1 files changed, 1000 insertions, 0 deletions

diff --git a/drivers/staging/greybus/tools/loopback_test.c b/drivers/staging/greybus/tools/loopback_test.c
new file mode 100644
index 000000000000..f7f4cd6fb55b
--- /dev/null
+++ b/drivers/staging/greybus/tools/loopback_test.c
@@ -0,0 +1,1000 @@
+/*
+ * Loopback test application
+ *
+ * Copyright 2015 Google Inc.
+ * Copyright 2015 Linaro Ltd.
+ *
+ * Provided under the three clause BSD license found in the LICENSE file.
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <poll.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <signal.h>
+
+#define MAX_NUM_DEVICES 10
+#define MAX_SYSFS_PATH	0x200
+#define CSV_MAX_LINE	0x1000
+#define SYSFS_MAX_INT	0x20
+#define MAX_STR_LEN	255
+#define DEFAULT_ASYNC_TIMEOUT 200000
+
+struct dict {
+	char *name;
+	int type;
+};
+
+static struct dict dict[] = {
+	{"ping", 2},
+	{"transfer", 3},
+	{"sink", 4},
+	{NULL,}		/* list termination */
+};
+
+struct loopback_results {
+	float latency_avg;
+	uint32_t latency_max;
+	uint32_t latency_min;
+	uint32_t latency_jitter;
+
+	float request_avg;
+	uint32_t request_max;
+	uint32_t request_min;
+	uint32_t request_jitter;
+
+	float throughput_avg;
+	uint32_t throughput_max;
+	uint32_t throughput_min;
+	uint32_t throughput_jitter;
+
+	float apbridge_unipro_latency_avg;
+	uint32_t apbridge_unipro_latency_max;
+	uint32_t apbridge_unipro_latency_min;
+	uint32_t apbridge_unipro_latency_jitter;
+
+	float gbphy_firmware_latency_avg;
+	uint32_t gbphy_firmware_latency_max;
+	uint32_t gbphy_firmware_latency_min;
+	uint32_t gbphy_firmware_latency_jitter;
+
+	uint32_t error;
+};
+
+struct loopback_device {
+	char name[MAX_SYSFS_PATH];
+	char sysfs_entry[MAX_SYSFS_PATH];
+	char debugfs_entry[MAX_SYSFS_PATH];
+	struct loopback_results results;
+};
+
+struct loopback_test {
+	int verbose;
+	int debug;
+	int raw_data_dump;
+	int porcelain;
+	int mask;
+	int size;
+	int iteration_max;
+	int aggregate_output;
+	int test_id;
+	int device_count;
+	int list_devices;
+	int use_async;
+	int async_timeout;
+	int async_outstanding_operations;
+	int us_wait;
+	int file_output;
+	int stop_all;
+	int poll_count;
+	char test_name[MAX_STR_LEN];
+	char sysfs_prefix[MAX_SYSFS_PATH];
+	char debugfs_prefix[MAX_SYSFS_PATH];
+	struct timespec poll_timeout;
+	struct loopback_device devices[MAX_NUM_DEVICES];
+	struct loopback_results aggregate_results;
+	struct pollfd fds[MAX_NUM_DEVICES];
+};
+
+struct loopback_test t;
+
+/* Helper macros to calculate the aggregate results for all devices */
+static inline int device_enabled(struct loopback_test *t, int dev_idx);
+
+#define GET_MAX(field)							\
+static int get_##field##_aggregate(struct loopback_test *t)		\
+{									\
+	uint32_t max = 0;						\
+	int i;								\
+	for (i = 0; i < t->device_count; i++) {				\
+		if (!device_enabled(t, i))				\
+			continue;					\
+		if (t->devices[i].results.field > max)			\
+			max = t->devices[i].results.field;		\
+	}								\
+	return max;							\
+}									\
+
+#define GET_MIN(field)							\
+static int get_##field##_aggregate(struct loopback_test *t)		\
+{									\
+	uint32_t min = ~0;						\
+	int i;								\
+	for (i = 0; i < t->device_count; i++) {				\
+		if (!device_enabled(t, i))				\
+			continue;					\
+		if (t->devices[i].results.field < min)			\
