#include <linux/init.h>
#include <linux/kbd_kern.h>
#include <linux/kernel.h>
-#include <linux/kobject.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/module.h>
/* Picks up late kicks after list walk but before schedule() */
static int hvc_kicked;
+static int hvc_init(void);
+
#ifdef CONFIG_MAGIC_SYSRQ
static int sysrq_pressed;
#endif
-struct hvc_struct {
- spinlock_t lock;
- int index;
- struct tty_struct *tty;
- unsigned int count;
- int do_wakeup;
- char *outbuf;
- int outbuf_size;
- int n_outbuf;
- uint32_t vtermno;
- struct hv_ops *ops;
- int irq_requested;
- int irq;
- struct list_head next;
- struct kobject kobj; /* ref count & hvc_struct lifetime */
-};
-
/* dynamic list of hvc_struct instances */
-static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs);
+static LIST_HEAD(hvc_structs);
/*
* Protect the list of hvc_struct instances from inserts and removals during
/*
* Do not call this function with either the hvc_structs_lock or the hvc_struct
- * lock held. If successful, this function increments the kobject reference
+ * lock held. If successful, this function increments the kref reference
* count against the target hvc_struct so it should be released when finished.
*/
static struct hvc_struct *hvc_get_by_index(int index)
list_for_each_entry(hp, &hvc_structs, next) {
spin_lock_irqsave(&hp->lock, flags);
if (hp->index == index) {
- kobject_get(&hp->kobj);
+ kref_get(&hp->kref);
spin_unlock_irqrestore(&hp->lock, flags);
spin_unlock(&hvc_structs_lock);
return hp;
}
} else {
r = cons_ops[index]->put_chars(vtermnos[index], c, i);
- if (r < 0) {
+ if (r <= 0) {
/* throw away chars on error */
i = 0;
} else if (r > 0) {
}
console_initcall(hvc_console_init);
+/* callback when the kboject ref count reaches zero. */
+static void destroy_hvc_struct(struct kref *kref)
+{
+ struct hvc_struct *hp = container_of(kref, struct hvc_struct, kref);
+ unsigned long flags;
+
+ spin_lock(&hvc_structs_lock);
+
+ spin_lock_irqsave(&hp->lock, flags);
+ list_del(&(hp->next));
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ spin_unlock(&hvc_structs_lock);
+
+ kfree(hp);
+}
+
/*
* hvc_instantiate() is an early console discovery method which locates
* consoles * prior to the vio subsystem discovering them. Hotplugged
/* make sure no no tty has been registered in this index */
hp = hvc_get_by_index(index);
if (hp) {
- kobject_put(&hp->kobj);
+ kref_put(&hp->kref, destroy_hvc_struct);
return -1;
}
return 0;
}
+EXPORT_SYMBOL_GPL(hvc_instantiate);
/* Wake the sleeping khvcd */
-static void hvc_kick(void)
+void hvc_kick(void)
{
hvc_kicked = 1;
wake_up_process(hvc_task);
}
-
-static int hvc_poll(struct hvc_struct *hp);
-
-/*
- * NOTE: This API isn't used if the console adapter doesn't support interrupts.
- * In this case the console is poll driven.
- */
-static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
-{
- /* if hvc_poll request a repoll, then kick the hvcd thread */
- if (hvc_poll(dev_instance))
- hvc_kick();
- return IRQ_HANDLED;
-}
+EXPORT_SYMBOL_GPL(hvc_kick);
static void hvc_unthrottle(struct tty_struct *tty)
{
{
struct hvc_struct *hp;
unsigned long flags;
- int irq = 0;
int rc = 0;
- struct kobject *kobjp;
- /* Auto increments kobject reference if found. */
+ /* Auto increments kref reference if found. */
if (!(hp = hvc_get_by_index(tty->index)))
return -ENODEV;
} /* else count == 0 */
tty->driver_data = hp;
- tty->low_latency = 1; /* Makes flushes to ldisc synchronous. */
hp->tty = tty;
- /* Save for request_irq outside of spin_lock. */
- irq = hp->irq;
- if (irq)
- hp->irq_requested = 1;
-
- kobjp = &hp->kobj;
spin_unlock_irqrestore(&hp->lock, flags);
- /* check error, fallback to non-irq */
- if (irq)
- rc = request_irq(irq, hvc_handle_interrupt, IRQF_DISABLED, "hvc_console", hp);
+
+ if (hp->ops->notifier_add)
+ rc = hp->ops->notifier_add(hp, hp->data);
/*
- * If the request_irq() fails and we return an error. The tty layer
+ * If the notifier fails we return an error. The tty layer
* will call hvc_close() after a failed open but we don't want to clean
* up there so we'll clean up here and clear out the previously set
- * tty fields and return the kobject reference.
+ * tty fields and return the kref reference.
*/
if (rc) {
spin_lock_irqsave(&hp->lock, flags);
hp->tty = NULL;
- hp->irq_requested = 0;
spin_unlock_irqrestore(&hp->lock, flags);
tty->driver_data = NULL;
- kobject_put(kobjp);
+ kref_put(&hp->kref, destroy_hvc_struct);
printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
}
/* Force wakeup of the polling thread */
static void hvc_close(struct tty_struct *tty, struct file * filp)
{
struct hvc_struct *hp;
- struct kobject *kobjp;
- int irq = 0;
unsigned long flags;
if (tty_hung_up_p(filp))
/*
* No driver_data means that this close was issued after a failed
* hvc_open by the tty layer's release_dev() function and we can just
- * exit cleanly because the kobject reference wasn't made.
+ * exit cleanly because the kref reference wasn't made.
*/
if (!tty->driver_data)
return;
hp = tty->driver_data;
spin_lock_irqsave(&hp->lock, flags);
- kobjp = &hp->kobj;
if (--hp->count == 0) {
- if (hp->irq_requested)
- irq = hp->irq;
- hp->irq_requested = 0;
-
/* We are done with the tty pointer now. */
hp->tty = NULL;
spin_unlock_irqrestore(&hp->lock, flags);
+ if (hp->ops->notifier_del)
+ hp->ops->notifier_del(hp, hp->data);
+
+ /* cancel pending tty resize work */
+ cancel_work_sync(&hp->tty_resize);
+
/*
* Chain calls chars_in_buffer() and returns immediately if
* there is no buffered data otherwise sleeps on a wait queue
* waking periodically to check chars_in_buffer().
*/
tty_wait_until_sent(tty, HVC_CLOSE_WAIT);
-
- if (irq)
- free_irq(irq, hp);
-
} else {
if (hp->count < 0)
printk(KERN_ERR "hvc_close %X: oops, count is %d\n",
spin_unlock_irqrestore(&hp->lock, flags);
}
- kobject_put(kobjp);
+ kref_put(&hp->kref, destroy_hvc_struct);
}
static void hvc_hangup(struct tty_struct *tty)
{
struct hvc_struct *hp = tty->driver_data;
unsigned long flags;
- int irq = 0;
int temp_open_count;
- struct kobject *kobjp;
if (!hp)
return;
+ /* cancel pending tty resize work */
+ cancel_work_sync(&hp->tty_resize);
+
spin_lock_irqsave(&hp->lock, flags);
/*
return;
}
- kobjp = &hp->kobj;
temp_open_count = hp->count;
hp->count = 0;
hp->n_outbuf = 0;
hp->tty = NULL;
- if (hp->irq_requested)
- /* Saved for use outside of spin_lock. */
- irq = hp->irq;
- hp->irq_requested = 0;
+
spin_unlock_irqrestore(&hp->lock, flags);
- if (irq)
- free_irq(irq, hp);
+
+ if (hp->ops->notifier_hangup)
+ hp->ops->notifier_hangup(hp, hp->data);
+
while(temp_open_count) {
--temp_open_count;
- kobject_put(kobjp);
+ kref_put(&hp->kref, destroy_hvc_struct);
}
}
* Push buffered characters whether they were just recently buffered or waiting
* on a blocked hypervisor. Call this function with hp->lock held.
*/
-static void hvc_push(struct hvc_struct *hp)
+static int hvc_push(struct hvc_struct *hp)
{
int n;
if (n <= 0) {
if (n == 0) {
hp->do_wakeup = 1;
- return;
+ return 0;
}
/* throw away output on error; this happens when
there is no session connected to the vterm. */
memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf);
else
hp->do_wakeup = 1;
+
+ return n;
}
static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count)
return written;
}
+/**
+ * hvc_set_winsz() - Resize the hvc tty terminal window.
+ * @work: work structure.
+ *
+ * The routine shall not be called within an atomic context because it
+ * might sleep.
