Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758903AbcJYMCc (ORCPT ); Tue, 25 Oct 2016 08:02:32 -0400 Received: from mail-pf0-f171.google.com ([209.85.192.171]:34016 "EHLO mail-pf0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758869AbcJYMC1 (ORCPT ); Tue, 25 Oct 2016 08:02:27 -0400 From: Binoy Jayan To: Doug Ledford , Sean Hefty , Hal Rosenstock Cc: Arnd Bergmann , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Binoy Jayan Subject: [PATCH v2 6/8] IB/hns: Replace counting semaphore event_sem with wait_event Date: Tue, 25 Oct 2016 17:31:57 +0530 Message-Id: <1477396919-27669-7-git-send-email-binoy.jayan@linaro.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1477396919-27669-1-git-send-email-binoy.jayan@linaro.org> References: <1477396919-27669-1-git-send-email-binoy.jayan@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3892 Lines: 114 Counting semaphores are going away in the future, so replace the semaphore mthca_cmd::event_sem with a conditional wait_event. Signed-off-by: Binoy Jayan --- drivers/infiniband/hw/hns/hns_roce_cmd.c | 37 +++++++++++++++++++++-------- drivers/infiniband/hw/hns/hns_roce_device.h | 2 +- 2 files changed, 28 insertions(+), 11 deletions(-) diff --git a/drivers/infiniband/hw/hns/hns_roce_cmd.c b/drivers/infiniband/hw/hns/hns_roce_cmd.c index 51a0675..efc5c48 100644 --- a/drivers/infiniband/hw/hns/hns_roce_cmd.c +++ b/drivers/infiniband/hw/hns/hns_roce_cmd.c @@ -189,6 +189,26 @@ void hns_roce_cmd_event(struct hns_roce_dev *hr_dev, u16 token, u8 status, complete(&context->done); } +/* Similar to atomic_cmpxchg but with the complimentary condition. Returns + * index to a free node. It also sets cmd->free_head to 'new' so it ensures + * atomicity between a call to 'wait_event' and manipulating the free_head. + */ + +static inline int atomic_free_node(struct hns_roce_cmdq *cmd, int new) +{ + int orig; + + spin_lock(&cmd->context_lock); + + orig = cmd->free_head; + if (likely(cmd->free_head != -1)) + cmd->free_head = new; + + spin_unlock(&cmd->context_lock); + + return orig; +} + /* this should be called with "use_events" */ static int __hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param, u64 out_param, unsigned long in_modifier, @@ -198,11 +218,12 @@ static int __hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param, struct hns_roce_cmdq *cmd = &hr_dev->cmd; struct device *dev = &hr_dev->pdev->dev; struct hns_roce_cmd_context *context; - int ret = 0; + int orig_free_head, ret = 0; + + wait_event(cmd->wq, (orig_free_head = atomic_free_node(cmd, -1)) != -1); spin_lock(&cmd->context_lock); - WARN_ON(cmd->free_head < 0); - context = &cmd->context[cmd->free_head]; + context = &cmd->context[orig_free_head]; context->token += cmd->token_mask + 1; cmd->free_head = context->next; spin_unlock(&cmd->context_lock); @@ -238,6 +259,7 @@ static int __hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param, context->next = cmd->free_head; cmd->free_head = context - cmd->context; spin_unlock(&cmd->context_lock); + wake_up(&cmd->wq); return ret; } @@ -248,10 +270,8 @@ static int hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param, { int ret = 0; - down(&hr_dev->cmd.event_sem); ret = __hns_roce_cmd_mbox_wait(hr_dev, in_param, out_param, in_modifier, op_modifier, op, timeout); - up(&hr_dev->cmd.event_sem); return ret; } @@ -313,7 +333,7 @@ int hns_roce_cmd_use_events(struct hns_roce_dev *hr_dev) hr_cmd->context[hr_cmd->max_cmds - 1].next = -1; hr_cmd->free_head = 0; - sema_init(&hr_cmd->event_sem, hr_cmd->max_cmds); + init_waitqueue_head(&hr_cmd->wq); spin_lock_init(&hr_cmd->context_lock); hr_cmd->token_mask = CMD_TOKEN_MASK; @@ -325,12 +345,9 @@ int hns_roce_cmd_use_events(struct hns_roce_dev *hr_dev) void hns_roce_cmd_use_polling(struct hns_roce_dev *hr_dev) { struct hns_roce_cmdq *hr_cmd = &hr_dev->cmd; - int i; hr_cmd->use_events = 0; - - for (i = 0; i < hr_cmd->max_cmds; ++i) - down(&hr_cmd->event_sem); + hr_cmd->free_head = -1; kfree(hr_cmd->context); } diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h index 2afe075..ac95f52 100644 --- a/drivers/infiniband/hw/hns/hns_roce_device.h +++ b/drivers/infiniband/hw/hns/hns_roce_device.h @@ -364,7 +364,7 @@ struct hns_roce_cmdq { * Event mode: cmd register mutex protection, * ensure to not exceed max_cmds and user use limit region */ - struct semaphore event_sem; + wait_queue_head_t wq; int max_cmds; spinlock_t context_lock; int free_head; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project