// SPDX-License-Identifier: GPL-2.0 /* * Loopback bridge driver for the Greybus loopback module. * * Copyright 2014 Google Inc. * Copyright 2014 Linaro Ltd. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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; 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; ktime_t ts; int (*completion)(struct gb_loopback_async_operation *op_async); }; struct gb_loopback { struct gb_connection *connection; struct dentry *file; struct kfifo kfifo_lat; struct mutex mutex; struct task_struct *task; struct device *dev; wait_queue_head_t wq; wait_queue_head_t wq_completion; atomic_t outstanding_operations; /* Per connection stats */ ktime_t 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; u64 elapsed_nsecs; u32 apbridge_latency_ts; u32 gbphy_latency_ts; u32 send_count; }; static struct class loopback_class = { .name = "gb_loopback", }; 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 int 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 succeeded */ \ 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); 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) { do_div(elapsed_nsecs, NSEC_PER_USEC); return elapsed_nsecs; } 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(ktime_t ts, ktime_t te) { return __gb_loopback_calc_latency(ktime_to_ns(ts), ktime_to_ns(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; ktime_t ts, te; int ret; ts = ktime_get(); 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; } } te = ktime_get(); /* Calculate the total time the message took */ gb->elapsed_nsecs = gb_loopback_calc_latency(ts, te); out_put_operation: gb_operation_put(operation); return ret; } 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; ktime_t te; int result; te = ktime_get(); result = gb_operation_result(operation); op_async = gb_operation_get_data(operation); gb = op_async->gb; mutex_lock(&gb->mutex); if (!result && op_async->completion) result = op_async->completion(op_async); if (!result) { gb->elapsed_nsecs = gb_loopback_calc_latency(op_async->ts, te); } else { gb->error++; if (result == -ETIMEDOUT) gb->requests_timedout++; } gb->iteration_count++; gb_loopback_calculate_stats(gb, result); mutex_unlock(&gb->mutex); dev_dbg(&gb->connection->bundle->dev, "complete operation %d\n", operation->id); /* Wake up waiters */ atomic_dec(&op_async->gb->outstanding_operations); wake_up(&gb->wq_completion); /* Release resources */ gb_operation_put(operation); kfree(op_async); } 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; op_async = kzalloc(sizeof(*op_async), GFP_KERNEL); if (!op_async) return -ENOMEM; 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); gb_operation_set_data(operation, op_async); op_async->gb = gb; op_async->operation = operation; op_async->completion = completion; op_async->ts = ktime_get(); atomic_inc(&gb->outstanding_operations); ret = gb_operation_request_send(operation, gb_loopback_async_operation_callback, jiffies_to_msecs(gb->jiffy_timeout), GFP_KERNEL); if (ret) { atomic_dec(&gb->outstanding_operations); gb_operation_put(operation); kfree(op_async); } 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; gb->ts = ktime_set(0, 0); } 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; ktime_t te; if (!error) { gb->requests_completed++; gb_loopback_calculate_latency_stats(gb); } te = ktime_get(); 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()) break; /* Limit the maximum number of in-flight async operations */ gb_loopback_async_wait_to_send(gb); if (kthread_should_stop()) break; mutex_lock(&gb->mutex); /* Optionally terminate */ if (gb->send_count == gb->iteration_max) { mutex_unlock(&gb->mutex); /* Wait for synchronous and asynchronous completion */ gb_loopback_async_wait_all(gb); /* Mark complete unless user-space has poked us */ mutex_lock(&gb->mutex); if (gb->iteration_count == gb->iteration_max) { gb->type = 0; gb->send_count = 0; sysfs_notify(&gb->dev->kobj, NULL, "iteration_count"); dev_dbg(&bundle->dev, "load test complete\n"); } else { dev_dbg(&bundle->dev, "continuing on with new test set\n"); } mutex_unlock(&gb->mutex); continue; } size = gb->size; us_wait = gb->us_wait; type = gb->type; if (ktime_to_ns(gb->ts) == 0) gb->ts = ktime_get(); /* Else operations to perform */ if (gb->async) { if (type == GB_LOOPBACK_TYPE_PING) error = gb_loopback_async_ping(gb); else if (type == GB_LOOPBACK_TYPE_TRANSFER) error = gb_loopback_async_transfer(gb, size); else if (type == GB_LOOPBACK_TYPE_SINK) error = gb_loopback_async_sink(gb, size); if (error) { gb->error++; gb->iteration_count++; } } else { /* We are effectively single threaded here */ if (type == GB_LOOPBACK_TYPE_PING) error = gb_loopback_sync_ping(gb); else if (type == GB_LOOPBACK_TYPE_TRANSFER) error = gb_loopback_sync_transfer(gb, size); else if (type == GB_LOOPBACK_TYPE_SINK) error = gb_loopback_sync_sink(gb, size); if (error) gb->error++; gb->iteration_count++; gb_loopback_calculate_stats(gb, !!error); } gb->send_count++; mutex_unlock(&gb->mutex); if (us_wait) { if (us_wait < 20000) usleep_range(us_wait, us_wait + 100); else msleep(us_wait / 1000); } } gb_pm_runtime_put_autosuspend(bundle); return 0; } static int gb_loopback_dbgfs_latency_show_common(struct seq_file *s, struct kfifo *kfifo, struct mutex *mutex) { u32 latency; int retval; if (kfifo_len(kfifo) == 0) { retval = -EAGAIN; goto done; } mutex_lock(mutex); retval = kfifo_out(kfifo, &latency, sizeof(latency)); if (retval > 0) { seq_printf(s, "%u", latency); retval = 0; } mutex_unlock(mutex); done: return retval; } static int gb_loopback_dbgfs_latency_show(struct seq_file *s, void *unused) { struct gb_loopback *gb = s->private; return gb_loopback_dbgfs_latency_show_common(s, &gb->kfifo_lat, &gb->mutex); } DEFINE_SHOW_ATTRIBUTE(gb_loopback_dbgfs_latency); #define DEBUGFS_NAMELEN 32 static int gb_loopback_probe(struct gb_bundle *bundle, const struct greybus_bundle_id *id) { struct greybus_descriptor_cport *cport_desc; struct gb_connection *connection; struct gb_loopback *gb; struct device *dev; int retval; char name[DEBUGFS_NAMELEN]; unsigned long flags; if (bundle->num_cports != 1) return -ENODEV; cport_desc = &bundle->cport_desc[0]; if (cport_desc->protocol_id != GREYBUS_PROTOCOL_LOOPBACK) return -ENODEV; gb = kzalloc(sizeof(*gb), GFP_KERNEL); if (!gb) return -ENOMEM; connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id), gb_loopback_request_handler); if (IS_ERR(connection)) { retval = PTR_ERR(connection); goto out_kzalloc; } gb->connection = connection; greybus_set_drvdata(bundle, gb); init_waitqueue_head(&gb->wq); init_waitqueue_head(&gb->wq_completion); atomic_set(&gb->outstanding_operations, 0); gb_loopback_reset_stats(gb); /* Reported values to user-space for min/max timeouts */ gb->timeout_min = jiffies_to_usecs(GB_LOOPBACK_TIMEOUT_MIN); gb->timeout_max = jiffies_to_usecs(GB_LOOPBACK_TIMEOUT_MAX); if (!gb_dev.count) { /* Calculate maximum payload */ gb_dev.size_max = gb_operation_get_payload_size_max(connection); if (gb_dev.size_max <= sizeof(struct gb_loopback_transfer_request)) { retval = -EINVAL; goto out_connection_destroy; } gb_dev.size_max -= sizeof(struct gb_loopback_transfer_request); } /* Create per-connection sysfs and debugfs data-points */ snprintf(name, sizeof(name), "raw_latency_%s", dev_name(&connection->bundle->dev)); gb->file = debugfs_create_file(name, S_IFREG | 0444, gb_dev.root, gb, &gb_loopback_dbgfs_latency_fops); gb->id = ida_alloc(&loopback_ida, GFP_KERNEL); if (gb->id < 0) { retval = gb->id; goto out_debugfs_remove; } retval = gb_connection_enable(connection); if (retval) goto out_ida_remove; dev = device_create_with_groups(&loopback_class, &connection->bundle->dev, MKDEV(0, 0), gb, loopback_groups, "gb_loopback%d", gb->id); if (IS_ERR(dev)) { retval = PTR_ERR(dev); goto out_connection_disable; } gb->dev = dev; /* Allocate kfifo */ if (kfifo_alloc(&gb->kfifo_lat, kfifo_depth * sizeof(u32), GFP_KERNEL)) { retval = -ENOMEM; goto out_conn; } /* Fork worker thread */ mutex_init(&gb->mutex); gb->task = kthread_run(gb_loopback_fn, gb, "gb_loopback"); if (IS_ERR(gb->task)) { retval = PTR_ERR(gb->task); goto out_kfifo; } spin_lock_irqsave(&gb_dev.lock, flags); gb_dev.count++; spin_unlock_irqrestore(&gb_dev.lock, flags); gb_connection_latency_tag_enable(connection); gb_pm_runtime_put_autosuspend(bundle); return 0; out_kfifo: kfifo_free(&gb->kfifo_lat); out_conn: device_unregister(dev); out_connection_disable: gb_connection_disable(connection); out_ida_remove: ida_free(&loopback_ida, gb->id); out_debugfs_remove: debugfs_remove(gb->file); out_connection_destroy: gb_connection_destroy(connection); out_kzalloc: kfree(gb); return retval; } static void gb_loopback_disconnect(struct gb_bundle *bundle) { struct gb_loopback *gb = greybus_get_drvdata(bundle); unsigned long flags; int ret; ret = gb_pm_runtime_get_sync(bundle); if (ret) gb_pm_runtime_get_noresume(bundle); gb_connection_disable(gb->connection); if (!IS_ERR_OR_NULL(gb->task)) kthread_stop(gb->task); kfifo_free(&gb->kfifo_lat); gb_connection_latency_tag_disable(gb->connection); debugfs_remove(gb->file); /* * FIXME: gb_loopback_async_wait_all() is redundant now, as connection * is disabled at the beginning and so we can't have any more * incoming/outgoing requests. */ gb_loopback_async_wait_all(gb); spin_lock_irqsave(&gb_dev.lock, flags); gb_dev.count--; spin_unlock_irqrestore(&gb_dev.lock, flags); device_unregister(gb->dev); ida_free(&loopback_ida, gb->id); gb_connection_destroy(gb->connection); kfree(gb); } static const struct greybus_bundle_id gb_loopback_id_table[] = { { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_LOOPBACK) }, { } }; MODULE_DEVICE_TABLE(greybus, gb_loopback_id_table); static struct greybus_driver gb_loopback_driver = { .name = "loopback", .probe = gb_loopback_probe, .disconnect = gb_loopback_disconnect, .id_table = gb_loopback_id_table, }; static int loopback_init(void) { int retval; spin_lock_init(&gb_dev.lock); gb_dev.root = debugfs_create_dir("gb_loopback", NULL); retval = class_register(&loopback_class); if (retval) goto err; retval = greybus_register(&gb_loopback_driver); if (retval) goto err_unregister; return 0; err_unregister: class_unregister(&loopback_class); err: debugfs_remove_recursive(gb_dev.root); return retval; } module_init(loopback_init); static void __exit loopback_exit(void) { debugfs_remove_recursive(gb_dev.root); greybus_deregister(&gb_loopback_driver); class_unregister(&loopback_class); ida_destroy(&loopback_ida); } module_exit(loopback_exit); MODULE_LICENSE("GPL v2");