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James" Subject: [PATCH linux dev-4.10 v2 2/9] drivers: fsi: SBEFIFO: Fix probe() and remove() Date: Fri, 29 Sep 2017 17:41:01 -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: 17092922-0024-0000-0000-000017452337 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 22:41:19 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17092922-0025-0000-0000-00004CEAABA1 Message-Id: <1506724868-13010-3-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 22:41:24 -0000 X-List-Received-Date: Fri, 29 Sep 2017 22:41:24 -0000 From: "Edward A. James" Probe didn't handle a failed misc device registration properly. Remove had the potential for hangs. Also, remove the list of SBEFIFOs and instead just use the device "driver data" pointer. Signed-off-by: Edward A. James --- drivers/fsi/fsi-sbefifo.c | 109 ++++++++++++++++++++++------------------------ 1 file changed, 52 insertions(+), 57 deletions(-) diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c index a4cd353..fa34bd8 100644 --- a/drivers/fsi/fsi-sbefifo.c +++ b/drivers/fsi/fsi-sbefifo.c @@ -58,7 +58,6 @@ struct sbefifo { struct fsi_device *fsi_dev; struct miscdevice mdev; wait_queue_head_t wait; - struct list_head link; struct list_head xfrs; struct kref kref; spinlock_t lock; @@ -96,8 +95,6 @@ struct sbefifo_client { unsigned long f_flags; }; -static struct list_head sbefifo_fifos; - static DEFINE_IDA(sbefifo_ida); static int sbefifo_inw(struct sbefifo *sbefifo, int reg, u32 *word) @@ -267,9 +264,12 @@ static struct sbefifo_xfr *sbefifo_enq_xfr(struct sbefifo_client *client) struct sbefifo *sbefifo = client->dev; struct sbefifo_xfr *xfr; + if (READ_ONCE(sbefifo->rc)) + return ERR_PTR(sbefifo->rc); + xfr = kzalloc(sizeof(*xfr), GFP_KERNEL); if (!xfr) - return NULL; + return ERR_PTR(-ENOMEM); xfr->rbuf = &client->rbuf; xfr->wbuf = &client->wbuf; @@ -490,7 +490,7 @@ static void sbefifo_poll_timer(unsigned long data) } sbefifo_put(sbefifo); - wake_up(&sbefifo->wait); + wake_up_interruptible(&sbefifo->wait); out_unlock: spin_unlock(&sbefifo->lock); @@ -604,7 +604,7 @@ static ssize_t sbefifo_read_common(struct sbefifo_client *client, } else { kfree(xfr); list_del(&xfr->client); - wake_up(&sbefifo->wait); + wake_up_interruptible(&sbefifo->wait); } } @@ -664,7 +664,7 @@ static ssize_t sbefifo_write_common(struct sbefifo_client *client, } xfr = sbefifo_enq_xfr(client); /* this xfr queued up */ - if (!xfr) { + if (IS_ERR(xfr)) { spin_unlock_irq(&sbefifo->lock); ret = PTR_ERR(xfr); goto out; @@ -766,18 +766,15 @@ static int sbefifo_release(struct inode *inode, struct file *file) struct sbefifo_client *sbefifo_drv_open(struct device *dev, unsigned long flags) { - struct sbefifo_client *client = NULL; - struct sbefifo *sbefifo; - struct fsi_device *fsi_dev = to_fsi_dev(dev); + struct sbefifo_client *client; + struct sbefifo *sbefifo = dev_get_drvdata(dev); - list_for_each_entry(sbefifo, &sbefifo_fifos, link) { - if (sbefifo->fsi_dev != fsi_dev) - continue; + if (!sbefifo) + return NULL; - client = sbefifo_new_client(sbefifo); - if (client) - client->f_flags = flags; - } + client = sbefifo_new_client(sbefifo); + if (client) + client->f_flags = flags; return client; } @@ -850,69 +847,68 @@ static int sbefifo_probe(struct device *dev) return -EIO; } - sbefifo->mdev.minor = MISC_DYNAMIC_MINOR; - sbefifo->mdev.fops = &sbefifo_fops; - sbefifo->mdev.name = sbefifo->name; - sbefifo->mdev.parent = dev; spin_lock_init(&sbefifo->lock); kref_init(&sbefifo->kref); + init_waitqueue_head(&sbefifo->wait); + INIT_LIST_HEAD(&sbefifo->xfrs); sbefifo->idx = ida_simple_get(&sbefifo_ida, 1, INT_MAX, GFP_KERNEL); snprintf(sbefifo->name, sizeof(sbefifo->name), "sbefifo%d", sbefifo->idx); - init_waitqueue_head(&sbefifo->wait); - INIT_LIST_HEAD(&sbefifo->xfrs); /* This bit of silicon doesn't offer any interrupts... */ setup_timer(&sbefifo->poll_timer, sbefifo_poll_timer, (unsigned long)sbefifo); - if (dev->of_node) { - /* create platform devs for dts child nodes (occ, etc) */ - for_each_child_of_node(dev->of_node, np) { - snprintf(child_name, sizeof(child_name), "%s-dev%d", - sbefifo->name, child_idx++); - child = of_platform_device_create(np, child_name, dev); - if (!child) - dev_warn(dev, - "failed to create child node dev\n"); - } + sbefifo->mdev.minor = MISC_DYNAMIC_MINOR; + sbefifo->mdev.fops = &sbefifo_fops; + sbefifo->mdev.name = sbefifo->name; + sbefifo->mdev.parent = dev; + ret = misc_register(&sbefifo->mdev); + if (ret) { + dev_err(dev, "failed to register miscdevice: %d\n", ret); + ida_simple_remove(&sbefifo_ida, sbefifo->idx); + sbefifo_put(sbefifo); + return ret; } - list_add(&sbefifo->link, &sbefifo_fifos); - - return misc_register(&sbefifo->mdev); + /* create platform devs for dts child nodes (occ, etc) */ + for_each_available_child_of_node(dev->of_node, np) { + snprintf(child_name, sizeof(child_name), "%s-dev%d", + sbefifo->name, child_idx++); + child = of_platform_device_create(np, child_name, dev); + if (!child) + dev_warn(dev, "failed to create child %s dev\n", + child_name); + } + + dev_set_drvdata(dev, sbefifo); + + return 0; } static int sbefifo_remove(struct device *dev) { - struct fsi_device *fsi_dev = to_fsi_dev(dev); - struct sbefifo *sbefifo, *sbefifo_tmp; + struct sbefifo *sbefifo = dev_get_drvdata(dev); struct sbefifo_xfr *xfr; - list_for_each_entry_safe(sbefifo, sbefifo_tmp, &sbefifo_fifos, link) { - if (sbefifo->fsi_dev != fsi_dev) - continue; + WRITE_ONCE(sbefifo->rc, -ENODEV); + wake_up_interruptible_all(&sbefifo->wait); - device_for_each_child(dev, NULL, sbefifo_unregister_child); + misc_deregister(&sbefifo->mdev); + device_for_each_child(dev, NULL, sbefifo_unregister_child); - misc_deregister(&sbefifo->mdev); - list_del(&sbefifo->link); - ida_simple_remove(&sbefifo_ida, sbefifo->idx); - - if (del_timer_sync(&sbefifo->poll_timer)) - sbefifo_put(sbefifo); + ida_simple_remove(&sbefifo_ida, sbefifo->idx); - spin_lock(&sbefifo->lock); - list_for_each_entry(xfr, &sbefifo->xfrs, xfrs) - kfree(xfr); - spin_unlock(&sbefifo->lock); + if (del_timer_sync(&sbefifo->poll_timer)) + sbefifo_put(sbefifo); - WRITE_ONCE(sbefifo->rc, -ENODEV); + spin_lock(&sbefifo->lock); + list_for_each_entry(xfr, &sbefifo->xfrs, xfrs) + kfree(xfr); + spin_unlock(&sbefifo->lock); - wake_up(&sbefifo->wait); - sbefifo_put(sbefifo); - } + sbefifo_put(sbefifo); return 0; } @@ -937,7 +933,6 @@ static int sbefifo_remove(struct device *dev) static int sbefifo_init(void) { - INIT_LIST_HEAD(&sbefifo_fifos); return fsi_driver_register(&sbefifo_drv); } -- 1.8.3.1