linux/drivers/tty/hvc/hvc_beat.c

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/*
* Beat hypervisor console driver
*
* (C) Copyright 2006 TOSHIBA CORPORATION
*
* This code is based on drivers/char/hvc_rtas.c:
* (C) Copyright IBM Corporation 2001-2005
* (C) Copyright Red Hat, Inc. 2005
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/console.h>
#include <asm/prom.h>
#include <asm/hvconsole.h>
#include <asm/firmware.h>
#include "hvc_console.h"
extern int64_t beat_get_term_char(uint64_t, uint64_t *, uint64_t *, uint64_t *);
extern int64_t beat_put_term_char(uint64_t, uint64_t, uint64_t, uint64_t);
struct hvc_struct *hvc_beat_dev = NULL;
/* bug: only one queue is available regardless of vtermno */
static int hvc_beat_get_chars(uint32_t vtermno, char *buf, int cnt)
{
static unsigned char q[sizeof(unsigned long) * 2]
__attribute__((aligned(sizeof(unsigned long))));
static int qlen = 0;
u64 got;
again:
if (qlen) {
if (qlen > cnt) {
memcpy(buf, q, cnt);
qlen -= cnt;
memmove(q + cnt, q, qlen);
return cnt;
} else { /* qlen <= cnt */
int r;
memcpy(buf, q, qlen);
r = qlen;
qlen = 0;
return r;
}
}
if (beat_get_term_char(vtermno, &got,
((u64 *)q), ((u64 *)q) + 1) == 0) {
qlen = got;
goto again;
}
return 0;
}
static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt)
{
unsigned long kb[2];
int rest, nlen;
for (rest = cnt; rest > 0; rest -= nlen) {
nlen = (rest > 16) ? 16 : rest;
memcpy(kb, buf, nlen);
beat_put_term_char(vtermno, nlen, kb[0], kb[1]);
buf += nlen;
}
return cnt;
}
static const struct hv_ops hvc_beat_get_put_ops = {
.get_chars = hvc_beat_get_chars,
.put_chars = hvc_beat_put_chars,
};
static int hvc_beat_useit = 1;
static int hvc_beat_config(char *p)
{
hvc_beat_useit = simple_strtoul(p, NULL, 0);
return 0;
}
static int __init hvc_beat_console_init(void)
{
if (hvc_beat_useit && of_machine_is_compatible("Beat")) {
hvc_instantiate(0, 0, &hvc_beat_get_put_ops);
}
return 0;
}
/* temp */
static int __init hvc_beat_init(void)
{
struct hvc_struct *hp;
if (!firmware_has_feature(FW_FEATURE_BEAT))
return -ENODEV;
hp = hvc_alloc(0, NO_IRQ, &hvc_beat_get_put_ops, 16);
if (IS_ERR(hp))
return PTR_ERR(hp);
hvc_beat_dev = hp;
return 0;
}
static void __exit hvc_beat_exit(void)
{
if (hvc_beat_dev)
hvc_remove(hvc_beat_dev);
}
module_init(hvc_beat_init);
module_exit(hvc_beat_exit);
__setup("hvc_beat=", hvc_beat_config);
console_initcall(hvc_beat_console_init);