value_name, value_len, value, &value_len); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get platform info for platform %d: %s\n", id, get_cl_error_string(ret)); + return NULL; + } + + return value; +} + +/** + * Set the trampoline's selected OpenCL platform to the first one with a name + * matching the one in `preferred_platform`. If no exact match is found, + * the first available platform is selected instead. + * + * Returns 0 when any platform was selected. Returns non-zero if no platform + * could be selected + */ +int select_platform(const char *preferred_platform) +{ + cl_uint i = 0; + cl_platform_id *platforms = NULL; + cl_uint platform_count = 0; + cl_int ret = 0; + int preferred_platform_found = 0; + char *p_name = NULL; + char *p_vendor = NULL; + char *p_version = NULL; + + ret = clGetPlatformIDs(0, NULL, &platform_count); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get CL platform count: %s ", get_cl_error_string(ret)); + return 1; + } + + if (platform_count == 0) { + fprintf(stderr, "No OpenCL platforms available "); + return 1; + } + + platforms = calloc(platform_count, sizeof(cl_platform_id)); + if (platforms == NULL) { + perror("platform ID array calloc"); + return 1; + } + + ret = clGetPlatformIDs(platform_count, platforms, NULL); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get CL platform IDs: %s ", get_cl_error_string(ret)); + return 1; + } + + fprintf(stderr, "\nAvailable platforms:\n"); + for (i = 0; i < platform_count; i++) { + p_name = get_platform_info(platforms[i], CL_PLATFORM_NAME); + p_vendor = get_platform_info(platforms[i], CL_PLATFORM_VENDOR); + p_version = get_platform_info(platforms[i], CL_PLATFORM_VERSION); + if ( p_name == NULL + || p_version == NULL + || p_vendor == NULL) { + free(p_name); + free(p_vendor); + free(p_version); + free(platforms); + return 1; + } + /* Is this platform the first preferred one? Select it for the lovely lady or gentleman */ + if (strcmp(preferred_platform, p_name) == 0 && !preferred_platform_found) { + platform = platforms[i]; + preferred_platform_found = 1; + } + fprintf(stderr, "\t* Platform \"%s\" - From %s (%s)%s\n", + p_name, p_vendor, p_version, platform == platforms[i] ? " [SELECTED]" : "" ); + + free(p_name); + free(p_vendor); + free(p_version); + } + + if (!preferred_platform_found) { + fprintf(stderr, "Warning: Preferred platform not found, falling back on first available platform.\n"); + platform = platforms[0]; + } + + free(platforms); + + return 0; +} + + +/** + * Initialise the OpenCL trampoline, specifying the name of the OpenCL platform + * to use if it is available + * + * Returns 0 on success, non-zero on failure. + */ +int tramp_init(const char *preferred_platform) +{ + cl_int ret = 0; + + if (select_platform(preferred_platform)) { + return 1; + } + + /* FIXME expose device type to user */ + ret = clGetDeviceIDs(platform, CL_DEVICE_TYPE_ALL, 0, NULL, &device_count); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get device count: %s ", get_cl_error_string(ret)); + return 1; + } + + devices = malloc(device_count * sizeof(cl_device_id)); + if (!devices) { + perror("device list malloc"); + return 1; + } + + /* FIXME expose device type to user */ + ret = clGetDeviceIDs(platform, CL_DEVICE_TYPE_ALL, device_count, devices, NULL); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get device ID list: %s ", get_cl_error_string(ret)); + return 1; + } + + context = clCreateContext(0, 1, devices, NULL, NULL, &ret); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to create CL context: %s ", get_cl_error_string(ret)); + return 1; + } + + /* FIXME expose to user */ + device_in_use = 0; + command_queue = clCreateCommandQueue(context, devices[device_in_use], 0, &ret); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to create command queue on context: %s ", get_cl_error_string(ret)); + return 1; + } + + return 0; +} + +/** + * Destroy the trampoline, deallocating/freeing resources allocated in a + * previous call to tramp_init(char*) + */ +void tramp_destroy() +{ + clReleaseKernel(kernel); + clReleaseProgram(program); + clReleaseCommandQueue(command_queue); + clReleaseContext(context); + + if (devices) { + free(devices); + devices = NULL; + } +} + +/** + * Load OpenCL kernel source from the file `filename` and create an OpenCL + * program from it. + * + * Returns 0 on success, non-zero on failure. + */ +int tramp_load_kernel(const char *filename) +{ + cl_int ret = 0; + size_t length = 0; + FILE *fin = NULL; + char *source = NULL; + + fin = fopen(filename, "r"); + if (!fin) { + perror("fopen"); + return 1; + } + + source = slurp(fin, &length); + if (!source) + return 1; + + fclose(fin); + + program = clCreateProgramWithSource(context, 1, (const char **)&source, &length, &ret); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to create program from source code: %s ", get_cl_error_string(ret)); + return 1; + } + + free(source); + source = NULL; + + return 0; +} + +/** + * Get a string showing the logged output (if any) of the build stage of OpenCL + * program compilation. + * + * On success, returns a char* which must be passed to free(1) when no longer + * needed. Else, returns NULL. + */ +char *tramp_get_build_log() +{ + cl_int ret = 0; + cl_build_status build_status; + char *build_log = NULL; + size_t log_size = 0; + + ret = clGetProgramBuildInfo(program, devices[device_in_use], + CL_PROGRAM_BUILD_STATUS, + sizeof(cl_build_status), + &build_status, NULL); + + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get program build status: %s ", get_cl_error_string(ret)); + return NULL; + } + + ret = clGetProgramBuildInfo(program, devices[device_in_use], + CL_PROGRAM_BUILD_LOG, 0, NULL, &log_size); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get program build log size: %s ", get_cl_error_string(ret)); + return NULL; + } + + /* + 1 for null-terminator */ + build_log = malloc(log_size + 1); + if (!build_log) { + perror("malloc"); + return NULL; + } + ret = clGetProgramBuildInfo(program, devices[device_in_use], + CL_PROGRAM_BUILD_LOG, + log_size, build_log, NULL); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to get program build log: %s ", get_cl_error_string(ret)); + return NULL; + } + + /* null-terminate log */ + build_log[log_size] = '\0'; + + return build_log; +} + +/** + * Compile the loaded program/kernel to make it ready for execution. + * + * Returns 0 on success, non-zero otherwise. + */ +int tramp_compile_kernel() +{ + cl_int ret = 0; + + ret = clBuildProgram(program, 0, NULL, NULL, NULL, NULL); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to build program: %s ", get_cl_error_string(ret)); + return 1; + } + + kernel = clCreateKernel(program, "fractal_gen", &ret); + + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to create kernel: %s ", get_cl_error_string(ret)); + return 1; + } + + return 0; +} + +/** + * Set the arguments to be passed to the OpenCL kernel when run on the device. + * + * Returns 0 on success, non-zero otherwise. + * + * FIXME investigate using something more flexible? + */ +int tramp_set_kernel_args(unsigned int s, unsigned int it) +{ + cl_int ret = 0; + + size = s; + iterations = it; + + device_buffer = clCreateBuffer(context, CL_MEM_WRITE_ONLY, size*size, NULL, &ret); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to create buffer for slave device: %s ", get_cl_error_string(ret)); + return 1; + } + + ret = clSetKernelArg(kernel, 0, sizeof(cl_mem), &device_buffer); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Error on buffer argument: %s ", get_cl_error_string(ret)); + return 1; + } + + ret = clSetKernelArg(kernel, 1, sizeof(unsigned int), &size); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Error on size argument: %s ", get_cl_error_string(ret)); + return 1; + } + + ret = clSetKernelArg(kernel, 2, sizeof(unsigned long), &iterations); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Error on iteration argument: %s ", get_cl_error_string(ret)); + return 1; + } + + return 0; +} + +/** + * Run the OpenCL kernel on the device with the specified arguments and wait + * for it to complete execution + * + * Returns 0 on success, otherwise 1 + * + */ +int tramp_run_kernel() +{ + cl_event event; + cl_int ret = 0; + size_t workgroup_sizes[2]; + workgroup_sizes[0] = size; + workgroup_sizes[1] = size; + + ret = clEnqueueNDRangeKernel(command_queue, kernel, 2, NULL, workgroup_sizes, NULL, 0, NULL, &event); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to enqueue kernel run command: %s ", get_cl_error_string(ret)); + return 1; + } + + clReleaseEvent(event); + clFinish(command_queue); + + return 0; +} + +/** + * Copy the data buffer from the device to the host. + * `buffer` must point to a pointer to a valid location in memory at least + * `size` bytes large. + * + * Returns 0 on success, non-zero otherwise. + */ +int tramp_copy_data(void **buffer, size_t size) +{ + cl_event event; + cl_int ret = 0; + + ret = clEnqueueReadBuffer(command_queue, device_buffer, CL_TRUE, 0, size, *buffer, 0, NULL, &event); + if (ret != CL_SUCCESS) { + fprintf(stderr, "Failed to enqueue read command for data: %s ", get_cl_error_string(ret)); + return 1; + } + clReleaseEvent(event); + + return 0; +} |