#include <linux/bootmem.h>
#include <linux/interrupt.h>
#include <linux/init.h>
+#include <linux/reboot.h>
+
#include <asm/uaccess.h>
#include "sclp.h"
-#define SCLP_VT220_PRINT_HEADER "sclp vt220 tty driver: "
#define SCLP_VT220_MAJOR TTY_MAJOR
#define SCLP_VT220_MINOR 65
#define SCLP_VT220_DRIVER_NAME "sclp_vt220"
/* Number of requests in outqueue */
static int sclp_vt220_outqueue_count;
-/* Wait queue used to delay write requests while we've run out of buffers */
-static wait_queue_head_t sclp_vt220_waitq;
-
/* Timer used for delaying write requests to merge subsequent messages into
* a single buffer */
static struct timer_list sclp_vt220_timer;
/* Number of characters in current request buffer */
static int sclp_vt220_buffered_chars;
-/* Flag indicating whether this driver has already been initialized */
-static int sclp_vt220_initialized = 0;
+/* Counter controlling core driver initialization. */
+static int __initdata sclp_vt220_init_count;
/* Flag indicating that sclp_vt220_current_request should really
* have been already queued but wasn't because the SCLP was processing
} while (request && __sclp_vt220_emit(request));
if (request == NULL && sclp_vt220_flush_later)
sclp_vt220_emit_current();
- wake_up(&sclp_vt220_waitq);
/* Check if the tty needs a wake up call */
if (sclp_vt220_tty != NULL) {
tty_wakeup(sclp_vt220_tty);
*/
static int
__sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
- int convertlf, int may_schedule)
+ int convertlf, int may_fail)
{
unsigned long flags;
void *page;
overall_written = 0;
spin_lock_irqsave(&sclp_vt220_lock, flags);
do {
- /* Create a sclp output buffer if none exists yet */
+ /* Create an sclp output buffer if none exists yet */
if (sclp_vt220_current_request == NULL) {
while (list_empty(&sclp_vt220_empty)) {
spin_unlock_irqrestore(&sclp_vt220_lock, flags);
- if (in_interrupt() || !may_schedule)
- sclp_sync_wait();
+ if (may_fail)
+ goto out;
else
- wait_event(sclp_vt220_waitq,
- !list_empty(&sclp_vt220_empty));
+ sclp_sync_wait();
spin_lock_irqsave(&sclp_vt220_lock, flags);
}
page = (void *) sclp_vt220_empty.next;
add_timer(&sclp_vt220_timer);
}
spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+out:
return overall_written;
}
* character to the tty device. If the kernel uses this routine,
* it must call the flush_chars() routine (if defined) when it is
* done stuffing characters into the driver.
- *
- * NOTE: include/linux/tty_driver.h specifies that a character should be
- * ignored if there is no room in the queue. This driver implements a different
- * semantic in that it will block when there is no more room left.
*/
-static void
+static int
sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
{
- __sclp_vt220_write(&ch, 1, 0, 0, 1);
+ return __sclp_vt220_write(&ch, 1, 0, 0, 1);
}
/*
return count;
}
-static void
-__sclp_vt220_flush_buffer(void)
-{
- unsigned long flags;
-
- sclp_vt220_emit_current();
- spin_lock_irqsave(&sclp_vt220_lock, flags);
- if (timer_pending(&sclp_vt220_timer))
- del_timer(&sclp_vt220_timer);
- while (sclp_vt220_outqueue_count > 0) {
- spin_unlock_irqrestore(&sclp_vt220_lock, flags);
- sclp_sync_wait();
- spin_lock_irqsave(&sclp_vt220_lock, flags);
- }
- spin_unlock_irqrestore(&sclp_vt220_lock, flags);
-}
-
/*
* Pass on all buffers to the hardware. Return only when there are no more
* buffers pending.
sclp_vt220_emit_current();
}
-/*
- * Initialize all relevant components and register driver with system.
- */
-static void __init __sclp_vt220_cleanup(void)
+/* Release allocated pages. */
+static void __init __sclp_vt220_free_pages(void)
{
struct list_head *page, *p;
else
free_bootmem((unsigned long) page, PAGE_SIZE);
}
- if (!list_empty(&sclp_vt220_register.list))
- sclp_unregister(&sclp_vt220_register);
- sclp_vt220_initialized = 0;
}
-static int __init __sclp_vt220_init(void)
+/* Release memory and unregister from sclp core. Controlled by init counting -
+ * only the last invoker will actually perform these actions. */
+static void __init __sclp_vt220_cleanup(void)
+{
+ sclp_vt220_init_count--;
+ if (sclp_vt220_init_count != 0)
+ return;
+ sclp_unregister(&sclp_vt220_register);
+ __sclp_vt220_free_pages();
+}
+
+/* Allocate buffer pages and register with sclp core. Controlled by init
+ * counting - only the first invoker will actually perform these actions. */
+static int __init __sclp_vt220_init(int num_pages)
{
void *page;
int i;
- int num_pages;
int rc;
- if (sclp_vt220_initialized)
+ sclp_vt220_init_count++;
+ if (sclp_vt220_init_count != 1)
return 0;
- sclp_vt220_initialized = 1;
spin_lock_init(&sclp_vt220_lock);
INIT_LIST_HEAD(&sclp_vt220_empty);
INIT_LIST_HEAD(&sclp_vt220_outqueue);
- init_waitqueue_head(&sclp_vt220_waitq);
init_timer(&sclp_vt220_timer);
sclp_vt220_current_request = NULL;
sclp_vt220_buffered_chars = 0;
sclp_vt220_flush_later = 0;
/* Allocate pages for output buffering */
- num_pages = slab_is_available() ? MAX_KMEM_PAGES : MAX_CONSOLE_PAGES;
for (i = 0; i < num_pages; i++) {
if (slab_is_available())
page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
else
page = alloc_bootmem_low_pages(PAGE_SIZE);
if (!page) {
- __sclp_vt220_cleanup();
- return -ENOMEM;
+ rc = -ENOMEM;
+ goto out;
}
list_add_tail((struct list_head *) page, &sclp_vt220_empty);
}
rc = sclp_register(&sclp_vt220_register);
+out:
if (rc) {
- printk(KERN_ERR SCLP_VT220_PRINT_HEADER
- "could not register vt220 - "
- "sclp_register returned %d\n", rc);
- __sclp_vt220_cleanup();
+ __sclp_vt220_free_pages();
+ sclp_vt220_init_count--;
}
return rc;
}
{
struct tty_driver *driver;
int rc;
- int cleanup;
/* Note: we're not testing for CONSOLE_IS_SCLP here to preserve
* symmetry between VM and LPAR systems regarding ttyS1. */
driver = alloc_tty_driver(1);
if (!driver)
return -ENOMEM;
- cleanup = !sclp_vt220_initialized;
- rc = __sclp_vt220_init();
+ rc = __sclp_vt220_init(MAX_KMEM_PAGES);
if (rc)
goto out_driver;
tty_set_operations(driver, &sclp_vt220_ops);
rc = tty_register_driver(driver);
- if (rc) {
- printk(KERN_ERR SCLP_VT220_PRINT_HEADER
- "could not register tty - "
- "tty_register_driver returned %d\n", rc);
+ if (rc)
goto out_init;
- }
sclp_vt220_driver = driver;
return 0;
out_init:
- if (cleanup)
- __sclp_vt220_cleanup();
+ __sclp_vt220_cleanup();
out_driver:
put_tty_driver(driver);
return rc;
return sclp_vt220_driver;
}
-/*
- * This routine is called from panic when the kernel is going to give up.
- * We have to make sure that all buffers will be flushed to the SCLP.
- * Note that this function may be called from within an interrupt context.
- */
-static void
-sclp_vt220_con_unblank(void)
+static void __sclp_vt220_flush_buffer(void)
+{
+ unsigned long flags;
+
+ sclp_vt220_emit_current();
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ if (timer_pending(&sclp_vt220_timer))
+ del_timer(&sclp_vt220_timer);
+ while (sclp_vt220_outqueue_count > 0) {
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ sclp_sync_wait();
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ }
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+}
+
+static int
+sclp_vt220_notify(struct notifier_block *self,
+ unsigned long event, void *data)
{
__sclp_vt220_flush_buffer();
+ return NOTIFY_OK;
}
+static struct notifier_block on_panic_nb = {
+ .notifier_call = sclp_vt220_notify,
+ .priority = 1,
+};
+
+static struct notifier_block on_reboot_nb = {
+ .notifier_call = sclp_vt220_notify,
+ .priority = 1,
+};
+
/* Structure needed to register with printk */
static struct console sclp_vt220_console =
{
.name = SCLP_VT220_CONSOLE_NAME,
.write = sclp_vt220_con_write,
.device = sclp_vt220_con_device,
- .unblank = sclp_vt220_con_unblank,
.flags = CON_PRINTBUFFER,
.index = SCLP_VT220_CONSOLE_INDEX
};
if (!CONSOLE_IS_SCLP)
return 0;
- rc = __sclp_vt220_init();
+ rc = __sclp_vt220_init(MAX_CONSOLE_PAGES);
if (rc)
return rc;
/* Attach linux console */
+ atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
+ register_reboot_notifier(&on_reboot_nb);
register_console(&sclp_vt220_console);
return 0;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff