1 files changed, 159 insertions, 42 deletions

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index ca5183bdad8..2f07cd61566 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -19,6 +19,7 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -26,9 +27,13 @@
 #include <linux/sched.h>
 #include <linux/uaccess.h>
 #include <linux/idr.h>
+#include <linux/mutex.h>
 #include <linux/cdev.h>
 #include <linux/poll.h>
 #include <linux/pps_kernel.h>
+#include <linux/slab.h>
+
+#include "kc.h"
 
 /*
  * Local variables
@@ -37,6 +42,9 @@
 static dev_t pps_devt;
 static struct class *pps_class;
 
+static DEFINE_MUTEX(pps_idr_lock);
+static DEFINE_IDR(pps_idr);
+
 /*
  * Char device methods
  */
@@ -61,15 +69,13 @@ static long pps_cdev_ioctl(struct file *file,
 {
 	struct pps_device *pps = file->private_data;
 	struct pps_kparams params;
-	struct pps_fdata fdata;
-	unsigned long ticks;
 	void __user *uarg = (void __user *) arg;
 	int __user *iuarg = (int __user *) arg;
 	int err;
 
 	switch (cmd) {
 	case PPS_GETPARAMS:
-		pr_debug("PPS_GETPARAMS: source %d\n", pps->id);
+		dev_dbg(pps->dev, "PPS_GETPARAMS\n");
 
 		spin_lock_irq(&pps->lock);
 
@@ -85,7 +91,7 @@ static long pps_cdev_ioctl(struct file *file,
 		break;
 
 	case PPS_SETPARAMS:
-		pr_debug("PPS_SETPARAMS: source %d\n", pps->id);
+		dev_dbg(pps->dev, "PPS_SETPARAMS\n");
 
 		/* Check the capabilities */
 		if (!capable(CAP_SYS_TIME))
@@ -95,14 +101,14 @@ static long pps_cdev_ioctl(struct file *file,
 		if (err)
 			return -EFAULT;
 		if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) {
-			pr_debug("capture mode unspecified (%x)\n",
+			dev_dbg(pps->dev, "capture mode unspecified (%x)\n",
 								params.mode);
 			return -EINVAL;
 		}
 
 		/* Check for supported capabilities */
 		if ((params.mode & ~pps->info.mode) != 0) {
-			pr_debug("unsupported capabilities (%x)\n",
+			dev_dbg(pps->dev, "unsupported capabilities (%x)\n",
 								params.mode);
 			return -EINVAL;
 		}
@@ -115,7 +121,7 @@ static long pps_cdev_ioctl(struct file *file,
 		/* Restore the read only parameters */
 		if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
 			/* section 3.3 of RFC 2783 interpreted */
-			pr_debug("time format unspecified (%x)\n",
+			dev_dbg(pps->dev, "time format unspecified (%x)\n",
 								params.mode);
 			pps->params.mode |= PPS_TSFMT_TSPEC;
 		}
@@ -128,7 +134,7 @@ static long pps_cdev_ioctl(struct file *file,
 		break;
 
 	case PPS_GETCAP:
-		pr_debug("PPS_GETCAP: source %d\n", pps->id);
+		dev_dbg(pps->dev, "PPS_GETCAP\n");
 
 		err = put_user(pps->info.mode, iuarg);
 		if (err)
@@ -136,20 +142,26 @@ static long pps_cdev_ioctl(struct file *file,
 
 		break;
 
-	case PPS_FETCH:
-		pr_debug("PPS_FETCH: source %d\n", pps->id);
+	case PPS_FETCH: {
+		struct pps_fdata fdata;
+		unsigned int ev;
+
+		dev_dbg(pps->dev, "PPS_FETCH\n");
 
 		err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
 		if (err)
 			return -EFAULT;
 
-		pps->go = 0;
+		ev = pps->last_ev;
 
 		/* Manage the timeout */
 		if (fdata.timeout.flags & PPS_TIME_INVALID)
-			err = wait_event_interruptible(pps->queue, pps->go);
+			err = wait_event_interruptible(pps->queue,
+					ev != pps->last_ev);
 		else {
-			pr_debug("timeout %lld.%09d\n",
+			unsigned long ticks;
+
+			dev_dbg(pps->dev, "timeout %lld.%09d\n",
 					(long long) fdata.timeout.sec,
 					fdata.timeout.nsec);
 			ticks = fdata.timeout.sec * HZ;
@@ -157,7 +169,9 @@ static long pps_cdev_ioctl(struct file *file,
 
 			if (ticks != 0) {
 				err = wait_event_interruptible_timeout(
-						pps->queue, pps->go, ticks);
+						pps->queue,
+						ev != pps->last_ev,
+						ticks);
 				if (err == 0)
 					return -ETIMEDOUT;
 			}
@@ -165,7 +179,7 @@ static long pps_cdev_ioctl(struct file *file,
 
 		/* Check for pending signals */
 		if (err == -ERESTARTSYS) {
-			pr_debug("pending signal caught\n");
+			dev_dbg(pps->dev, "pending signal caught\n");
 			return -EINTR;
 		}
 
@@ -185,10 +199,44 @@ static long pps_cdev_ioctl(struct file *file,
 			return -EFAULT;
 
 		break;
+	}
+	case PPS_KC_BIND: {
+		struct pps_bind_args bind_args;
+
+		dev_dbg(pps->dev, "PPS_KC_BIND\n");
+
+		/* Check the capabilities */
+		if (!capable(CAP_SYS_TIME))
+			return -EPERM;
 
+		if (copy_from_user(&bind_args, uarg,
+					sizeof(struct pps_bind_args)))
+			return -EFAULT;
+
+		/* Check for supported capabilities */
+		if ((bind_args.edge & ~pps->info.mode) != 0) {
+			dev_err(pps->dev, "unsupported capabilities (%x)\n",
+					bind_args.edge);
+			return -EINVAL;
+		}
+
+		/* Validate parameters roughly */
+		if (bind_args.tsformat != PPS_TSFMT_TSPEC ||
+				(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 ||
+				bind_args.consumer != PPS_KC_HARDPPS) {
+			dev_err(pps->dev, "invalid kernel consumer bind"
+					" parameters (%x)\n", bind_args.edge);
+			return -EINVAL;
+		}
+
+		err = pps_kc_bind(pps, &bind_args);
+		if (err < 0)
+			return err;
+
+		break;
+	}
 	default:
 		return -ENOTTY;
-		break;
 	}
 
 	return 0;
@@ -198,24 +246,16 @@ static int pps_cdev_open(struct inode *inode, struct file *file)
 {
 	struct pps_device *pps = container_of(inode->i_cdev,
 						struct pps_device, cdev);
-	int found;
-
-	found = pps_get_source(pps->id) != 0;
-	if (!found)
-		return -ENODEV;
-
 	file->private_data = pps;
-
+	kobject_get(&pps->dev->kobj);
 	return 0;
 }
 
 static int pps_cdev_release(struct inode *inode, struct file *file)
 {
-	struct pps_device *pps = file->private_data;
-
-	/* Free the PPS source and wake up (possible) deregistration */
-	pps_put_source(pps);
-
+	struct pps_device *pps = container_of(inode->i_cdev,
+						struct pps_device, cdev);
+	kobject_put(&pps->dev->kobj);
 	return 0;
 }
 
@@ -233,25 +273,64 @@ static const struct file_operations pps_cdev_fops = {
 	.release	= pps_cdev_release,
 };
 
+static void pps_device_destruct(struct device *dev)
+{
+	struct pps_device *pps = dev_get_drvdata(dev);
+
+	cdev_del(&pps->cdev);
+
+	/* Now we can release the ID for re-use */
+	pr_debug("deallocating pps%d\n", pps->id);
+	mutex_lock(&pps_idr_lock);
+	idr_remove(&pps_idr, pps->id);
+	mutex_unlock(&pps_idr_lock);
+
+	kfree(dev);
+	kfree(pps);
+}
+
 int pps_register_cdev(struct pps_device *pps)
 {
 	int err;
+	dev_t devt;
+
+	mutex_lock(&pps_idr_lock);
+	/*
+	 * Get new ID for the new PPS source.  After idr_alloc() calling
+	 * the new source will be freely available into the kernel.
+	 */
+	err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
+	if (err < 0) {
+		if (err == -ENOSPC) {
+			pr_err("%s: too many PPS sources in the system\n",
+			       pps->info.name);
+			err = -EBUSY;
+		}
+		goto out_unlock;
+	}
+	pps->id = err;
+	mutex_unlock(&pps_idr_lock);
+
+	devt = MKDEV(MAJOR(pps_devt), pps->id);
 
-	pps->devno = MKDEV(MAJOR(pps_devt), pps->id);
 	cdev_init(&pps->cdev, &pps_cdev_fops);
 	pps->cdev.owner = pps->info.owner;
 
-	err = cdev_add(&pps->cdev, pps->devno, 1);
+	err = cdev_add(&pps->cdev, devt, 1);
 	if (err) {
-		printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n",
+		pr_err("%s: failed to add char device %d:%d\n",
 				pps->info.name, MAJOR(pps_devt), pps->id);
-		return err;
+		goto free_idr;
 	}
-	pps->dev = device_create(pps_class, pps->info.dev, pps->devno, NULL,
+	pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
 							"pps%d", pps->id);
-	if (IS_ERR(pps->dev))
+	if (IS_ERR(pps->dev)) {
+		err = PTR_ERR(pps->dev);
 		goto del_cdev;
-	dev_set_drvdata(pps->dev, pps);
+	}
+
+	/* Override the release function with our own */
+	pps->dev->release = pps_device_destruct;
 
 	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
 			MAJOR(pps_devt), pps->id);
@@ -261,14 +340,52 @@ int pps_register_cdev(struct pps_device *pps)
 del_cdev:
 	cdev_del(&pps->cdev);
 
+free_idr:
+	mutex_lock(&pps_idr_lock);
+	idr_remove(&pps_idr, pps->id);
+out_unlock:
+	mutex_unlock(&pps_idr_lock);
 	return err;
 }
 
 void pps_unregister_cdev(struct pps_device *pps)
 {
-	device_destroy(pps_class, pps->devno);
-	cdev_del(&pps->cdev);
+	pr_debug("unregistering pps%d\n", pps->id);
+	pps->lookup_cookie = NULL;
+	device_destroy(pps_class, pps->dev->devt);
+}
+
+/*
+ * Look up a pps device by magic cookie.
+ * The cookie is usually a pointer to some enclosing device, but this
+ * code doesn't care; you should never be dereferencing it.
+ *
+ * This is a bit of a kludge that is currently used only by the PPS
+ * serial line discipline.  It may need to be tweaked when a second user
+ * is found.
+ *
+ * There is no function interface for setting the lookup_cookie field.
+ * It's initialized to NULL when the pps device is created, and if a
+ * client wants to use it, just fill it in afterward.
+ *
+ * The cookie is automatically set to NULL in pps_unregister_source()
+ * so that it will not be used again, even if the pps device cannot
+ * be removed from the idr due to pending references holding the minor
+ * number in use.
+ */
+struct pps_device *pps_lookup_dev(void const *cookie)
+{
+	struct pps_device *pps;
+	unsigned id;
+
+	rcu_read_lock();
+	idr_for_each_entry(&pps_idr, pps, id)
+		if (cookie == pps->lookup_cookie)
+			break;
+	rcu_read_unlock();
+	return pps;
 }
+EXPORT_SYMBOL(pps_lookup_dev);
 
 /*
  * Module stuff
@@ -285,15 +402,15 @@ static int __init pps_init(void)
 	int err;
 
 	pps_class = class_create(THIS_MODULE, "pps");
-	if (!pps_class) {
-		printk(KERN_ERR "pps: failed to allocate class\n");
-		return -ENOMEM;
+	if (IS_ERR(pps_class)) {
+		pr_err("failed to allocate class\n");
+		return PTR_ERR(pps_class);
 	}
-	pps_class->dev_attrs = pps_attrs;
+	pps_class->dev_groups = pps_groups;
 
 	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
 	if (err < 0) {
-		printk(KERN_ERR "pps: failed to allocate char device region\n");
+		pr_err("failed to allocate char device region\n");
 		goto remove_class;
 	}