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James" Subject: [PATCH linux dev-4.10 v2 6/9] drivers: fsi: occ: Add cancel to remove() and fix probe() Date: Fri, 29 Sep 2017 17:41:05 -0500 X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1506724868-13010-1-git-send-email-eajames@linux.vnet.ibm.com> References: <1506724868-13010-1-git-send-email-eajames@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17092922-0024-0000-0000-000017452340 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007813; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000233; SDB=6.00924260; UDB=6.00464728; IPR=6.00704398; BA=6.00005613; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017330; XFM=3.00000015; UTC=2017-09-29 22:41:29 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17092922-0025-0000-0000-00004CEAABB5 Message-Id: <1506724868-13010-7-git-send-email-eajames@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-09-29_06:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1709290322 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 29 Sep 2017 22:41:34 -0000 From: "Edward A. James" Need some data to indicate to clients and the rest of the driver when the device is being removed, so add a cancel boolean. Fix up both the probe and remove functions to properly handle failures and prevent deadlocks. Signed-off-by: Edward A. James --- drivers/fsi/occ.c | 86 +++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 62 insertions(+), 24 deletions(-) diff --git a/drivers/fsi/occ.c b/drivers/fsi/occ.c index a554550..550ae11 100644 --- a/drivers/fsi/occ.c +++ b/drivers/fsi/occ.c @@ -46,6 +46,7 @@ struct occ { spinlock_t list_lock; /* lock access to the xfrs list */ struct mutex occ_lock; /* lock access to the hardware */ struct work_struct work; + bool cancel; }; #define to_occ(x) container_of((x), struct occ, mdev) @@ -117,12 +118,15 @@ struct occ_client { static DEFINE_IDA(occ_ida); -static void occ_enqueue_xfr(struct occ_xfr *xfr) +static int occ_enqueue_xfr(struct occ_xfr *xfr) { int empty; struct occ_client *client = to_client(xfr); struct occ *occ = client->occ; + if (occ->cancel) + return -ECANCELED; + spin_lock_irq(&occ->list_lock); empty = list_empty(&occ->xfrs); @@ -132,14 +136,20 @@ static void occ_enqueue_xfr(struct occ_xfr *xfr) if (empty) queue_work(occ_wq, &occ->work); + + return 0; } static struct occ_client *occ_open_common(struct occ *occ, unsigned long flags) { - struct occ_client *client = kzalloc(sizeof(*client), GFP_KERNEL); + struct occ_client *client; + + if (occ->cancel) + return ERR_PTR(-ECANCELED); + client = kzalloc(sizeof(*client), GFP_KERNEL); if (!client) - return NULL; + return ERR_PTR(-ENOMEM); client->occ = occ; spin_lock_init(&client->lock); @@ -158,8 +168,8 @@ static int occ_open(struct inode *inode, struct file *file) struct occ *occ = to_occ(mdev); client = occ_open_common(occ, file->f_flags); - if (!client) - return -ENOMEM; + if (IS_ERR(client)) + return PTR_ERR(client); file->private_data = client; @@ -172,6 +182,7 @@ static ssize_t occ_read_common(struct occ_client *client, char __user *ubuf, int rc; size_t bytes; struct occ_xfr *xfr = &client->xfr; + struct occ *occ = client->occ; if (len > OCC_SRAM_BYTES) return -EINVAL; @@ -204,7 +215,8 @@ static ssize_t occ_read_common(struct occ_client *client, char __user *ubuf, test_bit(XFR_COMPLETE, &xfr->flags) || test_bit(XFR_CANCELED, - &xfr->flags)); + &xfr->flags) || + occ->cancel); spin_lock_irq(&client->lock); @@ -272,7 +284,7 @@ static ssize_t occ_write_common(struct occ_client *client, spin_lock_irq(&client->lock); - if (test_and_set_bit(CLIENT_XFR_PENDING, &client->flags)) { + if (test_bit(CLIENT_XFR_PENDING, &client->flags)) { rc = -EBUSY; goto done; } @@ -309,8 +321,11 @@ static ssize_t occ_write_common(struct occ_client *client, xfr->cmd_data_length = data_length + 6; client->read_offset = 0; - occ_enqueue_xfr(xfr); + rc = occ_enqueue_xfr(xfr); + if (rc) + goto done; + set_bit(CLIENT_XFR_PENDING, &client->flags); rc = len; done: @@ -579,6 +594,9 @@ static void occ_worker(struct work_struct *work) struct device *sbefifo = occ->sbefifo; again: + if (occ->cancel) + return; + spin_lock_irq(&occ->list_lock); xfr = list_first_entry_or_null(&occ->xfrs, struct occ_xfr, link); @@ -672,12 +690,17 @@ static void occ_worker(struct work_struct *work) struct occ_client *occ_drv_open(struct device *dev, unsigned long flags) { + struct occ_client *client; struct occ *occ = dev_get_drvdata(dev); if (!occ) return NULL; - return occ_open_common(occ, flags); + client = occ_open_common(occ, flags); + if (IS_ERR(client)) + return NULL; + + return client; } EXPORT_SYMBOL_GPL(occ_drv_open); @@ -748,23 +771,13 @@ static int occ_probe(struct platform_device *pdev) if (occ->idx < 0) occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX, GFP_KERNEL); - } else + } else { occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX, GFP_KERNEL); - - /* create platform devs for dts child nodes (hwmon, etc) */ - for_each_child_of_node(dev->of_node, np) { - snprintf(child_name, sizeof(child_name), "occ%d-dev%d", - occ->idx, child_idx++); - child = of_platform_device_create(np, child_name, dev); - if (!child) - dev_warn(dev, - "failed to create child node dev\n"); } - } else + } else { occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX, GFP_KERNEL); - - platform_set_drvdata(pdev, occ); + } snprintf(occ->name, sizeof(occ->name), "occ%d", occ->idx); occ->mdev.fops = &occ_fops; @@ -774,20 +787,45 @@ static int occ_probe(struct platform_device *pdev) rc = misc_register(&occ->mdev); if (rc) { - dev_err(dev, "failed to register miscdevice\n"); + dev_err(dev, "failed to register miscdevice: %d\n", rc); + ida_simple_remove(&occ_ida, occ->idx); return rc; } + /* create platform devs for dts child nodes (hwmon, etc) */ + for_each_available_child_of_node(dev->of_node, np) { + snprintf(child_name, sizeof(child_name), "occ%d-dev%d", + occ->idx, child_idx++); + child = of_platform_device_create(np, child_name, dev); + if (!child) + dev_warn(dev, "failed to create child node dev\n"); + } + + platform_set_drvdata(pdev, occ); + return 0; } static int occ_remove(struct platform_device *pdev) { struct occ *occ = platform_get_drvdata(pdev); + struct occ_xfr *xfr; + struct occ_client *client; + + occ->cancel = true; + + spin_lock_irq(&occ->list_lock); + list_for_each_entry(xfr, &occ->xfrs, link) { + client = to_client(xfr); + wake_up_interruptible(&client->wait); + } + spin_unlock_irq(&occ->list_lock); - flush_work(&occ->work); misc_deregister(&occ->mdev); device_for_each_child(&pdev->dev, NULL, occ_unregister_child); + + cancel_work_sync(&occ->work); + ida_simple_remove(&occ_ida, occ->idx); return 0; -- 1.8.3.1