#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
+#include <linux/freezer.h>
#include <asm/uaccess.h>
#define HVC_MAJOR 229
#define HVC_MINOR 0
-#define TIMEOUT (10)
-
/*
* Wait this long per iteration while trying to push buffered data to the
* hypervisor before allowing the tty to complete a close operation.
/*
* This value is used to assign a tty->index value to a hvc_struct based
* upon order of exposure via hvc_probe(), when we can not match it to
- * a console canidate registered with hvc_instantiate().
+ * a console candidate registered with hvc_instantiate().
*/
static int last_hvc = -1;
/*
- * Do not call this function with either the hvc_strucst_lock or the hvc_struct
+ * Do not call this function with either the hvc_structs_lock or the hvc_struct
* lock held. If successful, this function increments the kobject reference
* count against the target hvc_struct so it should be released when finished.
*/
-struct hvc_struct *hvc_get_by_index(int index)
+static struct hvc_struct *hvc_get_by_index(int index)
{
struct hvc_struct *hp;
unsigned long flags;
* hvc_console_setup() finds adapters.
*/
-void hvc_console_print(struct console *co, const char *b, unsigned count)
+static void hvc_console_print(struct console *co, const char *b,
+ unsigned count)
{
char c[N_OUTBUF] __ALIGNED__;
unsigned i = 0, n = 0;
if (index >= MAX_NR_HVC_CONSOLES)
return;
- /* This console adapter was removed so it is not useable. */
+ /* This console adapter was removed so it is not usable. */
if (vtermnos[index] < 0)
return;
return 0;
}
-struct console hvc_con_driver = {
+static struct console hvc_con_driver = {
.name = "hvc",
.write = hvc_console_print,
.device = hvc_console_device,
};
/*
- * Early console initialization. Preceeds driver initialization.
+ * Early console initialization. Precedes driver initialization.
*
* (1) we are first, and the user specified another driver
* -- index will remain -1
if (vtermnos[index] != -1)
return -1;
- /* make sure no no tty has been registerd in this index */
+ /* make sure no no tty has been registered in this index */
hp = hvc_get_by_index(index);
if (hp) {
kobject_put(&hp->kobj);
vtermnos[index] = vtermno;
cons_ops[index] = ops;
- /* reserve all indices upto and including this index */
+ /* reserve all indices up to and including this index */
if (last_hvc < index)
last_hvc = index;
return 0;
}
-EXPORT_SYMBOL(hvc_instantiate);
/* Wake the sleeping khvcd */
static void hvc_kick(void)
* NOTE: This API isn't used if the console adapter doesn't support interrupts.
* In this case the console is poll driven.
*/
-static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
+static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
{
/* if hvc_poll request a repoll, then kick the hvcd thread */
if (hvc_poll(dev_instance))
{
struct hvc_struct *hp;
unsigned long flags;
- int irq = NO_IRQ;
+ int irq = 0;
int rc = 0;
struct kobject *kobjp;
hp->tty = tty;
/* Save for request_irq outside of spin_lock. */
irq = hp->irq;
- if (irq != NO_IRQ)
+ if (irq)
hp->irq_requested = 1;
kobjp = &hp->kobj;
spin_unlock_irqrestore(&hp->lock, flags);
/* check error, fallback to non-irq */
- if (irq != NO_IRQ)
+ if (irq)
rc = request_irq(irq, hvc_handle_interrupt, IRQF_DISABLED, "hvc_console", hp);
/*
{
struct hvc_struct *hp;
struct kobject *kobjp;
- int irq = NO_IRQ;
+ int irq = 0;
unsigned long flags;
if (tty_hung_up_p(filp))
*/
tty_wait_until_sent(tty, HVC_CLOSE_WAIT);
- if (irq != NO_IRQ)
+ if (irq)
free_irq(irq, hp);
} else {
{
struct hvc_struct *hp = tty->driver_data;
unsigned long flags;
- int irq = NO_IRQ;
+ int irq = 0;
int temp_open_count;
struct kobject *kobjp;
irq = hp->irq;
hp->irq_requested = 0;
spin_unlock_irqrestore(&hp->lock, flags);
- if (irq != NO_IRQ)
+ if (irq)
free_irq(irq, hp);
while(temp_open_count) {
--temp_open_count;
/*
* 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
+ * how much write room the driver can guarantee will be sent OR BUFFERED. This
* driver MUST honor the return value.
*/
static int hvc_write_room(struct tty_struct *tty)
return hp->n_outbuf;
}
+/*
+ * timeout will vary between the MIN and MAX values defined here. By default
+ * and during console activity we will use a default MIN_TIMEOUT of 10. When
+ * the console is idle, we increase the timeout value on each pass through
+ * msleep until we reach the max. This may be noticeable as a brief (average
+ * one second) delay on the console before the console responds to input when
+ * there has been no input for some time.
+ */
+#define MIN_TIMEOUT (10)
+#define MAX_TIMEOUT (2000)
+static u32 timeout = MIN_TIMEOUT;
+
#define HVC_POLL_READ 0x00000001
#define HVC_POLL_WRITE 0x00000002
/* If we aren't interrupt driven and aren't throttled, we always
* request a reschedule
*/
- if (hp->irq == NO_IRQ)
+ if (hp->irq == 0)
poll_mask |= HVC_POLL_READ;
/* Read data if any */
sysrq_pressed = 1;
continue;
} else if (sysrq_pressed) {
- handle_sysrq(buf[i], NULL, tty);
+ handle_sysrq(buf[i], tty);
sysrq_pressed = 0;
continue;
}
bail:
spin_unlock_irqrestore(&hp->lock, flags);
- if (read_total)
+ if (read_total) {
+ /* Activity is occurring, so reset the polling backoff value to
+ a minimum for performance. */
+ timeout = MIN_TIMEOUT;
+
tty_flip_buffer_push(tty);
-
+ }
+
return poll_mask;
}
* calling hvc_poll() who determines whether a console adapter support
* interrupts.
*/
-int khvcd(void *unused)
+static int khvcd(void *unused)
{
int poll_mask;
struct hvc_struct *hp;
+ set_freezable();
__set_current_state(TASK_RUNNING);
do {
poll_mask = 0;
if (!hvc_kicked) {
if (poll_mask == 0)
schedule();
- else
- msleep_interruptible(TIMEOUT);
+ else {
+ if (timeout < MAX_TIMEOUT)
+ timeout += (timeout >> 6) + 1;
+
+ msleep_interruptible(timeout);
+ }
}
__set_current_state(TASK_RUNNING);
} while (!kthread_should_stop());
return hp;
}
-EXPORT_SYMBOL(hvc_alloc);
int __devexit hvc_remove(struct hvc_struct *hp)
{
/*
* We 'put' the instance that was grabbed when the kobject instance
- * was intialized using kobject_init(). Let the last holder of this
+ * was initialized using kobject_init(). Let the last holder of this
* kobject cause it to be removed, which will probably be the tty_hangup
* below.
*/
tty_hangup(tty);
return 0;
}
-EXPORT_SYMBOL(hvc_remove);
/* Driver initialization. Follow console initialization. This is where the TTY
* interfaces start to become available. */
-int __init hvc_init(void)
+static int __init hvc_init(void)
{
struct tty_driver *drv;
}
module_init(hvc_init);
-/* This isn't particularily necessary due to this being a console driver
+/* This isn't particularly necessary due to this being a console driver
* but it is nice to be thorough.
*/
static void __exit hvc_exit(void)
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff