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authorChristian Borntraeger <borntraeger@de.ibm.com>2008-06-20 15:24:08 +0200
committerRusty Russell <rusty@rustcorp.com.au>2008-07-25 12:06:06 +1000
commit611e097d7707741a336a0677d9d69bec40f29f3d (patch)
tree0b0059544914bf027ada51a1ba90f694c54df835 /drivers/char/hvc_vio.c
parent066f4d82a67f621ddd547bfa4b9c94631d8457b0 (diff)
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_vio.c')
-rw-r--r--drivers/char/hvc_vio.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c
index 79711aa4b41d..93f3840c1682 100644
--- a/drivers/char/hvc_vio.c
+++ b/drivers/char/hvc_vio.c
@@ -80,6 +80,8 @@ static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
static struct hv_ops hvc_get_put_ops = {
.get_chars = filtered_get_chars,
.put_chars = hvc_put_chars,
+ .notifier_add = notifier_add_irq,
+ .notifier_del = notifier_del_irq,
};
static int __devinit hvc_vio_probe(struct vio_dev *vdev,