+			min = t->devices[i].results.field;		\
+	}								\
+	return min;							\
+}									\
+
+#define GET_AVG(field)							\
+static int get_##field##_aggregate(struct loopback_test *t)		\
+{									\
+	uint32_t val = 0;						\
+	uint32_t count = 0;						\
+	int i;								\
+	for (i = 0; i < t->device_count; i++) {				\
+		if (!device_enabled(t, i))				\
+			continue;					\
+		count++;						\
+		val += t->devices[i].results.field;			\
+	}								\
+	if (count)							\
+		val /= count;						\
+	return val;							\
+}									\
+
+GET_MAX(throughput_max);
+GET_MAX(request_max);
+GET_MAX(latency_max);
+GET_MAX(apbridge_unipro_latency_max);
+GET_MAX(gbphy_firmware_latency_max);
+GET_MIN(throughput_min);
+GET_MIN(request_min);
+GET_MIN(latency_min);
+GET_MIN(apbridge_unipro_latency_min);
+GET_MIN(gbphy_firmware_latency_min);
+GET_AVG(throughput_avg);
+GET_AVG(request_avg);
+GET_AVG(latency_avg);
+GET_AVG(apbridge_unipro_latency_avg);
+GET_AVG(gbphy_firmware_latency_avg);
+
+void abort()
+{
+	_exit(1);
+}
+
+void usage(void)
+{
+	fprintf(stderr, "Usage: loopback_test TEST [SIZE] ITERATIONS [SYSPATH] [DBGPATH]\n\n"
+	"  Run TEST for a number of ITERATIONS with operation data SIZE bytes\n"
+	"  TEST may be \'ping\' \'transfer\' or \'sink\'\n"
+	"  SIZE indicates the size of transfer <= greybus max payload bytes\n"
+	"  ITERATIONS indicates the number of times to execute TEST at SIZE bytes\n"
+	"             Note if ITERATIONS is set to zero then this utility will\n"
+	"             initiate an infinite (non terminating) test and exit\n"
+	"             without logging any metrics data\n"
+	"  SYSPATH indicates the sysfs path for the loopback greybus entries e.g.\n"
+	"          /sys/bus/greybus/devices\n"
+	"  DBGPATH indicates the debugfs path for the loopback greybus entries e.g.\n"
+	"          /sys/kernel/debug/gb_loopback/\n"
+	" Mandatory arguments\n"
+	"   -t     must be one of the test names - sink, transfer or ping\n"
+	"   -i     iteration count - the number of iterations to run the test over\n"
+	" Optional arguments\n"
+	"   -S     sysfs location - location for greybus 'endo' entires default /sys/bus/greybus/devices/\n"
+	"   -D     debugfs location - location for loopback debugfs entries default /sys/kernel/debug/gb_loopback/\n"
+	"   -s     size of data packet to send during test - defaults to zero\n"
+	"   -m     mask - a bit mask of connections to include example: -m 8 = 4th connection -m 9 = 1st and 4th connection etc\n"
+	"                 default is zero which means broadcast to all connections\n"
+	"   -v     verbose output\n"
+	"   -d     debug output\n"
+	"   -r     raw data output - when specified the full list of latency values are included in the output CSV\n"
+	"   -p     porcelain - when specified printout is in a user-friendly non-CSV format. This option suppresses writing to CSV file\n"
+	"   -a     aggregate - show aggregation of all enabled devices\n"
+	"   -l     list found loopback devices and exit\n"
+	"   -x     Async - Enable async transfers\n"
+	"   -o     Async Timeout - Timeout in uSec for async operations\n"
+	"   -O     Poll loop time out in seconds(max time a test is expected to last, default: 30sec)\n"
+	"   -c     Max number of outstanding operations for async operations\n"
+	"   -w     Wait in uSec between operations\n"
