From patchwork Sun Jul 24 19:43:17 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Pearson X-Patchwork-Id: 1005202 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p6PG3OAg025144 for ; Mon, 25 Jul 2011 16:03:36 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752331Ab1GYQDf (ORCPT ); Mon, 25 Jul 2011 12:03:35 -0400 Received: from cdptpa-bc-oedgelb.mail.rr.com ([75.180.133.32]:63903 "EHLO cdptpa-bc-oedgelb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752302Ab1GYQDe (ORCPT ); Mon, 25 Jul 2011 12:03:34 -0400 Authentication-Results: cdptpa-bc-oedgelb.mail.rr.com smtp.user=fzago@systemfabricworks.com; auth=pass (PLAIN) X-Authority-Analysis: v=1.1 cv=QcSFu2tMqX8VyBnwf4xZriMeG3TVj1s8v1Rcea0EwGI= c=1 sm=0 a=vhdKIqpQuCYA:10 a=fzUmiSEeFbUA:10 a=ozIaqLvjkoIA:10 a=DCwX0kaxZCiV3mmbfDr8nQ==:17 a=YORvzBCaAAAA:8 a=bC7xisPkAAAA:8 a=jt3Njj63qoUsJSY0fXIA:9 a=jsHTb0jitoIFhCLXaMkA:7 a=QLxd5cu_Zb8A:10 a=VV2__AUApEoA:10 a=DCwX0kaxZCiV3mmbfDr8nQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.79.195.91 Received: from [67.79.195.91] ([67.79.195.91:33014] helo=[10.0.2.91]) by cdptpa-bc-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTPA id FD/19-18213-5D39D2E4; Mon, 25 Jul 2011 16:03:33 +0000 Message-Id: <20110724201228.964102039@systemfabricworks.com> User-Agent: quilt/0.48-1 Date: Sun, 24 Jul 2011 14:43:17 -0500 From: rpearson@systemfabricworks.com To: linux-rdma@vger.kernel.org Cc: rpearson@systemfabricworks.com Subject: [patch v2 17/37] add rxe_task.c References: <20110724194300.421253331@systemfabricworks.com> Content-Disposition: inline; filename=add-rxe_task.c Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Mon, 25 Jul 2011 16:03:36 +0000 (UTC) Tasklet handling details. Signed-off-by: Bob Pearson --- drivers/infiniband/hw/rxe/rxe_task.c | 169 +++++++++++++++++++++++++++++++++++ 1 file changed, 169 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: infiniband/drivers/infiniband/hw/rxe/rxe_task.c =================================================================== --- /dev/null +++ infiniband/drivers/infiniband/hw/rxe/rxe_task.c @@ -0,0 +1,169 @@ +/* + * Copyright (c) 2009-2011 Mellanox Technologies Ltd. All rights reserved. + * Copyright (c) 2009-2011 System Fabric Works, Inc. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include +#include +#include + +#include "rxe_task.h" + +int __rxe_do_task(struct rxe_task *task) + +{ + int ret; + + while ((ret = task->func(task->arg)) == 0) + ; + + task->ret = ret; + + return ret; +} + +/* + * this locking is due to a potential race where + * a second caller finds the task already running + * but looks just after the last call to func + */ +void rxe_do_task(unsigned long data) +{ + int cont; + int ret; + unsigned long flags; + struct rxe_task *task = (struct rxe_task *)data; + + spin_lock_irqsave(&task->state_lock, flags); + switch (task->state) { + case TASK_STATE_START: + task->state = TASK_STATE_BUSY; + spin_unlock_irqrestore(&task->state_lock, flags); + break; + + case TASK_STATE_BUSY: + task->state = TASK_STATE_ARMED; + /* fall through to */ + case TASK_STATE_ARMED: + spin_unlock_irqrestore(&task->state_lock, flags); + return; + + default: + spin_unlock_irqrestore(&task->state_lock, flags); + pr_warn("bad state = %d in rxe_do_task\n", task->state); + return; + } + + do { + cont = 0; + ret = task->func(task->arg); + + spin_lock_irqsave(&task->state_lock, flags); + switch (task->state) { + case TASK_STATE_BUSY: + if (ret) + task->state = TASK_STATE_START; + else + cont = 1; + break; + + /* soneone tried to run the task since the + last time we called func, so we will call + one more time regardless of the return value */ + case TASK_STATE_ARMED: + task->state = TASK_STATE_BUSY; + cont = 1; + break; + + default: + pr_warn("bad state = %d in rxe_do_task\n", + task->state); + } + spin_unlock_irqrestore(&task->state_lock, flags); + } while (cont); + + task->ret = ret; +} + +int rxe_init_task(void *obj, struct rxe_task *task, int *fast, + void *arg, int (*func)(void *), char *name) +{ + task->obj = obj; + task->fast = fast; + task->arg = arg; + task->func = func; + snprintf(task->name, sizeof(task->name), "%s", name); + + tasklet_init(&task->tasklet, rxe_do_task, (unsigned long)task); + + task->state = TASK_STATE_START; + spin_lock_init(&task->state_lock); + + return 0; +} + +void rxe_cleanup_task(struct rxe_task *task) +{ + tasklet_kill(&task->tasklet); +} + +/* + * depending on value of fast allow bypassing + * tasklet call or not + * 0 => never + * 1 => only if not in interrupt level + * >1 => always + */ +static inline int rxe_fast_path_ok(int fast) +{ + if (fast == 0 || (fast == 1 && (in_irq() || irqs_disabled()))) + return 0; + else + return 1; +} + +void rxe_run_task(struct rxe_task *task, int sched) +{ + if (sched || !rxe_fast_path_ok(*task->fast)) + tasklet_schedule(&task->tasklet); + else + rxe_do_task((unsigned long)task); +} + +void rxe_disable_task(struct rxe_task *task) +{ + tasklet_disable(&task->tasklet); +} + +void rxe_enable_task(struct rxe_task *task) +{ + tasklet_enable(&task->tasklet); +}