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1264 lines
35 KiB
1264 lines
35 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
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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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#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 <linux/greybus.h> |
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|
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#include "greybus_trace.h" |
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|
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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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|
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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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|
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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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/* |
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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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|
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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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/* |
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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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|
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trace_gb_operation_get_active(operation); |
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|
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spin_unlock_irqrestore(&connection->lock, flags); |
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|
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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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|
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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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|
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spin_lock_irqsave(&connection->lock, flags); |
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|
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trace_gb_operation_put_active(operation); |
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|
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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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|
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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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|
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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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|
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return ret; |
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} |
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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 |
|
* 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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/* |
|
* Looks up an outgoing operation on a connection and returns a refcounted |
|
* 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 |
|
* 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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|
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operation->callback(operation); |
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} |
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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(struct timer_list *t) |
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{ |
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struct gb_operation *operation = from_timer(operation, t, timer); |
|
|
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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, |
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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 |
|
* 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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* The result field in a request message must be |
|
* zero. It will be set just prior to sending for |
|
* 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. |
|
* Both types of message contain a common header. The request message |
|
* for an outgoing operation is outbound, as is the response message |
|
* for an incoming operation. The message header for an outbound |
|
* message is partially initialized here. |
|
* |
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* The headers for inbound messages don't need to be initialized; |
|
* they'll be filled in by arriving data. |
|
* |
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* Our message buffers have the following layout: |
|
* message header \_ these combined are |
|
* 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, |
|
size_t payload_size, gfp_t gfp_flags) |
|
{ |
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struct gb_message *message; |
|
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", |
|
message_size, hd->buffer_size_max); |
|
return NULL; |
|
} |
|
|
|
/* Allocate the message structure and buffer. */ |
|
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); |
|
if (!message->buffer) |
|
goto err_free_message; |
|
|
|
/* Initialize the message. Operation id is filled in later. */ |
|
gb_operation_message_init(hd, message, 0, payload_size, type); |
|
|
|
return message; |
|
|
|
err_free_message: |
|
kmem_cache_free(gb_message_cache, message); |
|
|
|
return NULL; |
|
} |
|
|
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static void gb_operation_message_free(struct gb_message *message) |
|
{ |
|
kfree(message->buffer); |
|
kmem_cache_free(gb_message_cache, message); |
|
} |
|
|
|
/* |
|
* Map an enum gb_operation_status value (which is represented in a |
|
* message as a single byte) to an appropriate Linux negative errno. |
|
*/ |
|
static int gb_operation_status_map(u8 status) |
|
{ |
|
switch (status) { |
|
case GB_OP_SUCCESS: |
|
return 0; |
|
case GB_OP_INTERRUPTED: |
|
return -EINTR; |
|
case GB_OP_TIMEOUT: |
|
return -ETIMEDOUT; |
|
case GB_OP_NO_MEMORY: |
|
return -ENOMEM; |
|
case GB_OP_PROTOCOL_BAD: |
|
return -EPROTONOSUPPORT; |
|
case GB_OP_OVERFLOW: |
|
return -EMSGSIZE; |
|
case GB_OP_INVALID: |
|
return -EINVAL; |
|
case GB_OP_RETRY: |
|
return -EAGAIN; |
|
case GB_OP_NONEXISTENT: |
|
return -ENODEV; |
|
case GB_OP_MALFUNCTION: |
|
return -EILSEQ; |
|
case GB_OP_UNKNOWN_ERROR: |
|
default: |
|
return -EIO; |
|
} |
|
} |
|
|
|
/* |
|
* Map a Linux errno value (from operation->errno) into the value |
|
* that should represent it in a response message status sent |
|
* over the wire. Returns an enum gb_operation_status value (which |
|
* is represented in a message as a single byte). |
|
*/ |
|
static u8 gb_operation_errno_map(int errno) |
|
{ |
|
switch (errno) { |
|
case 0: |
|
return GB_OP_SUCCESS; |
|
case -EINTR: |
|
return GB_OP_INTERRUPTED; |
|
case -ETIMEDOUT: |
|
return GB_OP_TIMEOUT; |
|
case -ENOMEM: |
|
return GB_OP_NO_MEMORY; |
|
case -EPROTONOSUPPORT: |
|
return GB_OP_PROTOCOL_BAD; |
|
case -EMSGSIZE: |
|
return GB_OP_OVERFLOW; /* Could be underflow too */ |
|
case -EINVAL: |
|
return GB_OP_INVALID; |
|
case -EAGAIN: |
|
return GB_OP_RETRY; |
|
case -EILSEQ: |
|
return GB_OP_MALFUNCTION; |
|
case -ENODEV: |
|
return GB_OP_NONEXISTENT; |
|
case -EIO: |
|
default: |
|
return GB_OP_UNKNOWN_ERROR; |
|
} |
|
} |
|
|
|
bool gb_operation_response_alloc(struct gb_operation *operation, |
|
size_t response_size, gfp_t gfp) |
|
{ |
|
struct gb_host_device *hd = operation->connection->hd; |
|
struct gb_operation_msg_hdr *request_header; |
|
struct gb_message *response; |
|
u8 type; |
|
|
|
type = operation->type | GB_MESSAGE_TYPE_RESPONSE; |
|
response = gb_operation_message_alloc(hd, type, response_size, gfp); |
|
if (!response) |
|
return false; |
|
response->operation = operation; |
|
|
|
/* |
|
* Size and type get initialized when the message is |
|
* allocated. The errno will be set before sending. All |
|
* that's left is the operation id, which we copy from the |
|
* request message header (as-is, in little-endian order). |
|
*/ |
|
request_header = operation->request->header; |
|
response->header->operation_id = request_header->operation_id; |
|
operation->response = response; |
|
|
|
return true; |
|
} |
|
EXPORT_SYMBOL_GPL(gb_operation_response_alloc); |
|
|
|
/* |
|
* Create a Greybus operation to be sent over the given connection. |
|
* The request buffer will be big enough for a payload of the given |
|
* size. |
|
* |
|
* For outgoing requests, the request message's header will be |
|
* initialized with the type of the request and the message size. |
|
* Outgoing operations must also specify the response buffer size, |
|
* which must be sufficient to hold all expected response data. The |
|
* response message header will eventually be overwritten, so there's |
|
* no need to initialize it here. |
|
* |
|
* Request messages for incoming operations can arrive in interrupt |
|
* context, so they must be allocated with GFP_ATOMIC. In this case |
|
* the request buffer will be immediately overwritten, so there is |
|
* no need to initialize the message header. Responsibility for |
|
* allocating a response buffer lies with the incoming request |
|
* handler for a protocol. So we don't allocate that here. |
|
* |
|
* Returns a pointer to the new operation or a null pointer if an |
|
* error occurs. |
|
*/ |
|
static struct gb_operation * |
|
gb_operation_create_common(struct gb_connection *connection, u8 type, |
|
size_t request_size, size_t response_size, |
|
unsigned long op_flags, gfp_t gfp_flags) |
|
{ |
|
struct gb_host_device *hd = connection->hd; |
|
struct gb_operation *operation; |
|
|
|
operation = kmem_cache_zalloc(gb_operation_cache, gfp_flags); |
|
if (!operation) |
|
return NULL; |
|
operation->connection = connection; |
|
|
|
operation->request = gb_operation_message_alloc(hd, type, request_size, |
|
gfp_flags); |
|
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; |
|
} |
|
|
|
timer_setup(&operation->timer, gb_operation_timeout, 0); |
|
} |
|
|
|
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; |
|
}
|
|
|