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drivers/char/hvc_console.c
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/* * 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/console.h> #include <linux/cpumask.h> #include <linux/init.h> #include <linux/kbd_kern.h> #include <linux/kernel.h> |
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#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> |
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#include <linux/freezer.h> |
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#include <asm/uaccess.h> |
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#include "hvc_console.h" |
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#define HVC_MAJOR 229 #define HVC_MINOR 0 |
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/* * 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 */ /* |
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* 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. |
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*/ |
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#define N_OUTBUF 16 #define N_INBUF 16 |
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#define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) |
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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; |
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static int hvc_init(void); |
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#ifdef CONFIG_MAGIC_SYSRQ static int sysrq_pressed; #endif |
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/* dynamic list of hvc_struct instances */ |
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static LIST_HEAD(hvc_structs); |
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/* * Protect the list of hvc_struct instances from inserts and removals during * list traversal. */ static DEFINE_SPINLOCK(hvc_structs_lock); /* |
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* 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 |
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* a console candidate registered with hvc_instantiate(). |
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*/ |
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static int last_hvc = -1; |
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/* |
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* Do not call this function with either the hvc_structs_lock or the hvc_struct |
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* lock held. If successful, this function increments the kref reference |
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* count against the target hvc_struct so it should be released when finished. */ |
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static struct hvc_struct *hvc_get_by_index(int index) |
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{ 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) { |
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kref_get(&hp->kref); |
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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; } /* |
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* 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. */ |
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static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; |
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static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; |
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/* * Console APIs, NOT TTY. These APIs are available immediately when * hvc_console_setup() finds adapters. */ |
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static void hvc_console_print(struct console *co, const char *b, unsigned count) |
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{ |
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char c[N_OUTBUF] __ALIGNED__; |
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unsigned i = 0, n = 0; |
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int r, donecr = 0, index = co->index; |
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/* Console access attempt outside of acceptable console range. */ |
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if (index >= MAX_NR_HVC_CONSOLES) |
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return; |
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/* This console adapter was removed so it is not usable. */ |
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if (vtermnos[index] < 0) |
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return; while (count > 0 || i > 0) { if (count > 0 && i < sizeof(c)) { if (b[n] == ' ' && !donecr) { c[i++] = '\r'; donecr = 1; } else { c[i++] = b[n++]; donecr = 0; --count; } } else { |
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r = cons_ops[index]->put_chars(vtermnos[index], c, i); |
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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) { |