+ *
+ * Locking: hp->lock
+ */
+static void hvc_set_winsz(struct work_struct *work)
+{
+ struct hvc_struct *hp;
+ unsigned long hvc_flags;
+ struct tty_struct *tty;
+ struct winsize ws;
+
+ hp = container_of(work, struct hvc_struct, tty_resize);
+ if (!hp)
+ return;
+
+ spin_lock_irqsave(&hp->lock, hvc_flags);
+ if (!hp->tty) {
+ spin_unlock_irqrestore(&hp->lock, hvc_flags);
+ return;
+ }
+ ws = hp->ws;
+ tty = tty_kref_get(hp->tty);
+ spin_unlock_irqrestore(&hp->lock, hvc_flags);
+
+ tty_do_resize(tty, &ws);
+ tty_kref_put(tty);
+}
+
/*
* This is actually a contract between the driver and the tty layer outlining
* how much write room the driver can guarantee will be sent OR BUFFERED. This
#define HVC_POLL_READ 0x00000001
#define HVC_POLL_WRITE 0x00000002
-static int hvc_poll(struct hvc_struct *hp)
+int hvc_poll(struct hvc_struct *hp)
{
struct tty_struct *tty;
int i, n, poll_mask = 0;
char buf[N_INBUF] __ALIGNED__;
unsigned long flags;
int read_total = 0;
+ int written_total = 0;
spin_lock_irqsave(&hp->lock, flags);
/* Push pending writes */
if (hp->n_outbuf > 0)
- hvc_push(hp);
+ written_total = hvc_push(hp);
/* Reschedule us if still some write pending */
- if (hp->n_outbuf > 0)
+ if (hp->n_outbuf > 0) {
poll_mask |= HVC_POLL_WRITE;
+ /* If hvc_push() was not able to write, sleep a few msecs */
+ timeout = (written_total) ? 0 : MIN_TIMEOUT;
+ }
/* No tty attached, just skip */
tty = hp->tty;
if (test_bit(TTY_THROTTLED, &tty->flags))
goto throttled;
- /* If we aren't interrupt driven and aren't throttled, we always
+ /* If we aren't notifier driven and aren't throttled, we always
* request a reschedule
*/
- if (hp->irq == 0)
+ if (!hp->irq_requested)
poll_mask |= HVC_POLL_READ;
/* Read data if any */
/* Handle the SysRq Hack */
/* XXX should support a sequence */
if (buf[i] == '\x0f') { /* ^O */
- sysrq_pressed = 1;
- continue;
+ /* if ^O is pressed again, reset
+ * sysrq_pressed and flip ^O char */
+ sysrq_pressed = !sysrq_pressed;
+ if (sysrq_pressed)
+ continue;
} else if (sysrq_pressed) {
handle_sysrq(buf[i], tty);
sysrq_pressed = 0;
return poll_mask;
}
+EXPORT_SYMBOL_GPL(hvc_poll);
-#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
-extern cpumask_t cpus_in_xmon;
-#else
-static const cpumask_t cpus_in_xmon = CPU_MASK_NONE;
-#endif
+/**
+ * hvc_resize() - Update terminal window size information.
+ * @hp: HVC console pointer
+ * @ws: Terminal window size structure
+ *
+ * Stores the specified window size information in the hvc structure of @hp.
+ * The function schedule the tty resize update.
+ *
+ * Locking: Locking free; the function MUST be called holding hp->lock
+ */
+void hvc_resize(struct hvc_struct *hp, struct winsize ws)
+{
+ hp->ws = ws;
+ schedule_work(&hp->tty_resize);
+}
+EXPORT_SYMBOL_GPL(hvc_resize);
/*
* This kthread is either polling or interrupt driven. This is determined by
hvc_kicked = 0;
try_to_freeze();
wmb();
- if (cpus_empty(cpus_in_xmon)) {
+ if (!cpus_are_in_xmon()) {
spin_lock(&hvc_structs_lock);
list_for_each_entry(hp, &hvc_structs, next) {
poll_mask |= hvc_poll(hp);
poll_mask |= HVC_POLL_READ;
if (hvc_kicked)
continue;
- if (poll_mask & HVC_POLL_WRITE) {
- yield();
- continue;
- }
set_current_state(TASK_INTERRUPTIBLE);
if (!hvc_kicked) {
if (poll_mask == 0)
.chars_in_buffer = hvc_chars_in_buffer,
};
-/* callback when the kboject ref count reaches zero. */
-static void destroy_hvc_struct(struct kobject *kobj)
-{
- struct hvc_struct *hp = container_of(kobj, struct hvc_struct, kobj);
- unsigned long flags;
-
- spin_lock(&hvc_structs_lock);
-
- spin_lock_irqsave(&hp->lock, flags);
- list_del(&(hp->next));
- spin_unlock_irqrestore(&hp->lock, flags);
-
- spin_unlock(&hvc_structs_lock);
-
- kfree(hp);
-}
-
-static struct kobj_type hvc_kobj_type = {
- .release = destroy_hvc_struct,
-};
-
-struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int irq,
+struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data,
struct hv_ops *ops, int outbuf_size)
{
struct hvc_struct *hp;
int i;
- hp = kmalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size,
+ /* We wait until a driver actually comes along */
+ if (!hvc_driver) {
+ int err = hvc_init();
+ if (err)
+ return ERR_PTR(err);
+ }
+
+ hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size,
GFP_KERNEL);
if (!hp)
return ERR_PTR(-ENOMEM);
- memset(hp, 0x00, sizeof(*hp));
-
hp->vtermno = vtermno;
- hp->irq = irq;
+ hp->data = data;
hp->ops = ops;
hp->outbuf_size = outbuf_size;
hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))];
- kobject_init(&hp->kobj);
- hp->kobj.ktype = &hvc_kobj_type;
+ kref_init(&hp->kref);
+ INIT_WORK(&hp->tty_resize, hvc_set_winsz);
spin_lock_init(&hp->lock);
spin_lock(&hvc_structs_lock);
return hp;
}
+EXPORT_SYMBOL_GPL(hvc_alloc);
-int __devexit hvc_remove(struct hvc_struct *hp)
+int hvc_remove(struct hvc_struct *hp)
{
unsigned long flags;
- struct kobject *kobjp;
struct tty_struct *tty;
spin_lock_irqsave(&hp->lock, flags);
tty = hp->tty;
- kobjp = &hp->kobj;
if (hp->index < MAX_NR_HVC_CONSOLES)
vtermnos[hp->index] = -1;
spin_unlock_irqrestore(&hp->lock, flags);
/*
- * We 'put' the instance that was grabbed when the kobject instance
- * was initialized using kobject_init(). Let the last holder of this
- * kobject cause it to be removed, which will probably be the tty_hangup
+ * We 'put' the instance that was grabbed when the kref instance
+ * was initialized using kref_init(). Let the last holder of this
+ * kref cause it to be removed, which will probably be the tty_hangup
* below.
*/
- kobject_put(kobjp);
+ kref_put(&hp->kref, destroy_hvc_struct);
/*
* This function call will auto chain call hvc_hangup. The tty should
return 0;
}
-/* Driver initialization. Follow console initialization. This is where the TTY
- * interfaces start to become available. */
-static int __init hvc_init(void)
+/* Driver initialization: called as soon as someone uses hvc_alloc(). */
+static int hvc_init(void)
{
struct tty_driver *drv;
+ int err;
/* We need more than hvc_count adapters due to hotplug additions. */
drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
- if (!drv)
- return -ENOMEM;
+ if (!drv) {
+ err = -ENOMEM;
+ goto out;
+ }
drv->owner = THIS_MODULE;
drv->driver_name = "hvc";
drv->minor_start = HVC_MINOR;
drv->type = TTY_DRIVER_TYPE_SYSTEM;
drv->init_termios = tty_std_termios;
- drv->flags = TTY_DRIVER_REAL_RAW;
+ drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
tty_set_operations(drv, &hvc_ops);
/* Always start the kthread because there can be hotplug vty adapters
* added later. */
hvc_task = kthread_run(khvcd, NULL, "khvcd");
if (IS_ERR(hvc_task)) {
- panic("Couldn't create kthread for console.\n");
- put_tty_driver(drv);
- return -EIO;
+ printk(KERN_ERR "Couldn't create kthread for console.\n");
+ err = PTR_ERR(hvc_task);
+ goto put_tty;
}
- if (tty_register_driver(drv))
- panic("Couldn't register hvc console driver\n");
+ err = tty_register_driver(drv);
+ if (err) {
+ printk(KERN_ERR "Couldn't register hvc console driver\n");
+ goto stop_thread;
+ }
- mb();
+ /*
+ * Make sure tty is fully registered before allowing it to be
+ * found by hvc_console_device.
+ */
+ smp_mb();
hvc_driver = drv;
return 0;
+
+stop_thread:
+ kthread_stop(hvc_task);
+ hvc_task = NULL;
+put_tty:
+ put_tty_driver(drv);
+out:
+ return err;
}
-module_init(hvc_init);
/* This isn't particularly necessary due to this being a console driver
* but it is nice to be thorough.
*/
static void __exit hvc_exit(void)
{
- kthread_stop(hvc_task);
+ if (hvc_driver) {
+ kthread_stop(hvc_task);
- tty_unregister_driver(hvc_driver);
- /* return tty_struct instances allocated in hvc_init(). */
- put_tty_driver(hvc_driver);
- unregister_console(&hvc_con_driver);
+ tty_unregister_driver(hvc_driver);
+ /* return tty_struct instances allocated in hvc_init(). */
+ put_tty_driver(hvc_driver);
+ unregister_console(&hvc_con_driver);
+ }
}
module_exit(hvc_exit);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff