![Johan Hovold](/assets/img/avatar_default.png)
Add a struct timer_list to struct gb_operation and use that to implement generic operation timeouts. This simplifies the synchronous operation handling somewhat while also providing a generic timeout mechanism that drivers can use for asynchronous operations. Signed-off-by: Johan Hovold <johan@kernel.org> Acked-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1262 lines
35 KiB
C
1262 lines
35 KiB
C
/*
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* Greybus operations
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*
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* Copyright 2014-2015 Google Inc.
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* Copyright 2014-2015 Linaro Ltd.
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*
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* Released under the GPLv2 only.
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <linux/workqueue.h>
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#include "greybus.h"
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#include "greybus_trace.h"
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static struct kmem_cache *gb_operation_cache;
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static struct kmem_cache *gb_message_cache;
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/* Workqueue to handle Greybus operation completions. */
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static struct workqueue_struct *gb_operation_completion_wq;
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/* Wait queue for synchronous cancellations. */
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static DECLARE_WAIT_QUEUE_HEAD(gb_operation_cancellation_queue);
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/*
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* Protects updates to operation->errno.
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*/
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static DEFINE_SPINLOCK(gb_operations_lock);
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static int gb_operation_response_send(struct gb_operation *operation,
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int errno);
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/*
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* Increment operation active count and add to connection list unless the
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* connection is going away.
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*
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* Caller holds operation reference.
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*/
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static int gb_operation_get_active(struct gb_operation *operation)
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{
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struct gb_connection *connection = operation->connection;
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unsigned long flags;
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spin_lock_irqsave(&connection->lock, flags);
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switch (connection->state) {
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case GB_CONNECTION_STATE_ENABLED:
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break;
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case GB_CONNECTION_STATE_ENABLED_TX:
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if (gb_operation_is_incoming(operation))
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goto err_unlock;
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break;
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case GB_CONNECTION_STATE_DISCONNECTING:
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if (!gb_operation_is_core(operation))
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goto err_unlock;
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break;
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default:
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goto err_unlock;
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}
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if (operation->active++ == 0)
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list_add_tail(&operation->links, &connection->operations);
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trace_gb_operation_get_active(operation);
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spin_unlock_irqrestore(&connection->lock, flags);
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return 0;
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err_unlock:
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spin_unlock_irqrestore(&connection->lock, flags);
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return -ENOTCONN;
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}
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/* Caller holds operation reference. */
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static void gb_operation_put_active(struct gb_operation *operation)
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{
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struct gb_connection *connection = operation->connection;
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unsigned long flags;
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spin_lock_irqsave(&connection->lock, flags);
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trace_gb_operation_put_active(operation);
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if (--operation->active == 0) {
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list_del(&operation->links);
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if (atomic_read(&operation->waiters))
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wake_up(&gb_operation_cancellation_queue);
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}
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spin_unlock_irqrestore(&connection->lock, flags);
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}
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static bool gb_operation_is_active(struct gb_operation *operation)
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{
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struct gb_connection *connection = operation->connection;
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unsigned long flags;
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bool ret;
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spin_lock_irqsave(&connection->lock, flags);
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ret = operation->active;
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spin_unlock_irqrestore(&connection->lock, flags);
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return ret;
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}
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/*
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* Set an operation's result.
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*
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* Initially an outgoing operation's errno value is -EBADR.
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* If no error occurs before sending the request message the only
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* valid value operation->errno can be set to is -EINPROGRESS,
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* indicating the request has been (or rather is about to be) sent.
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* At that point nobody should be looking at the result until the
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* response arrives.
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*
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* The first time the result gets set after the request has been
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* sent, that result "sticks." That is, if two concurrent threads
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* race to set the result, the first one wins. The return value
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* tells the caller whether its result was recorded; if not the
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* caller has nothing more to do.
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*
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* The result value -EILSEQ is reserved to signal an implementation
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* error; if it's ever observed, the code performing the request has
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* done something fundamentally wrong. It is an error to try to set
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* the result to -EBADR, and attempts to do so result in a warning,
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* and -EILSEQ is used instead. Similarly, the only valid result
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* value to set for an operation in initial state is -EINPROGRESS.
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* Attempts to do otherwise will also record a (successful) -EILSEQ
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* operation result.
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*/
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static bool gb_operation_result_set(struct gb_operation *operation, int result)
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{
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unsigned long flags;
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int prev;
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if (result == -EINPROGRESS) {
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/*
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* -EINPROGRESS is used to indicate the request is
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* in flight. It should be the first result value
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* set after the initial -EBADR. Issue a warning
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* and record an implementation error if it's
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* set at any other time.
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*/
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spin_lock_irqsave(&gb_operations_lock, flags);
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prev = operation->errno;
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if (prev == -EBADR)
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operation->errno = result;
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else
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operation->errno = -EILSEQ;
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spin_unlock_irqrestore(&gb_operations_lock, flags);
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WARN_ON(prev != -EBADR);
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return true;
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}
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/*
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* The first result value set after a request has been sent
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* will be the final result of the operation. Subsequent
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* attempts to set the result are ignored.
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*
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* Note that -EBADR is a reserved "initial state" result
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* value. Attempts to set this value result in a warning,
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* and the result code is set to -EILSEQ instead.
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*/
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if (WARN_ON(result == -EBADR))
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result = -EILSEQ; /* Nobody should be setting -EBADR */
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spin_lock_irqsave(&gb_operations_lock, flags);
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prev = operation->errno;
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if (prev == -EINPROGRESS)
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operation->errno = result; /* First and final result */
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spin_unlock_irqrestore(&gb_operations_lock, flags);
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return prev == -EINPROGRESS;
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}
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int gb_operation_result(struct gb_operation *operation)
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{
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int result = operation->errno;
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WARN_ON(result == -EBADR);
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WARN_ON(result == -EINPROGRESS);
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return result;
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}
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EXPORT_SYMBOL_GPL(gb_operation_result);
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/*
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* Looks up an outgoing operation on a connection and returns a refcounted
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* pointer if found, or NULL otherwise.
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*/
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static struct gb_operation *
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gb_operation_find_outgoing(struct gb_connection *connection, u16 operation_id)
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{
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struct gb_operation *operation;
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unsigned long flags;
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bool found = false;
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spin_lock_irqsave(&connection->lock, flags);
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list_for_each_entry(operation, &connection->operations, links)
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if (operation->id == operation_id &&
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!gb_operation_is_incoming(operation)) {
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gb_operation_get(operation);
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found = true;
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break;
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}
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spin_unlock_irqrestore(&connection->lock, flags);
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return found ? operation : NULL;
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}
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static int gb_message_send(struct gb_message *message, gfp_t gfp)
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{
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struct gb_connection *connection = message->operation->connection;
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trace_gb_message_send(message);
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return connection->hd->driver->message_send(connection->hd,
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connection->hd_cport_id,
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message,
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gfp);
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}
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/*
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* Cancel a message we have passed to the host device layer to be sent.
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*/
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static void gb_message_cancel(struct gb_message *message)
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{
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struct gb_host_device *hd = message->operation->connection->hd;
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hd->driver->message_cancel(message);
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}
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static void gb_operation_request_handle(struct gb_operation *operation)
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{
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struct gb_connection *connection = operation->connection;
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int status;
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int ret;
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if (connection->handler) {
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status = connection->handler(operation);
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} else {
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dev_err(&connection->hd->dev,
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"%s: unexpected incoming request of type 0x%02x\n",
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connection->name, operation->type);
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status = -EPROTONOSUPPORT;
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}
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ret = gb_operation_response_send(operation, status);
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if (ret) {
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dev_err(&connection->hd->dev,
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"%s: failed to send response %d for type 0x%02x: %d\n",
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connection->name, status, operation->type, ret);
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return;
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}
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}
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/*
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* Process operation work.
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*
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* For incoming requests, call the protocol request handler. The operation
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* result should be -EINPROGRESS at this point.
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*
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* For outgoing requests, the operation result value should have
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* been set before queueing this. The operation callback function
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* allows the original requester to know the request has completed
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* and its result is available.
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*/
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static void gb_operation_work(struct work_struct *work)
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{
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struct gb_operation *operation;
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int ret;
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operation = container_of(work, struct gb_operation, work);
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if (gb_operation_is_incoming(operation)) {
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gb_operation_request_handle(operation);
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} else {
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ret = del_timer_sync(&operation->timer);
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if (!ret) {
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/* Cancel request message if scheduled by timeout. */
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if (gb_operation_result(operation) == -ETIMEDOUT)
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gb_message_cancel(operation->request);
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}
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operation->callback(operation);
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}
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gb_operation_put_active(operation);
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gb_operation_put(operation);
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}
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static void gb_operation_timeout(unsigned long arg)
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{
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struct gb_operation *operation = (void *)arg;
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if (gb_operation_result_set(operation, -ETIMEDOUT)) {
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/*
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* A stuck request message will be cancelled from the
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* workqueue.
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*/
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queue_work(gb_operation_completion_wq, &operation->work);
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}
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}
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static void gb_operation_message_init(struct gb_host_device *hd,
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struct gb_message *message, u16 operation_id,
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size_t payload_size, u8 type)
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{
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struct gb_operation_msg_hdr *header;
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header = message->buffer;
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message->header = header;
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message->payload = payload_size ? header + 1 : NULL;
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message->payload_size = payload_size;
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/*
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* The type supplied for incoming message buffers will be
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* GB_REQUEST_TYPE_INVALID. Such buffers will be overwritten by
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* arriving data so there's no need to initialize the message header.
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*/
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if (type != GB_REQUEST_TYPE_INVALID) {
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u16 message_size = (u16)(sizeof(*header) + payload_size);
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/*
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* For a request, the operation id gets filled in
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* when the message is sent. For a response, it
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* will be copied from the request by the caller.
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*
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* The result field in a request message must be
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* zero. It will be set just prior to sending for
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* a response.
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*/
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header->size = cpu_to_le16(message_size);
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header->operation_id = 0;
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header->type = type;
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header->result = 0;
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}
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}
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/*
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* Allocate a message to be used for an operation request or response.
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* Both types of message contain a common header. The request message
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* for an outgoing operation is outbound, as is the response message
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* for an incoming operation. The message header for an outbound
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* message is partially initialized here.
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*
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* The headers for inbound messages don't need to be initialized;
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* they'll be filled in by arriving data.
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*
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* Our message buffers have the following layout:
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* message header \_ these combined are
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* message payload / the message size
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*/
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static struct gb_message *
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gb_operation_message_alloc(struct gb_host_device *hd, u8 type,
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size_t payload_size, gfp_t gfp_flags)
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{
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struct gb_message *message;
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struct gb_operation_msg_hdr *header;
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size_t message_size = payload_size + sizeof(*header);
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if (message_size > hd->buffer_size_max) {
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dev_warn(&hd->dev, "requested message size too big (%zu > %zu)\n",
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message_size, hd->buffer_size_max);
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return NULL;
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}
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/* Allocate the message structure and buffer. */
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message = kmem_cache_zalloc(gb_message_cache, gfp_flags);
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if (!message)
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return NULL;
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message->buffer = kzalloc(message_size, gfp_flags);
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if (!message->buffer)
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goto err_free_message;
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/* Initialize the message. Operation id is filled in later. */
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gb_operation_message_init(hd, message, 0, payload_size, type);
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return message;
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err_free_message:
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kmem_cache_free(gb_message_cache, message);
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return NULL;
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}
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static void gb_operation_message_free(struct gb_message *message)
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{
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kfree(message->buffer);
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kmem_cache_free(gb_message_cache, message);
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}
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/*
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* Map an enum gb_operation_status value (which is represented in a
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* message as a single byte) to an appropriate Linux negative errno.
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*/
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static int gb_operation_status_map(u8 status)
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{
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switch (status) {
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case GB_OP_SUCCESS:
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return 0;
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case GB_OP_INTERRUPTED:
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return -EINTR;
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case GB_OP_TIMEOUT:
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return -ETIMEDOUT;
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case GB_OP_NO_MEMORY:
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return -ENOMEM;
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case GB_OP_PROTOCOL_BAD:
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return -EPROTONOSUPPORT;
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case GB_OP_OVERFLOW:
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return -EMSGSIZE;
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case GB_OP_INVALID:
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return -EINVAL;
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case GB_OP_RETRY:
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return -EAGAIN;
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case GB_OP_NONEXISTENT:
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return -ENODEV;
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case GB_OP_MALFUNCTION:
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return -EILSEQ;
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case GB_OP_UNKNOWN_ERROR:
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default:
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return -EIO;
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}
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}
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/*
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* Map a Linux errno value (from operation->errno) into the value
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* that should represent it in a response message status sent
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* over the wire. Returns an enum gb_operation_status value (which
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* is represented in a message as a single byte).
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*/
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static u8 gb_operation_errno_map(int errno)
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{
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switch (errno) {
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case 0:
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return GB_OP_SUCCESS;
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case -EINTR:
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return GB_OP_INTERRUPTED;
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case -ETIMEDOUT:
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return GB_OP_TIMEOUT;
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case -ENOMEM:
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return GB_OP_NO_MEMORY;
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case -EPROTONOSUPPORT:
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return GB_OP_PROTOCOL_BAD;
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case -EMSGSIZE:
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return GB_OP_OVERFLOW; /* Could be underflow too */
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case -EINVAL:
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return GB_OP_INVALID;
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case -EAGAIN:
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return GB_OP_RETRY;
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case -EILSEQ:
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return GB_OP_MALFUNCTION;
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case -ENODEV:
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return GB_OP_NONEXISTENT;
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case -EIO:
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default:
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return GB_OP_UNKNOWN_ERROR;
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}
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}
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bool gb_operation_response_alloc(struct gb_operation *operation,
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size_t response_size, gfp_t gfp)
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{
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struct gb_host_device *hd = operation->connection->hd;
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struct gb_operation_msg_hdr *request_header;
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struct gb_message *response;
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u8 type;
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type = operation->type | GB_MESSAGE_TYPE_RESPONSE;
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response = gb_operation_message_alloc(hd, type, response_size, gfp);
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if (!response)
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return false;
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response->operation = operation;
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/*
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* Size and type get initialized when the message is
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* allocated. The errno will be set before sending. All
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* that's left is the operation id, which we copy from the
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* request message header (as-is, in little-endian order).
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*/
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request_header = operation->request->header;
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response->header->operation_id = request_header->operation_id;
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operation->response = response;
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return true;
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}
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EXPORT_SYMBOL_GPL(gb_operation_response_alloc);
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/*
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* Create a Greybus operation to be sent over the given connection.
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* The request buffer will be big enough for a payload of the given
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* size.
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*
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* For outgoing requests, the request message's header will be
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* initialized with the type of the request and the message size.
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* Outgoing operations must also specify the response buffer size,
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* which must be sufficient to hold all expected response data. The
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* response message header will eventually be overwritten, so there's
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* no need to initialize it here.
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*
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* Request messages for incoming operations can arrive in interrupt
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* context, so they must be allocated with GFP_ATOMIC. In this case
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* the request buffer will be immediately overwritten, so there is
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* no need to initialize the message header. Responsibility for
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* allocating a response buffer lies with the incoming request
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* handler for a protocol. So we don't allocate that here.
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*
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* Returns a pointer to the new operation or a null pointer if an
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* error occurs.
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*/
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static struct gb_operation *
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gb_operation_create_common(struct gb_connection *connection, u8 type,
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size_t request_size, size_t response_size,
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unsigned long op_flags, gfp_t gfp_flags)
|
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{
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struct gb_host_device *hd = connection->hd;
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struct gb_operation *operation;
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|
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operation = kmem_cache_zalloc(gb_operation_cache, gfp_flags);
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if (!operation)
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return NULL;
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operation->connection = connection;
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|
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operation->request = gb_operation_message_alloc(hd, type, request_size,
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gfp_flags);
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if (!operation->request)
|
|
goto err_cache;
|
|
operation->request->operation = operation;
|
|
|
|
/* Allocate the response buffer for outgoing operations */
|
|
if (!(op_flags & GB_OPERATION_FLAG_INCOMING)) {
|
|
if (!gb_operation_response_alloc(operation, response_size,
|
|
gfp_flags)) {
|
|
goto err_request;
|
|
}
|
|
|
|
setup_timer(&operation->timer, gb_operation_timeout,
|
|
(unsigned long)operation);
|
|
}
|
|
|
|
operation->flags = op_flags;
|
|
operation->type = type;
|
|
operation->errno = -EBADR; /* Initial value--means "never set" */
|
|
|
|
INIT_WORK(&operation->work, gb_operation_work);
|
|
init_completion(&operation->completion);
|
|
kref_init(&operation->kref);
|
|
atomic_set(&operation->waiters, 0);
|
|
|
|
return operation;
|
|
|
|
err_request:
|
|
gb_operation_message_free(operation->request);
|
|
err_cache:
|
|
kmem_cache_free(gb_operation_cache, operation);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Create a new operation associated with the given connection. The
|
|
* request and response sizes provided are the number of bytes
|
|
* required to hold the request/response payload only. Both of
|
|
* these are allowed to be 0. Note that 0x00 is reserved as an
|
|
* invalid operation type for all protocols, and this is enforced
|
|
* here.
|
|
*/
|
|
struct gb_operation *
|
|
gb_operation_create_flags(struct gb_connection *connection,
|
|
u8 type, size_t request_size,
|
|
size_t response_size, unsigned long flags,
|
|
gfp_t gfp)
|
|
{
|
|
struct gb_operation *operation;
|
|
|
|
if (WARN_ON_ONCE(type == GB_REQUEST_TYPE_INVALID))
|
|
return NULL;
|
|
if (WARN_ON_ONCE(type & GB_MESSAGE_TYPE_RESPONSE))
|
|
type &= ~GB_MESSAGE_TYPE_RESPONSE;
|
|
|
|
if (WARN_ON_ONCE(flags & ~GB_OPERATION_FLAG_USER_MASK))
|
|
flags &= GB_OPERATION_FLAG_USER_MASK;
|
|
|
|
operation = gb_operation_create_common(connection, type,
|
|
request_size, response_size,
|
|
flags, gfp);
|
|
if (operation)
|
|
trace_gb_operation_create(operation);
|
|
|
|
return operation;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_create_flags);
|
|
|
|
struct gb_operation *
|
|
gb_operation_create_core(struct gb_connection *connection,
|
|
u8 type, size_t request_size,
|
|
size_t response_size, unsigned long flags,
|
|
gfp_t gfp)
|
|
{
|
|
struct gb_operation *operation;
|
|
|
|
flags |= GB_OPERATION_FLAG_CORE;
|
|
|
|
operation = gb_operation_create_common(connection, type,
|
|
request_size, response_size,
|
|
flags, gfp);
|
|
if (operation)
|
|
trace_gb_operation_create_core(operation);
|
|
|
|
return operation;
|
|
}
|
|
/* Do not export this function. */
|
|
|
|
size_t gb_operation_get_payload_size_max(struct gb_connection *connection)
|
|
{
|
|
struct gb_host_device *hd = connection->hd;
|
|
|
|
return hd->buffer_size_max - sizeof(struct gb_operation_msg_hdr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_get_payload_size_max);
|
|
|
|
static struct gb_operation *
|
|
gb_operation_create_incoming(struct gb_connection *connection, u16 id,
|
|
u8 type, void *data, size_t size)
|
|
{
|
|
struct gb_operation *operation;
|
|
size_t request_size;
|
|
unsigned long flags = GB_OPERATION_FLAG_INCOMING;
|
|
|
|
/* Caller has made sure we at least have a message header. */
|
|
request_size = size - sizeof(struct gb_operation_msg_hdr);
|
|
|
|
if (!id)
|
|
flags |= GB_OPERATION_FLAG_UNIDIRECTIONAL;
|
|
|
|
operation = gb_operation_create_common(connection, type,
|
|
request_size,
|
|
GB_REQUEST_TYPE_INVALID,
|
|
flags, GFP_ATOMIC);
|
|
if (!operation)
|
|
return NULL;
|
|
|
|
operation->id = id;
|
|
memcpy(operation->request->header, data, size);
|
|
trace_gb_operation_create_incoming(operation);
|
|
|
|
return operation;
|
|
}
|
|
|
|
/*
|
|
* Get an additional reference on an operation.
|
|
*/
|
|
void gb_operation_get(struct gb_operation *operation)
|
|
{
|
|
kref_get(&operation->kref);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_get);
|
|
|
|
/*
|
|
* Destroy a previously created operation.
|
|
*/
|
|
static void _gb_operation_destroy(struct kref *kref)
|
|
{
|
|
struct gb_operation *operation;
|
|
|
|
operation = container_of(kref, struct gb_operation, kref);
|
|
|
|
trace_gb_operation_destroy(operation);
|
|
|
|
if (operation->response)
|
|
gb_operation_message_free(operation->response);
|
|
gb_operation_message_free(operation->request);
|
|
|
|
kmem_cache_free(gb_operation_cache, operation);
|
|
}
|
|
|
|
/*
|
|
* Drop a reference on an operation, and destroy it when the last
|
|
* one is gone.
|
|
*/
|
|
void gb_operation_put(struct gb_operation *operation)
|
|
{
|
|
if (WARN_ON(!operation))
|
|
return;
|
|
|
|
kref_put(&operation->kref, _gb_operation_destroy);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_put);
|
|
|
|
/* Tell the requester we're done */
|
|
static void gb_operation_sync_callback(struct gb_operation *operation)
|
|
{
|
|
complete(&operation->completion);
|
|
}
|
|
|
|
/**
|
|
* gb_operation_request_send() - send an operation request message
|
|
* @operation: the operation to initiate
|
|
* @callback: the operation completion callback
|
|
* @timeout: operation timeout in milliseconds, or zero for no timeout
|
|
* @gfp: the memory flags to use for any allocations
|
|
*
|
|
* The caller has filled in any payload so the request message is ready to go.
|
|
* The callback function supplied will be called when the response message has
|
|
* arrived, a unidirectional request has been sent, or the operation is
|
|
* cancelled, indicating that the operation is complete. The callback function
|
|
* can fetch the result of the operation using gb_operation_result() if
|
|
* desired.
|
|
*
|
|
* Return: 0 if the request was successfully queued in the host-driver queues,
|
|
* or a negative errno.
|
|
*/
|
|
int gb_operation_request_send(struct gb_operation *operation,
|
|
gb_operation_callback callback,
|
|
unsigned int timeout,
|
|
gfp_t gfp)
|
|
{
|
|
struct gb_connection *connection = operation->connection;
|
|
struct gb_operation_msg_hdr *header;
|
|
unsigned int cycle;
|
|
int ret;
|
|
|
|
if (gb_connection_is_offloaded(connection))
|
|
return -EBUSY;
|
|
|
|
if (!callback)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Record the callback function, which is executed in
|
|
* non-atomic (workqueue) context when the final result
|
|
* of an operation has been set.
|
|
*/
|
|
operation->callback = callback;
|
|
|
|
/*
|
|
* Assign the operation's id, and store it in the request header.
|
|
* Zero is a reserved operation id for unidirectional operations.
|
|
*/
|
|
if (gb_operation_is_unidirectional(operation)) {
|
|
operation->id = 0;
|
|
} else {
|
|
cycle = (unsigned int)atomic_inc_return(&connection->op_cycle);
|
|
operation->id = (u16)(cycle % U16_MAX + 1);
|
|
}
|
|
|
|
header = operation->request->header;
|
|
header->operation_id = cpu_to_le16(operation->id);
|
|
|
|
gb_operation_result_set(operation, -EINPROGRESS);
|
|
|
|
/*
|
|
* Get an extra reference on the operation. It'll be dropped when the
|
|
* operation completes.
|
|
*/
|
|
gb_operation_get(operation);
|
|
ret = gb_operation_get_active(operation);
|
|
if (ret)
|
|
goto err_put;
|
|
|
|
ret = gb_message_send(operation->request, gfp);
|
|
if (ret)
|
|
goto err_put_active;
|
|
|
|
if (timeout) {
|
|
operation->timer.expires = jiffies + msecs_to_jiffies(timeout);
|
|
add_timer(&operation->timer);
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_put_active:
|
|
gb_operation_put_active(operation);
|
|
err_put:
|
|
gb_operation_put(operation);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_request_send);
|
|
|
|
/*
|
|
* Send a synchronous operation. This function is expected to
|
|
* block, returning only when the response has arrived, (or when an
|
|
* error is detected. The return value is the result of the
|
|
* operation.
|
|
*/
|
|
int gb_operation_request_send_sync_timeout(struct gb_operation *operation,
|
|
unsigned int timeout)
|
|
{
|
|
int ret;
|
|
|
|
ret = gb_operation_request_send(operation, gb_operation_sync_callback,
|
|
timeout, GFP_KERNEL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = wait_for_completion_interruptible(&operation->completion);
|
|
if (ret < 0) {
|
|
/* Cancel the operation if interrupted */
|
|
gb_operation_cancel(operation, -ECANCELED);
|
|
}
|
|
|
|
return gb_operation_result(operation);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_request_send_sync_timeout);
|
|
|
|
/*
|
|
* Send a response for an incoming operation request. A non-zero
|
|
* errno indicates a failed operation.
|
|
*
|
|
* If there is any response payload, the incoming request handler is
|
|
* responsible for allocating the response message. Otherwise the
|
|
* it can simply supply the result errno; this function will
|
|
* allocate the response message if necessary.
