From 91fcad19d03ed67cb50fd0e1913a8b89cc3ed3ec Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 20 Jun 2008 15:24:15 +0200 Subject: [PATCH] virtio_console: use virtqueue notification for hvc_console This patch exploits the new notifier callbacks of the hvc_console. We can use the virtio callbacks instead of the polling code. Signed-off-by: Christian Borntraeger Signed-off-by: Rusty Russell --- drivers/char/virtio_console.c | 40 +++++++++++++++++++++++++++++------ 1 file changed, 33 insertions(+), 7 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index dc17fe3a88bc..d0f4eb6fdb7f 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -46,6 +46,9 @@ static char *in, *inbuf; /* The operations for our console. */ static struct hv_ops virtio_cons; +/* The hvc device */ +static struct hvc_struct *hvc; + /*D:310 The put_chars() callback is pretty straightforward. * * We turn the characters into a scatter-gather list, add it to the output @@ -134,6 +137,27 @@ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)) return hvc_instantiate(0, 0, &virtio_cons); } +/* + * we support only one console, the hvc struct is a global var + * There is no need to do anything + */ +static int notifier_add_vio(struct hvc_struct *hp, int data) +{ + hp->irq_requested = 1; + return 0; +} + +static void notifier_del_vio(struct hvc_struct *hp, int data) +{ + hp->irq_requested = 0; +} + +static void hvc_handle_input(struct virtqueue *vq) +{ + if (hvc_poll(hvc)) + hvc_kick(); +} + /*D:370 Once we're further in boot, we get probed like any other virtio device. * At this stage we set up the output virtqueue. * @@ -144,7 +168,6 @@ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)) static int __devinit virtcons_probe(struct virtio_device *dev) { int err; - struct hvc_struct *hvc; vdev = dev; @@ -158,7 +181,7 @@ static int __devinit virtcons_probe(struct virtio_device *dev) /* Find the input queue. */ /* FIXME: This is why we want to wean off hvc: we do nothing * when input comes in. */ - in_vq = vdev->config->find_vq(vdev, 0, NULL); + in_vq = vdev->config->find_vq(vdev, 0, hvc_handle_input); if (IS_ERR(in_vq)) { err = PTR_ERR(in_vq); goto free; @@ -173,15 +196,18 @@ static int __devinit virtcons_probe(struct virtio_device *dev) /* Start using the new console output. */ virtio_cons.get_chars = get_chars; virtio_cons.put_chars = put_chars; + virtio_cons.notifier_add = notifier_add_vio; + virtio_cons.notifier_del = notifier_del_vio; /* The first argument of hvc_alloc() is the virtual console number, so - * we use zero. The second argument is the interrupt number; we - * currently leave this as zero: it would be better not to use the - * hvc mechanism and fix this (FIXME!). + * we use zero. The second argument is the parameter for the + * notification mechanism (like irq number). We currently leave this + * as zero, virtqueues have implicit notifications. * * The third argument is a "struct hv_ops" containing the put_chars() - * and get_chars() pointers. The final argument is the output buffer - * size: we can do any size, so we put PAGE_SIZE here. */ + * get_chars(), notifier_add() and notifier_del() pointers. + * The final argument is the output buffer size: we can do any size, + * so we put PAGE_SIZE here. */ hvc = hvc_alloc(0, 0, &virtio_cons, PAGE_SIZE); if (IS_ERR(hvc)) { err = PTR_ERR(hvc); -- 2.20.1