/*
* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
* Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
+ * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ * Copyright (C) 2004 IBM Corporation
+ *
+ * Additional Author(s):
+ * Ryan S. Arnold <rsa@us.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/config.h>
+#include <linux/console.h>
+#include <linux/cpumask.h>
#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>
-#include <linux/console.h>
#include <linux/major.h>
-#include <linux/kernel.h>
#include <linux/sysrq.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/sched.h>
-#include <linux/kbd_kern.h>
-#include <asm/uaccess.h>
#include <linux/spinlock.h>
-#include <linux/cpumask.h>
+#include <linux/delay.h>
-extern int hvc_count(int *);
-extern int hvc_get_chars(int index, char *buf, int count);
-extern int hvc_put_chars(int index, const char *buf, int count);
+#include <asm/uaccess.h>
+
+#include "hvc_console.h"
#define HVC_MAJOR 229
#define HVC_MINOR 0
-#define MAX_NR_HVC_CONSOLES 4
+#define TIMEOUT (10)
+
+/*
+ * Wait this long per iteration while trying to push buffered data to the
+ * hypervisor before allowing the tty to complete a close operation.
+ */
+#define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
+
+/*
+ * These sizes are most efficient for vio, because they are the
+ * native transfer size. We could make them selectable in the
+ * future to better deal with backends that want other buffer sizes.
+ */
+#define N_OUTBUF 16
+#define N_INBUF 16
-#define TIMEOUT ((HZ + 99) / 100)
+#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
static struct tty_driver *hvc_driver;
-static int hvc_offset;
+static struct task_struct *hvc_task;
+
+/* Picks up late kicks after list walk but before schedule() */
+static int hvc_kicked;
+
#ifdef CONFIG_MAGIC_SYSRQ
static int sysrq_pressed;
#endif
-#define N_OUTBUF 16
-
-#define __ALIGNED__ __attribute__((__aligned__(8)))
-
struct hvc_struct {
spinlock_t lock;
int index;
int do_wakeup;
char outbuf[N_OUTBUF] __ALIGNED__;
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 */
};
-struct hvc_struct hvc_struct[MAX_NR_HVC_CONSOLES];
+/* dynamic list of hvc_struct instances */
+static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs);
+
+/*
+ * Protect the list of hvc_struct instances from inserts and removals during
+ * list traversal.
+ */
+static DEFINE_SPINLOCK(hvc_structs_lock);
+/*
+ * This value is used to assign a tty->index value to a hvc_struct based
+ * upon order of exposure via hvc_probe(), when we can not match it to
+ * a console canidate registered with hvc_instantiate().
+ */
+static int last_hvc = -1;
+
+/*
+ * Do not call this function with either the hvc_strucst_lock or the hvc_struct
+ * lock held. If successful, this function increments the kobject reference
+ * count against the target hvc_struct so it should be released when finished.
+ */
+struct hvc_struct *hvc_get_by_index(int index)
+{
+ struct hvc_struct *hp;
+ unsigned long flags;
+
+ spin_lock(&hvc_structs_lock);
+
+ list_for_each_entry(hp, &hvc_structs, next) {
+ spin_lock_irqsave(&hp->lock, flags);
+ if (hp->index == index) {
+ kobject_get(&hp->kobj);
+ spin_unlock_irqrestore(&hp->lock, flags);
+ spin_unlock(&hvc_structs_lock);
+ return hp;
+ }
+ spin_unlock_irqrestore(&hp->lock, flags);
+ }
+ hp = NULL;
+
+ spin_unlock(&hvc_structs_lock);
+ return hp;
+}
+
+
+/*
+ * Initial console vtermnos for console API usage prior to full console
+ * initialization. Any vty adapter outside this range will not have usable
+ * console interfaces but can still be used as a tty device. This has to be
+ * static because kmalloc will not work during early console init.
+ */
+static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES];
+static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] =
+ {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1};
+
+/*
+ * Console APIs, NOT TTY. These APIs are available immediately when
+ * hvc_console_setup() finds adapters.
+ */
+
+void hvc_console_print(struct console *co, const char *b, unsigned count)
+{
+ char c[N_OUTBUF] __ALIGNED__;
+ unsigned i = 0, n = 0;
+ int r, donecr = 0, index = co->index;
+
+ /* Console access attempt outside of acceptable console range. */
+ if (index >= MAX_NR_HVC_CONSOLES)
+ return;
+
+ /* This console adapter was removed so it is not useable. */
+ if (vtermnos[index] < 0)
+ return;
+
+ while (count > 0 || i > 0) {
+ if (count > 0 && i < sizeof(c)) {
+ if (b[n] == '\n' && !donecr) {
+ c[i++] = '\r';
+ donecr = 1;
+ } else {
+ c[i++] = b[n++];
+ donecr = 0;
+ --count;
+ }
+ } else {
+ r = cons_ops[index]->put_chars(vtermnos[index], c, i);
+ if (r < 0) {
+ /* throw away chars on error */
+ i = 0;
+ } else if (r > 0) {
+ i -= r;
+ if (i > 0)
+ memmove(c, c+r, i);
+ }
+ }
+ }
+}
+
+static struct tty_driver *hvc_console_device(struct console *c, int *index)
+{
+ if (vtermnos[c->index] == -1)
+ return NULL;
+
+ *index = c->index;
+ return hvc_driver;
+}
+
+static int __init hvc_console_setup(struct console *co, char *options)
+{
+ if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES)
+ return -ENODEV;
+
+ if (vtermnos[co->index] == -1)
+ return -ENODEV;
+
+ return 0;
+}
+
+struct console hvc_con_driver = {
+ .name = "hvc",
+ .write = hvc_console_print,
+ .device = hvc_console_device,
+ .setup = hvc_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+/*
+ * Early console initialization. Preceeds driver initialization.
+ *
+ * (1) we are first, and the user specified another driver
+ * -- index will remain -1
+ * (2) we are first and the user specified no driver
+ * -- index will be set to 0, then we will fail setup.
+ * (3) we are first and the user specified our driver
+ * -- index will be set to user specified driver, and we will fail
+ * (4) we are after driver, and this initcall will register us
+ * -- if the user didn't specify a driver then the console will match
+ *
+ * Note that for cases 2 and 3, we will match later when the io driver
+ * calls hvc_instantiate() and call register again.
+ */
+static int __init hvc_console_init(void)
+{
+ register_console(&hvc_con_driver);
+ return 0;
+}
+console_initcall(hvc_console_init);
+
+/*
+ * hvc_instantiate() is an early console discovery method which locates
+ * consoles * prior to the vio subsystem discovering them. Hotplugged
+ * vty adapters do NOT get an hvc_instantiate() callback since they
+ * appear after early console init.
+ */
+int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops)
+{
+ struct hvc_struct *hp;
+
+ if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
+ return -1;
+
+ if (vtermnos[index] != -1)
+ return -1;
+
+ /* make sure no no tty has been registerd in this index */
+ hp = hvc_get_by_index(index);
+ if (hp) {
+ kobject_put(&hp->kobj);
+ return -1;
+ }
+
+ vtermnos[index] = vtermno;
+ cons_ops[index] = ops;
+
+ /* reserve all indices upto and including this index */
+ if (last_hvc < index)
+ last_hvc = index;
+
+ /* if this index is what the user requested, then register
+ * now (setup won't fail at this point). It's ok to just
+ * call register again if previously .setup failed.
+ */
+ if (index == hvc_con_driver.index)
+ register_console(&hvc_con_driver);
+
+ return 0;
+}
+EXPORT_SYMBOL(hvc_instantiate);
+
+/* Wake the sleeping khvcd */
+static 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, struct pt_regs *regs)
+{
+ /* if hvc_poll request a repoll, then kick the hvcd thread */
+ if (hvc_poll(dev_instance))
+ hvc_kick();
+ return IRQ_HANDLED;
+}
+
+static void hvc_unthrottle(struct tty_struct *tty)
+{
+ hvc_kick();
+}
+
+/*
+ * The TTY interface won't be used until after the vio layer has exposed the vty
+ * adapter to the kernel.