|
|
*/
|
|
static int gb_operation_response_send(struct gb_operation *operation,
|
|
int errno)
|
|
{
|
|
struct gb_connection *connection = operation->connection;
|
|
int ret;
|
|
|
|
if (!operation->response &&
|
|
!gb_operation_is_unidirectional(operation)) {
|
|
if (!gb_operation_response_alloc(operation, 0, GFP_KERNEL))
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Record the result */
|
|
if (!gb_operation_result_set(operation, errno)) {
|
|
dev_err(&connection->hd->dev, "request result already set\n");
|
|
return -EIO; /* Shouldn't happen */
|
|
}
|
|
|
|
/* Sender of request does not care about response. */
|
|
if (gb_operation_is_unidirectional(operation))
|
|
return 0;
|
|
|
|
/* Reference will be dropped when message has been sent. */
|
|
gb_operation_get(operation);
|
|
ret = gb_operation_get_active(operation);
|
|
if (ret)
|
|
goto err_put;
|
|
|
|
/* Fill in the response header and send it */
|
|
operation->response->header->result = gb_operation_errno_map(errno);
|
|
|
|
ret = gb_message_send(operation->response, GFP_KERNEL);
|
|
if (ret)
|
|
goto err_put_active;
|
|
|
|
return 0;
|
|
|
|
err_put_active:
|
|
gb_operation_put_active(operation);
|
|
err_put:
|
|
gb_operation_put(operation);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* This function is called when a message send request has completed.
|
|
*/
|
|
void greybus_message_sent(struct gb_host_device *hd,
|
|
struct gb_message *message, int status)
|
|
{
|
|
struct gb_operation *operation = message->operation;
|
|
struct gb_connection *connection = operation->connection;
|
|
|
|
/*
|
|
* If the message was a response, we just need to drop our
|
|
* reference to the operation. If an error occurred, report
|
|
* it.
|
|
*
|
|
* For requests, if there's no error and the operation in not
|
|
* unidirectional, there's nothing more to do until the response
|
|
* arrives. If an error occurred attempting to send it, or if the
|
|
* operation is unidrectional, record the result of the operation and
|
|
* schedule its completion.
|
|
*/
|
|
if (message == operation->response) {
|
|
if (status) {
|
|
dev_err(&connection->hd->dev,
|
|
"%s: error sending response 0x%02x: %d\n",
|
|
connection->name, operation->type, status);
|
|
}
|
|
|
|
gb_operation_put_active(operation);
|
|
gb_operation_put(operation);
|
|
} else if (status || gb_operation_is_unidirectional(operation)) {
|
|
if (gb_operation_result_set(operation, status)) {
|
|
queue_work(gb_operation_completion_wq,
|
|
&operation->work);
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(greybus_message_sent);
|
|
|
|
/*
|
|
* We've received data on a connection, and it doesn't look like a
|
|
* response, so we assume it's a request.
|
|
*
|
|
* This is called in interrupt context, so just copy the incoming
|
|
* data into the request buffer and handle the rest via workqueue.
|
|
*/
|
|
static void gb_connection_recv_request(struct gb_connection *connection,
|
|
const struct gb_operation_msg_hdr *header,
|
|
void *data, size_t size)
|
|
{
|
|
struct gb_operation *operation;
|
|
u16 operation_id;
|
|
u8 type;
|
|
int ret;
|
|
|
|
operation_id = le16_to_cpu(header->operation_id);
|
|
type = header->type;
|
|
|
|
operation = gb_operation_create_incoming(connection, operation_id,
|
|
type, data, size);
|
|
if (!operation) {
|
|
dev_err(&connection->hd->dev,
|
|
"%s: can't create incoming operation\n",
|
|
connection->name);
|
|
return;
|
|
}
|
|
|
|
ret = gb_operation_get_active(operation);
|
|
if (ret) {
|
|
gb_operation_put(operation);
|
|
return;
|
|
}
|
|
trace_gb_message_recv_request(operation->request);
|
|
|
|
/*
|
|
* The initial reference to the operation will be dropped when the
|
|
* request handler returns.
|
|
*/
|
|
if (gb_operation_result_set(operation, -EINPROGRESS))
|
|
queue_work(connection->wq, &operation->work);
|
|
}
|
|
|
|
/*
|
|
* We've received data that appears to be an operation response
|
|
* message. Look up the operation, and record that we've received
|
|
* its response.
|
|
*
|
|
* This is called in interrupt context, so just copy the incoming
|
|
* data into the response buffer and handle the rest via workqueue.
