Expose platform selection to user

3 files changed, 114 insertions, 13 deletions

diff --git a/fractal-gen.c b/fractal-gen.c
index 60b27e3..5f9e899 100644
--- a/fractal-gen.c
+++ b/fractal-gen.c
@@ -4,10 +4,10 @@
 
 #include "trampoline.h"
 
-int run(unsigned int size, unsigned int iterations)
+int run(const char *preferred_platform, unsigned int size, unsigned int iterations)
 {
 	fprintf(stderr, "Building CL trampoline... ");
-	if (tramp_init()) {
+	if (tramp_init(preferred_platform)) {
 		fprintf(stderr, "Failed.\n");
 		return 1;
 	}
@@ -63,7 +63,7 @@ int run(unsigned int size, unsigned int iterations)
 
 void die_help()
 {
-	fprintf(stderr, "Syntax:\nfractal-gen [-s size] [-i max_iteratons]\n");
+	fprintf(stderr, "Syntax:\nfractal-gen [-p platform] [-s size] [-i max_iteratons]\n");
 	exit(1);
 }
 
@@ -71,9 +71,10 @@ int main(int argc, char **argv)
 {
 	long size = 0;
 	long iterations = 0;
+	char *preferred_platform = NULL;
 	char c = '\0';
 
-	while ((c = getopt(argc, argv, "s:i:")) != -1) {
+	while ((c = getopt(argc, argv, "s:i:p:")) != -1) {
 		switch (c) {
 		case 's':
 			size = atoi(optarg);
@@ -81,6 +82,9 @@ int main(int argc, char **argv)
 		case 'i':
 			iterations = atoi(optarg);
 			break;
+		case 'p':
+			preferred_platform = optarg;
+			break;
 		case '?':
 			die_help();
 			return 1; /* mostly unreachable */
@@ -88,11 +92,11 @@ int main(int argc, char **argv)
 		}
 	}
 
-	if (size <= 0 || iterations <= 0) {
+	if (size <= 0 || iterations <= 0 || preferred_platform == NULL) {
 		die_help();
 		return 1; /* mostly unreachable */
 	}
 
-	run(size, iterations);
+	run(preferred_platform, size, iterations);
 	return 0;
 }
diff --git a/trampoline.c b/trampoline.c
index 9be250a..174ff26 100644
--- a/trampoline.c
+++ b/trampoline.c
@@ -20,16 +20,113 @@ static unsigned int size;
 static unsigned int iterations;
 
 
+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;
+}
+
+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];
+	}
+
+
+
+	return 0;
+}
+
+
 /* FIXME print cl error messages with oclErrorString */
-int tramp_init()
+int tramp_init(const char *preferred_platform)
 {
 	cl_int ret;
 
-	/* FIXME expose platform selection to user and flarg the blopple */
-//	ret = oclGetPlatformID(&platform);
-//	if (ret != CL_SUCCESS)
-//		return 1;
-	platform=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);
diff --git a/trampoline.h b/trampoline.h
index fbcc453..35624a9 100644
--- a/trampoline.h
+++ b/trampoline.h
@@ -1,4 +1,4 @@
-int tramp_init(void);
+int tramp_init(const char *preferred_platform);
 void tramp_destroy(void);
 int tramp_load_kernel(const char *filename);
 char *tramp_get_build_log(void);