Merge commit '31d9adca82ce65e5c99d045b5fd917c702b6fce3' into tmp

Conflicts:
	arch/arm/plat-omap/dmtimer.c

5 files changed, 81 insertions, 42 deletions

diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
index 445197d..6efd9b6 100644
--- a/drivers/pps/clients/Kconfig
+++ b/drivers/pps/clients/Kconfig
@@ -17,7 +17,7 @@ config PPS_CLIENT_KTIMER
 
 config PPS_CLIENT_LDISC
 	tristate "PPS line discipline"
-	depends on PPS
+	depends on PPS && TTY
 	help
 	  If you say yes here you get support for a PPS source connected
 	  with the CD (Carrier Detect) pin of your serial port.
diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c
index 2bf0c1b..d3db26e 100644
--- a/drivers/pps/clients/pps-gpio.c
+++ b/drivers/pps/clients/pps-gpio.c
@@ -128,7 +128,8 @@ static int pps_gpio_probe(struct platform_device *pdev)
 	}
 
 	/* allocate space for device info */
-	data = kzalloc(sizeof(struct pps_gpio_device_data), GFP_KERNEL);
+	data = devm_kzalloc(&pdev->dev, sizeof(struct pps_gpio_device_data),
+			    GFP_KERNEL);
 	if (data == NULL) {
 		err = -ENOMEM;
 		goto return_error;
@@ -150,7 +151,6 @@ static int pps_gpio_probe(struct platform_device *pdev)
 		pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR;
 	data->pps = pps_register_source(&data->info, pps_default_params);
 	if (data->pps == NULL) {
-		kfree(data);
 		pr_err("failed to register IRQ %d as PPS source\n", irq);
 		err = -EINVAL;
 		goto return_error;
@@ -164,7 +164,6 @@ static int pps_gpio_probe(struct platform_device *pdev)
 			get_irqf_trigger_flags(pdata), data->info.name, data);
 	if (ret) {
 		pps_unregister_source(data->pps);
-		kfree(data);
 		pr_err("failed to acquire IRQ %d\n", irq);
 		err = -EINVAL;
 		goto return_error;
@@ -190,7 +189,6 @@ static int pps_gpio_remove(struct platform_device *pdev)
 	gpio_free(pdata->gpio_pin);
 	pps_unregister_source(data->pps);
 	pr_info("removed IRQ %d as PPS source\n", data->irq);
-	kfree(data);
 	return 0;
 }
 
diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c
index 79451f2..73bd3bb 100644
--- a/drivers/pps/clients/pps-ldisc.c
+++ b/drivers/pps/clients/pps-ldisc.c
@@ -25,18 +25,27 @@
 #include <linux/serial_core.h>
 #include <linux/tty.h>
 #include <linux/pps_kernel.h>
+#include <linux/bug.h>
 
 #define PPS_TTY_MAGIC		0x0001
 
-static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status,
-				struct pps_event_time *ts)
+static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status)
 {
-	struct pps_device *pps = (struct pps_device *)tty->disc_data;
+	struct pps_device *pps;
+	struct pps_event_time ts;
+
+	pps_get_ts(&ts);
 
-	BUG_ON(pps == NULL);
+	pps = pps_lookup_dev(tty);
+	/*
+	 * This should never fail, but the ldisc locking is very
+	 * convoluted, so don't crash just in case.
+	 */
+	if (WARN_ON_ONCE(pps == NULL))
+		return;
 
 	/* Now do the PPS event report */
-	pps_event(pps, ts, status ? PPS_CAPTUREASSERT :
+	pps_event(pps, &ts, status ? PPS_CAPTUREASSERT :
 			PPS_CAPTURECLEAR, NULL);
 
 	dev_dbg(pps->dev, "PPS %s at %lu\n",
@@ -67,9 +76,9 @@ static int pps_tty_open(struct tty_struct *tty)
 		pr_err("cannot register PPS source \"%s\"\n", info.path);
 		return -ENOMEM;
 	}
-	tty->disc_data = pps;
+	pps->lookup_cookie = tty;
 