+	"   -z     Enable output to a CSV file (incompatible with -p)\n"
+	"   -f     When starting new loopback test, stop currently running tests on all devices\n"
+	"Examples:\n"
+	"  Send 10000 transfers with a packet size of 128 bytes to all active connections\n"
+	"  loopback_test -t transfer -s 128 -i 10000 -S /sys/bus/greybus/devices/ -D /sys/kernel/debug/gb_loopback/\n"
+	"  loopback_test -t transfer -s 128 -i 10000 -m 0\n"
+	"  Send 10000 transfers with a packet size of 128 bytes to connection 1 and 4\n"
+	"  loopback_test -t transfer -s 128 -i 10000 -m 9\n"
+	"  loopback_test -t ping -s 0 128 -i -S /sys/bus/greybus/devices/ -D /sys/kernel/debug/gb_loopback/\n"
+	"  loopback_test -t sink -s 2030 -i 32768 -S /sys/bus/greybus/devices/ -D /sys/kernel/debug/gb_loopback/\n");
+	abort();
+}
+
+static inline int device_enabled(struct loopback_test *t, int dev_idx)
+{
+	if (!t->mask || (t->mask & (1 << dev_idx)))
+		return 1;
+
+	return 0;
+}
+
+static void show_loopback_devices(struct loopback_test *t)
+{
+	int i;
+
+	if (t->device_count == 0) {
+		printf("No loopback devices.\n");
+		return;
+	}
+
+	for (i = 0; i < t->device_count; i++)
+		printf("device[%d] = %s\n", i, t->devices[i].name);
+
+}
+
+int open_sysfs(const char *sys_pfx, const char *node, int flags)
+{
+	int fd;
+	char path[MAX_SYSFS_PATH];
+
+	snprintf(path, sizeof(path), "%s%s", sys_pfx, node);
+	fd = open(path, flags);
+	if (fd < 0) {
+		fprintf(stderr, "unable to open %s\n", path);
+		abort();
+	}
+	return fd;
+}
+
+int read_sysfs_int_fd(int fd, const char *sys_pfx, const char *node)
+{
+	char buf[SYSFS_MAX_INT];
+
+	if (read(fd, buf, sizeof(buf)) < 0) {
+		fprintf(stderr, "unable to read from %s%s %s\n", sys_pfx, node,
+			strerror(errno));
+		close(fd);
+		abort();
+	}
+	return atoi(buf);
+}
+
+float read_sysfs_float_fd(int fd, const char *sys_pfx, const char *node)
+{
+	char buf[SYSFS_MAX_INT];
+
+	if (read(fd, buf, sizeof(buf)) < 0) {
+
+		fprintf(stderr, "unable to read from %s%s %s\n", sys_pfx, node,
+			strerror(errno));
+		close(fd);
+		abort();
+	}
+	return atof(buf);
+}
+
+int read_sysfs_int(const char *sys_pfx, const char *node)
+{
+	int fd, val;
+
+	fd = open_sysfs(sys_pfx, node, O_RDONLY);
+	val = read_sysfs_int_fd(fd, sys_pfx, node);
+	close(fd);
+	return val;
+}
+
+float read_sysfs_float(const char *sys_pfx, const char *node)
+{
+	int fd;
+	float val;
+
+	fd = open_sysfs(sys_pfx, node, O_RDONLY);
+	val = read_sysfs_float_fd(fd, sys_pfx, node);
+	close(fd);
+	return val;
+}
+
+void write_sysfs_val(const char *sys_pfx, const char *node, int val)
+{
+	int fd, len;
+	char buf[SYSFS_MAX_INT];
+
+	fd = open_sysfs(sys_pfx, node, O_RDWR);
+	len = snprintf(buf, sizeof(buf), "%d", val);
+	if (write(fd, buf, len) < 0) {
+		fprintf(stderr, "unable to write to %s%s %s\n", sys_pfx, node,
+			strerror(errno));
+		close(fd);
+		abort();
+	}
+	close(fd);
+}
+
+static int get_results(struct loopback_test *t)
+{
+	struct loopback_device *d;
+	struct loopback_results *r;
+	int i;
+
+	for (i = 0; i < t->device_count; i++) {
+		if (!device_enabled(t, i))
+			continue;
+
+		d = &t->devices[i];
+		r = &d->results;
+
+		r->error = read_sysfs_int(d->sysfs_entry, "error");
+		r->request_min = read_sysfs_int(d->sysfs_entry, "requests_per_second_min");