+ */
static int hvc_open(struct tty_struct *tty, struct file * filp)
{
- int line = tty->index;
struct hvc_struct *hp;
unsigned long flags;
+ int irq = NO_IRQ;
+ int rc = 0;
+ struct kobject *kobjp;
- if (line < 0 || line >= MAX_NR_HVC_CONSOLES)
+ /* Auto increments kobject reference if found. */
+ if (!(hp = hvc_get_by_index(tty->index))) {
+ printk(KERN_WARNING "hvc_console: tty open failed, no vty associated with tty.\n");
return -ENODEV;
- hp = &hvc_struct[line];
+ }
- tty->driver_data = hp;
spin_lock_irqsave(&hp->lock, flags);
+ /* Check and then increment for fast path open. */
+ if (hp->count++ > 0) {
+ spin_unlock_irqrestore(&hp->lock, flags);
+ hvc_kick();
+ return 0;
+ } /* else count == 0 */
+
+ tty->driver_data = hp;
+ tty->low_latency = 1; /* Makes flushes to ldisc synchronous. */
+
hp->tty = tty;
- hp->count++;
+ /* Save for request_irq outside of spin_lock. */
+ irq = hp->irq;
+ if (irq != NO_IRQ)
+ hp->irq_requested = 1;
+
+ kobjp = &hp->kobj;
+
spin_unlock_irqrestore(&hp->lock, flags);
+ /* check error, fallback to non-irq */
+ if (irq != NO_IRQ)
+ rc = request_irq(irq, hvc_handle_interrupt, SA_INTERRUPT, "hvc_console", hp);
+
+ /*
+ * If the request_irq() fails and 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.
+ */
+ 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);
+ printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
+ }
+ /* Force wakeup of the polling thread */
+ hvc_kick();
- return 0;
+ return rc;
}
static void hvc_close(struct tty_struct *tty, struct file * filp)
{
- struct hvc_struct *hp = tty->driver_data;
+ struct hvc_struct *hp;
+ struct kobject *kobjp;
+ int irq = NO_IRQ;
unsigned long flags;
if (tty_hung_up_p(filp))
return;
+
+ /*
+ * 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.
+ */
+ if (!tty->driver_data)
+ return;
+
+ hp = tty->driver_data;
spin_lock_irqsave(&hp->lock, flags);
- if (--hp->count == 0)
+
+ 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;
- else if (hp->count < 0)
- printk(KERN_ERR "hvc_close %lu: oops, count is %d\n",
- hp - hvc_struct, hp->count);
- spin_unlock_irqrestore(&hp->lock, flags);
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ /*
+ * 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 != NO_IRQ)
+ free_irq(irq, hp);
+
+ } else {
+ if (hp->count < 0)
+ printk(KERN_ERR "hvc_close %X: oops, count is %d\n",
+ hp->vtermno, hp->count);
+ spin_unlock_irqrestore(&hp->lock, flags);
+ }
+
+ kobject_put(kobjp);
}
static void hvc_hangup(struct tty_struct *tty)
{
struct hvc_struct *hp = tty->driver_data;
+ unsigned long flags;
+ int irq = NO_IRQ;
+ int temp_open_count;
+ struct kobject *kobjp;
+
+ if (!hp)
+ return;
+
+ spin_lock_irqsave(&hp->lock, flags);
+
+ /*
+ * The N_TTY line discipline has problems such that in a close vs
+ * open->hangup case this can be called after the final close so prevent
+ * that from happening for now.
+ */
+ if (hp->count <= 0) {
+ spin_unlock_irqrestore(&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 != NO_IRQ)
+ free_irq(irq, hp);
+ while(temp_open_count) {
+ --temp_open_count;
+ kobject_put(kobjp);
+ }
}
-/* called with hp->lock held */
+/*
+ * 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)
{
int n;
- n = hvc_put_chars(hp->index + hvc_offset, hp->outbuf, hp->n_outbuf);
+ n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);
if (n <= 0) {
- if (n == 0)
+ if (n == 0) {
+ hp->do_wakeup = 1;
return;
+ }
/* throw away output on error; this happens when
there is no session connected to the vterm. */
hp->n_outbuf = 0;
hp->do_wakeup = 1;
}
-static int hvc_write(struct tty_struct *tty, int from_user,
- const unsigned char *buf, int count)
+static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
struct hvc_struct *hp = tty->driver_data;
- char *tbuf, *p;
- int tbsize, rsize, written = 0;
unsigned long flags;
+ int rsize, written = 0;
- if (from_user) {
- tbsize = min(count, (int)PAGE_SIZE);
- if (!(tbuf = kmalloc(tbsize, GFP_KERNEL)))
- return -ENOMEM;
-
- while ((rsize = count - written) > 0) {
- int wsize;
- if (rsize > tbsize)
- rsize = tbsize;
-
- p = tbuf;
- rsize -= copy_from_user(p, buf, rsize);
- if (!rsize) {
- if (written == 0)
- written = -EFAULT;
- break;
- }
- buf += rsize;
- written += rsize;
-
- spin_lock_irqsave(&hp->lock, flags);
- for (wsize = N_OUTBUF - hp->n_outbuf; rsize && wsize;
- wsize = N_OUTBUF - hp->n_outbuf) {
- if (wsize > rsize)
- wsize = rsize;
- memcpy(hp->outbuf + hp->n_outbuf, p, wsize);
- hp->n_outbuf += wsize;
- hvc_push(hp);
- rsize -= wsize;
- p += wsize;
- }
- spin_unlock_irqrestore(&hp->lock, flags);
+ /* This write was probably executed during a tty close. */
+ if (!hp)
+ return -EPIPE;
- if (rsize)
- break;
+ if (hp->count <= 0)
+ return -EIO;
- if (count < tbsize)
- tbsize = count;
- }
+ spin_lock_irqsave(&hp->lock, flags);
- kfree(tbuf);
- } else {
- spin_lock_irqsave(&hp->lock, flags);
- while (count > 0 && (rsize = N_OUTBUF - hp->n_outbuf) > 0) {
- if (rsize > count)
- rsize = count;
- memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
- count -= rsize;
- buf += rsize;
- hp->n_outbuf += rsize;
- written += rsize;
- hvc_push(hp);
- }
- spin_unlock_irqrestore(&hp->lock, flags);
+ /* Push pending writes */
+ if (hp->n_outbuf > 0)
+ hvc_push(hp);
+
+ while (count > 0 && (rsize = N_OUTBUF - hp->n_outbuf) > 0) {
+ if (rsize > count)
+ rsize = count;
+ memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
+ count -= rsize;
+ buf += rsize;
+ hp->n_outbuf += rsize;
+ written += rsize;
+ hvc_push(hp);
}
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ /*
+ * Racy, but harmless, kick thread if there is still pending data.
+ */
+ if (hp->n_outbuf)
+ hvc_kick();
return written;
}
+/*
+ * This is actually a contract between the driver and the tty layer outlining
+ * how much write room the driver can guarentee will be sent OR BUFFERED. This
+ * driver MUST honor the return value.
