From patchwork Tue Sep 22 07:30:57 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Heib X-Patchwork-Id: 7235481 Return-Path: X-Original-To: patchwork-linux-rdma@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D8CE89F4DC for ; Tue, 22 Sep 2015 07:32:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A0C7C20603 for ; Tue, 22 Sep 2015 07:32:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E5B220630 for ; Tue, 22 Sep 2015 07:32:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757597AbbIVHcK (ORCPT ); Tue, 22 Sep 2015 03:32:10 -0400 Received: from [193.47.165.129] ([193.47.165.129]:59973 "EHLO mellanox.co.il" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S932140AbbIVHcJ (ORCPT ); Tue, 22 Sep 2015 03:32:09 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from kamalh@mellanox.com) with ESMTPS (AES256-SHA encrypted); 22 Sep 2015 09:31:51 +0200 Received: from r-vnc04.mtr.labs.mlnx (r-vnc04.mtr.labs.mlnx [10.208.0.116]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id t8M7Vdta020646; Tue, 22 Sep 2015 10:31:41 +0300 From: Kamal Heib To: Doug Ledford Cc: linux-rdma@vger.kernel.org, Tal Alon , Liran Liss , Kamal Heib , Amir Vadai Subject: [PATCH rdma-next V1 14/32] IB/rxe: RXE tasks handling Date: Tue, 22 Sep 2015 10:30:57 +0300 Message-Id: <1442907075-13228-15-git-send-email-kamalh@mellanox.com> X-Mailer: git-send-email 1.7.8.2 In-Reply-To: <1442907075-13228-1-git-send-email-kamalh@mellanox.com> References: <1442907075-13228-1-git-send-email-kamalh@mellanox.com> Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A 'task' is a short function that returns 0 as long as it needs to be called again. rxe tasks are based on the kernel's tasklet infrastructure. Signed-off-by: Kamal Heib Signed-off-by: Amir Vadai Reviewed-by: Haggai Eran --- drivers/staging/rxe/rxe_task.c | 154 +++++++++++++++++++++++++++++++++++++++++ drivers/staging/rxe/rxe_task.h | 95 +++++++++++++++++++++++++ 2 files changed, 249 insertions(+) create mode 100644 drivers/staging/rxe/rxe_task.c create mode 100644 drivers/staging/rxe/rxe_task.h diff --git a/drivers/staging/rxe/rxe_task.c b/drivers/staging/rxe/rxe_task.c new file mode 100644 index 0000000..162fa1a --- /dev/null +++ b/drivers/staging/rxe/rxe_task.c @@ -0,0 +1,154 @@ +/* + * Copyright (c) 2015 Mellanox Technologies Ltd. All rights reserved. + * Copyright (c) 2015 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, + void *arg, int (*func)(void *), char *name) +{ + task->obj = obj; + 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); +} + +void rxe_run_task(struct rxe_task *task, int sched) +{ + if (sched) + 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); +} diff --git a/drivers/staging/rxe/rxe_task.h b/drivers/staging/rxe/rxe_task.h new file mode 100644 index 0000000..1183662 --- /dev/null +++ b/drivers/staging/rxe/rxe_task.h @@ -0,0 +1,95 @@ +/* + * Copyright (c) 2015 Mellanox Technologies Ltd. All rights reserved. + * Copyright (c) 2015 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. + */ + +#ifndef RXE_TASK_H +#define RXE_TASK_H + +enum { + TASK_STATE_START = 0, + TASK_STATE_BUSY = 1, + TASK_STATE_ARMED = 2, +}; + +/* + * data structure to describe a 'task' which is a short + * function that returns 0 as long as it needs to be + * called again. + */ +struct rxe_task { + void *obj; + struct tasklet_struct tasklet; + int state; + spinlock_t state_lock; /* spinlock for task state */ + void *arg; + int (*func)(void *arg); + int ret; + char name[16]; +}; + +/* + * init rxe_task structure + * arg => parameter to pass to fcn + * fcn => function to call until it returns != 0 + */ +int rxe_init_task(void *obj, struct rxe_task *task, + void *arg, int (*func)(void *), char *name); + +/* cleanup task */ +void rxe_cleanup_task(struct rxe_task *task); + +/* + * raw call to func in loop without any checking + * can call when tasklets are disabled + */ +int __rxe_do_task(struct rxe_task *task); + +/* + * common function called by any of the main tasklets + * If there is any chance that there is additional + * work to do someone must reschedule the task before + * leaving + */ +void rxe_do_task(unsigned long data); + +/* run a task, else schedule it to run as a tasklet, The decision + * to run or schedule tasklet is based on the parameter sched. + * */ +void rxe_run_task(struct rxe_task *task, int sched); + +/* keep a task from scheduling */ +void rxe_disable_task(struct rxe_task *task); + +/* allow task to run */ +void rxe_enable_task(struct rxe_task *task); + +#endif /* RXE_TASK_H */