mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 10:04:12 +08:00
c9602ee7d1
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Instead of creating an external static data variable, just define a separate callback which encodes the "force restart" desire. Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kees Cook <keescook@chromium.org> [heiko.carstens@de.ibm.com: get rid of compile warning] Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
355 lines
8.6 KiB
C
355 lines
8.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* SCLP line mode console driver
|
|
*
|
|
* Copyright IBM Corp. 1999, 2009
|
|
* Author(s): Martin Peschke <mpeschke@de.ibm.com>
|
|
* Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/kmod.h>
|
|
#include <linux/console.h>
|
|
#include <linux/init.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/termios.h>
|
|
#include <linux/err.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/gfp.h>
|
|
|
|
#include "sclp.h"
|
|
#include "sclp_rw.h"
|
|
#include "sclp_tty.h"
|
|
|
|
#define sclp_console_major 4 /* TTYAUX_MAJOR */
|
|
#define sclp_console_minor 64
|
|
#define sclp_console_name "ttyS"
|
|
|
|
/* Lock to guard over changes to global variables */
|
|
static spinlock_t sclp_con_lock;
|
|
/* List of free pages that can be used for console output buffering */
|
|
static struct list_head sclp_con_pages;
|
|
/* List of full struct sclp_buffer structures ready for output */
|
|
static struct list_head sclp_con_outqueue;
|
|
/* Pointer to current console buffer */
|
|
static struct sclp_buffer *sclp_conbuf;
|
|
/* Timer for delayed output of console messages */
|
|
static struct timer_list sclp_con_timer;
|
|
/* Suspend mode flag */
|
|
static int sclp_con_suspended;
|
|
/* Flag that output queue is currently running */
|
|
static int sclp_con_queue_running;
|
|
|
|
/* Output format for console messages */
|
|
static unsigned short sclp_con_columns;
|
|
static unsigned short sclp_con_width_htab;
|
|
|
|
static void
|
|
sclp_conbuf_callback(struct sclp_buffer *buffer, int rc)
|
|
{
|
|
unsigned long flags;
|
|
void *page;
|
|
|
|
do {
|
|
page = sclp_unmake_buffer(buffer);
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
|
|
/* Remove buffer from outqueue */
|
|
list_del(&buffer->list);
|
|
list_add_tail((struct list_head *) page, &sclp_con_pages);
|
|
|
|
/* Check if there is a pending buffer on the out queue. */
|
|
buffer = NULL;
|
|
if (!list_empty(&sclp_con_outqueue))
|
|
buffer = list_first_entry(&sclp_con_outqueue,
|
|
struct sclp_buffer, list);
|
|
if (!buffer || sclp_con_suspended) {
|
|
sclp_con_queue_running = 0;
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
break;
|
|
}
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
} while (sclp_emit_buffer(buffer, sclp_conbuf_callback));
|
|
}
|
|
|
|
/*
|
|
* Finalize and emit first pending buffer.
|
|
*/
|
|
static void sclp_conbuf_emit(void)
|
|
{
|
|
struct sclp_buffer* buffer;
|
|
unsigned long flags;
|
|
int rc;
|
|
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
if (sclp_conbuf)
|
|
list_add_tail(&sclp_conbuf->list, &sclp_con_outqueue);
|
|
sclp_conbuf = NULL;
|
|
if (sclp_con_queue_running || sclp_con_suspended)
|
|
goto out_unlock;
|
|
if (list_empty(&sclp_con_outqueue))
|
|
goto out_unlock;
|
|
buffer = list_first_entry(&sclp_con_outqueue, struct sclp_buffer,
|
|
list);
|
|
sclp_con_queue_running = 1;
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
|
|
rc = sclp_emit_buffer(buffer, sclp_conbuf_callback);
|
|
if (rc)
|
|
sclp_conbuf_callback(buffer, rc);
|
|
return;
|
|
out_unlock:
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* Wait until out queue is empty
|
|
*/
|
|
static void sclp_console_sync_queue(void)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
if (timer_pending(&sclp_con_timer))
|
|
del_timer(&sclp_con_timer);
|
|
while (sclp_con_queue_running) {
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
sclp_sync_wait();
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
}
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* When this routine is called from the timer then we flush the
|
|
* temporary write buffer without further waiting on a final new line.
|
|
*/
|
|
static void
|
|
sclp_console_timeout(struct timer_list *unused)
|
|
{
|
|
sclp_conbuf_emit();
|
|
}
|
|
|
|
/*
|
|
* Drop oldest console buffer if sclp_con_drop is set
|
|
*/
|
|
static int
|
|
sclp_console_drop_buffer(void)
|
|
{
|
|
struct list_head *list;
|
|
struct sclp_buffer *buffer;
|
|
void *page;
|
|
|
|
if (!sclp_console_drop)
|
|
return 0;
|
|
list = sclp_con_outqueue.next;
|
|
if (sclp_con_queue_running)
|
|
/* The first element is in I/O */
|
|
list = list->next;
|
|
if (list == &sclp_con_outqueue)
|
|
return 0;
|
|
list_del(list);
|
|
buffer = list_entry(list, struct sclp_buffer, list);
|
|
page = sclp_unmake_buffer(buffer);
|
|
list_add_tail((struct list_head *) page, &sclp_con_pages);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Writes the given message to S390 system console
|
|
*/
|
|
static void
|
|
sclp_console_write(struct console *console, const char *message,
|
|
unsigned int count)
|
|
{
|
|
unsigned long flags;
|
|
void *page;
|
|
int written;
|
|
|
|
if (count == 0)
|
|
return;
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
/*
|
|
* process escape characters, write message into buffer,
|
|
* send buffer to SCLP
|
|
*/
|
|
do {
|
|
/* make sure we have a console output buffer */
|
|
if (sclp_conbuf == NULL) {
|
|
if (list_empty(&sclp_con_pages))
|
|
sclp_console_full++;
|
|
while (list_empty(&sclp_con_pages)) {
|
|
if (sclp_con_suspended)
|
|
goto out;
|
|
if (sclp_console_drop_buffer())
|
|
break;
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
sclp_sync_wait();
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
}
|
|
page = sclp_con_pages.next;
|
|
list_del((struct list_head *) page);
|
|
sclp_conbuf = sclp_make_buffer(page, sclp_con_columns,
|
|
sclp_con_width_htab);
|
|
}
|
|
/* try to write the string to the current output buffer */
|
|
written = sclp_write(sclp_conbuf, (const unsigned char *)
|
|
message, count);
|
|
if (written == count)
|
|
break;
|
|
/*
|
|
* Not all characters could be written to the current
|
|
* output buffer. Emit the buffer, create a new buffer
|
|
* and then output the rest of the string.
|
|
*/
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
sclp_conbuf_emit();
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
message += written;
|
|
count -= written;
|
|
} while (count > 0);
|
|
/* Setup timer to output current console buffer after 1/10 second */
|
|
if (sclp_conbuf != NULL && sclp_chars_in_buffer(sclp_conbuf) != 0 &&
|
|
!timer_pending(&sclp_con_timer)) {
|
|
mod_timer(&sclp_con_timer, jiffies + HZ / 10);
|
|
}
|
|
out:
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
}
|
|
|
|
static struct tty_driver *
|
|
sclp_console_device(struct console *c, int *index)
|
|
{
|
|
*index = c->index;
|
|
return sclp_tty_driver;
|
|
}
|
|
|
|
/*
|
|
* Make sure that all buffers will be flushed to the SCLP.
|
|
*/
|
|
static void
|
|
sclp_console_flush(void)
|
|
{
|
|
sclp_conbuf_emit();
|
|
sclp_console_sync_queue();
|
|
}
|
|
|
|
/*
|
|
* Resume console: If there are cached messages, emit them.
|
|
*/
|
|
static void sclp_console_resume(void)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
sclp_con_suspended = 0;
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
sclp_conbuf_emit();
|
|
}
|
|
|
|
/*
|
|
* Suspend console: Set suspend flag and flush console
|
|
*/
|
|
static void sclp_console_suspend(void)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&sclp_con_lock, flags);
|
|
sclp_con_suspended = 1;
|
|
spin_unlock_irqrestore(&sclp_con_lock, flags);
|
|
sclp_console_flush();
|
|
}
|
|
|
|
static int sclp_console_notify(struct notifier_block *self,
|
|
unsigned long event, void *data)
|
|
{
|
|
sclp_console_flush();
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block on_panic_nb = {
|
|
.notifier_call = sclp_console_notify,
|
|
.priority = SCLP_PANIC_PRIO_CLIENT,
|
|
};
|
|
|
|
static struct notifier_block on_reboot_nb = {
|
|
.notifier_call = sclp_console_notify,
|
|
.priority = 1,
|
|
};
|
|
|
|
/*
|
|
* used to register the SCLP console to the kernel and to
|
|
* give printk necessary information
|
|
*/
|
|
static struct console sclp_console =
|
|
{
|
|
.name = sclp_console_name,
|
|
.write = sclp_console_write,
|
|
.device = sclp_console_device,
|
|
.flags = CON_PRINTBUFFER,
|
|
.index = 0 /* ttyS0 */
|
|
};
|
|
|
|
/*
|
|
* This function is called for SCLP suspend and resume events.
|
|
*/
|
|
void sclp_console_pm_event(enum sclp_pm_event sclp_pm_event)
|
|
{
|
|
switch (sclp_pm_event) {
|
|
case SCLP_PM_EVENT_FREEZE:
|
|
sclp_console_suspend();
|
|
break;
|
|
case SCLP_PM_EVENT_RESTORE:
|
|
case SCLP_PM_EVENT_THAW:
|
|
sclp_console_resume();
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* called by console_init() in drivers/char/tty_io.c at boot-time.
|
|
*/
|
|
static int __init
|
|
sclp_console_init(void)
|
|
{
|
|
void *page;
|
|
int i;
|
|
int rc;
|
|
|
|
/* SCLP consoles are handled together */
|
|
if (!(CONSOLE_IS_SCLP || CONSOLE_IS_VT220))
|
|
return 0;
|
|
rc = sclp_rw_init();
|
|
if (rc)
|
|
return rc;
|
|
/* Allocate pages for output buffering */
|
|
INIT_LIST_HEAD(&sclp_con_pages);
|
|
for (i = 0; i < sclp_console_pages; i++) {
|
|
page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
|
|
list_add_tail(page, &sclp_con_pages);
|
|
}
|
|
INIT_LIST_HEAD(&sclp_con_outqueue);
|
|
spin_lock_init(&sclp_con_lock);
|
|
sclp_conbuf = NULL;
|
|
timer_setup(&sclp_con_timer, sclp_console_timeout, 0);
|
|
|
|
/* Set output format */
|
|
if (MACHINE_IS_VM)
|
|
/*
|
|
* save 4 characters for the CPU number
|
|
* written at start of each line by VM/CP
|
|
*/
|
|
sclp_con_columns = 76;
|
|
else
|
|
sclp_con_columns = 80;
|
|
sclp_con_width_htab = 8;
|
|
|
|
/* enable printk-access to this driver */
|
|
atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
|
|
register_reboot_notifier(&on_reboot_nb);
|
|
register_console(&sclp_console);
|
|
return 0;
|
|
}
|
|
|
|
console_initcall(sclp_console_init);
|