From patchwork Thu Feb 22 22:28:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uma Krishnan X-Patchwork-Id: 10236537 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 9293660224 for ; Thu, 22 Feb 2018 22:28:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8CFC228E3E for ; Thu, 22 Feb 2018 22:28:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 81D7828E42; Thu, 22 Feb 2018 22:28:24 +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 EB38F28DE6 for ; Thu, 22 Feb 2018 22:28:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751910AbeBVW2X (ORCPT ); Thu, 22 Feb 2018 17:28:23 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:37620 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751731AbeBVW2W (ORCPT ); Thu, 22 Feb 2018 17:28:22 -0500 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1MMSLnS057815 for ; Thu, 22 Feb 2018 17:28:21 -0500 Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ga25r2ach-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 22 Feb 2018 17:28:21 -0500 Received: from localhost by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 22 Feb 2018 15:28:20 -0700 Received: from b03cxnp08028.gho.boulder.ibm.com (9.17.130.20) by e38.co.us.ibm.com (192.168.1.138) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Thu, 22 Feb 2018 15:28:18 -0700 Received: from b03ledav001.gho.boulder.ibm.com (b03ledav001.gho.boulder.ibm.com [9.17.130.232]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w1MMSIUw11206990; Thu, 22 Feb 2018 15:28:18 -0700 Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3F5E46E048; Thu, 22 Feb 2018 15:28:18 -0700 (MST) Received: from p8tul1-build.aus.stglabs.ibm.com (unknown [9.3.141.206]) by b03ledav001.gho.boulder.ibm.com (Postfix) with ESMTP id C7BB86E038; Thu, 22 Feb 2018 15:28:17 -0700 (MST) 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 35/38] cxlflash: Introduce OCXL context state machine Date: Thu, 22 Feb 2018 16:28:16 -0600 X-Mailer: git-send-email 2.1.0 In-Reply-To: <1519338010-51782-1-git-send-email-ukrishn@linux.vnet.ibm.com> References: <1519338010-51782-1-git-send-email-ukrishn@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18022222-0028-0000-0000-00000935EBF8 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008579; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000254; SDB=6.00993626; UDB=6.00504906; IPR=6.00772966; MB=3.00019695; MTD=3.00000008; XFM=3.00000015; UTC=2018-02-22 22:28:19 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022222-0029-0000-0000-000039B59C50 Message-Id: <1519338496-53048-1-git-send-email-ukrishn@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-22_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-1802220278 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 In order to protect the OCXL hardware contexts from getting clobbered, a simple state machine is added to indicate when a context is in open, close or start state. The expected states are validated throughout the code to prevent illegal operations on a context. A mutex is added to protect writes to the context state field. Signed-off-by: Uma Krishnan --- drivers/scsi/cxlflash/ocxl_hw.c | 59 ++++++++++++++++++++++++++++++++++++++--- drivers/scsi/cxlflash/ocxl_hw.h | 8 ++++++ 2 files changed, 64 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/cxlflash/ocxl_hw.c b/drivers/scsi/cxlflash/ocxl_hw.c index 1044bee..535b21a 100644 --- a/drivers/scsi/cxlflash/ocxl_hw.c +++ b/drivers/scsi/cxlflash/ocxl_hw.c @@ -163,6 +163,16 @@ static struct file *ocxlflash_getfile(struct device *dev, const char *name, static void __iomem *ocxlflash_psa_map(void *ctx_cookie) { struct ocxlflash_context *ctx = ctx_cookie; + struct device *dev = ctx->hw_afu->dev; + + mutex_lock(&ctx->state_mutex); + if (ctx->state != STARTED) { + dev_err(dev, "%s: Context not started, state=%d\n", __func__, + ctx->state); + mutex_unlock(&ctx->state_mutex); + return NULL; + } + mutex_unlock(&ctx->state_mutex); return ioremap(ctx->psn_phys, ctx->psn_size); } @@ -343,6 +353,14 @@ static int start_context(struct ocxlflash_context *ctx) int rc = 0; u32 pid; + mutex_lock(&ctx->state_mutex); + if (ctx->state != OPENED) { + dev_err(dev, "%s: Context state invalid, state=%d\n", + __func__, ctx->state); + rc = -EINVAL; + goto out; + } + if (master) { ctx->psn_size = acfg->global_mmio_size; ctx->psn_phys = afu->gmmio_phys; @@ -366,7 +384,10 @@ static int start_context(struct ocxlflash_context *ctx) __func__, rc); goto out; } + + ctx->state = STARTED; out: + mutex_unlock(&ctx->state_mutex); return rc; } @@ -396,7 +417,15 @@ static int ocxlflash_stop_context(void *ctx_cookie) struct ocxl_afu_config *acfg = &afu->acfg; struct pci_dev *pdev = afu->pdev; struct device *dev = afu->dev; - int rc; + enum ocxlflash_ctx_state state; + int rc = 0; + + mutex_lock(&ctx->state_mutex); + state = ctx->state; + ctx->state = CLOSED; + mutex_unlock(&ctx->state_mutex); + if (state != STARTED) + goto out; rc = ocxl_config_terminate_pasid(pdev, acfg->dvsec_afu_control_pos, ctx->pe); @@ -474,7 +503,9 @@ static void *ocxlflash_dev_context_init(struct pci_dev *pdev, void *afu_cookie) spin_lock_init(&ctx->slock); init_waitqueue_head(&ctx->wq); + mutex_init(&ctx->state_mutex); + ctx->state = OPENED; ctx->pe = rc; ctx->master = false; ctx->mapping = NULL; @@ -499,11 +530,23 @@ static void *ocxlflash_dev_context_init(struct pci_dev *pdev, void *afu_cookie) static int ocxlflash_release_context(void *ctx_cookie) { struct ocxlflash_context *ctx = ctx_cookie; + struct device *dev; int rc = 0; if (!ctx) goto out; + dev = ctx->hw_afu->dev; + mutex_lock(&ctx->state_mutex); + if (ctx->state >= STARTED) { + dev_err(dev, "%s: Context in use, state=%d\n", __func__, + ctx->state); + mutex_unlock(&ctx->state_mutex); + rc = -EBUSY; + goto out; + } + mutex_unlock(&ctx->state_mutex); + idr_remove(&ctx->hw_afu->idr, ctx->pe); ocxlflash_release_mapping(ctx); kfree(ctx); @@ -939,7 +982,7 @@ static unsigned int afu_poll(struct file *file, struct poll_table_struct *poll) spin_lock_irqsave(&ctx->slock, lock_flags); if (ctx_event_pending(ctx)) mask |= POLLIN | POLLRDNORM; - else + else if (ctx->state == CLOSED) mask |= POLLERR; spin_unlock_irqrestore(&ctx->slock, lock_flags); @@ -982,7 +1025,7 @@ static ssize_t afu_read(struct file *file, char __user *buf, size_t count, for (;;) { prepare_to_wait(&ctx->wq, &event_wait, TASK_INTERRUPTIBLE); - if (ctx_event_pending(ctx)) + if (ctx_event_pending(ctx) || (ctx->state == CLOSED)) break; if (file->f_flags & O_NONBLOCK) { @@ -1068,12 +1111,22 @@ static int ocxlflash_mmap_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct ocxlflash_context *ctx = vma->vm_file->private_data; + struct device *dev = ctx->hw_afu->dev; u64 mmio_area, offset; offset = vmf->pgoff << PAGE_SHIFT; if (offset >= ctx->psn_size) return VM_FAULT_SIGBUS; + mutex_lock(&ctx->state_mutex); + if (ctx->state != STARTED) { + dev_err(dev, "%s: Context not started, state=%d\n", + __func__, ctx->state); + mutex_unlock(&ctx->state_mutex); + return VM_FAULT_SIGBUS; + } + mutex_unlock(&ctx->state_mutex); + mmio_area = ctx->psn_phys; mmio_area += offset; diff --git a/drivers/scsi/cxlflash/ocxl_hw.h b/drivers/scsi/cxlflash/ocxl_hw.h index bdf9422..c23b681 100644 --- a/drivers/scsi/cxlflash/ocxl_hw.h +++ b/drivers/scsi/cxlflash/ocxl_hw.h @@ -45,6 +45,12 @@ struct ocxl_hw_afu { int max_pasid; /* Maximum number of contexts */ }; +enum ocxlflash_ctx_state { + CLOSED, + OPENED, + STARTED +}; + struct ocxlflash_context { struct ocxl_hw_afu *hw_afu; /* HW AFU back pointer */ struct address_space *mapping; /* Mapping for pseudo filesystem */ @@ -56,6 +62,8 @@ struct ocxlflash_context { spinlock_t slock; /* Protects irq/fault/event updates */ wait_queue_head_t wq; /* Wait queue for poll and interrupts */ + struct mutex state_mutex; /* Mutex to update context state */ + enum ocxlflash_ctx_state state; /* Context state */ struct ocxlflash_irqs *irqs; /* Pointer to array of structures */ int num_irqs; /* Number of interrupts */