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if (vtermnos[c->index] == -1) return NULL; |
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*index = c->index; return hvc_driver; } static int __init hvc_console_setup(struct console *co, char *options) { |
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if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) return -ENODEV; if (vtermnos[co->index] == -1) return -ENODEV; |
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return 0; } |
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static struct console hvc_con_driver = { |
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.name = "hvc", .write = hvc_console_print, .device = hvc_console_device, .setup = hvc_console_setup, .flags = CON_PRINTBUFFER, .index = -1, }; |
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/* |
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* Early console initialization. Precedes driver initialization. |
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* * (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. */ |
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static int __init hvc_console_init(void) { |
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register_console(&hvc_con_driver); return 0; } console_initcall(hvc_console_init); |
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/* 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); } |
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/* |
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* 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. |
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*/ |
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int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops) |
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{ |
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struct hvc_struct *hp; |
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if (index < 0 || index >= MAX_NR_HVC_CONSOLES) return -1; |
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if (vtermnos[index] != -1) return -1; |
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/* make sure no no tty has been registered in this index */ |
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hp = hvc_get_by_index(index); if (hp) { |
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kref_put(&hp->kref, destroy_hvc_struct); |
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return -1; } |
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vtermnos[index] = vtermno; |
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cons_ops[index] = ops; |
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/* reserve all indices up to and including this index */ |
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if (last_hvc < index) last_hvc = index; |
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/* 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); |
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return 0; } |
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EXPORT_SYMBOL_GPL(hvc_instantiate); |
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/* Wake the sleeping khvcd */ |
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void hvc_kick(void) |
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{ hvc_kicked = 1; wake_up_process(hvc_task); } |
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EXPORT_SYMBOL_GPL(hvc_kick); |
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static void hvc_unthrottle(struct tty_struct *tty) { hvc_kick(); } /* |
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* 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; |
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int rc = 0; |
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/* Auto increments kref reference if found. */ |
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if (!(hp = hvc_get_by_index(tty->index))) |
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return -ENODEV; |
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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; |
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tty->low_latency = 1; /* Makes flushes to ldisc synchronous. */ |
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hp->tty = tty; |
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if (hp->ops->notifier_add) rc = hp->ops->notifier_add(hp, hp->data); |
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spin_unlock_irqrestore(&hp->lock, flags); |
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/* |
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* If the notifier fails we return an error. The tty layer |
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* 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 |
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* tty fields and return the kref reference. |
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*/ if (rc) { spin_lock_irqsave(&hp->lock, flags); hp->tty = NULL; |
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spin_unlock_irqrestore(&hp->lock, flags); tty->driver_data = NULL; |
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kref_put(&hp->kref, destroy_hvc_struct); |
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printk(KERN_ERR "hvc_open: request_irq failed with rc %d. ", 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; |
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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 |
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* exit cleanly because the kref reference wasn't made. |
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*/ if (!tty->driver_data) return; hp = tty->driver_data; spin_lock_irqsave(&hp->lock, flags); |
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if (--hp->count == 0) { |
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if (hp->ops->notifier_del) hp->ops->notifier_del(hp, hp->data); |
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/* 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); |
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} else { if (hp->count < 0) printk(KERN_ERR "hvc_close %X: oops, count is %d ", hp->vtermno, hp->count); spin_unlock_irqrestore(&hp->lock, flags); } |
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kref_put(&hp->kref, destroy_hvc_struct); |
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} static void hvc_hangup(struct tty_struct *tty) { struct hvc_struct *hp = tty->driver_data; unsigned long flags; |
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int temp_open_count; |
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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; } |
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temp_open_count = hp->count; hp->count = 0; hp->n_outbuf = 0; hp->tty = NULL; |
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if (hp->ops->notifier_del) hp->ops->notifier_del(hp, hp->data); |
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spin_unlock_irqrestore(&hp->lock, flags); |
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while(temp_open_count) { --temp_open_count; |
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kref_put(&hp->kref, destroy_hvc_struct); |
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} } /* * 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; |
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n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); |
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if (n <= 0) { |
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if (n == 0) { hp->do_wakeup = 1; |
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return; |
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} |
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/* 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; } |
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static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) |
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{ |
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struct hvc_struct *hp = tty->driver_data; |
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unsigned long flags; int rsize, written = 0; |
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/* This write was probably executed during a tty close. */ if (!hp) return -EPIPE; if (hp->count <= 0) return -EIO; |
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spin_lock_irqsave(&hp->lock, flags); /* Push pending writes */ if (hp->n_outbuf > 0) hvc_push(hp); |
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while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) { |
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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); |
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/* * Racy, but harmless, kick thread if there is still pending data. |
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*/ if (hp->n_outbuf) hvc_kick(); return written; } /* * This is actually a contract between the driver and the tty layer outlining |
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* how much write room the driver can guarantee will be sent OR BUFFERED. This |
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* 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; |
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return hp->outbuf_size - hp->n_outbuf; |
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} 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; } |
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/* * timeout will vary between the MIN and MAX values defined here. By default * and during console activity we will use a default MIN_TIMEOUT of 10. When * the console is idle, we increase the timeout value on each pass through * msleep until we reach the max. This may be noticeable as a brief (average * one second) delay on the console before the console responds to input when * there has been no input for some time. */ #define MIN_TIMEOUT (10) #define MAX_TIMEOUT (2000) static u32 timeout = MIN_TIMEOUT; |
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#define HVC_POLL_READ 0x00000001 #define HVC_POLL_WRITE 0x00000002 |
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|
611e097d7 hvc_console: rewo... |
507 |
int hvc_poll(struct hvc_struct *hp) |
1da177e4c Linux-2.6.12-rc2 |
508 509 510 511 512 513 514 515 516 517 518 519 |
{ 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); |
b53744612 [PATCH] powerpc: ... |
520 |
|
1da177e4c Linux-2.6.12-rc2 |
521 522 523 524 525 526 527 528 529 530 531 532 |
/* 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; |
611e097d7 hvc_console: rewo... |
533 |
/* If we aren't notifier driven and aren't throttled, we always |
1da177e4c Linux-2.6.12-rc2 |
534 535 |
* request a reschedule */ |
611e097d7 hvc_console: rewo... |
536 |
if (!hp->irq_requested) |
1da177e4c Linux-2.6.12-rc2 |
537 538 539 540 |
poll_mask |= HVC_POLL_READ; /* Read data if any */ for (;;) { |
33f0f88f1 [PATCH] TTY layer... |
541 |
int count = tty_buffer_request_room(tty, N_INBUF); |
1da177e4c Linux-2.6.12-rc2 |
542 543 544 545 546 547 |
/* If flip is full, just reschedule a later read */ if (count == 0) { poll_mask |= HVC_POLL_READ; break; } |
030ffad23 [PATCH] hvc_conso... |
548 |
n = hp->ops->get_chars(hp->vtermno, buf, count); |
1da177e4c Linux-2.6.12-rc2 |
549 550 551 552 553 554 |
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); |
45d607ed9 [PATCH] powerpc: ... |
555 556 557 558 559 560 561 |
} 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; |
1da177e4c Linux-2.6.12-rc2 |
562 563 564 565 566 |
} break; } for (i = 0; i < n; ++i) { #ifdef CONFIG_MAGIC_SYSRQ |
2b9e0bac9 [PATCH] hvc_conso... |
567 568 569 570 571 572 573 |
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) { |
7d12e780e IRQ: Maintain reg... |
574 |
handle_sysrq(buf[i], tty); |
2b9e0bac9 [PATCH] hvc_conso... |
575 576 577 |
sysrq_pressed = 0; continue; } |
1da177e4c Linux-2.6.12-rc2 |
578 579 580 581 |
} #endif /* CONFIG_MAGIC_SYSRQ */ tty_insert_flip_char(tty, buf[i], 0); } |
1da177e4c Linux-2.6.12-rc2 |
582 |
read_total += n; |
1da177e4c Linux-2.6.12-rc2 |
583 584 585 586 587 588 589 590 591 |
} throttled: /* Wakeup write queue if necessary */ if (hp->do_wakeup) { hp->do_wakeup = 0; tty_wakeup(tty); } bail: spin_unlock_irqrestore(&hp->lock, flags); |
b791072ba [POWERPC] hvc_con... |
592 593 594 595 |
if (read_total) { /* Activity is occurring, so reset the polling backoff value to a minimum for performance. */ timeout = MIN_TIMEOUT; |
fb5c594c2 [PATCH] Fix race ... |
596 |
tty_flip_buffer_push(tty); |
b791072ba [POWERPC] hvc_con... |
597 |
} |
1da177e4c Linux-2.6.12-rc2 |
598 599 |
return poll_mask; } |
7721c494a virtio: console a... |
600 |
EXPORT_SYMBOL_GPL(hvc_poll); |
1da177e4c Linux-2.6.12-rc2 |
601 |
|
1da177e4c Linux-2.6.12-rc2 |
602 603 604 605 606 |
/* * This kthread is either polling or interrupt driven. This is determined by * calling hvc_poll() who determines whether a console adapter support * interrupts. */ |
5605d4def [POWERPC] Make dr... |
607 |
static int khvcd(void *unused) |
1da177e4c Linux-2.6.12-rc2 |
608 609 610 |
{ int poll_mask; struct hvc_struct *hp; |
831441862 Freezer: make ker... |
611 |
set_freezable(); |
1da177e4c Linux-2.6.12-rc2 |
612 613 614 615 |
__set_current_state(TASK_RUNNING); do { poll_mask = 0; hvc_kicked = 0; |
b64074e46 [PATCH] hvc_conso... |
616 |
try_to_freeze(); |
1da177e4c Linux-2.6.12-rc2 |
617 |
wmb(); |
1c8950ff8 [POWERPC] Make cp... |
618 |
if (!cpus_are_in_xmon()) { |
1da177e4c Linux-2.6.12-rc2 |
619 620 |
spin_lock(&hvc_structs_lock); list_for_each_entry(hp, &hvc_structs, next) { |
1da177e4c Linux-2.6.12-rc2 |
621 622 623 624 625 626 627 |
poll_mask |= hvc_poll(hp); } spin_unlock(&hvc_structs_lock); } else poll_mask |= HVC_POLL_READ; if (hvc_kicked) continue; |
b53744612 [PATCH] powerpc: ... |
628 |
if (poll_mask & HVC_POLL_WRITE) { |
1da177e4c Linux-2.6.12-rc2 |
629 630 631 632 633 634 635 |
yield(); continue; } set_current_state(TASK_INTERRUPTIBLE); if (!hvc_kicked) { if (poll_mask == 0) schedule(); |
b791072ba [POWERPC] hvc_con... |
636 637 638 639 640 641 |
else { if (timeout < MAX_TIMEOUT) timeout += (timeout >> 6) + 1; msleep_interruptible(timeout); } |
1da177e4c Linux-2.6.12-rc2 |
642 643 644 645 646 647 |
} __set_current_state(TASK_RUNNING); } while (!kthread_should_stop()); return 0; } |
b68e31d0e [PATCH] const str... |
648 |
static const struct tty_operations hvc_ops = { |
1da177e4c Linux-2.6.12-rc2 |
649 650 651 652 653 654 655 656 |
.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, }; |
611e097d7 hvc_console: rewo... |
657 |
struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data, |
4e9e95a35 [POWERPC] Make th... |
658 |
struct hv_ops *ops, int outbuf_size) |
1da177e4c Linux-2.6.12-rc2 |
659 660 |
{ struct hvc_struct *hp; |
6f24808ee [PATCH] hvc_conso... |
661 |
int i; |
1da177e4c Linux-2.6.12-rc2 |
662 |
|
3e6c6f630 Delay creation of... |
663 664 665 666 667 668 |
/* We wait until a driver actually comes along */ if (!hvc_driver) { int err = hvc_init(); if (err) return ERR_PTR(err); } |
4e9e95a35 [POWERPC] Make th... |
669 670 |
hp = kmalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size, GFP_KERNEL); |
1da177e4c Linux-2.6.12-rc2 |
671 |
if (!hp) |
acad9559f [PATCH] hvc_conso... |
672 |
return ERR_PTR(-ENOMEM); |
1da177e4c Linux-2.6.12-rc2 |
673 674 |
memset(hp, 0x00, sizeof(*hp)); |
acad9559f [PATCH] hvc_conso... |
675 676 |
hp->vtermno = vtermno; |
611e097d7 hvc_console: rewo... |
677 |
hp->data = data; |
030ffad23 [PATCH] hvc_conso... |
678 |
hp->ops = ops; |
4e9e95a35 [POWERPC] Make th... |
679 680 |
hp->outbuf_size = outbuf_size; hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; |
1da177e4c Linux-2.6.12-rc2 |
681 |
|
12b20ded6 kobject: convert ... |
682 |
kref_init(&hp->kref); |
1da177e4c Linux-2.6.12-rc2 |
683 684 685 |
spin_lock_init(&hp->lock); spin_lock(&hvc_structs_lock); |
6f24808ee [PATCH] hvc_conso... |
686 687 688 689 690 691 |
/* * find index to use: * see if this vterm id matches one registered for console. */ for (i=0; i < MAX_NR_HVC_CONSOLES; i++) |
45d607ed9 [PATCH] powerpc: ... |
692 693 |
if (vtermnos[i] == hp->vtermno && cons_ops[i] == hp->ops) |
6f24808ee [PATCH] hvc_conso... |
694 695 696 697 698 699 700 |
break; /* no matching slot, just use a counter */ if (i >= MAX_NR_HVC_CONSOLES) i = ++last_hvc; hp->index = i; |
1da177e4c Linux-2.6.12-rc2 |
701 702 |
list_add_tail(&(hp->next), &hvc_structs); spin_unlock(&hvc_structs_lock); |
acad9559f [PATCH] hvc_conso... |
703 |
return hp; |
1da177e4c Linux-2.6.12-rc2 |
704 |
} |
7721c494a virtio: console a... |
705 |
EXPORT_SYMBOL_GPL(hvc_alloc); |
1da177e4c Linux-2.6.12-rc2 |
706 |
|
acad9559f [PATCH] hvc_conso... |
707 |
int __devexit hvc_remove(struct hvc_struct *hp) |
1da177e4c Linux-2.6.12-rc2 |
708 |
{ |
1da177e4c Linux-2.6.12-rc2 |
709 |
unsigned long flags; |
1da177e4c Linux-2.6.12-rc2 |
710 711 712 713 |
struct tty_struct *tty; spin_lock_irqsave(&hp->lock, flags); tty = hp->tty; |
1da177e4c Linux-2.6.12-rc2 |
714 715 716 717 718 719 720 721 722 |
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); /* |
12b20ded6 kobject: convert ... |
723 724 725 |
* 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 |
1da177e4c Linux-2.6.12-rc2 |
726 727 |
* below. */ |
12b20ded6 kobject: convert ... |
728 |
kref_put(&hp->kref, destroy_hvc_struct); |
1da177e4c Linux-2.6.12-rc2 |
729 730 731 732 733 734 735 736 737 738 |
/* * 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; } |
1da177e4c Linux-2.6.12-rc2 |
739 |
|
3e6c6f630 Delay creation of... |
740 741 |
/* Driver initialization: called as soon as someone uses hvc_alloc(). */ static int hvc_init(void) |
1da177e4c Linux-2.6.12-rc2 |
742 |
{ |
55aab8cd3 [PATCH] powerpc: ... |
743 |
struct tty_driver *drv; |
3e6c6f630 Delay creation of... |
744 |
int err; |
55aab8cd3 [PATCH] powerpc: ... |
745 |
|
5f6d9c072 [PATCH] hvc_conso... |
746 |
/* We need more than hvc_count adapters due to hotplug additions. */ |
55aab8cd3 [PATCH] powerpc: ... |
747 |
drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); |
3e6c6f630 Delay creation of... |
748 749 750 751 |
if (!drv) { err = -ENOMEM; goto out; } |
1da177e4c Linux-2.6.12-rc2 |
752 |
|
55aab8cd3 [PATCH] powerpc: ... |
753 |
drv->owner = THIS_MODULE; |
55aab8cd3 [PATCH] powerpc: ... |
754 755 756 757 758 759 760 761 |
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); |
1da177e4c Linux-2.6.12-rc2 |
762 |
|
1da177e4c Linux-2.6.12-rc2 |
763 764 765 766 |
/* 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)) { |
3e6c6f630 Delay creation of... |
767 768 769 770 |
printk(KERN_ERR "Couldn't create kthread for console. "); err = PTR_ERR(hvc_task); goto put_tty; |
1da177e4c Linux-2.6.12-rc2 |
771 |
} |
3e6c6f630 Delay creation of... |
772 773 774 775 776 777 |
err = tty_register_driver(drv); if (err) { printk(KERN_ERR "Couldn't register hvc console driver "); goto stop_thread; } |
ef4cbee0b [PATCH] hvc_conso... |
778 |
|
3e6c6f630 Delay creation of... |
779 |
/* FIXME: This mb() seems completely random. Remove it. */ |
55aab8cd3 [PATCH] powerpc: ... |
780 781 |
mb(); hvc_driver = drv; |
acad9559f [PATCH] hvc_conso... |
782 |
return 0; |
3e6c6f630 Delay creation of... |
783 784 785 786 787 788 789 790 |
put_tty: put_tty_driver(hvc_driver); stop_thread: kthread_stop(hvc_task); hvc_task = NULL; out: return err; |
1da177e4c Linux-2.6.12-rc2 |
791 |
} |
c3ea6921a [POWERPC] hvc_con... |
792 |
/* This isn't particularly necessary due to this being a console driver |
320da0d23 [PATCH] hvc_conso... |
793 794 |
* but it is nice to be thorough. */ |
1da177e4c Linux-2.6.12-rc2 |
795 796 |
static void __exit hvc_exit(void) { |
3e6c6f630 Delay creation of... |
797 798 |
if (hvc_driver) { kthread_stop(hvc_task); |
1da177e4c Linux-2.6.12-rc2 |
799 |
|
3e6c6f630 Delay creation of... |
800 801 802 803 804 |
tty_unregister_driver(hvc_driver); /* return tty_struct instances allocated in hvc_init(). */ put_tty_driver(hvc_driver); unregister_console(&hvc_con_driver); } |
1da177e4c Linux-2.6.12-rc2 |
805 |
} |
1da177e4c Linux-2.6.12-rc2 |
806 |
module_exit(hvc_exit); |