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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2008-06-20 17:24:08 +0400 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2008-07-25 06:06:06 +0400 |
| commit | 611e097d7707741a336a0677d9d69bec40f29f3d (patch) | |
| tree | 0b0059544914bf027ada51a1ba90f694c54df835 /drivers/char/hvc_xen.c | |
| parent | 066f4d82a67f621ddd547bfa4b9c94631d8457b0 (diff) | |
| download | linux-611e097d7707741a336a0677d9d69bec40f29f3d.tar.xz | |
hvc_console: rework setup to replace irq functions with callbacks
This patch tries to change hvc_console to not use request_irq/free_irq if
the backend does not use irqs. This allows virtio_console to use hvc_console
without having a linker reference to request_irq/free_irq.
In addition, together with patch 2/3 it improves the performance for virtio
console input. (an earlier version of this patch was tested by Yajin on lguest)
The irq specific code is moved to hvc_irq.c and selected by the drivers that
use irqs (System p, System i, XEN).
I replaced "int irq" with the opaque "int data". The request_irq and
free_irq calls are replaced with notifier_add and notifier_del. I have also
changed the code a bit to call the notifier_add and notifier_del inside the
spinlock area as the callbacks are found via hp->ops.
Changes since last version:
o remove ifdef
o reintroduce "irq_requested" as "notified"
o cleanups, sparse..
I did not move the timer based polling into a separate polling scheme. I
played with several variants, but it seems we need to sleep/schedule in
a thread even for irq based consoles, as there are throttleing and buffer
size constraints.
I also kept hvc_struct defined in hvc_console.h so that hvc_irq.c can access
the irq_requested element.
Feedback is appreciated. virtio_console is currently the only available console
for kvm on s390. I plan to push this change as soon as all affected parties
agree on it. I would love to get test results from System p, Xen etc.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/char/hvc_xen.c')
| -rw-r--r-- | drivers/char/hvc_xen.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c index db2ae4216279..6b70aa66a587 100644 --- a/drivers/char/hvc_xen.c +++ b/drivers/char/hvc_xen.c @@ -100,6 +100,8 @@ static int read_console(uint32_t vtermno, char *buf, int len) static struct hv_ops hvc_ops = { .get_chars = read_console, .put_chars = write_console, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, }; static int __init xen_init(void) |