From patchwork Mon Feb 26 22:23:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uma Krishnan X-Patchwork-Id: 10243843 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9B54B602A0 for ; Mon, 26 Feb 2018 22:23:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7F8D92A43A for ; Mon, 26 Feb 2018 22:23:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 72B882A443; Mon, 26 Feb 2018 22:23:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E822D2A43A for ; Mon, 26 Feb 2018 22:23:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751668AbeBZWX5 (ORCPT ); Mon, 26 Feb 2018 17:23:57 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:54896 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877AbeBZWX4 (ORCPT ); Mon, 26 Feb 2018 17:23:56 -0500 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1QMKdw2108855 for ; Mon, 26 Feb 2018 17:23:56 -0500 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0a-001b2d01.pphosted.com with ESMTP id 2gcpa1k6kc-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 26 Feb 2018 17:23:56 -0500 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 26 Feb 2018 17:23:55 -0500 Received: from b01cxnp22035.gho.pok.ibm.com (9.57.198.25) by e15.ny.us.ibm.com (146.89.104.202) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 26 Feb 2018 17:23:53 -0500 Received: from b01ledav001.gho.pok.ibm.com (b01ledav001.gho.pok.ibm.com [9.57.199.106]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w1QMNqDl48758956; Mon, 26 Feb 2018 22:23:52 GMT Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2C5F12803A; Mon, 26 Feb 2018 17:23:16 -0500 (EST) Received: from p8tul1-build.aus.stglabs.ibm.com (unknown [9.3.141.206]) by b01ledav001.gho.pok.ibm.com (Postfix) with ESMTP id 787E22803E; Mon, 26 Feb 2018 17:23:15 -0500 (EST) From: Uma Krishnan To: linux-scsi@vger.kernel.org, James Bottomley , "Martin K. Petersen" , "Matthew R. Ochs" , "Manoj N. Kumar" Cc: linuxppc-dev@lists.ozlabs.org, Andrew Donnellan , Frederic Barrat , Christophe Lombard Subject: [PATCH v2 28/38] cxlflash: Support adapter context reading Date: Mon, 26 Feb 2018 16:23:50 -0600 X-Mailer: git-send-email 2.1.0 In-Reply-To: <1519683513-16731-1-git-send-email-ukrishn@linux.vnet.ibm.com> References: <1519683513-16731-1-git-send-email-ukrishn@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18022622-0036-0000-0000-000002C6DB28 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008601; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000254; SDB=6.00995540; UDB=6.00506039; IPR=6.00774869; MB=3.00019751; MTD=3.00000008; XFM=3.00000015; UTC=2018-02-26 22:23:54 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022622-0037-0000-0000-0000437851D0 Message-Id: <1519683830-17763-1-git-send-email-ukrishn@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-26_08:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802260280 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The cxlflash userspace API requires that users be able to read the adapter context for any pending events or interrupts from the AFU. Support reading various events by implementing the AFU read fop to copy out event data. Signed-off-by: Uma Krishnan Acked-by: Matthew R. Ochs --- drivers/scsi/cxlflash/ocxl_hw.c | 94 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) diff --git a/drivers/scsi/cxlflash/ocxl_hw.c b/drivers/scsi/cxlflash/ocxl_hw.c index b49136a..a6ae9fd 100644 --- a/drivers/scsi/cxlflash/ocxl_hw.c +++ b/drivers/scsi/cxlflash/ocxl_hw.c @@ -17,9 +17,12 @@ #include #include #include +#include #include +#include + #include "backend.h" #include "ocxl_hw.h" @@ -929,9 +932,99 @@ static unsigned int afu_poll(struct file *file, struct poll_table_struct *poll) return mask; } +/** + * afu_read() - perform a read on the context for any event + * @file: File associated with the adapter context. + * @buf: Buffer to receive the data. + * @count: Size of buffer (maximum bytes that can be read). + * @off: Offset. + * + * Return: size of the data read on success, -errno on failure + */ +static ssize_t afu_read(struct file *file, char __user *buf, size_t count, + loff_t *off) +{ + struct ocxlflash_context *ctx = file->private_data; + struct device *dev = ctx->hw_afu->dev; + struct cxl_event event; + ulong lock_flags; + ssize_t esize; + ssize_t rc; + int bit; + DEFINE_WAIT(event_wait); + + if (*off != 0) { + dev_err(dev, "%s: Non-zero offset not supported, off=%lld\n", + __func__, *off); + rc = -EINVAL; + goto out; + } + + spin_lock_irqsave(&ctx->slock, lock_flags); + + for (;;) { + prepare_to_wait(&ctx->wq, &event_wait, TASK_INTERRUPTIBLE); + + if (ctx_event_pending(ctx)) + break; + + if (file->f_flags & O_NONBLOCK) { + dev_err(dev, "%s: File cannot be blocked on I/O\n", + __func__); + rc = -EAGAIN; + goto err; + } + + if (signal_pending(current)) { + dev_err(dev, "%s: Signal pending on the process\n", + __func__); + rc = -ERESTARTSYS; + goto err; + } + + spin_unlock_irqrestore(&ctx->slock, lock_flags); + schedule(); + spin_lock_irqsave(&ctx->slock, lock_flags); + } + + finish_wait(&ctx->wq, &event_wait); + + memset(&event, 0, sizeof(event)); + event.header.process_element = ctx->pe; + event.header.size = sizeof(struct cxl_event_header); + if (ctx->pending_irq) { + esize = sizeof(struct cxl_event_afu_interrupt); + event.header.size += esize; + event.header.type = CXL_EVENT_AFU_INTERRUPT; + + bit = find_first_bit(&ctx->irq_bitmap, ctx->num_irqs); + clear_bit(bit, &ctx->irq_bitmap); + event.irq.irq = bit + 1; + if (bitmap_empty(&ctx->irq_bitmap, ctx->num_irqs)) + ctx->pending_irq = false; + } + + spin_unlock_irqrestore(&ctx->slock, lock_flags); + + if (copy_to_user(buf, &event, event.header.size)) { + dev_err(dev, "%s: copy_to_user failed\n", __func__); + rc = -EFAULT; + goto out; + } + + rc = event.header.size; +out: + return rc; +err: + finish_wait(&ctx->wq, &event_wait); + spin_unlock_irqrestore(&ctx->slock, lock_flags); + goto out; +} + static const struct file_operations ocxl_afu_fops = { .owner = THIS_MODULE, .poll = afu_poll, + .read = afu_read, }; #define PATCH_FOPS(NAME) \ @@ -977,6 +1070,7 @@ static struct file *ocxlflash_get_fd(void *ctx_cookie, /* Patch the file ops that are not defined */ if (fops) { PATCH_FOPS(poll); + PATCH_FOPS(read); } else /* Use default ops */ fops = (struct file_operations *)&ocxl_afu_fops;