From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wtQCV0S3RzDr8r for ; Thu, 22 Jun 2017 12:15:17 +1000 (AEST) Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v5M2EgqI034697 for ; Wed, 21 Jun 2017 22:15:15 -0400 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0a-001b2d01.pphosted.com with ESMTP id 2b7w13m1jk-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 21 Jun 2017 22:15:15 -0400 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 21 Jun 2017 20:15:14 -0600 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, Ian Munsie , Andrew Donnellan , Frederic Barrat , Christophe Lombard Subject: [PATCH 08/17] cxlflash: Add scsi command abort handler Date: Wed, 21 Jun 2017 21:15:06 -0500 In-Reply-To: <1498097563-8680-1-git-send-email-ukrishn@linux.vnet.ibm.com> References: <1498097563-8680-1-git-send-email-ukrishn@linux.vnet.ibm.com> Message-Id: <1498097706-8970-1-git-send-email-ukrishn@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To date, CXL flash devices do not support a single command abort operation. Instead, the SISLite specification provides a context reset operation to cleanup all pending commands for a given context. When a context reset is successful, it is guaranteed that the AFU has aborted all currently pending I/O. This sequence is less invasive than a device or host reset and can be executed to support scsi command abort requests. Add eh_abort_handler callback support to process command timeouts and abort requests. Signed-off-by: Uma Krishnan --- drivers/scsi/cxlflash/main.c | 61 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index 0a3de42..ceb247b 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -228,6 +228,10 @@ static void flush_pending_cmds(struct hwq *hwq) * @hwq: Hardware queue owning the context to be reset. * @reset_reg: MMIO register to perform reset. * + * When the reset is successful, the SISLite specification guarantees that + * the AFU has aborted all currently pending I/O. Accordingly, these commands + * must be flushed. + * * Return: 0 on success, -errno on failure */ static int context_reset(struct hwq *hwq, __be64 __iomem *reset_reg) @@ -237,9 +241,12 @@ static int context_reset(struct hwq *hwq, __be64 __iomem *reset_reg) int rc = -ETIMEDOUT; int nretry = 0; u64 val = 0x1; + ulong lock_flags; dev_dbg(dev, "%s: hwq=%p\n", __func__, hwq); + spin_lock_irqsave(&hwq->hsq_slock, lock_flags); + writeq_be(val, reset_reg); do { val = readq_be(reset_reg); @@ -252,6 +259,11 @@ static int context_reset(struct hwq *hwq, __be64 __iomem *reset_reg) udelay(1 << nretry); } while (nretry++ < MC_ROOM_RETRY_CNT); + if (!rc) + flush_pending_cmds(hwq); + + spin_unlock_irqrestore(&hwq->hsq_slock, lock_flags); + dev_dbg(dev, "%s: returning rc=%d, val=%016llx nretry=%d\n", __func__, rc, val, nretry); return rc; @@ -2256,6 +2268,54 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u, } /** + * cxlflash_eh_abort_handler() - abort a SCSI command + * @scp: SCSI command to abort. + * + * CXL Flash devices do not support a single command abort. Reset the context + * as per SISLite specification. Flush any pending commands in the hardware + * queue before the reset. + * + * Return: SUCCESS/FAILED as defined in scsi/scsi.h + */ +static int cxlflash_eh_abort_handler(struct scsi_cmnd *scp) +{ + int rc = FAILED; + struct Scsi_Host *host = scp->device->host; + struct cxlflash_cfg *cfg = shost_priv(host); + struct afu_cmd *cmd = sc_to_afuc(scp); + struct device *dev = &cfg->dev->dev; + struct afu *afu = cfg->afu; + struct hwq *hwq = get_hwq(afu, cmd->hwq_index); + + dev_dbg(dev, "%s: (scp=%p) %d/%d/%d/%llu " + "cdb=(%08x-%08x-%08x-%08x)\n", __func__, scp, host->host_no, + scp->device->channel, scp->device->id, scp->device->lun, + get_unaligned_be32(&((u32 *)scp->cmnd)[0]), + get_unaligned_be32(&((u32 *)scp->cmnd)[1]), + get_unaligned_be32(&((u32 *)scp->cmnd)[2]), + get_unaligned_be32(&((u32 *)scp->cmnd)[3])); + + /* When the state is not normal, another reset/reload is in progress. + * Return failed and the mid-layer will invoke host reset handler. + */ + if (cfg->state != STATE_NORMAL) { + dev_dbg(dev, "%s: Invalid state for abort, state=%d\n", + __func__, cfg->state); + goto out; + } + + rc = afu->context_reset(hwq); + if (unlikely(rc)) + goto out; + + rc = SUCCESS; + +out: + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** * cxlflash_eh_device_reset_handler() - reset a single LUN * @scp: SCSI command to send. * @@ -2969,6 +3029,7 @@ static struct scsi_host_template driver_template = { .ioctl = cxlflash_ioctl, .proc_name = CXLFLASH_NAME, .queuecommand = cxlflash_queuecommand, + .eh_abort_handler = cxlflash_eh_abort_handler, .eh_device_reset_handler = cxlflash_eh_device_reset_handler, .eh_host_reset_handler = cxlflash_eh_host_reset_handler, .change_queue_depth = cxlflash_change_queue_depth, -- 2.1.0