+		r->request_max = read_sysfs_int(d->sysfs_entry, "requests_per_second_max");
+		r->request_avg = read_sysfs_float(d->sysfs_entry, "requests_per_second_avg");
+
+		r->latency_min = read_sysfs_int(d->sysfs_entry, "latency_min");
+		r->latency_max = read_sysfs_int(d->sysfs_entry, "latency_max");
+		r->latency_avg = read_sysfs_float(d->sysfs_entry, "latency_avg");
+
+		r->throughput_min = read_sysfs_int(d->sysfs_entry, "throughput_min");
+		r->throughput_max = read_sysfs_int(d->sysfs_entry, "throughput_max");
+		r->throughput_avg = read_sysfs_float(d->sysfs_entry, "throughput_avg");
+
+		r->apbridge_unipro_latency_min =
+			read_sysfs_int(d->sysfs_entry, "apbridge_unipro_latency_min");
+		r->apbridge_unipro_latency_max =
+			read_sysfs_int(d->sysfs_entry, "apbridge_unipro_latency_max");
+		r->apbridge_unipro_latency_avg =
+			read_sysfs_float(d->sysfs_entry, "apbridge_unipro_latency_avg");
+
+		r->gbphy_firmware_latency_min =
+			read_sysfs_int(d->sysfs_entry, "gbphy_firmware_latency_min");
+		r->gbphy_firmware_latency_max =
+			read_sysfs_int(d->sysfs_entry, "gbphy_firmware_latency_max");
+		r->gbphy_firmware_latency_avg =
+			read_sysfs_float(d->sysfs_entry, "gbphy_firmware_latency_avg");
+
+		r->request_jitter = r->request_max - r->request_min;
+		r->latency_jitter = r->latency_max - r->latency_min;
+		r->throughput_jitter = r->throughput_max - r->throughput_min;
+		r->apbridge_unipro_latency_jitter =
+			r->apbridge_unipro_latency_max - r->apbridge_unipro_latency_min;
+		r->gbphy_firmware_latency_jitter =
+			r->gbphy_firmware_latency_max - r->gbphy_firmware_latency_min;
+
+	}
+
+	/*calculate the aggregate results of all enabled devices */
+	if (t->aggregate_output) {
+		r = &t->aggregate_results;
+
+		r->request_min = get_request_min_aggregate(t);
+		r->request_max = get_request_max_aggregate(t);
+		r->request_avg = get_request_avg_aggregate(t);
+
+		r->latency_min = get_latency_min_aggregate(t);
+		r->latency_max = get_latency_max_aggregate(t);
+		r->latency_avg = get_latency_avg_aggregate(t);
+
+		r->throughput_min = get_throughput_min_aggregate(t);
+		r->throughput_max = get_throughput_max_aggregate(t);
+		r->throughput_avg = get_throughput_avg_aggregate(t);
+
+		r->apbridge_unipro_latency_min =
+			get_apbridge_unipro_latency_min_aggregate(t);
+		r->apbridge_unipro_latency_max =
+			get_apbridge_unipro_latency_max_aggregate(t);
+		r->apbridge_unipro_latency_avg =
+			get_apbridge_unipro_latency_avg_aggregate(t);
+
+		r->gbphy_firmware_latency_min =
+			get_gbphy_firmware_latency_min_aggregate(t);
+		r->gbphy_firmware_latency_max =
+			get_gbphy_firmware_latency_max_aggregate(t);
+		r->gbphy_firmware_latency_avg =
+			get_gbphy_firmware_latency_avg_aggregate(t);
+
+		r->request_jitter = r->request_max - r->request_min;
+		r->latency_jitter = r->latency_max - r->latency_min;
+		r->throughput_jitter = r->throughput_max - r->throughput_min;
+		r->apbridge_unipro_latency_jitter =
+			r->apbridge_unipro_latency_max - r->apbridge_unipro_latency_min;
+		r->gbphy_firmware_latency_jitter =
+			r->gbphy_firmware_latency_max - r->gbphy_firmware_latency_min;
+
+	}
+
+	return 0;
+}
+
+void log_csv_error(int len, int err)
+{
+	fprintf(stderr, "unable to write %d bytes to csv %s\n", len,
+		strerror(err));
+}
+
+int format_output(struct loopback_test *t,
+			struct loopback_results *r,
