X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fchar%2Fhvc_console.c;h=cc2cd46bedc6ac6dac8dd7d256a3605c784128cf;hb=a2f44b27303a5353859d77a3e96a1d3f33f56ab7;hp=d4bf205fd8821eefaaf5a18470ba2fe6b6ba550f;hpb=daddc0d38b3571bed170afa273a49a0eba090c1e;p=linux-2.6.git diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index d4bf205fd..cc2cd46be 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -1,6 +1,11 @@ /* * Copyright (C) 2001 Anton Blanchard , IBM * Copyright (C) 2001 Paul Mackerras , IBM + * Copyright (C) 2004 Benjamin Herrenschmidt , IBM Corp. + * Copyright (C) 2004 IBM Corporation + * + * Additional Author(s): + * Ryan S. Arnold * * 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 @@ -17,105 +22,459 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include +#include #include +#include +#include +#include +#include +#include #include -#include #include -#include #include #include #include #include -#include -#include #include -#include +#include +#include -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 + +#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; struct tty_struct *tty; unsigned int count; int do_wakeup; - char outbuf[N_OUTBUF] __ALIGNED__; + 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 */ }; -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) +{ + /* 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))) 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, IRQF_DISABLED, "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; @@ -127,135 +486,166 @@ static void hvc_push(struct hvc_struct *hp) 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 = hp->outbuf_size - 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; - return N_OUTBUF - hp->n_outbuf; + if (!hp) + return -1; + + return hp->outbuf_size - hp->n_outbuf; } static int hvc_chars_in_buffer(struct tty_struct *tty) { 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 + +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) { - handle_sysrq(buf[i], NULL, tty); + handle_sysrq(buf[i], tty); 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) @@ -264,132 +654,212 @@ extern cpumask_t cpus_in_xmon; 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; + try_to_freeze(); + 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_WRITE) { + 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 = { +static const struct tty_operations hvc_ops = { .open = hvc_open, .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, int outbuf_size) +{ + struct hvc_struct *hp; int i; - if (num > MAX_NR_HVC_CONSOLES) - num = MAX_NR_HVC_CONSOLES; + hp = kmalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size, + 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; + hp->outbuf_size = outbuf_size; + hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; - 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->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);