| /* |
| * 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 |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * 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/major.h> |
| #include <linux/sysrq.h> |
| #include <linux/tty.h> |
| #include <linux/tty_flip.h> |
| #include <linux/sched.h> |
| #include <linux/spinlock.h> |
| #include <linux/delay.h> |
| #include <asm/uaccess.h> |
| #include <asm/hvconsole.h> |
| |
| #define HVC_MAJOR 229 |
| #define HVC_MINOR 0 |
| |
| #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 */ |
| |
| /* |
| * The Linux TTY code does not support dynamic addition of tty derived devices |
| * so we need to know how many tty devices we might need when space is allocated |
| * for the tty device. Since this driver supports hotplug of vty adapters we |
| * need to make sure we have enough allocated. |
| */ |
| #define HVC_ALLOC_TTY_ADAPTERS 8 |
| |
| #define N_OUTBUF 16 |
| #define N_INBUF 16 |
| |
| #define __ALIGNED__ __attribute__((__aligned__(8))) |
| |
| static struct tty_driver *hvc_driver; |
| 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 |
| |
| struct hvc_struct { |
| spinlock_t lock; |
| int index; |
| struct tty_struct *tty; |
| unsigned int count; |
| 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 */ |
| }; |
| |
| /* 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[16] __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) |
| { |
| struct hvc_struct *hp; |
| unsigned long flags; |
| int irq = NO_IRQ; |
| int rc = 0; |
| struct kobject *kobjp; |
| |
| /* 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; |
| } |
| |
| 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; |
| hp->tty = tty; |
| /* 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 rc; |
| } |
| |
| static void hvc_close(struct tty_struct *tty, struct file * filp) |
| { |
| 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); |
| |
| 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); |
| |
| /* |
| * 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); |
| } |
| } |
| |
| /* |
| * 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 = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); |
| if (n <= 0) { |
| if (n == 0) |
| return; |
| /* throw away output on error; this happens when |
| there is no session connected to the vterm. */ |
| hp->n_outbuf = 0; |
| } else |
| hp->n_outbuf -= n; |
| if (hp->n_outbuf > 0) |
| memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); |
| else |
| hp->do_wakeup = 1; |
| } |
| |
| static inline int __hvc_write_kernel(struct hvc_struct *hp, |
| const unsigned char *buf, int count) |
| { |
| unsigned long flags; |
| int rsize, written = 0; |
| |
| spin_lock_irqsave(&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); |
| |
| return written; |
| } |
| static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) |
| { |
| struct hvc_struct *hp = tty->driver_data; |
| int written; |
| |
| /* This write was probably executed during a tty close. */ |
| if (!hp) |
| return -EPIPE; |
| |
| if (hp->count <= 0) |
| return -EIO; |
| |
| written = __hvc_write_kernel(hp, buf, count); |
| |
| /* |
| * Racy, but harmless, kick thread if there is still pending data. |
| * There really is nothing wrong with kicking the thread, even if there |
| * is no buffered 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; |
| } |
| |
| 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; |
| } |
| |
| #define HVC_POLL_READ 0x00000001 |
| #define HVC_POLL_WRITE 0x00000002 |
| #define HVC_POLL_QUICK 0x00000004 |
| |
| static 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; |
| |
| 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 == 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 = N_INBUF; |
| if (count > (TTY_FLIPBUF_SIZE - tty->flip.count)) |
| count = TTY_FLIPBUF_SIZE - tty->flip.count; |
| |
| /* 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); |
| } |
| 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); |
| sysrq_pressed = 0; |
| continue; |
| } |
| } |
| #endif /* CONFIG_MAGIC_SYSRQ */ |
| tty_insert_flip_char(tty, buf[i], 0); |
| } |
| |
| if (tty->flip.count) |
| tty_schedule_flip(tty); |
| |
| /* |
| * Account for the total amount read in one loop, and if above |
| * 64 bytes, we do a quick schedule loop to let the tty grok |
| * the data and eventually throttle us. |
| */ |
| read_total += n; |
| if (read_total >= 64) { |
| poll_mask |= HVC_POLL_QUICK; |
| break; |
| } |
| } |
| throttled: |
| /* Wakeup write queue if necessary */ |
| if (hp->do_wakeup) { |
| hp->do_wakeup = 0; |
| tty_wakeup(tty); |
| } |
| bail: |
| spin_unlock_irqrestore(&hp->lock, flags); |
| |
| return poll_mask; |
| } |
| |
| #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 |
| |
| /* |
| * 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 poll_mask; |
| struct hvc_struct *hp; |
| |
| __set_current_state(TASK_RUNNING); |
| do { |
| poll_mask = 0; |
| hvc_kicked = 0; |
| wmb(); |
| if (cpus_empty(cpus_in_xmon)) { |
| 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); |
| 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 = { |
| .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, |
| }; |
| |
| /* 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 hv_ops *ops) |
| { |
| struct hvc_struct *hp; |
| int i; |
| |
| hp = kmalloc(sizeof(*hp), GFP_KERNEL); |
| if (!hp) |
| return ERR_PTR(-ENOMEM); |
| |
| memset(hp, 0x00, sizeof(*hp)); |
| |
| hp->vtermno = vtermno; |
| hp->irq = irq; |
| hp->ops = ops; |
| |
| kobject_init(&hp->kobj); |
| hp->kobj.ktype = &hvc_kobj_type; |
| |
| spin_lock_init(&hp->lock); |
| spin_lock(&hvc_structs_lock); |
| |
| /* |
| * 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) |
| 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); |
| |
| 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); |
| |
| /* Driver initialization. Follow console initialization. This is where the TTY |
| * interfaces start to become available. */ |
| int __init hvc_init(void) |
| { |
| /* We need more than hvc_count adapters due to hotplug additions. */ |
| hvc_driver = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); |
| if (!hvc_driver) |
| return -ENOMEM; |
| |
| 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); |
| |
| /* 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(hvc_driver); |
| return -EIO; |
| } |
| |
| if (tty_register_driver(hvc_driver)) |
| panic("Couldn't register hvc console driver\n"); |
| |
| return 0; |
| } |
| module_init(hvc_init); |
| |
| /* 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) |
| { |
| 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); |
| } |
| module_exit(hvc_exit); |