[S390] pm: hvc_iucv power management callbacks (0259162e) · Commits · e / devices / android_kernel_teracube_emerald

drivers/char/hvc_iucv.c

+161 −43

Original line number	Diff line number	Diff line
		@@ -4,7 +4,7 @@
		* This HVC device driver provides terminal access using
		* z/VM IUCV communication paths.
		*
		* Copyright IBM Corp. 2008
		* Copyright IBM Corp. 2008, 2009
		*
		* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
		*/
		@@ -15,6 +15,7 @@
		#include <asm/ebcdic.h>
		#include <linux/ctype.h>
		#include <linux/delay.h>
		#include <linux/device.h>
		#include <linux/init.h>
		#include <linux/mempool.h>
		#include <linux/moduleparam.h>
		@@ -74,6 +75,7 @@ struct hvc_iucv_private {
		wait_queue_head_t sndbuf_waitq; /* wait for send completion */
		struct list_head tty_outqueue; /* outgoing IUCV messages */
		struct list_head tty_inqueue; /* incoming IUCV messages */
		struct device dev; / device structure */
		};

		struct iucv_tty_buffer {
		@@ -542,7 +544,68 @@ static void flush_sndbuf_sync(struct hvc_iucv_private *priv)

		if (sync_wait)
		wait_event_timeout(priv->sndbuf_waitq,
		tty_outqueue_empty(priv), HZ);
		tty_outqueue_empty(priv), HZ/10);
		}

		/**
		* hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up
		* @priv: Pointer to hvc_iucv_private structure
		*
		* This routine severs an existing IUCV communication path and hangs
		* up the underlying HVC terminal device.
		* The hang-up occurs only if an IUCV communication path is established;
		* otherwise there is no need to hang up the terminal device.
		*
		* The IUCV HVC hang-up is separated into two steps:
		* 1. After the IUCV path has been severed, the iucv_state is set to
		* IUCV_SEVERED.
		* 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the
		* IUCV_SEVERED state causes the tty hang-up in the HVC layer.
		*
		* If the tty has not yet been opened, clean up the hvc_iucv_private
		* structure to allow re-connects.
		* If the tty has been opened, let get_chars() return -EPIPE to signal
		* the HVC layer to hang up the tty and, if so, wake up the HVC thread
		* to call get_chars()...
		*
		* Special notes on hanging up a HVC terminal instantiated as console:
		* Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops)
		* 2. do_tty_hangup() calls tty->ops->close() for console_filp
		* => no hangup notifier is called by HVC (default)
		* 2. hvc_close() returns because of tty_hung_up_p(filp)
		* => no delete notifier is called!
		* Finally, the back-end is not being notified, thus, the tty session is
		* kept active (TTY_OPEN) to be ready for re-connects.
		*
		* Locking: spin_lock(&priv->lock) w/o disabling bh
		*/
		static void hvc_iucv_hangup(struct hvc_iucv_private *priv)
		{
		struct iucv_path *path;

		path = NULL;
		spin_lock(&priv->lock);
		if (priv->iucv_state == IUCV_CONNECTED) {
		path = priv->path;
		priv->path = NULL;
		priv->iucv_state = IUCV_SEVERED;
		if (priv->tty_state == TTY_CLOSED)
		hvc_iucv_cleanup(priv);
		else
		/* console is special (see above) */
		if (priv->is_console) {
		hvc_iucv_cleanup(priv);
		priv->tty_state = TTY_OPENED;
		} else
		hvc_kick();
		}
		spin_unlock(&priv->lock);

		/* finally sever path (outside of priv->lock due to lock ordering) */
		if (path) {
		iucv_path_sever(path, NULL);
		iucv_path_free(path);
		}
		}

		/**
		@@ -735,11 +798,8 @@ static int hvc_iucv_path_pending(struct iucv_path *path,
		* @ipuser: User specified data for this path
		* (AF_IUCV: port/service name and originator port)
		*
		* The function also severs the path (as required by the IUCV protocol) and
		* sets the iucv state to IUCV_SEVERED for the associated struct
		* hvc_iucv_private instance. Later, the IUCV_SEVERED state triggers a tty
		* hangup (hvc_iucv_get_chars() / hvc_iucv_write()).
		* If tty portion of the HVC is closed, clean up the outqueue.
		* This function calls the hvc_iucv_hangup() function for the
		* respective IUCV HVC terminal.
		*
		* Locking: struct hvc_iucv_private->lock
		*/
		@@ -747,33 +807,7 @@ static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
		{
		struct hvc_iucv_private *priv = path->private;

		spin_lock(&priv->lock);
		priv->iucv_state = IUCV_SEVERED;

		/* If the tty has not yet been opened, clean up the hvc_iucv_private
		* structure to allow re-connects.
		* This is also done for our console device because console hangups
		* are handled specially and no notifier is called by HVC.
		* The tty session is active (TTY_OPEN) and ready for re-connects...
		*
		* If it has been opened, let get_chars() return -EPIPE to signal the
		* HVC layer to hang up the tty.
		* If so, we need to wake up the HVC thread to call get_chars()...
		*/
		priv->path = NULL;
		if (priv->tty_state == TTY_CLOSED)
		hvc_iucv_cleanup(priv);
		else
		if (priv->is_console) {
		hvc_iucv_cleanup(priv);
		priv->tty_state = TTY_OPENED;
		} else
		hvc_kick();
		spin_unlock(&priv->lock);

		/* finally sever path (outside of priv->lock due to lock ordering) */
		iucv_path_sever(path, ipuser);
		iucv_path_free(path);
		hvc_iucv_hangup(priv);
		}

		/**
		@@ -853,6 +887,37 @@ static void hvc_iucv_msg_complete(struct iucv_path *path,
		destroy_tty_buffer_list(&list_remove);
		}

		/**
		* hvc_iucv_pm_freeze() - Freeze PM callback
		* @dev: IUVC HVC terminal device
		*
		* Sever an established IUCV communication path and
		* trigger a hang-up of the underlying HVC terminal.
		*/
		static int hvc_iucv_pm_freeze(struct device *dev)
		{
		struct hvc_iucv_private *priv = dev_get_drvdata(dev);

		local_bh_disable();
		hvc_iucv_hangup(priv);
		local_bh_enable();

		return 0;
		}

		/**
		* hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback
		* @dev: IUVC HVC terminal device
		*
		* Wake up the HVC thread to trigger hang-up and respective
		* HVC back-end notifier invocations.
		*/
		static int hvc_iucv_pm_restore_thaw(struct device *dev)
		{
		hvc_kick();
		return 0;
		}


		/* HVC operations */
		static struct hv_ops hvc_iucv_ops = {
		@@ -863,6 +928,20 @@ static struct hv_ops hvc_iucv_ops = {
		.notifier_hangup = hvc_iucv_notifier_hangup,
		};

		/* Suspend / resume device operations */
		static struct dev_pm_ops hvc_iucv_pm_ops = {
		.freeze = hvc_iucv_pm_freeze,
		.thaw = hvc_iucv_pm_restore_thaw,
		.restore = hvc_iucv_pm_restore_thaw,
		};

		/* IUCV HVC device driver */
		static struct device_driver hvc_iucv_driver = {
		.name = KMSG_COMPONENT,
		.bus = &iucv_bus,
		.pm = &hvc_iucv_pm_ops,
		};

		/**
		* hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
		* @id: hvc_iucv_table index
		@@ -897,14 +976,12 @@ static int __init hvc_iucv_alloc(int id, unsigned int is_console)
		/* set console flag */
		priv->is_console = is_console;

		/* finally allocate hvc */
		/* allocate hvc device */
		priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */
		HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256);
		if (IS_ERR(priv->hvc)) {
		rc = PTR_ERR(priv->hvc);
		free_page((unsigned long) priv->sndbuf);
		kfree(priv);
		return rc;
		goto out_error_hvc;
		}

		/* notify HVC thread instead of using polling */
		@@ -915,8 +992,45 @@ static int __init hvc_iucv_alloc(int id, unsigned int is_console)
		memcpy(priv->srv_name, name, 8);
		ASCEBC(priv->srv_name, 8);

		/* create and setup device */
		priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL);
		if (!priv->dev) {
		rc = -ENOMEM;
		goto out_error_dev;
		}
		dev_set_name(priv->dev, "hvc_iucv%d", id);
		dev_set_drvdata(priv->dev, priv);
		priv->dev->bus = &iucv_bus;
		priv->dev->parent = iucv_root;
		priv->dev->driver = &hvc_iucv_driver;
		priv->dev->release = (void ()(struct device )) kfree;
		rc = device_register(priv->dev);
		if (rc) {
		kfree(priv->dev);
		goto out_error_dev;
		}

		hvc_iucv_table[id] = priv;
		return 0;

		out_error_dev:
		hvc_remove(priv->hvc);
		out_error_hvc:
		free_page((unsigned long) priv->sndbuf);
		kfree(priv);

		return rc;
		}

		/**
		* hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances
		*/
		static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv)
		{
		hvc_remove(priv->hvc);
		device_unregister(priv->dev);
		free_page((unsigned long) priv->sndbuf);
		kfree(priv);
		}

		/**
		@@ -1109,6 +1223,11 @@ static int __init hvc_iucv_init(void)
		goto out_error;
		}

		/* register IUCV HVC device driver */
		rc = driver_register(&hvc_iucv_driver);
		if (rc)
		goto out_error;

		/* parse hvc_iucv_allow string and create z/VM user ID filter list */
		if (hvc_iucv_filter_string) {
		rc = hvc_iucv_setup_filter(hvc_iucv_filter_string);
		@@ -1183,15 +1302,14 @@ static int __init hvc_iucv_init(void)
		iucv_unregister(&hvc_iucv_handler, 0);
		out_error_hvc:
		for (i = 0; i < hvc_iucv_devices; i++)
		if (hvc_iucv_table[i]) {
		if (hvc_iucv_table[i]->hvc)
		hvc_remove(hvc_iucv_table[i]->hvc);
		kfree(hvc_iucv_table[i]);
		}
		if (hvc_iucv_table[i])
		hvc_iucv_destroy(hvc_iucv_table[i]);
		out_error_memory:
		mempool_destroy(hvc_iucv_mempool);
		kmem_cache_destroy(hvc_iucv_buffer_cache);
		out_error:
		if (hvc_iucv_filter)
		kfree(hvc_iucv_filter);
		hvc_iucv_devices = 0; /* ensure that we do not provide any device */
		return rc;
		}