From patchwork Tue Nov 14 13:33:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junhao He X-Patchwork-Id: 13455302 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D94F0C4332F for ; Tue, 14 Nov 2023 13:34:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=i2OevDbKfamDKGMcoQSOL6HdPz4zNXVn3xt6eA0W1RM=; b=tzPIoWKTgMHdd2 8vUOnMkAu4P598Qv1dCDFSekNEhNCtyVHU7uC5aYFvVZiLAAJt1KrOfNHWT2mkWmAJDl7AaZjcnm4 VY0CFpxfoVL9AMQwNuoyExA0EOC+M0RaJxQLcXCGaGsAOwMAf/Jny8LGvbZGulTx296RDW5VuyinX pucmCRrNlCFD+MDvZ2NXhcGTxkRGYBheMl+sTwEaYzOjpEetTXcnv7cMMfKMdPnNWi/9sP+Yh4v8J ezimb6/CeP1YdRdwPP2oS0ll27mXqe5GauRZVuTSKJTgNu6p/Lua8u3lsBJUqbItX0v1wwa/479AC fQwXAelTgtjmt277h4FQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r2tYC-00G3hQ-0i; Tue, 14 Nov 2023 13:33:56 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r2tY4-00G3bn-2C for linux-arm-kernel@lists.infradead.org; Tue, 14 Nov 2023 13:33:51 +0000 Received: from dggpeml500002.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4SV6gZ1VG7zWh5x; Tue, 14 Nov 2023 21:33:14 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpeml500002.china.huawei.com (7.185.36.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Tue, 14 Nov 2023 21:33:35 +0800 From: Junhao He To: , CC: , , , , , , , , Subject: [PATCH v3 4/4] coresight: ultrasoc-smb: Use guards to cleanup Date: Tue, 14 Nov 2023 21:33:46 +0800 Message-ID: <20231114133346.30489-5-hejunhao3@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20231114133346.30489-1-hejunhao3@huawei.com> References: <20231114133346.30489-1-hejunhao3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500002.china.huawei.com (7.185.36.158) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231114_053349_126970_15A9C648 X-CRM114-Status: GOOD ( 15.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Use guards to reduce gotos and simplify control flow. Signed-off-by: Junhao He Reviewed-by: James Clark --- drivers/hwtracing/coresight/ultrasoc-smb.c | 70 +++++++--------------- 1 file changed, 22 insertions(+), 48 deletions(-) diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c index 6e32d31a95fe..cd14b2eded4e 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.c +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c @@ -97,27 +97,19 @@ static int smb_open(struct inode *inode, struct file *file) { struct smb_drv_data *drvdata = container_of(file->private_data, struct smb_drv_data, miscdev); - int ret = 0; - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); - if (drvdata->reading) { - ret = -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; - if (atomic_read(&drvdata->csdev->refcnt)) { - ret = -EBUSY; - goto out; - } + if (atomic_read(&drvdata->csdev->refcnt)) + return -EBUSY; smb_update_data_size(drvdata); - drvdata->reading = true; -out: - spin_unlock(&drvdata->spinlock); - return ret; + return 0; } static ssize_t smb_read(struct file *file, char __user *data, size_t len, @@ -160,9 +152,8 @@ static int smb_release(struct inode *inode, struct file *file) struct smb_drv_data *drvdata = container_of(file->private_data, struct smb_drv_data, miscdev); - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); drvdata->reading = false; - spin_unlock(&drvdata->spinlock); return 0; } @@ -255,19 +246,15 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); int ret = 0; - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); /* Do nothing, the trace data is reading by other interface now */ - if (drvdata->reading) { - ret = -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; /* Do nothing, the SMB is already enabled as other mode */ - if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) { - ret = -EBUSY; - goto out; - } + if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) + return -EBUSY; switch (mode) { case CS_MODE_SYSFS: @@ -281,13 +268,10 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, } if (ret) - goto out; + return ret; atomic_inc(&csdev->refcnt); - dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); -out: - spin_unlock(&drvdata->spinlock); return ret; } @@ -295,19 +279,14 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, static int smb_disable(struct coresight_device *csdev) { struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); - int ret = 0; - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); - if (drvdata->reading) { - ret = -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; - if (atomic_dec_return(&csdev->refcnt)) { - ret = -EBUSY; - goto out; - } + if (atomic_dec_return(&csdev->refcnt)) + return -EBUSY; /* Complain if we (somehow) got out of sync */ WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED); @@ -317,12 +296,9 @@ static int smb_disable(struct coresight_device *csdev) /* Dissociate from the target process. */ drvdata->pid = -1; drvdata->mode = CS_MODE_DISABLED; - dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); -out: - spin_unlock(&drvdata->spinlock); - return ret; + return 0; } static void *smb_alloc_buffer(struct coresight_device *csdev, @@ -395,17 +371,17 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev, struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); struct smb_data_buffer *sdb = &drvdata->sdb; struct cs_buffers *buf = sink_config; - unsigned long data_size = 0; + unsigned long data_size; bool lost = false; if (!buf) return 0; - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); /* Don't do anything if another tracer is using this sink. */ if (atomic_read(&csdev->refcnt) != 1) - goto out; + return 0; smb_disable_hw(drvdata); smb_update_data_size(drvdata); @@ -424,8 +400,6 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev, smb_sync_perf_buffer(drvdata, buf, handle->head); if (!buf->snapshot && lost) perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); -out: - spin_unlock(&drvdata->spinlock); return data_size; }