|
|
*/
|
|
static void gb_connection_recv_response(struct gb_connection *connection,
|
|
const struct gb_operation_msg_hdr *header,
|
|
void *data, size_t size)
|
|
{
|
|
struct gb_operation *operation;
|
|
struct gb_message *message;
|
|
size_t message_size;
|
|
u16 operation_id;
|
|
int errno;
|
|
|
|
operation_id = le16_to_cpu(header->operation_id);
|
|
|
|
if (!operation_id) {
|
|
dev_err_ratelimited(&connection->hd->dev,
|
|
"%s: invalid response id 0 received\n",
|
|
connection->name);
|
|
return;
|
|
}
|
|
|
|
operation = gb_operation_find_outgoing(connection, operation_id);
|
|
if (!operation) {
|
|
dev_err_ratelimited(&connection->hd->dev,
|
|
"%s: unexpected response id 0x%04x received\n",
|
|
connection->name, operation_id);
|
|
return;
|
|
}
|
|
|
|
errno = gb_operation_status_map(header->result);
|
|
message = operation->response;
|
|
message_size = sizeof(*header) + message->payload_size;
|
|
if (!errno && size > message_size) {
|
|
dev_err_ratelimited(&connection->hd->dev,
|
|
"%s: malformed response 0x%02x received (%zu > %zu)\n",
|
|
connection->name, header->type,
|
|
size, message_size);
|
|
errno = -EMSGSIZE;
|
|
} else if (!errno && size < message_size) {
|
|
if (gb_operation_short_response_allowed(operation)) {
|
|
message->payload_size = size - sizeof(*header);
|
|
} else {
|
|
dev_err_ratelimited(&connection->hd->dev,
|
|
"%s: short response 0x%02x received (%zu < %zu)\n",
|
|
connection->name, header->type,
|
|
size, message_size);
|
|
errno = -EMSGSIZE;
|
|
}
|
|
}
|
|
|
|
/* We must ignore the payload if a bad status is returned */
|
|
if (errno)
|
|
size = sizeof(*header);
|
|
|
|
/* The rest will be handled in work queue context */
|
|
if (gb_operation_result_set(operation, errno)) {
|
|
memcpy(message->buffer, data, size);
|
|
|
|
trace_gb_message_recv_response(message);
|
|
|
|
queue_work(gb_operation_completion_wq, &operation->work);
|
|
}
|
|
|
|
gb_operation_put(operation);
|
|
}
|
|
|
|
/*
|
|
* Handle data arriving on a connection. As soon as we return the
|
|
* supplied data buffer will be reused (so unless we do something
|
|
* with, it's effectively dropped).
|
|
*/
|
|
void gb_connection_recv(struct gb_connection *connection,
|
|
void *data, size_t size)
|
|
{
|
|
struct gb_operation_msg_hdr header;
|
|
struct device *dev = &connection->hd->dev;
|
|
size_t msg_size;
|
|
|
|
if (connection->state == GB_CONNECTION_STATE_DISABLED ||
|
|
gb_connection_is_offloaded(connection)) {
|
|
dev_warn_ratelimited(dev, "%s: dropping %zu received bytes\n",
|
|
connection->name, size);
|
|
return;
|
|
}
|
|
|
|
if (size < sizeof(header)) {
|
|
dev_err_ratelimited(dev, "%s: short message received\n",
|
|
connection->name);
|
|
return;
|
|
}
|
|
|
|
/* Use memcpy as data may be unaligned */
|
|
memcpy(&header, data, sizeof(header));
|
|
msg_size = le16_to_cpu(header.size);
|
|
if (size < msg_size) {
|
|
dev_err_ratelimited(dev,
|
|
"%s: incomplete message 0x%04x of type 0x%02x received (%zu < %zu)\n",
|
|
connection->name,
|
|
le16_to_cpu(header.operation_id),
|
|
header.type, size, msg_size);
|
|
return; /* XXX Should still complete operation */
|
|
}
|
|
|
|
if (header.type & GB_MESSAGE_TYPE_RESPONSE) {
|
|
gb_connection_recv_response(connection, &header, data,
|
|
msg_size);
|
|
} else {
|
|
gb_connection_recv_request(connection, &header, data,
|
|
msg_size);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Cancel an outgoing operation synchronously, and record the given error to
|
|
* indicate why.
|
|
*/
|
|
void gb_operation_cancel(struct gb_operation *operation, int errno)
|
|
{
|
|
if (WARN_ON(gb_operation_is_incoming(operation)))
|
|
return;
|
|
|
|
if (gb_operation_result_set(operation, errno)) {
|
|
gb_message_cancel(operation->request);
|
|
queue_work(gb_operation_completion_wq, &operation->work);
|
|
}
|
|
trace_gb_message_cancel_outgoing(operation->request);
|
|
|
|
atomic_inc(&operation->waiters);
|
|
wait_event(gb_operation_cancellation_queue,
|
|
!gb_operation_is_active(operation));
|
|
atomic_dec(&operation->waiters);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_cancel);
|
|
|
|
/*
|
|
* Cancel an incoming operation synchronously. Called during connection tear
|
|
* down.
|
|
*/
|
|
void gb_operation_cancel_incoming(struct gb_operation *operation, int errno)
|
|
{
|
|
if (WARN_ON(!gb_operation_is_incoming(operation)))
|
|
return;
|
|
|
|
if (!gb_operation_is_unidirectional(operation)) {
|
|
/*
|
|
* Make sure the request handler has submitted the response
|
|
* before cancelling it.
|
|
*/
|
|
flush_work(&operation->work);
|
|
if (!gb_operation_result_set(operation, errno))
|
|
gb_message_cancel(operation->response);
|
|
}
|
|
trace_gb_message_cancel_incoming(operation->response);
|
|
|
|
atomic_inc(&operation->waiters);
|
|
wait_event(gb_operation_cancellation_queue,
|
|
!gb_operation_is_active(operation));
|
|
atomic_dec(&operation->waiters);
|
|
}
|
|
|
|
/**
|
|
* gb_operation_sync_timeout() - implement a "simple" synchronous operation
|
|
* @connection: the Greybus connection to send this to
|
|
* @type: the type of operation to send
|
|
* @request: pointer to a memory buffer to copy the request from
|
|
* @request_size: size of @request
|
|
* @response: pointer to a memory buffer to copy the response to
|
|
* @response_size: the size of @response.
|
|
* @timeout: operation timeout in milliseconds
|
|
*
|
|
* This function implements a simple synchronous Greybus operation. It sends
|
|
* the provided operation request and waits (sleeps) until the corresponding
|
|
* operation response message has been successfully received, or an error
|
|
* occurs. @request and @response are buffers to hold the request and response
|
|
* data respectively, and if they are not NULL, their size must be specified in
|
|
* @request_size and @response_size.
|
|
*
|
|
* If a response payload is to come back, and @response is not NULL,
|
|
* @response_size number of bytes will be copied into @response if the operation
|
|
* is successful.
|
|
*
|
|
* If there is an error, the response buffer is left alone.
|
|
*/
|
|
int gb_operation_sync_timeout(struct gb_connection *connection, int type,
|
|
void *request, int request_size,
|
|
void *response, int response_size,
|
|
unsigned int timeout)
|
|
{
|
|
struct gb_operation *operation;
|
|
int ret;
|
|
|
|
if ((response_size && !response) ||
|
|
(request_size && !request))
|
|
return -EINVAL;
|
|
|
|
operation = gb_operation_create(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_timeout(operation, timeout);
|
|
if (ret) {
|
|
dev_err(&connection->hd->dev,
|
|
"%s: synchronous operation id 0x%04x of type 0x%02x failed: %d\n",
|
|
connection->name, operation->id, type, ret);
|
|
} else {
|
|
if (response_size) {
|
|
memcpy(response, operation->response->payload,
|
|
response_size);
|
|
}
|
|
}
|
|
|
|
gb_operation_put(operation);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_sync_timeout);
|
|
|
|
/**
|
|
* gb_operation_unidirectional_timeout() - initiate a unidirectional operation
|
|
* @connection: connection to use
|
|
* @type: type of operation to send
|
|
* @request: memory buffer to copy the request from
|
|
* @request_size: size of @request
|
|
* @timeout: send timeout in milliseconds
|
|
*
|
|
* Initiate a unidirectional operation by sending a request message and
|
|
* waiting for it to be acknowledged as sent by the host device.
|
|
*
|
|
* Note that successful send of a unidirectional operation does not imply that
|
|
* the request as actually reached the remote end of the connection.
|
|
*/
|
|
int gb_operation_unidirectional_timeout(struct gb_connection *connection,
|
|
int type, void *request, int request_size,
|
|
unsigned int timeout)
|
|
{
|
|
struct gb_operation *operation;
|
|
int ret;
|
|
|
|
if (request_size && !request)
|
|
return -EINVAL;
|
|
|
|
operation = gb_operation_create_flags(connection, type,
|
|
request_size, 0,
|
|
GB_OPERATION_FLAG_UNIDIRECTIONAL,
|
|
GFP_KERNEL);
|
|
if (!operation)
|
|
return -ENOMEM;
|
|
|
|
if (request_size)
|
|
memcpy(operation->request->payload, request, request_size);
|
|
|
|
ret = gb_operation_request_send_sync_timeout(operation, timeout);
|
|
if (ret) {
|
|
dev_err(&connection->hd->dev,
|
|
"%s: unidirectional operation of type 0x%02x failed: %d\n",
|
|
connection->name, type, ret);
|
|
}
|
|
|
|
gb_operation_put(operation);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gb_operation_unidirectional_timeout);
|
|
|
|
int __init gb_operation_init(void)
|
|
{
|
|
gb_message_cache = kmem_cache_create("gb_message_cache",
|
|
sizeof(struct gb_message), 0, 0, NULL);
|
|
if (!gb_message_cache)
|
|
return -ENOMEM;
|
|
|
|
gb_operation_cache = kmem_cache_create("gb_operation_cache",
|
|
sizeof(struct gb_operation), 0, 0, NULL);
|
|
if (!gb_operation_cache)
|
|
goto err_destroy_message_cache;
|
|
|
|
gb_operation_completion_wq = alloc_workqueue("greybus_completion",
|
|
0, 0);
|
|
if (!gb_operation_completion_wq)
|
|
goto err_destroy_operation_cache;
|
|
|
|
return 0;
|
|
|
|
err_destroy_operation_cache:
|
|
kmem_cache_destroy(gb_operation_cache);
|
|
gb_operation_cache = NULL;
|
|
err_destroy_message_cache:
|
|
kmem_cache_destroy(gb_message_cache);
|
|
gb_message_cache = NULL;
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
void gb_operation_exit(void)
|
|
{
|
|
destroy_workqueue(gb_operation_completion_wq);
|
|
gb_operation_completion_wq = NULL;
|
|
kmem_cache_destroy(gb_operation_cache);
|
|
gb_operation_cache = NULL;
|
|
kmem_cache_destroy(gb_message_cache);
|
|
gb_message_cache = NULL;
|
|
}
|