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authorLinus Torvalds <torvalds@g5.osdl.org>2006-03-29 11:28:30 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-29 11:28:30 -0800
commit76babde121d2ffef04ca692ce64ef9f8a9866086 (patch)
tree294923bbb4974258d86d223e35eee691abacdfb1 /drivers/char/hvc_console.c
parente71ac6032edf77a1e4a81f3e3b260807e94b37a5 (diff)
parent15e812ad849e142e3dfc984d33c4d8042389f148 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (67 commits) [PATCH] powerpc: Remove oprofile spinlock backtrace code [PATCH] powerpc: Add oprofile calltrace support to all powerpc cpus [PATCH] powerpc: Add oprofile calltrace support [PATCH] for_each_possible_cpu: ppc [PATCH] for_each_possible_cpu: powerpc [PATCH] lock PTE before updating it in 440/BookE page fault handler [PATCH] powerpc: Kill _machine and hard-coded platform numbers ppc: Fix compile error in arch/ppc/lib/strcase.c [PATCH] git-powerpc: WARN was a dumb idea [PATCH] powerpc: a couple of trivial compile warning fixes powerpc: remove OCP references powerpc: Make uImage default build output for MPC8540 ADS powerpc: move math-emu over to arch/powerpc powerpc: use memparse() for mem= command line parsing ppc: fix strncasecmp prototype [PATCH] powerpc: make ISA floppies work again [PATCH] powerpc: Fix some initcall return values [PATCH] powerpc: Workaround for pSeries RTAS bug [PATCH] spufs: fix __init/__exit annotations [PATCH] powerpc: add hvc backend for rtas ...
Diffstat (limited to 'drivers/char/hvc_console.c')
-rw-r--r--drivers/char/hvc_console.c101
1 files changed, 47 insertions, 54 deletions
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index f65b2e14a48..2b6a56b2bf3 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -39,8 +39,10 @@
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
+
#include <asm/uaccess.h>
-#include <asm/hvconsole.h>
+
+#include "hvc_console.h"
#define HVC_MAJOR 229
#define HVC_MINOR 0
@@ -54,17 +56,14 @@
#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;
@@ -154,7 +153,7 @@ static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] =
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, index = co->index;
@@ -473,8 +472,10 @@ static void hvc_push(struct hvc_struct *hp)
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;
@@ -486,12 +487,19 @@ static void hvc_push(struct hvc_struct *hp)
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 */
@@ -510,26 +518,8 @@ static inline int __hvc_write_kernel(struct hvc_struct *hp,
}
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();
@@ -614,6 +604,13 @@ static int hvc_poll(struct hvc_struct *hp)
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;
}
@@ -635,16 +632,7 @@ static int hvc_poll(struct hvc_struct *hp)
tty_insert_flip_char(tty, buf[i], 0);
}
- /*
- * 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 */
@@ -767,7 +755,8 @@ struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int irq,
* 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 */
@@ -823,34 +812,38 @@ EXPORT_SYMBOL(hvc_remove);
* interfaces start to become available. */
int __init hvc_init(void)
{
+ struct tty_driver *drv;
+
/* We need more than hvc_count adapters due to hotplug additions. */
- hvc_driver = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
- if (!hvc_driver)
+ 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);
+ drv->owner = THIS_MODULE;
+ drv->devfs_name = "hvc/";
+ 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;
}
- if (tty_register_driver(hvc_driver))
+ if (tty_register_driver(drv))
panic("Couldn't register hvc console driver\n");
+ mb();
+ hvc_driver = drv;
return 0;
}
module_init(hvc_init);