+ */
static int hvc_write_room(struct tty_struct *tty)
{
struct hvc_struct *hp = tty->driver_data;
+ if (!hp)
+ return -1;
+
return N_OUTBUF - hp->n_outbuf;
}
{
struct hvc_struct *hp = tty->driver_data;
+ if (!hp)
+ return -1;
return hp->n_outbuf;
}
-static void hvc_poll(int index)
+#define HVC_POLL_READ 0x00000001
+#define HVC_POLL_WRITE 0x00000002
+#define HVC_POLL_QUICK 0x00000004
+
+static int hvc_poll(struct hvc_struct *hp)
{
- struct hvc_struct *hp = &hvc_struct[index];
struct tty_struct *tty;
- int i, n;
- char buf[16] __ALIGNED__;
+ int i, n, poll_mask = 0;
+ char buf[N_INBUF] __ALIGNED__;
unsigned long flags;
+ int read_total = 0;
spin_lock_irqsave(&hp->lock, flags);
+ /* Push pending writes */
if (hp->n_outbuf > 0)
hvc_push(hp);
+ /* Reschedule us if still some write pending */
+ if (hp->n_outbuf > 0)
+ poll_mask |= HVC_POLL_WRITE;
+ /* No tty attached, just skip */
tty = hp->tty;
- if (tty) {
- for (;;) {
- if (TTY_FLIPBUF_SIZE - tty->flip.count < sizeof(buf))
- break;
- n = hvc_get_chars(index + hvc_offset, buf, sizeof(buf));
- if (n <= 0)
- break;
- for (i = 0; i < n; ++i) {
-#ifdef CONFIG_MAGIC_SYSRQ /* Handle the SysRq Hack */
- if (buf[i] == '\x0f') { /* ^O -- should support a sequence */
+ if (tty == NULL)
+ goto bail;
+
+ /* Now check if we can get data (are we throttled ?) */
+ if (test_bit(TTY_THROTTLED, &tty->flags))
+ goto throttled;
+
+ /* If we aren't interrupt driven and aren't throttled, we always
+ * request a reschedule
+ */
+ if (hp->irq == NO_IRQ)
+ poll_mask |= HVC_POLL_READ;
+
+ /* Read data if any */
+ for (;;) {
+ int count = tty_buffer_request_room(tty, N_INBUF);
+
+ /* If flip is full, just reschedule a later read */
+ if (count == 0) {
+ poll_mask |= HVC_POLL_READ;
+ break;
+ }
+
+ n = hp->ops->get_chars(hp->vtermno, buf, count);
+ if (n <= 0) {
+ /* Hangup the tty when disconnected from host */
+ if (n == -EPIPE) {
+ spin_unlock_irqrestore(&hp->lock, flags);
+ tty_hangup(tty);
+ spin_lock_irqsave(&hp->lock, flags);
+ } else if ( n == -EAGAIN ) {
+ /*
+ * Some back-ends can only ensure a certain min
+ * num of bytes read, which may be > 'count'.
+ * Let the tty clear the flip buff to make room.
+ */
+ poll_mask |= HVC_POLL_READ;
+ }
+ break;
+ }
+ for (i = 0; i < n; ++i) {
+#ifdef CONFIG_MAGIC_SYSRQ
+ if (hp->index == hvc_con_driver.index) {
+ /* Handle the SysRq Hack */
+ /* XXX should support a sequence */
+ if (buf[i] == '\x0f') { /* ^O */
sysrq_pressed = 1;
continue;
} else if (sysrq_pressed) {
sysrq_pressed = 0;
continue;
}
-#endif
- tty_insert_flip_char(tty, buf[i], 0);
}
+#endif /* CONFIG_MAGIC_SYSRQ */
+ tty_insert_flip_char(tty, buf[i], 0);
}
- if (tty->flip.count)
- tty_schedule_flip(tty);
-
- if (hp->do_wakeup) {
- hp->do_wakeup = 0;
- if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP))
- && tty->ldisc.write_wakeup)
- (tty->ldisc.write_wakeup)(tty);
- wake_up_interruptible(&tty->write_wait);
- }
- }
+ read_total += n;
+ }
+ throttled:
+ /* Wakeup write queue if necessary */
+ if (hp->do_wakeup) {
+ hp->do_wakeup = 0;
+ tty_wakeup(tty);
+ }
+ bail:
spin_unlock_irqrestore(&hp->lock, flags);
+
+ if (read_total)
+ tty_flip_buffer_push(tty);
+
+ return poll_mask;
}
#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
static const cpumask_t cpus_in_xmon = CPU_MASK_NONE;
#endif
-
+/*
+ * This kthread is either polling or interrupt driven. This is determined by
+ * calling hvc_poll() who determines whether a console adapter support
+ * interrupts.
+ */
int khvcd(void *unused)
{
- int i;
-
- daemonize("khvcd");
+ int poll_mask;
+ struct hvc_struct *hp;
- for (;;) {
+ __set_current_state(TASK_RUNNING);
+ do {
+ poll_mask = 0;
+ hvc_kicked = 0;
+ wmb();
if (cpus_empty(cpus_in_xmon)) {
- for (i = 0; i < MAX_NR_HVC_CONSOLES; ++i)
- hvc_poll(i);
+ spin_lock(&hvc_structs_lock);
+ list_for_each_entry(hp, &hvc_structs, next) {
+ poll_mask |= hvc_poll(hp);
+ }
+ spin_unlock(&hvc_structs_lock);
+ } else
+ poll_mask |= HVC_POLL_READ;
+ if (hvc_kicked)
+ continue;
+ if (poll_mask & HVC_POLL_QUICK) {
+ yield();
+ continue;
}
set_current_state(TASK_INTERRUPTIBLE);
- schedule_timeout(TIMEOUT);
- }
+ if (!hvc_kicked) {
+ if (poll_mask == 0)
+ schedule();
+ else
+ msleep_interruptible(TIMEOUT);
+ }
+ __set_current_state(TASK_RUNNING);
+ } while (!kthread_should_stop());
+
+ return 0;
}
static struct tty_operations hvc_ops = {
.close = hvc_close,
.write = hvc_write,
.hangup = hvc_hangup,
+ .unthrottle = hvc_unthrottle,
.write_room = hvc_write_room,
.chars_in_buffer = hvc_chars_in_buffer,
};
-int __init hvc_init(void)
+/* callback when the kboject ref count reaches zero. */
+static void destroy_hvc_struct(struct kobject *kobj)
{
- int num = hvc_count(&hvc_offset);
+ 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 hv_ops *ops)
+{
+ struct hvc_struct *hp;
int i;
- if (num > MAX_NR_HVC_CONSOLES)
- num = MAX_NR_HVC_CONSOLES;
+ hp = kmalloc(sizeof(*hp), GFP_KERNEL);
+ if (!hp)
+ return ERR_PTR(-ENOMEM);
- hvc_driver = alloc_tty_driver(num);
- if (!hvc_driver)
- return -ENOMEM;
+ memset(hp, 0x00, sizeof(*hp));
- hvc_driver->owner = THIS_MODULE;
- hvc_driver->devfs_name = "hvc/";
- hvc_driver->driver_name = "hvc";
- hvc_driver->name = "hvc";
- hvc_driver->major = HVC_MAJOR;
- hvc_driver->minor_start = HVC_MINOR;
- hvc_driver->type = TTY_DRIVER_TYPE_SYSTEM;
- hvc_driver->init_termios = tty_std_termios;
- hvc_driver->flags = TTY_DRIVER_REAL_RAW;
- tty_set_operations(hvc_driver, &hvc_ops);
- for (i = 0; i < num; i++) {
- hvc_struct[i].lock = SPIN_LOCK_UNLOCKED;
- hvc_struct[i].index = i;
- }
+ hp->vtermno = vtermno;
+ hp->irq = irq;
+ hp->ops = ops;
- if (tty_register_driver(hvc_driver))
- panic("Couldn't register hvc console driver\n");
+ kobject_init(&hp->kobj);
+ hp->kobj.ktype = &hvc_kobj_type;
- if (num > 0)
- kernel_thread(khvcd, NULL, CLONE_KERNEL);
+ spin_lock_init(&hp->lock);
+ spin_lock(&hvc_structs_lock);
- return 0;
+ /*
+ * find index to use:
+ * see if this vterm id matches one registered for console.
+ */
+ for (i=0; i < MAX_NR_HVC_CONSOLES; i++)
+ if (vtermnos[i] == hp->vtermno &&
+ cons_ops[i] == hp->ops)
+ break;
+
+ /* no matching slot, just use a counter */
+ if (i >= MAX_NR_HVC_CONSOLES)
+ i = ++last_hvc;
+
+ hp->index = i;
+
+ list_add_tail(&(hp->next), &hvc_structs);
+ spin_unlock(&hvc_structs_lock);
+
+ return hp;
}
+EXPORT_SYMBOL(hvc_alloc);
-static void __exit hvc_exit(void)
+int __devexit 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;
+
+ /* Don't whack hp->irq because tty_hangup() will need to free the irq. */
+
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ /*
+ * We 'put' the instance that was grabbed when the kobject instance
+ * was intialized using kobject_init(). Let the last holder of this
+ * kobject cause it to be removed, which will probably be the tty_hangup
+ * below.
+ */
+ kobject_put(kobjp);
+
+ /*
+ * This function call will auto chain call hvc_hangup. The tty should
+ * always be valid at this time unless a simultaneous tty close already
+ * cleaned up the hvc_struct.
+ */
+ if (tty)
+ tty_hangup(tty);
+ return 0;
}
+EXPORT_SYMBOL(hvc_remove);
-void hvc_console_print(struct console *co, const char *b, unsigned count)
+/* Driver initialization. Follow console initialization. This is where the TTY
+ * interfaces start to become available. */
+int __init hvc_init(void)
{
- char c[16] __ALIGNED__;
- unsigned i, n;
- int r, donecr = 0;
+ struct tty_driver *drv;
- i = n = 0;
- while (count > 0 || i > 0) {
- if (count > 0 && i < sizeof(c)) {
- if (b[n] == '\n' && !donecr) {
- c[i++] = '\r';
- donecr = 1;
- } else {
- c[i++] = b[n++];
- donecr = 0;
- --count;
- }
- } else {
- r = hvc_put_chars(co->index + hvc_offset, c, i);
- if (r < 0) {
- /* throw away chars on error */
- i = 0;
- } else if (r > 0) {
- i -= r;
- if (i > 0)
- memmove(c, c+r, i);
- }
- }
+ /* We need more than hvc_count adapters due to hotplug additions. */
+ drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
+ if (!drv)
+ return -ENOMEM;
+
+ drv->owner = THIS_MODULE;
+ drv->devfs_name = "hvc/";
+ drv->driver_name = "hvc";
+ drv->name = "hvc";
+ drv->major = HVC_MAJOR;
+ drv->minor_start = HVC_MINOR;
+ drv->type = TTY_DRIVER_TYPE_SYSTEM;
+ drv->init_termios = tty_std_termios;
+ drv->flags = TTY_DRIVER_REAL_RAW;
+ 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;
}
-}
-static struct tty_driver *hvc_console_device(struct console *c, int *index)
-{
- *index = c->index;
- return hvc_driver;
-}
+ if (tty_register_driver(drv))
+ panic("Couldn't register hvc console driver\n");
-static int __init hvc_console_setup(struct console *co, char *options)
-{
- if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES
- || co->index >= hvc_count(&hvc_offset))
- return -1;
+ mb();
+ hvc_driver = drv;
return 0;
}
+module_init(hvc_init);
-struct console hvc_con_driver = {
- .name = "hvc",
- .write = hvc_console_print,
- .device = hvc_console_device,
- .setup = hvc_console_setup,
- .flags = CON_PRINTBUFFER,
- .index = -1,
-};
-
-static int __init hvc_console_init(void)
+/* This isn't particularily necessary due to this being a console driver
+ * but it is nice to be thorough.
+ */
+static void __exit hvc_exit(void)
{
- register_console(&hvc_con_driver);
- return 0;
-}
-console_initcall(hvc_console_init);
+ kthread_stop(hvc_task);
-module_init(hvc_init);
+ 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://git.onelab.eu / linux-2.6.git / blobdiff