174 lines
4.2 KiB
C
Executable file
174 lines
4.2 KiB
C
Executable file
/*
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* Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
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* Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include <linux/kernel.h>
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#include <linux/interrupt.h>
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#include <linux/hardirq.h>
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#include "rxe_task.h"
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int __rxe_do_task(struct rxe_task *task)
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{
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int ret;
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while ((ret = task->func(task->arg)) == 0)
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;
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task->ret = ret;
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return ret;
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}
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/*
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* this locking is due to a potential race where
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* a second caller finds the task already running
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* but looks just after the last call to func
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*/
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void rxe_do_task(unsigned long data)
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{
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int cont;
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int ret;
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unsigned long flags;
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struct rxe_task *task = (struct rxe_task *)data;
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spin_lock_irqsave(&task->state_lock, flags);
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switch (task->state) {
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case TASK_STATE_START:
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task->state = TASK_STATE_BUSY;
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spin_unlock_irqrestore(&task->state_lock, flags);
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break;
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case TASK_STATE_BUSY:
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task->state = TASK_STATE_ARMED;
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/* fall through */
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case TASK_STATE_ARMED:
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spin_unlock_irqrestore(&task->state_lock, flags);
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return;
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default:
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spin_unlock_irqrestore(&task->state_lock, flags);
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pr_warn("%s failed with bad state %d\n", __func__, task->state);
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return;
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}
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do {
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cont = 0;
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ret = task->func(task->arg);
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spin_lock_irqsave(&task->state_lock, flags);
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switch (task->state) {
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case TASK_STATE_BUSY:
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if (ret)
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task->state = TASK_STATE_START;
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else
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cont = 1;
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break;
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/* soneone tried to run the task since the last time we called
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* func, so we will call one more time regardless of the
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* return value
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*/
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case TASK_STATE_ARMED:
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task->state = TASK_STATE_BUSY;
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cont = 1;
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break;
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default:
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pr_warn("%s failed with bad state %d\n", __func__,
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task->state);
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}
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spin_unlock_irqrestore(&task->state_lock, flags);
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} while (cont);
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task->ret = ret;
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}
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int rxe_init_task(void *obj, struct rxe_task *task,
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void *arg, int (*func)(void *), char *name)
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{
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task->obj = obj;
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task->arg = arg;
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task->func = func;
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snprintf(task->name, sizeof(task->name), "%s", name);
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task->destroyed = false;
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tasklet_init(&task->tasklet, rxe_do_task, (unsigned long)task);
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task->state = TASK_STATE_START;
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spin_lock_init(&task->state_lock);
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return 0;
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}
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void rxe_cleanup_task(struct rxe_task *task)
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{
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unsigned long flags;
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bool idle;
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/*
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* Mark the task, then wait for it to finish. It might be
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* running in a non-tasklet (direct call) context.
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*/
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task->destroyed = true;
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do {
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spin_lock_irqsave(&task->state_lock, flags);
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idle = (task->state == TASK_STATE_START);
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spin_unlock_irqrestore(&task->state_lock, flags);
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} while (!idle);
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tasklet_kill(&task->tasklet);
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}
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void rxe_run_task(struct rxe_task *task, int sched)
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{
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if (task->destroyed)
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return;
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if (sched)
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tasklet_schedule(&task->tasklet);
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else
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rxe_do_task((unsigned long)task);
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}
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void rxe_disable_task(struct rxe_task *task)
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{
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tasklet_disable(&task->tasklet);
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}
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void rxe_enable_task(struct rxe_task *task)
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{
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tasklet_enable(&task->tasklet);
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}
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