#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
+#include <linux/freezer.h>
+
#include <asm/uaccess.h>
-#include <asm/hvconsole.h>
-#include <asm/vio.h>
+
+#include "hvc_console.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.
#define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
/*
- * The Linux TTY code does not support dynamic addition of tty derived devices
- * so we need to know how many tty devices we might need when space is allocated
- * for the tty device. Since this driver supports hotplug of vty adapters we
- * need to make sure we have enough allocated.
+ * These sizes are most efficient for vio, because they are the
+ * native transfer size. We could make them selectable in the
+ * future to better deal with backends that want other buffer sizes.
*/
-#define HVC_ALLOC_TTY_ADAPTERS 8
-
#define N_OUTBUF 16
#define N_INBUF 16
-#define __ALIGNED__ __attribute__((__aligned__(8)))
+#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
static struct tty_driver *hvc_driver;
static struct task_struct *hvc_task;
struct tty_struct *tty;
unsigned int count;
int do_wakeup;
- char outbuf[N_OUTBUF] __ALIGNED__;
+ char *outbuf;
+ int outbuf_size;
int n_outbuf;
uint32_t vtermno;
+ struct hv_ops *ops;
int irq_requested;
int irq;
struct list_head next;
struct kobject kobj; /* ref count & hvc_struct lifetime */
- struct vio_dev *vdev;
};
/* dynamic list of hvc_struct instances */
/*
* 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;
* console interfaces but can still be used as a tty device. This has to be
* static because kmalloc will not work during early console init.
*/
-static uint32_t vtermnos[MAX_NR_HVC_CONSOLES];
-
-/* Used for accounting purposes */
-static int num_vterms = 0;
+static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES];
+static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] =
+ {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1};
/*
* Console APIs, NOT TTY. These APIs are available immediately when
* 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[16] __ALIGNED__;
+ char c[N_OUTBUF] __ALIGNED__;
unsigned i = 0, n = 0;
- int r, donecr = 0;
+ int r, donecr = 0, index = co->index;
/* Console access attempt outside of acceptable console range. */
- if (co->index >= MAX_NR_HVC_CONSOLES)
+ if (index >= MAX_NR_HVC_CONSOLES)
return;
- /* This console adapter was removed so it is not useable. */
- if (vtermnos[co->index] < 0)
+ /* This console adapter was removed so it is not usable. */
+ if (vtermnos[index] < 0)
return;
while (count > 0 || i > 0) {
--count;
}
} else {
- r = hvc_put_chars(vtermnos[co->index], c, i);
+ r = cons_ops[index]->put_chars(vtermnos[index], c, i);
if (r < 0) {
/* throw away chars on error */
i = 0;
static struct tty_driver *hvc_console_device(struct console *c, int *index)
{
+ if (vtermnos[c->index] == -1)
+ return NULL;
+
*index = c->index;
return hvc_driver;
}
static int __init hvc_console_setup(struct console *co, char *options)
{
+ if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES)
+ return -ENODEV;
+
+ if (vtermnos[co->index] == -1)
+ return -ENODEV;
+
return 0;
}
-struct console hvc_con_driver = {
+static struct console hvc_con_driver = {
.name = "hvc",
.write = hvc_console_print,
.device = hvc_console_device,
.index = -1,
};
-/* 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
+ * (2) we are first and the user specified no driver
+ * -- index will be set to 0, then we will fail setup.
+ * (3) we are first and the user specified our driver
+ * -- index will be set to user specified driver, and we will fail
+ * (4) we are after driver, and this initcall will register us
+ * -- if the user didn't specify a driver then the console will match
+ *
+ * Note that for cases 2 and 3, we will match later when the io driver
+ * calls hvc_instantiate() and call register again.
+ */
static int __init hvc_console_init(void)
{
- int i;
-
- for (i=0; i<MAX_NR_HVC_CONSOLES; i++)
- vtermnos[i] = -1;
- num_vterms = hvc_find_vtys();
register_console(&hvc_con_driver);
return 0;
}
* vty adapters do NOT get an hvc_instantiate() callback since they
* appear after early console init.
*/
-int hvc_instantiate(uint32_t vtermno, int index)
+int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops)
{
+ struct hvc_struct *hp;
+
if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
return -1;
if (vtermnos[index] != -1)
return -1;
+ /* make sure no no tty has been registered in this index */
+ hp = hvc_get_by_index(index);
+ if (hp) {
+ kobject_put(&hp->kobj);
+ return -1;
+ }
+
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;
+ /* if this index is what the user requested, then register
+ * now (setup won't fail at this point). It's ok to just
+ * call register again if previously .setup failed.
+ */
+ if (index == hvc_con_driver.index)
+ register_console(&hvc_con_driver);
+
return 0;
}
* 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;
/* Auto increments kobject reference if found. */
- if (!(hp = hvc_get_by_index(tty->index))) {
- printk(KERN_WARNING "hvc_console: tty open failed, no vty associated with tty.\n");
+ if (!(hp = hvc_get_by_index(tty->index)))
return -ENODEV;
- }
spin_lock_irqsave(&hp->lock, flags);
/* Check and then increment for fast path open. */
} /* else count == 0 */
tty->driver_data = hp;
+ tty->low_latency = 1; /* Makes flushes to ldisc synchronous. */
+
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)
- rc = request_irq(irq, hvc_handle_interrupt, SA_INTERRUPT, "hvc_console", hp);
+ if (irq)
+ rc = request_irq(irq, hvc_handle_interrupt, IRQF_DISABLED, "hvc_console", hp);
/*
* If the request_irq() fails and we return an error. The tty layer
{
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;
{
int n;
- n = hvc_put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);
+ n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);
if (n <= 0) {
- if (n == 0)
+ if (n == 0) {
+ hp->do_wakeup = 1;
return;
+ }
/* throw away output on error; this happens when
there is no session connected to the vterm. */
hp->n_outbuf = 0;
hp->do_wakeup = 1;
}
-static inline int __hvc_write_kernel(struct hvc_struct *hp,
- const unsigned char *buf, int count)
+static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
+ struct hvc_struct *hp = tty->driver_data;
unsigned long flags;
int rsize, written = 0;
+ /* This write was probably executed during a tty close. */
+ if (!hp)
+ return -EPIPE;
+
+ if (hp->count <= 0)
+ return -EIO;
+
spin_lock_irqsave(&hp->lock, flags);
/* Push pending writes */
if (hp->n_outbuf > 0)
hvc_push(hp);
- while (count > 0 && (rsize = N_OUTBUF - hp->n_outbuf) > 0) {
+ while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) {
if (rsize > count)
rsize = count;
memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
}
spin_unlock_irqrestore(&hp->lock, flags);
- return written;
-}
-static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count)
-{
- struct hvc_struct *hp = tty->driver_data;
- int written;
-
- /* This write was probably executed during a tty close. */
- if (!hp)
- return -EPIPE;
-
- if (hp->count <= 0)
- return -EIO;
-
- written = __hvc_write_kernel(hp, buf, count);
-
/*
* Racy, but harmless, kick thread if there is still pending data.
- * There really is nothing wrong with kicking the thread, even if there
- * is no buffered data.
*/
if (hp->n_outbuf)
hvc_kick();
/*
* 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)
if (!hp)
return -1;
- return N_OUTBUF - hp->n_outbuf;
+ return hp->outbuf_size - hp->n_outbuf;
}
static int hvc_chars_in_buffer(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
-#define HVC_POLL_QUICK 0x00000004
static int hvc_poll(struct hvc_struct *hp)
{
/* Push pending writes */
if (hp->n_outbuf > 0)
hvc_push(hp);
+
/* Reschedule us if still some write pending */
if (hp->n_outbuf > 0)
poll_mask |= HVC_POLL_WRITE;
/* 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 */
for (;;) {
- int count = N_INBUF;
- if (count > (TTY_FLIPBUF_SIZE - tty->flip.count))
- count = TTY_FLIPBUF_SIZE - tty->flip.count;
+ int count = tty_buffer_request_room(tty, N_INBUF);
/* If flip is full, just reschedule a later read */
if (count == 0) {
break;
}
- n = hvc_get_chars(hp->vtermno, buf, count);
+ n = hp->ops->get_chars(hp->vtermno, buf, count);
if (n <= 0) {
/* Hangup the tty when disconnected from host */
if (n == -EPIPE) {
spin_unlock_irqrestore(&hp->lock, flags);
tty_hangup(tty);
spin_lock_irqsave(&hp->lock, flags);
+ } else if ( n == -EAGAIN ) {
+ /*
+ * Some back-ends can only ensure a certain min
+ * num of bytes read, which may be > 'count'.
+ * Let the tty clear the flip buff to make room.
+ */
+ poll_mask |= HVC_POLL_READ;
}
break;
}
sysrq_pressed = 1;
continue;
} else if (sysrq_pressed) {
- handle_sysrq(buf[i], NULL, tty);
+ handle_sysrq(buf[i], tty);
sysrq_pressed = 0;
continue;
}
tty_insert_flip_char(tty, buf[i], 0);
}
- if (tty->flip.count)
- tty_schedule_flip(tty);
-
- /*
- * Account for the total amount read in one loop, and if above
- * 64 bytes, we do a quick schedule loop to let the tty grok
- * the data and eventually throttle us.
- */
read_total += n;
- if (read_total >= 64) {
- poll_mask |= HVC_POLL_QUICK;
- break;
- }
}
throttled:
/* Wakeup write queue if necessary */
bail:
spin_unlock_irqrestore(&hp->lock, flags);
+ 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;
hvc_kicked = 0;
+ try_to_freeze();
wmb();
if (cpus_empty(cpus_in_xmon)) {
spin_lock(&hvc_structs_lock);
list_for_each_entry(hp, &hvc_structs, next) {
- /*hp = list_entry(node, struct hvc_struct, * next); */
poll_mask |= hvc_poll(hp);
}
spin_unlock(&hvc_structs_lock);
poll_mask |= HVC_POLL_READ;
if (hvc_kicked)
continue;
- if (poll_mask & HVC_POLL_QUICK) {
+ if (poll_mask & HVC_POLL_WRITE) {
yield();
continue;
}
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 0;
}
-static struct tty_operations hvc_ops = {
+static const struct tty_operations hvc_ops = {
.open = hvc_open,
.close = hvc_close,
.write = hvc_write,
.release = destroy_hvc_struct,
};
-static int __devinit hvc_probe(
- struct vio_dev *dev,
- const struct vio_device_id *id)
+struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int irq,
+ struct hv_ops *ops, int outbuf_size)
{
struct hvc_struct *hp;
int i;
- /* probed with invalid parameters. */
- if (!dev || !id)
- return -EPERM;
-
- hp = kmalloc(sizeof(*hp), GFP_KERNEL);
+ hp = kmalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size,
+ GFP_KERNEL);
if (!hp)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
memset(hp, 0x00, sizeof(*hp));
- hp->vtermno = dev->unit_address;
- hp->vdev = dev;
- hp->vdev->dev.driver_data = hp;
- hp->irq = dev->irq;
+
+ hp->vtermno = vtermno;
+ hp->irq = irq;
+ hp->ops = ops;
+ hp->outbuf_size = outbuf_size;
+ hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))];
kobject_init(&hp->kobj);
hp->kobj.ktype = &hvc_kobj_type;
* see if this vterm id matches one registered for console.
*/
for (i=0; i < MAX_NR_HVC_CONSOLES; i++)
- if (vtermnos[i] == hp->vtermno)
+ if (vtermnos[i] == hp->vtermno &&
+ cons_ops[i] == hp->ops)
break;
/* no matching slot, just use a counter */
list_add_tail(&(hp->next), &hvc_structs);
spin_unlock(&hvc_structs_lock);
- return 0;
+ return hp;
}
-static int __devexit hvc_remove(struct vio_dev *dev)
+int __devexit hvc_remove(struct hvc_struct *hp)
{
- struct hvc_struct *hp = dev->dev.driver_data;
unsigned long flags;
struct kobject *kobjp;
struct tty_struct *tty;
/*
* 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.
*/
return 0;
}
-char hvc_driver_name[] = "hvc_console";
-
-static struct vio_device_id hvc_driver_table[] __devinitdata= {
- {"serial", "hvterm1"},
- { NULL, }
-};
-MODULE_DEVICE_TABLE(vio, hvc_driver_table);
-
-static struct vio_driver hvc_vio_driver = {
- .name = hvc_driver_name,
- .id_table = hvc_driver_table,
- .probe = hvc_probe,
- .remove = 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)
{
- int rc;
+ struct tty_driver *drv;
- /* We need more than num_vterms adapters due to hotplug additions. */
- hvc_driver = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
- /* hvc_driver = alloc_tty_driver(num_vterms); */
- if (!hvc_driver)
+ /* We need more than hvc_count adapters due to hotplug additions. */
+ drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
+ if (!drv)
return -ENOMEM;
- hvc_driver->owner = THIS_MODULE;
- hvc_driver->devfs_name = "hvc/";
- hvc_driver->driver_name = "hvc";
- hvc_driver->name = "hvc";
- hvc_driver->major = HVC_MAJOR;
- hvc_driver->minor_start = HVC_MINOR;
- hvc_driver->type = TTY_DRIVER_TYPE_SYSTEM;
- hvc_driver->init_termios = tty_std_termios;
- hvc_driver->flags = TTY_DRIVER_REAL_RAW;
- tty_set_operations(hvc_driver, &hvc_ops);
-
- if (tty_register_driver(hvc_driver))
- panic("Couldn't register hvc console driver\n");
+ drv->owner = THIS_MODULE;
+ drv->driver_name = "hvc";
+ drv->name = "hvc";
+ drv->major = HVC_MAJOR;
+ drv->minor_start = HVC_MINOR;
+ drv->type = TTY_DRIVER_TYPE_SYSTEM;
+ drv->init_termios = tty_std_termios;
+ drv->flags = TTY_DRIVER_REAL_RAW;
+ tty_set_operations(drv, &hvc_ops);
/* Always start the kthread because there can be hotplug vty adapters
* added later. */
hvc_task = kthread_run(khvcd, NULL, "khvcd");
if (IS_ERR(hvc_task)) {
panic("Couldn't create kthread for console.\n");
- put_tty_driver(hvc_driver);
+ put_tty_driver(drv);
return -EIO;
}
- /* Register as a vio device to receive callbacks */
- rc = vio_register_driver(&hvc_vio_driver);
+ if (tty_register_driver(drv))
+ panic("Couldn't register hvc console driver\n");
- return rc;
+ mb();
+ hvc_driver = drv;
+ return 0;
}
module_init(hvc_init);
-/* This isn't particularily necessary due to this being a console driver but it
- * is nice to be thorough */
+/* 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)
{
kthread_stop(hvc_task);
- vio_unregister_driver(&hvc_vio_driver);
tty_unregister_driver(hvc_driver);
/* return tty_struct instances allocated in hvc_init(). */
put_tty_driver(hvc_driver);
+ unregister_console(&hvc_con_driver);
}
module_exit(hvc_exit);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff