From 12927835d21127d7e528b9ed56fc334ac96db985 Mon Sep 17 00:00:00 2001 From: Bryan O'Donoghue Date: Mon, 7 Dec 2015 01:59:06 +0000 Subject: [PATCH] greybus: loopback: Add asynchronous bi-directional support A particular ask from the firmware people for some time now has been the ability to drive multiple outstanding bi-directional operations from loopback to loopback Interfaces. This patch implments that change. The approach taken is to make a call to gb_operation_send() and have loopback capture the completion callback itself, with a parallel timer to timeout completion callbacks that take too long. The calling thread will issue each gb_operation_send() as fast as it can within the constraints of thread-safety. In order to support this addition the following new sysfs entries are created on a per-connection basis. - async Zero indicates loopback should use the traditional synchronous model i.e. gb_operation_request_send_sync(). Non-zero indicates loopback should use the new asynchronous model i.e. gb_operation_send() - requests_completed This value indicates the number of requests successfully completed. - requests_timedout This value indicates the number of requests which timed out. - timeout The number of microseconds to give an individual asynchronous request before timing that request out. - timeout_min Read-only attribute informs user-space of the minimum allowed timeout. - timeout_max Read-only attribute informs user-space of the maximum allowed timeout. Note requests_completed + requests_timedout should always equal iteration_max, once iteration_count == iteration_max. Also, at this time we support either synchronous or asynchronous operations in one set of transactions. Signed-off-by: Bryan O'Donoghue Signed-off-by: Greg Kroah-Hartman --- drivers/staging/greybus/loopback.c | 384 +++++++++++++++++++++++++++-- 1 file changed, 367 insertions(+), 17 deletions(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index b65e3e591105..392f9854ff56 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -20,6 +20,7 @@ #include #include #include +#include #include @@ -43,10 +44,24 @@ struct gb_loopback_device { /* 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; @@ -66,18 +81,29 @@ struct gb_loopback { struct gb_loopback_stats gpbridge_firmware_latency; int type; + int async; u32 mask; u32 size; u32 iteration_max; u32 iteration_count; int ms_wait; u32 error; + u32 requests_completed; + u32 requests_timedout; + u32 timeout; + u32 jiffy_timeout; + u32 timeout_min; + u32 timeout_max; u32 lbid; u64 elapsed_nsecs; u32 apbridge_latency_ts; u32 gpbridge_latency_ts; }; +/* 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; @@ -215,6 +241,8 @@ static void gb_loopback_check_attr(struct gb_loopback *gb, gb->ms_wait = GB_LOOPBACK_MS_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->error = 0; @@ -230,6 +258,11 @@ static void gb_loopback_check_attr(struct gb_loopback *gb, 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; @@ -252,6 +285,14 @@ gb_loopback_stats_attrs(gpbridge_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 @@ -270,8 +311,12 @@ gb_dev_loopback_rw_attr(ms_wait, d); 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 bit-mask of destination connecitons to include in the test run */ +/* A bit-mask of destination connections to include in the test run */ gb_dev_loopback_rw_attr(mask, u); +/* 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); static struct attribute *loopback_attrs[] = { &dev_attr_latency_min.attr, @@ -295,11 +340,19 @@ static struct attribute *loopback_attrs[] = { &dev_attr_iteration_count.attr, &dev_attr_iteration_max.attr, &dev_attr_mask.