Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
Linus Torvalds
831
drivers/char/hvc_console.c
Normal file
831
drivers/char/hvc_console.c
Normal file
@@ -0,0 +1,831 @@
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/*
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* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
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* Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
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* Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
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* Copyright (C) 2004 IBM Corporation
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*
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* Additional Author(s):
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* Ryan S. Arnold <rsa@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/console.h>
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#include <linux/cpumask.h>
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#include <linux/init.h>
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#include <linux/kbd_kern.h>
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#include <linux/kernel.h>
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#include <linux/kobject.h>
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#include <linux/kthread.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/major.h>
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#include <linux/sysrq.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/sched.h>
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#include <linux/spinlock.h>
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#include <linux/delay.h>
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#include <asm/uaccess.h>
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#include <asm/hvconsole.h>
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#include <asm/vio.h>
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#define HVC_MAJOR 229
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#define HVC_MINOR 0
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#define TIMEOUT (10)
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/*
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* Wait this long per iteration while trying to push buffered data to the
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* hypervisor before allowing the tty to complete a close operation.
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*/
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#define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
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/*
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* The Linux TTY code does not support dynamic addition of tty derived devices
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* so we need to know how many tty devices we might need when space is allocated
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* for the tty device. Since this driver supports hotplug of vty adapters we
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* need to make sure we have enough allocated.
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*/
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#define HVC_ALLOC_TTY_ADAPTERS 8
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static struct tty_driver *hvc_driver;
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#ifdef CONFIG_MAGIC_SYSRQ
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static int sysrq_pressed;
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#endif
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#define N_OUTBUF 16
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#define N_INBUF 16
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#define __ALIGNED__ __attribute__((__aligned__(8)))
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struct hvc_struct {
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spinlock_t lock;
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int index;
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struct tty_struct *tty;
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unsigned int count;
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int do_wakeup;
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char outbuf[N_OUTBUF] __ALIGNED__;
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int n_outbuf;
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uint32_t vtermno;
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int irq_requested;
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int irq;
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struct list_head next;
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struct kobject kobj; /* ref count & hvc_struct lifetime */
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struct vio_dev *vdev;
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};
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/* dynamic list of hvc_struct instances */
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static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs);
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/*
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* Protect the list of hvc_struct instances from inserts and removals during
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* list traversal.
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*/
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static DEFINE_SPINLOCK(hvc_structs_lock);
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/*
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* Initial console vtermnos for console API usage prior to full console
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* initialization. Any vty adapter outside this range will not have usable
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* console interfaces but can still be used as a tty device. This has to be
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* static because kmalloc will not work during early console init.
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*/
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static uint32_t vtermnos[MAX_NR_HVC_CONSOLES];
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/* Used for accounting purposes */
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static int num_vterms = 0;
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static struct task_struct *hvc_task;
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/*
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* This value is used to associate a tty->index value to a hvc_struct based
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* upon order of exposure via hvc_probe().
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*/
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static int hvc_count = -1;
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/* Picks up late kicks after list walk but before schedule() */
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static int hvc_kicked;
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/* Wake the sleeping khvcd */
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static void hvc_kick(void)
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{
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hvc_kicked = 1;
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wake_up_process(hvc_task);
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}
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/*
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* NOTE: This API isn't used if the console adapter doesn't support interrupts.
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* In this case the console is poll driven.
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*/
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static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
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{
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hvc_kick();
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return IRQ_HANDLED;
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}
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static void hvc_unthrottle(struct tty_struct *tty)
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{
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hvc_kick();
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}
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/*
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* Do not call this function with either the hvc_strucst_lock or the hvc_struct
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* lock held. If successful, this function increments the kobject reference
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* count against the target hvc_struct so it should be released when finished.
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*/
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struct hvc_struct *hvc_get_by_index(int index)
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{
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struct hvc_struct *hp;
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unsigned long flags;
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spin_lock(&hvc_structs_lock);
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list_for_each_entry(hp, &hvc_structs, next) {
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spin_lock_irqsave(&hp->lock, flags);
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if (hp->index == index) {
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kobject_get(&hp->kobj);
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spin_unlock_irqrestore(&hp->lock, flags);
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spin_unlock(&hvc_structs_lock);
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return hp;
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}
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spin_unlock_irqrestore(&hp->lock, flags);
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}
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hp = NULL;
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spin_unlock(&hvc_structs_lock);
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return hp;
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}
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/*
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* The TTY interface won't be used until after the vio layer has exposed the vty
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* adapter to the kernel.
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*/
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static int hvc_open(struct tty_struct *tty, struct file * filp)
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{
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struct hvc_struct *hp;
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unsigned long flags;
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int irq = NO_IRQ;
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int rc = 0;
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struct kobject *kobjp;
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/* Auto increments kobject reference if found. */
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if (!(hp = hvc_get_by_index(tty->index))) {
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printk(KERN_WARNING "hvc_console: tty open failed, no vty associated with tty.\n");
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return -ENODEV;
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}
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spin_lock_irqsave(&hp->lock, flags);
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/* Check and then increment for fast path open. */
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if (hp->count++ > 0) {
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spin_unlock_irqrestore(&hp->lock, flags);
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hvc_kick();
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return 0;
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} /* else count == 0 */
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tty->driver_data = hp;
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hp->tty = tty;
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/* Save for request_irq outside of spin_lock. */
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irq = hp->irq;
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if (irq != NO_IRQ)
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hp->irq_requested = 1;
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kobjp = &hp->kobj;
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spin_unlock_irqrestore(&hp->lock, flags);
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/* check error, fallback to non-irq */
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if (irq != NO_IRQ)
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rc = request_irq(irq, hvc_handle_interrupt, SA_INTERRUPT, "hvc_console", hp);
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/*
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* If the request_irq() fails and 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
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* up there so we'll clean up here and clear out the previously set
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* tty fields and return the kobject reference.
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*/
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if (rc) {
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spin_lock_irqsave(&hp->lock, flags);
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hp->tty = NULL;
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hp->irq_requested = 0;
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spin_unlock_irqrestore(&hp->lock, flags);
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tty->driver_data = NULL;
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kobject_put(kobjp);
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printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
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}
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/* Force wakeup of the polling thread */
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hvc_kick();
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return rc;
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}
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static void hvc_close(struct tty_struct *tty, struct file * filp)
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{
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struct hvc_struct *hp;
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struct kobject *kobjp;
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int irq = NO_IRQ;
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unsigned long flags;
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if (tty_hung_up_p(filp))
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return;
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/*
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* No driver_data means that this close was issued after a failed
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* hvc_open by the tty layer's release_dev() function and we can just
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* exit cleanly because the kobject reference wasn't made.
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*/
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if (!tty->driver_data)
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return;
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hp = tty->driver_data;
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spin_lock_irqsave(&hp->lock, flags);
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kobjp = &hp->kobj;
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if (--hp->count == 0) {
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if (hp->irq_requested)
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irq = hp->irq;
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hp->irq_requested = 0;
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/* We are done with the tty pointer now. */
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hp->tty = NULL;
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spin_unlock_irqrestore(&hp->lock, flags);
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/*
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* Chain calls chars_in_buffer() and returns immediately if
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* there is no buffered data otherwise sleeps on a wait queue
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* waking periodically to check chars_in_buffer().
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*/
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tty_wait_until_sent(tty, HVC_CLOSE_WAIT);
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if (irq != NO_IRQ)
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free_irq(irq, hp);
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} else {
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if (hp->count < 0)
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printk(KERN_ERR "hvc_close %X: oops, count is %d\n",
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hp->vtermno, hp->count);
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spin_unlock_irqrestore(&hp->lock, flags);
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}
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kobject_put(kobjp);
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}
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static void hvc_hangup(struct tty_struct *tty)
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{
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struct hvc_struct *hp = tty->driver_data;
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unsigned long flags;
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int irq = NO_IRQ;
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int temp_open_count;
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struct kobject *kobjp;
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if (!hp)
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return;
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spin_lock_irqsave(&hp->lock, flags);
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/*
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* The N_TTY line discipline has problems such that in a close vs
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* open->hangup case this can be called after the final close so prevent
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* that from happening for now.
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*/
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if (hp->count <= 0) {
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spin_unlock_irqrestore(&hp->lock, flags);
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return;
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}
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kobjp = &hp->kobj;
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temp_open_count = hp->count;
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hp->count = 0;
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hp->n_outbuf = 0;
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hp->tty = NULL;
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if (hp->irq_requested)
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/* Saved for use outside of spin_lock. */
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irq = hp->irq;
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hp->irq_requested = 0;
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spin_unlock_irqrestore(&hp->lock, flags);
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if (irq != NO_IRQ)
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free_irq(irq, hp);
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while(temp_open_count) {
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--temp_open_count;
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kobject_put(kobjp);
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}
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}
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/*
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* Push buffered characters whether they were just recently buffered or waiting
|
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* on a blocked hypervisor. Call this function with hp->lock held.
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*/
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static void hvc_push(struct hvc_struct *hp)
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{
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int n;
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n = hvc_put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);
|
||||
if (n <= 0) {
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||||
if (n == 0)
|
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return;
|
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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;
|
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if (hp->n_outbuf > 0)
|
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memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf);
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else
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hp->do_wakeup = 1;
|
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}
|
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|
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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)
|
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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 = hvc_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
|
||||
/* Handle the SysRq Hack */
|
||||
if (buf[i] == '\x0f') { /* ^O -- should support a sequence */
|
||||
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) {
|
||||
/*hp = list_entry(node, struct hvc_struct, * 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,
|
||||
};
|
||||
|
||||
char hvc_driver_name[] = "hvc_console";
|
||||
|
||||
static struct vio_device_id hvc_driver_table[] __devinitdata= {
|
||||
{"serial", "hvterm1"},
|
||||
{ NULL, }
|
||||
};
|
||||
MODULE_DEVICE_TABLE(vio, hvc_driver_table);
|
||||
|
||||
/* 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,
|
||||
};
|
||||
|
||||
static int __devinit hvc_probe(
|
||||
struct vio_dev *dev,
|
||||
const struct vio_device_id *id)
|
||||
{
|
||||
struct hvc_struct *hp;
|
||||
|
||||
/* probed with invalid parameters. */
|
||||
if (!dev || !id)
|
||||
return -EPERM;
|
||||
|
||||
hp = kmalloc(sizeof(*hp), GFP_KERNEL);
|
||||
if (!hp)
|
||||
return -ENOMEM;
|
||||
|
||||
memset(hp, 0x00, sizeof(*hp));
|
||||
hp->vtermno = dev->unit_address;
|
||||
hp->vdev = dev;
|
||||
hp->vdev->dev.driver_data = hp;
|
||||
hp->irq = dev->irq;
|
||||
|
||||
kobject_init(&hp->kobj);
|
||||
hp->kobj.ktype = &hvc_kobj_type;
|
||||
|
||||
spin_lock_init(&hp->lock);
|
||||
spin_lock(&hvc_structs_lock);
|
||||
hp->index = ++hvc_count;
|
||||
list_add_tail(&(hp->next), &hvc_structs);
|
||||
spin_unlock(&hvc_structs_lock);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int __devexit hvc_remove(struct vio_dev *dev)
|
||||
{
|
||||
struct hvc_struct *hp = dev->dev.driver_data;
|
||||
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;
|
||||
}
|
||||
|
||||
static struct vio_driver hvc_vio_driver = {
|
||||
.name = hvc_driver_name,
|
||||
.id_table = hvc_driver_table,
|
||||
.probe = hvc_probe,
|
||||
.remove = hvc_remove,
|
||||
};
|
||||
|
||||
/* Driver initialization. Follow console initialization. This is where the TTY
|
||||
* interfaces start to become available. */
|
||||
int __init hvc_init(void)
|
||||
{
|
||||
int rc;
|
||||
|
||||
/* We need more than num_vterms adapters due to hotplug additions. */
|
||||
hvc_driver = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
|
||||
/* hvc_driver = alloc_tty_driver(num_vterms); */
|
||||
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);
|
||||
|
||||
if (tty_register_driver(hvc_driver))
|
||||
panic("Couldn't register hvc console driver\n");
|
||||
|
||||
/* 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;
|
||||
}
|
||||
|
||||
/* Register as a vio device to receive callbacks */
|
||||
rc = vio_register_driver(&hvc_vio_driver);
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
/* 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);
|
||||
|
||||
vio_unregister_driver(&hvc_vio_driver);
|
||||
tty_unregister_driver(hvc_driver);
|
||||
/* return tty_struct instances allocated in hvc_init(). */
|
||||
put_tty_driver(hvc_driver);
|
||||
}
|
||||
|
||||
/*
|
||||
* Console APIs, NOT TTY. These APIs are available immediately when
|
||||
* hvc_console_setup() finds adapters.
|
||||
*/
|
||||
|
||||
/*
|
||||
* 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 the appear after early console init.
|
||||
*/
|
||||
int hvc_instantiate(uint32_t vtermno, int index)
|
||||
{
|
||||
if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
|
||||
return -1;
|
||||
|
||||
if (vtermnos[index] != -1)
|
||||
return -1;
|
||||
|
||||
vtermnos[index] = vtermno;
|
||||
return 0;
|
||||
}
|
||||
|
||||
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;
|
||||
|
||||
/* Console access attempt outside of acceptable console range. */
|
||||
if (co->index >= MAX_NR_HVC_CONSOLES)
|
||||
return;
|
||||
|
||||
/* This console adapter was removed so it is not useable. */
|
||||
if (vtermnos[co->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 = hvc_put_chars(vtermnos[co->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)
|
||||
{
|
||||
*index = c->index;
|
||||
return hvc_driver;
|
||||
}
|
||||
|
||||
static int __init hvc_console_setup(struct console *co, char *options)
|
||||
{
|
||||
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. */
|
||||
static int __init hvc_console_init(void)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i=0; i<MAX_NR_HVC_CONSOLES; i++)
|
||||
vtermnos[i] = -1;
|
||||
num_vterms = hvc_find_vtys();
|
||||
register_console(&hvc_con_driver);
|
||||
return 0;
|
||||
}
|
||||
console_initcall(hvc_console_init);
|
||||
|
||||
module_init(hvc_init);
|
||||
module_exit(hvc_exit);
|
||||
Reference in New Issue
Block a user