+			const char *dev_name,
+			char *buf, int buf_len,
+			struct tm *tm)
+{
+	int len = 0;
+
+	memset(buf, 0x00, buf_len);
+	len = snprintf(buf, buf_len, "%u-%u-%u %u:%u:%u",
+		       tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
+		       tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	if (t->porcelain) {
+		len += snprintf(&buf[len], buf_len - len,
+			"\n test:\t\t\t%s\n path:\t\t\t%s\n size:\t\t\t%u\n iterations:\t\t%u\n errors:\t\t%u\n async:\t\t\t%s\n",
+			t->test_name,
+			dev_name,
+			t->size,
+			t->iteration_max,
+			r->error,
+			t->use_async ? "Enabled" : "Disabled");
+
+		len += snprintf(&buf[len], buf_len - len,
+			" requests per-sec:\tmin=%u, max=%u, average=%f, jitter=%u\n",
+			r->request_min,
+			r->request_max,
+			r->request_avg,
+			r->request_jitter);
+
+		len += snprintf(&buf[len], buf_len - len,
+			" ap-throughput B/s:\tmin=%u max=%u average=%f jitter=%u\n",
+			r->throughput_min,
+			r->throughput_max,
+			r->throughput_avg,
+			r->throughput_jitter);
+		len += snprintf(&buf[len], buf_len - len,
+			" ap-latency usec:\tmin=%u max=%u average=%f jitter=%u\n",
+			r->latency_min,
+			r->latency_max,
+			r->latency_avg,
+			r->latency_jitter);
+		len += snprintf(&buf[len], buf_len - len,
+			" apbridge-latency usec:\tmin=%u max=%u average=%f jitter=%u\n",
+			r->apbridge_unipro_latency_min,
+			r->apbridge_unipro_latency_max,
+			r->apbridge_unipro_latency_avg,
+			r->apbridge_unipro_latency_jitter);
+
+		len += snprintf(&buf[len], buf_len - len,
+			" gbphy-latency usec:\tmin=%u max=%u average=%f jitter=%u\n",
+			r->gbphy_firmware_latency_min,
+			r->gbphy_firmware_latency_max,
+			r->gbphy_firmware_latency_avg,
+			r->gbphy_firmware_latency_jitter);
+
+	} else {
+		len += snprintf(&buf[len], buf_len- len, ",%s,%s,%u,%u,%u",
+			t->test_name, dev_name, t->size, t->iteration_max,
+			r->error);
+
+		len += snprintf(&buf[len], buf_len - len, ",%u,%u,%f,%u",
+			r->request_min,
+			r->request_max,
+			r->request_avg,
+			r->request_jitter);
+
+		len += snprintf(&buf[len], buf_len - len, ",%u,%u,%f,%u",
+			r->latency_min,
+			r->latency_max,
+			r->latency_avg,
+			r->latency_jitter);
+
+		len += snprintf(&buf[len], buf_len - len, ",%u,%u,%f,%u",
+			r->throughput_min,
+			r->throughput_max,
+			r->throughput_avg,
+			r->throughput_jitter);
+
+		len += snprintf(&buf[len], buf_len - len, ",%u,%u,%f,%u",
+			r->apbridge_unipro_latency_min,
+			r->apbridge_unipro_latency_max,
+			r->apbridge_unipro_latency_avg,
+			r->apbridge_unipro_latency_jitter);
+
+		len += snprintf(&buf[len], buf_len - len, ",%u,%u,%f,%u",
+			r->gbphy_firmware_latency_min,
+			r->gbphy_firmware_latency_max,
+			r->gbphy_firmware_latency_avg,
+			r->gbphy_firmware_latency_jitter);
+	}
+
+	printf("\n%s\n", buf);
+
+	return len;
+}
+
+static int log_results(struct loopback_test *t)
+{
+	int fd, i, len, ret;
+	struct tm tm;
+	time_t local_time;
+	mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
+	char file_name[MAX_SYSFS_PATH];
+	char data[CSV_MAX_LINE];
+
+	local_time = time(NULL);
+	tm = *localtime(&local_time);
+
+	/*
+	* file name will test_name_size_iteration_max.csv
+	* every time the same test with the same parameters is run we will then
+	* append to the same CSV with datestamp - representing each test
+	* dataset.
+	*/
+	if (t->file_output && !t->porcelain) {
+		snprintf(file_name, sizeof(file_name), "%s_%d_%d.csv",
+			t->test_name, t->size, t->iteration_max);
+
+		fd = open(file_name, O_WRONLY | O_CREAT | O_APPEND, mode);
+		if (fd < 0) {
+			fprintf(stderr, "unable to open %s for appendation\n", file_name);
+			abort();
+		}
+
+	}
+	for (i = 0; i < t->device_count; i++) {
+		if (!device_enabled(t, i))
+			continue;
+
+		len = format_output(t, &t->devices[i].results,
+					t->devices[i].name,
+					data, sizeof(data), &tm);
+		if (t->file_output && !t->porcelain) {
+			ret = write(fd, data, len);
+			if (ret == -1)
+				fprintf(stderr, "unable to write %d bytes to csv.\n", len);
+		}
+
+	}
+
+
+	if (t->aggregate_output) {
+		len = format_output(t, &t->aggregate_results, "aggregate",
+					data, sizeof(data), &tm);
+		if (t->file_output && !t->porcelain) {
+			ret = write(fd, data, len);
+			if (ret == -1)
+				fprintf(stderr, "unable to write %d bytes to csv.\n", len);
+		}
+	}
+
+	if (t->file_output && !t->porcelain)
+		close(fd);
+
+	return 0;
+}
+
+int is_loopback_device(const char *path, const char *node)
+{
+	char file[MAX_SYSFS_PATH];
+
+	snprintf(file, MAX_SYSFS_PATH, "%s%s/iteration_count", path, node);
+	if (access(file, F_OK) == 0)
+		return 1;
+	return 0;
+}
+
+int find_loopback_devices(struct loopback_test *t)
+{
+	struct dirent **namelist;
+	int i, n, ret;
+	unsigned int dev_id;
+	struct loopback_device *d;
+
+	n = scandir(t->sysfs_prefix, &namelist, NULL, alphasort);
+	if (n < 0) {
+		perror("scandir");
+		ret = -ENODEV;
+		goto baddir;
+	}
+
+	/* Don't include '.' and '..' */
+	if (n <= 2) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	for (i = 0; i < n; i++) {
+		ret = sscanf(namelist[i]->d_name, "gb_loopback%u", &dev_id);
+		if (ret != 1)
+			continue;
+
+		if (!is_loopback_device(t->sysfs_prefix, namelist[i]->d_name))
+			continue;
+
+		if (t->device_count == MAX_NUM_DEVICES) {
+			fprintf(stderr, "max number of devices reached!\n");
+			break;
+		}
+
+		d = &t->devices[t->device_count++];
+		snprintf(d->name, MAX_STR_LEN, "gb_loopback%u", dev_id);
+
+		snprintf(d->sysfs_entry, MAX_SYSFS_PATH, "%s%s/",
+			t->sysfs_prefix, d->name);
+
+		snprintf(d->debugfs_entry, MAX_SYSFS_PATH, "%sraw_latency_%s",
+			t->debugfs_prefix, d->name);
+
+		if (t->debug)
+			printf("add %s %s\n", d->sysfs_entry,
+				d->debugfs_entry);
+	}
+
+	ret = 0;
+done:
+	for (i = 0; i < n; i++)
+		free(namelist[n]);
+	free(namelist);
+baddir:
+	return ret;
+}
+
+static int open_poll_files(struct loopback_test *t)
+{
+	struct loopback_device *dev;
+	char buf[MAX_STR_LEN];
+	char dummy;
+	int fds_idx = 0;
+	int i;
+
+	for (i = 0; i < t->device_count; i++) {
+		dev = &t->devices[i];
+
+		if (!device_enabled(t, i))
+			continue;
+
+		snprintf(buf, sizeof(buf), "%s%s", dev->sysfs_entry, "iteration_count");
+		t->fds[fds_idx].fd = open(buf, O_RDONLY);
+		if (t->fds[fds_idx].fd < 0) {
+			fprintf(stderr, "Error opening poll file!\n");
+			goto err;
+		}
+		read(t->fds[fds_idx].fd, &dummy, 1);
+		t->fds[fds_idx].events = POLLERR|POLLPRI;
+		t->fds[fds_idx].revents = 0;
+		fds_idx++;
+	}
+
+	t->poll_count = fds_idx;
+
+	return 0;
+
+err:
+	for (i = 0; i < fds_idx; i++)
