611e097d77
This patch tries to change hvc_console to not use request_irq/free_irq if the backend does not use irqs. This allows virtio_console to use hvc_console without having a linker reference to request_irq/free_irq. In addition, together with patch 2/3 it improves the performance for virtio console input. (an earlier version of this patch was tested by Yajin on lguest) The irq specific code is moved to hvc_irq.c and selected by the drivers that use irqs (System p, System i, XEN). I replaced "int irq" with the opaque "int data". The request_irq and free_irq calls are replaced with notifier_add and notifier_del. I have also changed the code a bit to call the notifier_add and notifier_del inside the spinlock area as the callbacks are found via hp->ops. Changes since last version: o remove ifdef o reintroduce "irq_requested" as "notified" o cleanups, sparse.. I did not move the timer based polling into a separate polling scheme. I played with several variants, but it seems we need to sleep/schedule in a thread even for irq based consoles, as there are throttleing and buffer size constraints. I also kept hvc_struct defined in hvc_console.h so that hvc_irq.c can access the irq_requested element. Feedback is appreciated. virtio_console is currently the only available console for kvm on s390. I plan to push this change as soon as all affected parties agree on it. I would love to get test results from System p, Xen etc. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
100 lines
3.1 KiB
C
100 lines
3.1 KiB
C
/*
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* hvc_console.h
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* Copyright (C) 2005 IBM Corporation
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*
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* Author(s):
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* Ryan S. Arnold <rsa@us.ibm.com>
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*
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* hvc_console header information:
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* moved here from include/asm-powerpc/hvconsole.h
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* and drivers/char/hvc_console.c
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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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#ifndef HVC_CONSOLE_H
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#define HVC_CONSOLE_H
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#include <linux/kref.h>
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/*
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* This is the max number of console adapters that can/will be found as
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* console devices on first stage console init. Any number beyond this range
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* can't be used as a console device but is still a valid tty device.
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*/
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#define MAX_NR_HVC_CONSOLES 16
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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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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;
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int outbuf_size;
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int n_outbuf;
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uint32_t vtermno;
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struct hv_ops *ops;
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int irq_requested;
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int data;
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struct list_head next;
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struct kref kref; /* ref count & hvc_struct lifetime */
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};
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/* implemented by a low level driver */
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struct hv_ops {
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int (*get_chars)(uint32_t vtermno, char *buf, int count);
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int (*put_chars)(uint32_t vtermno, const char *buf, int count);
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/* Callbacks for notification. Called in open and close */
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int (*notifier_add)(struct hvc_struct *hp, int irq);
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void (*notifier_del)(struct hvc_struct *hp, int irq);
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};
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/* Register a vterm and a slot index for use as a console (console_init) */
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extern int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops);
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/* register a vterm for hvc tty operation (module_init or hotplug add) */
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extern struct hvc_struct * __devinit hvc_alloc(uint32_t vtermno, int data,
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struct hv_ops *ops, int outbuf_size);
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/* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
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extern int __devexit hvc_remove(struct hvc_struct *hp);
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/* data available */
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int hvc_poll(struct hvc_struct *hp);
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void hvc_kick(void);
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/* default notifier for irq based notification */
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extern int notifier_add_irq(struct hvc_struct *hp, int data);
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extern void notifier_del_irq(struct hvc_struct *hp, int data);
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#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
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#include <asm/xmon.h>
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#else
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static inline int cpus_are_in_xmon(void)
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{
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return 0;
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}
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#endif
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#endif // HVC_CONSOLE_H
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