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_timeout_min.attr, + &dev_attr_timeout_max.attr, NULL, }; ATTRIBUTE_GROUPS(loopback); +static void gb_loopback_calculate_stats(struct gb_loopback *gb); + static u32 gb_loopback_nsec_to_usec_latency(u64 elapsed_nsecs) { u32 lat; @@ -381,7 +434,200 @@ error: return ret; } -static int gb_loopback_sink(struct gb_loopback *gb, u32 len) +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); + 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_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->error++; + } else { + gb->requests_completed++; + gb_loopback_push_latency_ts(gb, &op_async->ts, &te); + gb->elapsed_nsecs = gb_loopback_calc_latency(&op_async->ts, + &te); + gb_loopback_calculate_stats(gb); + } + + if (op_async->pending) { + gb->iteration_count++; + op_async->pending = false; + del_timer_sync(&op_async->timer); + gb_loopback_async_operation_put(op_async); + } + 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); + if (!op_async) + return; + + 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); + } + 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) { + ret = -ENOMEM; + goto error; + } + + 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; + 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); + + return ret; +error: + gb_loopback_async_operation_put(op_async); + return ret; +} + +static int gb_loopback_sync_sink(struct gb_loopback *gb, u32 len) { struct gb_loopback_transfer_request *request; int retval; @@ -398,7 +644,7 @@ static int gb_loopback_sink(struct gb_loopback *gb, u32 len) return retval; } -static int gb_loopback_transfer(struct gb_loopback *gb, u32 len) +static int gb_loopback_sync_transfer(struct gb_loopback *gb, u32 len) { struct gb_loopback_transfer_request *request; struct gb_loopback_transfer_response *response; @@ -440,12 +686,91 @@ gb_error: return retval; } -static int gb_loopback_ping(struct gb_loopback *gb) +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->gpbridge_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_recv(u8 type, struct gb_operation *operation) { struct gb_connection *connection = operation->connection; @@ -512,6 +837,10 @@ static void gb_loopback_reset_stats(struct gb_loopback *gb) memcpy(&gb->gpbridge_firmware_latency, &reset, sizeof(struct gb_loopback_stats)); + /* Set values to report min/max timeout to user-space */ + gb->timeout_min = jiffies_to_usecs(GB_LOOPBACK_TIMEOUT_MIN); + gb->timeout_max = jiffies_to_usecs(GB_LOOPBACK_TIMEOUT_MAX); + /* Reset aggregate stats */ memcpy(&gb->latency, &reset, sizeof(struct gb_loopback_stats)); memcpy(&gb->throughput, &reset, sizeof(struct gb_loopback_stats)); @@ -599,23 +928,25 @@ static int gb_loopback_fn(void *data) int ms_wait = 0; int type; u32 size; + u32 send_count = 0; struct gb_loopback *gb = data; while (1) { if (!gb->type) wait_event_interruptible(gb->wq, gb->type || kthread_should_stop()); + if (kthread_should_stop()) break; mutex_lock(&gb->mutex); - sysfs_notify(&gb->connection->bundle->dev.kobj, NULL, "iteration_count"); /* Optionally terminate */ - if (gb->iteration_count == gb->iteration_max) { + if (send_count == gb->iteration_max) { gb->type = 0; + send_count = 0; mutex_unlock(&gb->mutex); continue; } @@ -625,19 +956,33 @@ static int gb_loopback_fn(void *data) mutex_unlock(&gb->mutex); /* Else operations to perform */ - if (type == GB_LOOPBACK_TYPE_PING) - error = gb_loopback_ping(gb); - else if (type == GB_LOOPBACK_TYPE_TRANSFER) - error = gb_loopback_transfer(gb, size); - else if (type == GB_LOOPBACK_TYPE_SINK) - error = gb_loopback_sink(gb, size); + if (gb->async) { + if (type == GB_LOOPBACK_TYPE_PING) { + error = gb_loopback_async_ping(gb); + gb_loopback_calculate_stats(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_loopback_calculate_stats(gb); - gb->iteration_count++; + if (error) + gb->error++; + } 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); + } + send_count++; if (ms_wait) msleep(ms_wait); } @@ -742,6 +1087,10 @@ static int gb_loopback_connection_init(struct gb_connection *connection) init_waitqueue_head(&gb->wq); 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); @@ -847,6 +1196,7 @@ static int loopback_init(void) int retval; INIT_LIST_HEAD(&gb_dev.list); + INIT_LIST_HEAD(&gb_dev.list_op_async); spin_lock_init(&gb_dev.lock); gb_dev.root = debugfs_create_dir("gb_loopback", NULL);