+		close(t->fds[fds_idx].fd);
+
+	return -1;
+}
+
+static int close_poll_files(struct loopback_test *t)
+{
+	int i;
+	for (i = 0; i < t->poll_count; i++)
+		close(t->fds[i].fd);
+
+	return 0;
+}
+static int is_complete(struct loopback_test *t)
+{
+	int iteration_count;
+	int i;
+
+	for (i = 0; i < t->device_count; i++) {
+		if (!device_enabled(t, i))
+			continue;
+
+		iteration_count = read_sysfs_int(t->devices[i].sysfs_entry,
+						 "iteration_count");
+
+		/* at least one device did not finish yet */
+		if (iteration_count != t->iteration_max)
+			return 0;
+	}
+
+	return 1;
+}
+
+static void stop_tests(struct loopback_test *t)
+{
+	int i;
+
+	for (i = 0; i < t->device_count; i++) {
+		if (!device_enabled(t, i))
+			continue;
+		write_sysfs_val(t->devices[i].sysfs_entry, "type", 0);
+	}
+}
+
+static void handler(int sig) { /* do nothing */  }
+
+static int wait_for_complete(struct loopback_test *t)
+{
+	int number_of_events = 0;
+	char dummy;
+	int ret;
+	int i;
+	struct timespec *ts = NULL;
+	struct sigaction sa;
+	sigset_t mask_old, mask;
+
+	sigemptyset(&mask);
+	sigemptyset(&mask_old);
+	sigaddset(&mask, SIGINT);
+	sigprocmask(SIG_BLOCK, &mask, &mask_old);
+
+	sa.sa_handler = handler;
+	sa.sa_flags = 0;
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(SIGINT, &sa, NULL) == -1) {
+		fprintf(stderr, "sigaction error\n");
+		return -1;
+	}
+
+	if (t->poll_timeout.tv_sec != 0)
+		ts = &t->poll_timeout;
+
+	while (1) {
+
+		ret = ppoll(t->fds, t->poll_count, ts, &mask_old);
+		if (ret <= 0) {
+			stop_tests(t);
+			fprintf(stderr, "Poll exit with errno %d\n", errno);
+			return -1;
+		}
+
+		for (i = 0; i < t->poll_count; i++) {
+			if (t->fds[i].revents & POLLPRI) {
+				/* Dummy read to clear the event */
+				read(t->fds[i].fd, &dummy, 1);
+				number_of_events++;
+			}
+		}
+
+		if (number_of_events == t->poll_count)
+			break;
+	}
+
+	if (!is_complete(t)) {
+		fprintf(stderr, "Iteration count did not finish!\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static void prepare_devices(struct loopback_test *t)
+{
+	int i;
+
+	/* Cancel any running tests on enabled devices. If
+	 * stop_all option is given, stop test on all devices.
+	 */
+	for (i = 0; i < t->device_count; i++)
+		if (t->stop_all || device_enabled(t, i))
+			write_sysfs_val(t->devices[i].sysfs_entry, "type", 0);
+
+
+	for (i = 0; i < t->device_count; i++) {
+		if (!device_enabled(t, i))
+			continue;
+
+		write_sysfs_val(t->devices[i].sysfs_entry, "us_wait",
+				t->us_wait);
+
+		/* Set operation size */
+		write_sysfs_val(t->devices[i].sysfs_entry, "size", t->size);
+
+		/* Set iterations */
+		write_sysfs_val(t->devices[i].sysfs_entry, "iteration_max",
+				t->iteration_max);
+
+		if (t->use_async) {
+			write_sysfs_val(t->devices[i].sysfs_entry,
+				"async", 1);
+			write_sysfs_val(t->devices[i].sysfs_entry,
+				"timeout", t->async_timeout);
+			write_sysfs_val(t->devices[i].sysfs_entry,
+				"outstanding_operations_max",
+				t->async_outstanding_operations);
+		} else
+			write_sysfs_val(t->devices[i].sysfs_entry,
+				"async", 0);
+	}
+}
+
+static int start(struct loopback_test *t)
+{
+	int i;
+
+	/* the test starts by writing test_id to the type file. */
