From: Rusty Russell Date: Mon, 18 Jan 2010 13:45:00 +0000 (+0530) Subject: virtio: console: port encapsulation X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=21206ede8826fd9d2eb72e05b429f3ccb1bdaff5;p=openwrt%2Fstaging%2Fblogic.git virtio: console: port encapsulation We are heading towards a multiple-"port" system, so as part of weaning off globals we encapsulate the information into 'struct port'. Signed-off-by: Rusty Russell Signed-off-by: Amit Shah Signed-off-by: Rusty Russell --- diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index bfc0abf825ed..9ea9223c5c5c 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -21,15 +21,19 @@ #include #include "hvc_console.h" -static struct virtqueue *in_vq, *out_vq; -static struct virtio_device *vdev; - -/* This is our input buffer, and how much data is left in it. */ -static unsigned int in_len; -static char *in, *inbuf; +struct port { + struct virtqueue *in_vq, *out_vq; + struct virtio_device *vdev; + /* This is our input buffer, and how much data is left in it. */ + char *inbuf; + unsigned int used_len, offset; + + /* The hvc device */ + struct hvc_struct *hvc; +}; -/* The hvc device */ -static struct hvc_struct *hvc; +/* We have one port ready to go immediately, for a console. */ +static struct port console; /* This is the very early arch-specified put chars function. */ static int (*early_put_chars)(u32, const char *, int); @@ -46,22 +50,21 @@ static int put_chars(u32 vtermno, const char *buf, int count) { struct scatterlist sg[1]; unsigned int len; + struct port *port; if (unlikely(early_put_chars)) return early_put_chars(vtermno, buf, count); + port = &console; + /* This is a convenient routine to initialize a single-elem sg list */ sg_init_one(sg, buf, count); - /* - * add_buf wants a token to identify this buffer: we hand it - * any non-NULL pointer, since there's only ever one buffer. - */ - if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) >= 0) { + /* This shouldn't fail: if it does, we lose chars. */ + if (port->out_vq->vq_ops->add_buf(port->out_vq, sg, 1, 0, port) >= 0) { /* Tell Host to go! */ - out_vq->vq_ops->kick(out_vq); - /* Chill out until it's done with the buffer. */ - while (!out_vq->vq_ops->get_buf(out_vq, &len)) + port->out_vq->vq_ops->kick(port->out_vq); + while (!port->out_vq->vq_ops->get_buf(port->out_vq, &len)) cpu_relax(); } @@ -73,15 +76,15 @@ static int put_chars(u32 vtermno, const char *buf, int count) * Create a scatter-gather list representing our input buffer and put * it in the queue. */ -static void add_inbuf(void) +static void add_inbuf(struct port *port) { struct scatterlist sg[1]; - sg_init_one(sg, inbuf, PAGE_SIZE); + sg_init_one(sg, port->inbuf, PAGE_SIZE); - /* We should always be able to add one buffer to an empty queue. */ - if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) < 0) + /* Should always be able to add one buffer to an empty queue. */ + if (port->in_vq->vq_ops->add_buf(port->in_vq, sg, 0, 1, port) < 0) BUG(); - in_vq->vq_ops->kick(in_vq); + port->in_vq->vq_ops->kick(port->in_vq); } /* @@ -94,28 +97,31 @@ static void add_inbuf(void) */ static int get_chars(u32 vtermno, char *buf, int count) { + struct port *port; + + port = &console; + /* If we don't have an input queue yet, we can't get input. */ - BUG_ON(!in_vq); + BUG_ON(!port->in_vq); - /* No buffer? Try to get one. */ - if (!in_len) { - in = in_vq->vq_ops->get_buf(in_vq, &in_len); - if (!in) + /* No more in buffer? See if they've (re)used it. */ + if (port->offset == port->used_len) { + if (!port->in_vq->vq_ops->get_buf(port->in_vq, &port->used_len)) return 0; + port->offset = 0; } /* You want more than we have to give? Well, try wanting less! */ - if (in_len < count) - count = in_len; + if (port->offset + count > port->used_len) + count = port->used_len - port->offset; /* Copy across to their buffer and increment offset. */ - memcpy(buf, in, count); - in += count; - in_len -= count; + memcpy(buf, port->inbuf + port->offset, count); + port->offset += count; /* Finished? Re-register buffer so Host will use it again. */ - if (in_len == 0) - add_inbuf(); + if (port->offset == port->used_len) + add_inbuf(port); return count; } @@ -135,7 +141,7 @@ static void virtcons_apply_config(struct virtio_device *dev) dev->config->get(dev, offsetof(struct virtio_console_config, rows), &ws.ws_row, sizeof(u16)); - hvc_resize(hvc, ws); + hvc_resize(console.hvc, ws); } } @@ -146,7 +152,7 @@ static void virtcons_apply_config(struct virtio_device *dev) static int notifier_add_vio(struct hvc_struct *hp, int data) { hp->irq_requested = 1; - virtcons_apply_config(vdev); + virtcons_apply_config(console.vdev); return 0; } @@ -158,7 +164,7 @@ static void notifier_del_vio(struct hvc_struct *hp, int data) static void hvc_handle_input(struct virtqueue *vq) { - if (hvc_poll(hvc)) + if (hvc_poll(console.hvc)) hvc_kick(); } @@ -197,23 +203,26 @@ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)) * Finally we put our input buffer in the input queue, ready to * receive. */ -static int __devinit virtcons_probe(struct virtio_device *dev) +static int __devinit virtcons_probe(struct virtio_device *vdev) { vq_callback_t *callbacks[] = { hvc_handle_input, NULL}; const char *names[] = { "input", "output" }; struct virtqueue *vqs[2]; + struct port *port; int err; - if (vdev) { - dev_warn(&vdev->dev, + port = &console; + if (port->vdev) { + dev_warn(&port->vdev->dev, "Multiple virtio-console devices not supported yet\n"); return -EEXIST; } - vdev = dev; + port->vdev = vdev; /* This is the scratch page we use to receive console input */ - inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!inbuf) { + port->used_len = 0; + port->inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!port->inbuf) { err = -ENOMEM; goto fail; } @@ -223,8 +232,8 @@ static int __devinit virtcons_probe(struct virtio_device *dev) if (err) goto free; - in_vq = vqs[0]; - out_vq = vqs[1]; + port->in_vq = vqs[0]; + port->out_vq = vqs[1]; /* * The first argument of hvc_alloc() is the virtual console @@ -238,14 +247,14 @@ static int __devinit virtcons_probe(struct virtio_device *dev) * 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, &hv_ops, PAGE_SIZE); - if (IS_ERR(hvc)) { - err = PTR_ERR(hvc); + port->hvc = hvc_alloc(0, 0, &hv_ops, PAGE_SIZE); + if (IS_ERR(port->hvc)) { + err = PTR_ERR(port->hvc); goto free_vqs; } /* Register the input buffer the first time. */ - add_inbuf(); + add_inbuf(port); /* Start using the new console output. */ early_put_chars = NULL; @@ -254,7 +263,7 @@ static int __devinit virtcons_probe(struct virtio_device *dev) free_vqs: vdev->config->del_vqs(vdev); free: - kfree(inbuf); + kfree(port->inbuf); fail: return err; }