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loopback.c
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loopback.c
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/*
* Loopback bridge driver for the Greybus loopback module.
*
* Copyright 2014 Google Inc.
* Copyright 2014 Linaro Ltd.
*
* Released under the GPLv2 only.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/random.h>
#include <linux/sizes.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/kfifo.h>
#include <linux/debugfs.h>
#include <linux/list_sort.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/atomic.h>
#include <linux/pm_runtime.h>
#include <asm/div64.h>
#include "greybus.h"
#include "connection.h"
#define NSEC_PER_DAY 86400000000000ULL
struct gb_loopback_stats {
u32 min;
u32 max;
u64 sum;
u32 count;
};
struct gb_loopback_device {
struct dentry *root;
u32 count;
size_t size_max;
/* We need to take a lock in atomic context */
spinlock_t lock;
struct list_head list;
struct list_head list_op_async;
wait_queue_head_t wq;
};
static struct gb_loopback_device gb_dev;
struct gb_loopback_async_operation {
struct gb_loopback *gb;
struct gb_operation *operation;
struct timeval ts;
struct timer_list timer;
struct list_head entry;
struct work_struct work;
struct kref kref;
bool pending;
int (*completion)(struct gb_loopback_async_operation *op_async);
};
struct gb_loopback {
struct gb_connection *connection;
struct dentry *file;
struct kfifo kfifo_lat;
struct kfifo kfifo_ts;
struct mutex mutex;
struct task_struct *task;
struct list_head entry;
struct device *dev;
wait_queue_head_t wq;
wait_queue_head_t wq_completion;
atomic_t outstanding_operations;
/* Per connection stats */
struct timeval ts;
struct gb_loopback_stats latency;
struct gb_loopback_stats throughput;
struct gb_loopback_stats requests_per_second;
struct gb_loopback_stats apbridge_unipro_latency;
struct gb_loopback_stats gbphy_firmware_latency;
int type;
int async;
int id;
u32 size;
u32 iteration_max;
u32 iteration_count;
int us_wait;
u32 error;
u32 requests_completed;
u32 requests_timedout;
u32 timeout;
u32 jiffy_timeout;
u32 timeout_min;
u32 timeout_max;
u32 outstanding_operations_max;
u32 lbid;
u64 elapsed_nsecs;
u32 apbridge_latency_ts;
u32 gbphy_latency_ts;
u32 send_count;
};
static struct class loopback_class = {
.name = "gb_loopback",
.owner = THIS_MODULE,
};
static DEFINE_IDA(loopback_ida);
/* Min/max values in jiffies */
#define GB_LOOPBACK_TIMEOUT_MIN 1
#define GB_LOOPBACK_TIMEOUT_MAX 10000
#define GB_LOOPBACK_FIFO_DEFAULT 8192
static unsigned kfifo_depth = GB_LOOPBACK_FIFO_DEFAULT;
module_param(kfifo_depth, uint, 0444);
/* Maximum size of any one send data buffer we support */
#define MAX_PACKET_SIZE (PAGE_SIZE * 2)
#define GB_LOOPBACK_US_WAIT_MAX 1000000
/* interface sysfs attributes */
#define gb_loopback_ro_attr(field) \
static ssize_t field##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct gb_loopback *gb = dev_get_drvdata(dev); \
return sprintf(buf, "%u\n", gb->field); \
} \
static DEVICE_ATTR_RO(field)
#define gb_loopback_ro_stats_attr(name, field, type) \
static ssize_t name##_##field##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct gb_loopback *gb = dev_get_drvdata(dev); \
/* Report 0 for min and max if no transfer successed */ \
if (!gb->requests_completed) \
return sprintf(buf, "0\n"); \
return sprintf(buf, "%"#type"\n", gb->name.field); \
} \
static DEVICE_ATTR_RO(name##_##field)
#define gb_loopback_ro_avg_attr(name) \
static ssize_t name##_avg_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct gb_loopback_stats *stats; \
struct gb_loopback *gb; \
u64 avg, rem; \
u32 count; \
gb = dev_get_drvdata(dev); \
stats = &gb->name; \
count = stats->count ? stats->count : 1; \
avg = stats->sum + count / 2000000; /* round closest */ \
rem = do_div(avg, count); \
rem *= 1000000; \
do_div(rem, count); \
return sprintf(buf, "%llu.%06u\n", avg, (u32)rem); \
} \
static DEVICE_ATTR_RO(name##_avg)
#define gb_loopback_stats_attrs(field) \
gb_loopback_ro_stats_attr(field, min, u); \
gb_loopback_ro_stats_attr(field, max, u); \
gb_loopback_ro_avg_attr(field)
#define gb_loopback_attr(field, type) \
static ssize_t field##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct gb_loopback *gb = dev_get_drvdata(dev); \
return sprintf(buf, "%"#type"\n", gb->field); \
} \
static ssize_t field##_store(struct device *dev, \
struct device_attribute *attr, \
const char *buf, \
size_t len) \
{ \
int ret; \
struct gb_loopback *gb = dev_get_drvdata(dev); \
mutex_lock(&gb->mutex); \
ret = sscanf(buf, "%"#type, &gb->field); \
if (ret != 1) \
len = -EINVAL; \
else \
gb_loopback_check_attr(gb, bundle); \
mutex_unlock(&gb->mutex); \
return len; \
} \
static DEVICE_ATTR_RW(field)
#define gb_dev_loopback_ro_attr(field, conn) \
static ssize_t field##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct gb_loopback *gb = dev_get_drvdata(dev); \
return sprintf(buf, "%u\n", gb->field); \
} \
static DEVICE_ATTR_RO(field)
#define gb_dev_loopback_rw_attr(field, type) \
static ssize_t field##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct gb_loopback *gb = dev_get_drvdata(dev); \
return sprintf(buf, "%"#type"\n", gb->field); \
} \
static ssize_t field##_store(struct device *dev, \
struct device_attribute *attr, \
const char *buf, \
size_t len) \
{ \
int ret; \
struct gb_loopback *gb = dev_get_drvdata(dev); \
mutex_lock(&gb->mutex); \
ret = sscanf(buf, "%"#type, &gb->field); \
if (ret != 1) \
len = -EINVAL; \
else \
gb_loopback_check_attr(gb); \
mutex_unlock(&gb->mutex); \
return len; \
} \
static DEVICE_ATTR_RW(field)
static void gb_loopback_reset_stats(struct gb_loopback *gb);
static void gb_loopback_check_attr(struct gb_loopback *gb)
{
if (gb->us_wait > GB_LOOPBACK_US_WAIT_MAX)
gb->us_wait = GB_LOOPBACK_US_WAIT_MAX;
if (gb->size > gb_dev.size_max)
gb->size = gb_dev.size_max;
gb->requests_timedout = 0;
gb->requests_completed = 0;
gb->iteration_count = 0;
gb->send_count = 0;
gb->error = 0;
if (kfifo_depth < gb->iteration_max) {
dev_warn(gb->dev,
"cannot log bytes %u kfifo_depth %u\n",
gb->iteration_max, kfifo_depth);
}
kfifo_reset_out(&gb->kfifo_lat);
kfifo_reset_out(&gb->kfifo_ts);
switch (gb->type) {
case GB_LOOPBACK_TYPE_PING:
case GB_LOOPBACK_TYPE_TRANSFER:
case GB_LOOPBACK_TYPE_SINK:
gb->jiffy_timeout = usecs_to_jiffies(gb->timeout);
if (!gb->jiffy_timeout)
gb->jiffy_timeout = GB_LOOPBACK_TIMEOUT_MIN;
else if (gb->jiffy_timeout > GB_LOOPBACK_TIMEOUT_MAX)
gb->jiffy_timeout = GB_LOOPBACK_TIMEOUT_MAX;
gb_loopback_reset_stats(gb);
wake_up(&gb->wq);
break;
default:
gb->type = 0;
break;
}
}
/* Time to send and receive one message */
gb_loopback_stats_attrs(latency);
/* Number of requests sent per second on this cport */
gb_loopback_stats_attrs(requests_per_second);
/* Quantity of data sent and received on this cport */
gb_loopback_stats_attrs(throughput);
/* Latency across the UniPro link from APBridge's perspective */
gb_loopback_stats_attrs(apbridge_unipro_latency);
/* Firmware induced overhead in the GPBridge */
gb_loopback_stats_attrs(gbphy_firmware_latency);
/* Number of errors encountered during loop */
gb_loopback_ro_attr(error);
/* Number of requests successfully completed async */
gb_loopback_ro_attr(requests_completed);
/* Number of requests timed out async */
gb_loopback_ro_attr(requests_timedout);
/* Timeout minimum in useconds */
gb_loopback_ro_attr(timeout_min);
/* Timeout minimum in useconds */
gb_loopback_ro_attr(timeout_max);
/*
* Type of loopback message to send based on protocol type definitions
* 0 => Don't send message
* 2 => Send ping message continuously (message without payload)
* 3 => Send transfer message continuously (message with payload,
* payload returned in response)
* 4 => Send a sink message (message with payload, no payload in response)
*/
gb_dev_loopback_rw_attr(type, d);
/* Size of transfer message payload: 0-4096 bytes */
gb_dev_loopback_rw_attr(size, u);
/* Time to wait between two messages: 0-1000 ms */
gb_dev_loopback_rw_attr(us_wait, d);
/* Maximum iterations for a given operation: 1-(2^32-1), 0 implies infinite */
gb_dev_loopback_rw_attr(iteration_max, u);
/* The current index of the for (i = 0; i < iteration_max; i++) loop */
gb_dev_loopback_ro_attr(iteration_count, false);
/* A flag to indicate synchronous or asynchronous operations */
gb_dev_loopback_rw_attr(async, u);
/* Timeout of an individual asynchronous request */
gb_dev_loopback_rw_attr(timeout, u);
/* Maximum number of in-flight operations before back-off */
gb_dev_loopback_rw_attr(outstanding_operations_max, u);
static struct attribute *loopback_attrs[] = {
&dev_attr_latency_min.attr,
&dev_attr_latency_max.attr,
&dev_attr_latency_avg.attr,
&dev_attr_requests_per_second_min.attr,
&dev_attr_requests_per_second_max.attr,
&dev_attr_requests_per_second_avg.attr,
&dev_attr_throughput_min.attr,
&dev_attr_throughput_max.attr,
&dev_attr_throughput_avg.attr,
&dev_attr_apbridge_unipro_latency_min.attr,
&dev_attr_apbridge_unipro_latency_max.attr,
&dev_attr_apbridge_unipro_latency_avg.attr,
&dev_attr_gbphy_firmware_latency_min.attr,
&dev_attr_gbphy_firmware_latency_max.attr,
&dev_attr_gbphy_firmware_latency_avg.attr,
&dev_attr_type.attr,
&dev_attr_size.attr,
&dev_attr_us_wait.attr,
&dev_attr_iteration_count.attr,
&dev_attr_iteration_max.attr,
&dev_attr_async.attr,
&dev_attr_error.attr,
&dev_attr_requests_completed.attr,
&dev_attr_requests_timedout.attr,
&dev_attr_timeout.attr,
&dev_attr_outstanding_operations_max.attr,
&dev_attr_timeout_min.attr,
&dev_attr_timeout_max.attr,
NULL,
};
ATTRIBUTE_GROUPS(loopback);
static void gb_loopback_calculate_stats(struct gb_loopback *gb, bool error);
static u32 gb_loopback_nsec_to_usec_latency(u64 elapsed_nsecs)
{
u32 lat;
do_div(elapsed_nsecs, NSEC_PER_USEC);
lat = elapsed_nsecs;
return lat;
}
static u64 __gb_loopback_calc_latency(u64 t1, u64 t2)
{
if (t2 > t1)
return t2 - t1;
else
return NSEC_PER_DAY - t2 + t1;
}
static u64 gb_loopback_calc_latency(struct timeval *ts, struct timeval *te)
{
u64 t1, t2;
t1 = timeval_to_ns(ts);
t2 = timeval_to_ns(te);
return __gb_loopback_calc_latency(t1, t2);
}
static void gb_loopback_push_latency_ts(struct gb_loopback *gb,
struct timeval *ts, struct timeval *te)
{
kfifo_in(&gb->kfifo_ts, (unsigned char *)ts, sizeof(*ts));
kfifo_in(&gb->kfifo_ts, (unsigned char *)te, sizeof(*te));
}
static int gb_loopback_operation_sync(struct gb_loopback *gb, int type,
void *request, int request_size,
void *response, int response_size)
{
struct gb_operation *operation;
struct timeval ts, te;
int ret;
do_gettimeofday(&ts);
operation = gb_operation_create(gb->connection, type, request_size,
response_size, GFP_KERNEL);
if (!operation)
return -ENOMEM;
if (request_size)
memcpy(operation->request->payload, request, request_size);
ret = gb_operation_request_send_sync(operation);
if (ret) {
dev_err(&gb->connection->bundle->dev,
"synchronous operation failed: %d\n", ret);
goto out_put_operation;
} else {
if (response_size == operation->response->payload_size) {
memcpy(response, operation->response->payload,
response_size);
} else {
dev_err(&gb->connection->bundle->dev,
"response size %zu expected %d\n",
operation->response->payload_size,
response_size);
ret = -EINVAL;
goto out_put_operation;
}
}
do_gettimeofday(&te);
/* Calculate the total time the message took */
gb_loopback_push_latency_ts(gb, &ts, &te);
gb->elapsed_nsecs = gb_loopback_calc_latency(&ts, &te);
out_put_operation:
gb_operation_put(operation);
return ret;
}
static void __gb_loopback_async_operation_destroy(struct kref *kref)
{
struct gb_loopback_async_operation *op_async;
op_async = container_of(kref, struct gb_loopback_async_operation, kref);
list_del(&op_async->entry);
if (op_async->operation)
gb_operation_put(op_async->operation);
atomic_dec(&op_async->gb->outstanding_operations);
wake_up(&op_async->gb->wq_completion);
kfree(op_async);
}
static void gb_loopback_async_operation_get(struct gb_loopback_async_operation
*op_async)
{
kref_get(&op_async->kref);
}
static void gb_loopback_async_operation_put(struct gb_loopback_async_operation
*op_async)
{
unsigned long flags;
spin_lock_irqsave(&gb_dev.lock, flags);
kref_put(&op_async->kref, __gb_loopback_async_operation_destroy);
spin_unlock_irqrestore(&gb_dev.lock, flags);
}
static struct gb_loopback_async_operation *
gb_loopback_operation_find(u16 id)
{
struct gb_loopback_async_operation *op_async;
bool found = false;
unsigned long flags;
spin_lock_irqsave(&gb_dev.lock, flags);
list_for_each_entry(op_async, &gb_dev.list_op_async, entry) {
if (op_async->operation->id == id) {
gb_loopback_async_operation_get(op_async);
found = true;
break;
}
}
spin_unlock_irqrestore(&gb_dev.lock, flags);
return found ? op_async : NULL;
}
static void gb_loopback_async_wait_all(struct gb_loopback *gb)
{
wait_event(gb->wq_completion,
!atomic_read(&gb->outstanding_operations));
}
static void gb_loopback_async_operation_callback(struct gb_operation *operation)
{
struct gb_loopback_async_operation *op_async;
struct gb_loopback *gb;
struct timeval te;
bool err = false;
do_gettimeofday(&te);
op_async = gb_loopback_operation_find(operation->id);
if (!op_async)
return;
gb = op_async->gb;
mutex_lock(&gb->mutex);
if (!op_async->pending || gb_operation_result(operation)) {
err = true;
} else {
if (op_async->completion)
if (op_async->completion(op_async))
err = true;
}
if (!err) {
gb_loopback_push_latency_ts(gb, &op_async->ts, &te);
gb->elapsed_nsecs = gb_loopback_calc_latency(&op_async->ts,
&te);
}
if (op_async->pending) {
if (err)
gb->error++;
gb->iteration_count++;
op_async->pending = false;
del_timer_sync(&op_async->timer);
gb_loopback_async_operation_put(op_async);
gb_loopback_calculate_stats(gb, err);
}
mutex_unlock(&gb->mutex);
dev_dbg(&gb->connection->bundle->dev, "complete operation %d\n",
operation->id);
gb_loopback_async_operation_put(op_async);
}
static void gb_loopback_async_operation_work(struct work_struct *work)
{
struct gb_loopback *gb;
struct gb_operation *operation;
struct gb_loopback_async_operation *op_async;
op_async = container_of(work, struct gb_loopback_async_operation, work);
gb = op_async->gb;
operation = op_async->operation;
mutex_lock(&gb->mutex);
if (op_async->pending) {
gb->requests_timedout++;
gb->error++;
gb->iteration_count++;
op_async->pending = false;
gb_loopback_async_operation_put(op_async);
gb_loopback_calculate_stats(gb, true);
}
mutex_unlock(&gb->mutex);
dev_dbg(&gb->connection->bundle->dev, "timeout operation %d\n",
operation->id);
gb_operation_cancel(operation, -ETIMEDOUT);
gb_loopback_async_operation_put(op_async);
}
static void gb_loopback_async_operation_timeout(unsigned long data)
{
struct gb_loopback_async_operation *op_async;
u16 id = data;
op_async = gb_loopback_operation_find(id);
if (!op_async) {
pr_err("operation %d not found - time out ?\n", id);
return;
}
schedule_work(&op_async->work);
}
static int gb_loopback_async_operation(struct gb_loopback *gb, int type,
void *request, int request_size,
int response_size,
void *completion)
{
struct gb_loopback_async_operation *op_async;
struct gb_operation *operation;
int ret;
unsigned long flags;
op_async = kzalloc(sizeof(*op_async), GFP_KERNEL);
if (!op_async)
return -ENOMEM;
INIT_WORK(&op_async->work, gb_loopback_async_operation_work);
init_timer(&op_async->timer);
kref_init(&op_async->kref);
operation = gb_operation_create(gb->connection, type, request_size,
response_size, GFP_KERNEL);
if (!operation) {
kfree(op_async);
return -ENOMEM;
}
if (request_size)
memcpy(operation->request->payload, request, request_size);
op_async->gb = gb;
op_async->operation = operation;
op_async->completion = completion;
spin_lock_irqsave(&gb_dev.lock, flags);
list_add_tail(&op_async->entry, &gb_dev.list_op_async);
spin_unlock_irqrestore(&gb_dev.lock, flags);
do_gettimeofday(&op_async->ts);
op_async->pending = true;
atomic_inc(&gb->outstanding_operations);
mutex_lock(&gb->mutex);
ret = gb_operation_request_send(operation,
gb_loopback_async_operation_callback,
GFP_KERNEL);
if (ret)
goto error;
op_async->timer.function = gb_loopback_async_operation_timeout;
op_async->timer.expires = jiffies + gb->jiffy_timeout;
op_async->timer.data = (unsigned long)operation->id;
add_timer(&op_async->timer);
goto done;
error:
gb_loopback_async_operation_put(op_async);
done:
mutex_unlock(&gb->mutex);
return ret;
}
static int gb_loopback_sync_sink(struct gb_loopback *gb, u32 len)
{
struct gb_loopback_transfer_request *request;
int retval;
request = kmalloc(len + sizeof(*request), GFP_KERNEL);
if (!request)
return -ENOMEM;
request->len = cpu_to_le32(len);
retval = gb_loopback_operation_sync(gb, GB_LOOPBACK_TYPE_SINK,
request, len + sizeof(*request),
NULL, 0);
kfree(request);
return retval;
}
static int gb_loopback_sync_transfer(struct gb_loopback *gb, u32 len)
{
struct gb_loopback_transfer_request *request;
struct gb_loopback_transfer_response *response;
int retval;
gb->apbridge_latency_ts = 0;
gb->gbphy_latency_ts = 0;
request = kmalloc(len + sizeof(*request), GFP_KERNEL);
if (!request)
return -ENOMEM;
response = kmalloc(len + sizeof(*response), GFP_KERNEL);
if (!response) {
kfree(request);
return -ENOMEM;
}
memset(request->data, 0x5A, len);
request->len = cpu_to_le32(len);
retval = gb_loopback_operation_sync(gb, GB_LOOPBACK_TYPE_TRANSFER,
request, len + sizeof(*request),
response, len + sizeof(*response));
if (retval)
goto gb_error;
if (memcmp(request->data, response->data, len)) {
dev_err(&gb->connection->bundle->dev,
"Loopback Data doesn't match\n");
retval = -EREMOTEIO;
}
gb->apbridge_latency_ts = (u32)__le32_to_cpu(response->reserved0);
gb->gbphy_latency_ts = (u32)__le32_to_cpu(response->reserved1);
gb_error:
kfree(request);
kfree(response);
return retval;
}
static int gb_loopback_sync_ping(struct gb_loopback *gb)
{
return gb_loopback_operation_sync(gb, GB_LOOPBACK_TYPE_PING,
NULL, 0, NULL, 0);
}
static int gb_loopback_async_sink(struct gb_loopback *gb, u32 len)
{
struct gb_loopback_transfer_request *request;
int retval;
request = kmalloc(len + sizeof(*request), GFP_KERNEL);
if (!request)
return -ENOMEM;
request->len = cpu_to_le32(len);
retval = gb_loopback_async_operation(gb, GB_LOOPBACK_TYPE_SINK,
request, len + sizeof(*request),
0, NULL);
kfree(request);
return retval;
}
static int gb_loopback_async_transfer_complete(
struct gb_loopback_async_operation *op_async)
{
struct gb_loopback *gb;
struct gb_operation *operation;
struct gb_loopback_transfer_request *request;
struct gb_loopback_transfer_response *response;
size_t len;
int retval = 0;
gb = op_async->gb;
operation = op_async->operation;
request = operation->request->payload;
response = operation->response->payload;
len = le32_to_cpu(request->len);
if (memcmp(request->data, response->data, len)) {
dev_err(&gb->connection->bundle->dev,
"Loopback Data doesn't match operation id %d\n",
operation->id);
retval = -EREMOTEIO;
} else {
gb->apbridge_latency_ts =
(u32)__le32_to_cpu(response->reserved0);
gb->gbphy_latency_ts =
(u32)__le32_to_cpu(response->reserved1);
}
return retval;
}
static int gb_loopback_async_transfer(struct gb_loopback *gb, u32 len)
{
struct gb_loopback_transfer_request *request;
int retval, response_len;
request = kmalloc(len + sizeof(*request), GFP_KERNEL);
if (!request)
return -ENOMEM;
memset(request->data, 0x5A, len);
request->len = cpu_to_le32(len);
response_len = sizeof(struct gb_loopback_transfer_response);
retval = gb_loopback_async_operation(gb, GB_LOOPBACK_TYPE_TRANSFER,
request, len + sizeof(*request),
len + response_len,
gb_loopback_async_transfer_complete);
if (retval)
goto gb_error;
gb_error:
kfree(request);
return retval;
}
static int gb_loopback_async_ping(struct gb_loopback *gb)
{
return gb_loopback_async_operation(gb, GB_LOOPBACK_TYPE_PING,
NULL, 0, 0, NULL);
}
static int gb_loopback_request_handler(struct gb_operation *operation)
{
struct gb_connection *connection = operation->connection;
struct gb_loopback_transfer_request *request;
struct gb_loopback_transfer_response *response;
struct device *dev = &connection->bundle->dev;
size_t len;
/* By convention, the AP initiates the version operation */
switch (operation->type) {
case GB_LOOPBACK_TYPE_PING:
case GB_LOOPBACK_TYPE_SINK:
return 0;
case GB_LOOPBACK_TYPE_TRANSFER:
if (operation->request->payload_size < sizeof(*request)) {
dev_err(dev, "transfer request too small (%zu < %zu)\n",
operation->request->payload_size,
sizeof(*request));
return -EINVAL; /* -EMSGSIZE */
}
request = operation->request->payload;
len = le32_to_cpu(request->len);
if (len > gb_dev.size_max) {
dev_err(dev, "transfer request too large (%zu > %zu)\n",
len, gb_dev.size_max);
return -EINVAL;
}
if (!gb_operation_response_alloc(operation,
len + sizeof(*response), GFP_KERNEL)) {
dev_err(dev, "error allocating response\n");
return -ENOMEM;
}
response = operation->response->payload;
response->len = cpu_to_le32(len);
if (len)
memcpy(response->data, request->data, len);
return 0;
default:
dev_err(dev, "unsupported request: %u\n", operation->type);
return -EINVAL;
}
}
static void gb_loopback_reset_stats(struct gb_loopback *gb)
{
struct gb_loopback_stats reset = {
.min = U32_MAX,
};
/* Reset per-connection stats */
memcpy(&gb->latency, &reset,
sizeof(struct gb_loopback_stats));
memcpy(&gb->throughput, &reset,
sizeof(struct gb_loopback_stats));
memcpy(&gb->requests_per_second, &reset,
sizeof(struct gb_loopback_stats));
memcpy(&gb->apbridge_unipro_latency, &reset,
sizeof(struct gb_loopback_stats));
memcpy(&gb->gbphy_firmware_latency, &reset,
sizeof(struct gb_loopback_stats));
/* Should be initialized at least once per transaction set */
gb->apbridge_latency_ts = 0;
gb->gbphy_latency_ts = 0;
memset(&gb->ts, 0, sizeof(struct timeval));
}
static void gb_loopback_update_stats(struct gb_loopback_stats *stats, u32 val)
{
if (stats->min > val)
stats->min = val;
if (stats->max < val)
stats->max = val;
stats->sum += val;
stats->count++;
}
static void gb_loopback_update_stats_window(struct gb_loopback_stats *stats,
u64 val, u32 count)
{
stats->sum += val;
stats->count += count;
do_div(val, count);
if (stats->min > val)
stats->min = val;
if (stats->max < val)
stats->max = val;
}
static void gb_loopback_requests_update(struct gb_loopback *gb, u32 latency)
{
u64 req = gb->requests_completed * USEC_PER_SEC;
gb_loopback_update_stats_window(&gb->requests_per_second, req, latency);
}
static void gb_loopback_throughput_update(struct gb_loopback *gb, u32 latency)
{
u64 aggregate_size = sizeof(struct gb_operation_msg_hdr) * 2;
switch (gb->type) {
case GB_LOOPBACK_TYPE_PING:
break;
case GB_LOOPBACK_TYPE_SINK:
aggregate_size += sizeof(struct gb_loopback_transfer_request) +
gb->size;
break;
case GB_LOOPBACK_TYPE_TRANSFER:
aggregate_size += sizeof(struct gb_loopback_transfer_request) +
sizeof(struct gb_loopback_transfer_response) +
gb->size * 2;
break;
default:
return;
}
aggregate_size *= gb->requests_completed;
aggregate_size *= USEC_PER_SEC;
gb_loopback_update_stats_window(&gb->throughput, aggregate_size,
latency);
}
static void gb_loopback_calculate_latency_stats(struct gb_loopback *gb)
{
u32 lat;
/* Express latency in terms of microseconds */
lat = gb_loopback_nsec_to_usec_latency(gb->elapsed_nsecs);
/* Log latency stastic */
gb_loopback_update_stats(&gb->latency, lat);
/* Raw latency log on a per thread basis */
kfifo_in(&gb->kfifo_lat, (unsigned char *)&lat, sizeof(lat));
/* Log the firmware supplied latency values */
gb_loopback_update_stats(&gb->apbridge_unipro_latency,
gb->apbridge_latency_ts);
gb_loopback_update_stats(&gb->gbphy_firmware_latency,
gb->gbphy_latency_ts);
}
static void gb_loopback_calculate_stats(struct gb_loopback *gb, bool error)
{
u64 nlat;
u32 lat;
struct timeval te;
if (!error) {
gb->requests_completed++;
gb_loopback_calculate_latency_stats(gb);
}
do_gettimeofday(&te);
nlat = gb_loopback_calc_latency(&gb->ts, &te);
if (nlat >= NSEC_PER_SEC || gb->iteration_count == gb->iteration_max) {
lat = gb_loopback_nsec_to_usec_latency(nlat);
gb_loopback_throughput_update(gb, lat);
gb_loopback_requests_update(gb, lat);
if (gb->iteration_count != gb->iteration_max) {
gb->ts = te;
gb->requests_completed = 0;
}
}
}
static void gb_loopback_async_wait_to_send(struct gb_loopback *gb)
{
if (!(gb->async && gb->outstanding_operations_max))
return;
wait_event_interruptible(gb->wq_completion,
(atomic_read(&gb->outstanding_operations) <
gb->outstanding_operations_max) ||
kthread_should_stop());
}
static int gb_loopback_fn(void *data)
{
int error = 0;
int us_wait = 0;
int type;
int ret;
u32 size;
struct gb_loopback *gb = data;
struct gb_bundle *bundle = gb->connection->bundle;
ret = gb_pm_runtime_get_sync(bundle);
if (ret)
return ret;
while (1) {
if (!gb->type) {
gb_pm_runtime_put_autosuspend(bundle);
wait_event_interruptible(gb->wq, gb->type ||
kthread_should_stop());
ret = gb_pm_runtime_get_sync(bundle);
if (ret)
return ret;
}
if (kthread_should_stop())