+	for (i = 0; i < t->device_count; i++) {
+		if (!device_enabled(t, i))
+			continue;
+
+		write_sysfs_val(t->devices[i].sysfs_entry, "type", t->test_id);
+	}
+
+	return 0;
+}
+
+
+void loopback_run(struct loopback_test *t)
+{
+	int i;
+	int ret;
+
+	for (i = 0; dict[i].name != NULL; i++) {
+		if (strstr(dict[i].name, t->test_name))
+			t->test_id = dict[i].type;
+	}
+	if (!t->test_id) {
+		fprintf(stderr, "invalid test %s\n", t->test_name);
+		usage();
+		return;
+	}
+
+	prepare_devices(t);
+
+	ret = open_poll_files(t);
+	if (ret)
+		goto err;
+
+	start(t);
+
+	ret = wait_for_complete(t);
+	close_poll_files(t);
+	if (ret)
+		goto err;
+
+
+	get_results(t);
+
+	log_results(t);
+
+	return;
+
+err:
+	printf("Error running test\n");
+	return;
+}
+
+static int sanity_check(struct loopback_test *t)
+{
+	int i;
+
+	if (t->device_count == 0) {
+		fprintf(stderr, "No loopback devices found\n");
+		return -1;
+	}
+
+	for (i = 0; i < MAX_NUM_DEVICES; i++) {
+		if (!device_enabled(t, i))
+			continue;
+
+		if (t->mask && !strcmp(t->devices[i].name, "")) {
+			fprintf(stderr, "Bad device mask %x\n", (1 << i));
+			return -1;
+		}
+
+	}
+
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	int o, ret;
+	char *sysfs_prefix = "/sys/class/gb_loopback/";
+	char *debugfs_prefix = "/sys/kernel/debug/gb_loopback/";
+
+	memset(&t, 0, sizeof(t));
+
+	while ((o = getopt(argc, argv,
+			   "t:s:i:S:D:m:v::d::r::p::a::l::x::o:O:c:w:z::f::")) != -1) {
+		switch (o) {
+		case 't':
+			snprintf(t.test_name, MAX_STR_LEN, "%s", optarg);
+			break;
+		case 's':
+			t.size = atoi(optarg);
+			break;
+		case 'i':
+			t.iteration_max = atoi(optarg);
+			break;
+		case 'S':
+			snprintf(t.sysfs_prefix, MAX_SYSFS_PATH, "%s", optarg);
+			break;
+		case 'D':
+			snprintf(t.debugfs_prefix, MAX_SYSFS_PATH, "%s", optarg);
+			break;
+		case 'm':
+			t.mask = atol(optarg);
+			break;
+		case 'v':
+			t.verbose = 1;
+			break;
+		case 'd':
+			t.debug = 1;
+			break;
+		case 'r':
+			t.raw_data_dump = 1;
+			break;
+		case 'p':
+			t.porcelain = 1;
+			break;
+		case 'a':
+			t.aggregate_output = 1;
+			break;
+		case 'l':
+			t.list_devices = 1;
+			break;
+		case 'x':
+			t.use_async = 1;
+			break;
+		case 'o':
+			t.async_timeout = atoi(optarg);
+			break;
+		case 'O':
+			t.poll_timeout.tv_sec = atoi(optarg);
+			break;
+		case 'c':
+			t.async_outstanding_operations = atoi(optarg);
+			break;
+		case 'w':
+			t.us_wait = atoi(optarg);
+			break;
+		case 'z':
+			t.file_output = 1;
+			break;
+		case 'f':
+			t.stop_all = 1;
+			break;
+		default:
+			usage();
+			return -EINVAL;
+		}
+	}
+
+	if (!strcmp(t.sysfs_prefix, ""))
+		snprintf(t.sysfs_prefix, MAX_SYSFS_PATH, "%s", sysfs_prefix);
+
+	if (!strcmp(t.debugfs_prefix, ""))
+		snprintf(t.debugfs_prefix, MAX_SYSFS_PATH, "%s", debugfs_prefix);
+
+	ret = find_loopback_devices(&t);
+	if (ret)
+		return ret;
+	ret = sanity_check(&t);
+	if (ret)
+		return ret;
+
+	if (t.list_devices) {
+		show_loopback_devices(&t);
+		return 0;
+	}
+
+	if (t.test_name[0] == '\0' || t.iteration_max == 0)
+		usage();
+
+	if (t.async_timeout == 0)
+		t.async_timeout = DEFAULT_ASYNC_TIMEOUT;
+
+	loopback_run(&t);
+
+	return 0;
+}