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Violators will be prosecuted for from ; Mon, 26 Mar 2018 12:34:17 -0400 Received: from b01cxnp22036.gho.pok.ibm.com (9.57.198.26) by e15.ny.us.ibm.com (146.89.104.202) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 26 Mar 2018 12:34:15 -0400 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w2QGYEYd57147518; Mon, 26 Mar 2018 16:34:14 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D5146AC03A; Mon, 26 Mar 2018 12:35:33 -0400 (EDT) Received: from p8tul1-build.aus.stglabs.ibm.com (unknown [9.3.141.206]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP id 2BCDEAC03F; Mon, 26 Mar 2018 12:35:33 -0400 (EDT) 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 v3 28/41] cxlflash: Support adapter context reading Date: Mon, 26 Mar 2018 11:34:12 -0500 X-Mailer: git-send-email 2.1.0 In-Reply-To: <1522081759-57431-1-git-send-email-ukrishn@linux.vnet.ibm.com> References: <1522081759-57431-1-git-send-email-ukrishn@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18032616-0036-0000-0000-000002D63730 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008748; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000255; SDB=6.01008739; UDB=6.00513807; IPR=6.00788022; MB=3.00020251; MTD=3.00000008; XFM=3.00000015; UTC=2018-03-26 16:34:16 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18032616-0037-0000-0000-000043C4C13B Message-Id: <1522082052-58489-1-git-send-email-ukrishn@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-03-26_07:, , 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-1803260169 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 655377d..f531403 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" @@ -937,9 +940,99 @@ 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) \ @@ -985,6 +1078,7 @@ 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;