-	/* Should open N_TTY ldisc too */
+	/* Now open the base class N_TTY ldisc */
 	ret = alias_n_tty_open(tty);
 	if (ret < 0) {
 		pr_err("cannot open tty ldisc \"%s\"\n", info.path);
@@ -81,7 +90,6 @@ static int pps_tty_open(struct tty_struct *tty)
 	return 0;
 
 err_unregister:
-	tty->disc_data = NULL;
 	pps_unregister_source(pps);
 	return ret;
 }
@@ -90,11 +98,13 @@ static void (*alias_n_tty_close)(struct tty_struct *tty);
 
 static void pps_tty_close(struct tty_struct *tty)
 {
-	struct pps_device *pps = (struct pps_device *)tty->disc_data;
+	struct pps_device *pps = pps_lookup_dev(tty);
 
 	alias_n_tty_close(tty);
 
-	tty->disc_data = NULL;
+	if (WARN_ON(!pps))
+		return;
+
 	dev_info(pps->dev, "removed\n");
 	pps_unregister_source(pps);
 }
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
index f197e8e..cdad4d9 100644
--- a/drivers/pps/kapi.c
+++ b/drivers/pps/kapi.c
@@ -102,7 +102,7 @@ struct pps_device *pps_register_source(struct pps_source_info *info,
 		goto pps_register_source_exit;
 	}
 
-	/* These initializations must be done before calling idr_get_new()
+	/* These initializations must be done before calling idr_alloc()
 	 * in order to avoid reces into pps_event().
 	 */
 	pps->params.api_version = PPS_API_VERS;
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 2420d5a..7173e3a 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -247,12 +247,15 @@ static int pps_cdev_open(struct inode *inode, struct file *file)
 	struct pps_device *pps = container_of(inode->i_cdev,
 						struct pps_device, cdev);
 	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 = container_of(inode->i_cdev,
+						struct pps_device, cdev);
+	kobject_put(&pps->dev->kobj);
 	return 0;
 }
 
@@ -274,8 +277,10 @@ static void pps_device_destruct(struct device *dev)
 {
 	struct pps_device *pps = dev_get_drvdata(dev);
 
-	/* release id here to protect others from using it while it's
-	 * still in use */
+	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);
@@ -290,29 +295,21 @@ int pps_register_cdev(struct pps_device *pps)
 	dev_t devt;
 
 	mutex_lock(&pps_idr_lock);
-	/* Get new ID for the new PPS source */
-	if (idr_pre_get(&pps_idr, GFP_KERNEL) == 0) {
-		mutex_unlock(&pps_idr_lock);
-		return -ENOMEM;
-	}
-
-	/* Now really allocate the PPS source.
-	 * After idr_get_new() calling the new source will be freely available
-	 * into the kernel.
+	/*
+	 * Get new ID for the new PPS source.  After idr_alloc() calling
+	 * the new source will be freely available into the kernel.
 	 */
-	err = idr_get_new(&pps_idr, pps, &pps->id);
-	mutex_unlock(&pps_idr_lock);
-
-	if (err < 0)
-		return err;
-
-	pps->id &= MAX_IDR_MASK;
-	if (pps->id >= PPS_MAX_SOURCES) {
-		pr_err("%s: too many PPS sources in the system\n",
-					pps->info.name);
-		err = -EBUSY;
-		goto free_idr;
+	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);
 
@@ -332,6 +329,7 @@ int pps_register_cdev(struct pps_device *pps)
 		goto del_cdev;
 	}
 
+	/* 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,
@@ -345,18 +343,51 @@ del_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)
 {
+	pr_debug("unregistering pps%d\n", pps->id);
+	pps->lookup_cookie = NULL;
 	device_destroy(pps_class, pps->dev->devt);
-	cdev_del(&pps->cdev);
 }
 
 /*
+ * 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
  */