[linux.git] / drivers / video / xen-fbfront.c

/*
 * Xen para-virtual frame buffer device
 *
 * Copyright (C) 2005-2006 Anthony Liguori <[email protected]>
 * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <[email protected]>
 *
 *  Based on linux/drivers/video/q40fb.c
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */

/*
 * TODO:
 *
 * Switch to grant tables when they become capable of dealing with the
 * frame buffer.
 */

#include <linux/console.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>

#include <asm/xen/hypervisor.h>

#include <xen/xen.h>
#include <xen/events.h>
#include <xen/page.h>
#include <xen/interface/io/fbif.h>
#include <xen/interface/io/protocols.h>
#include <xen/xenbus.h>

struct xenfb_info {
	unsigned char		*fb;
	struct fb_info		*fb_info;
	int			x1, y1, x2, y2;	/* dirty rectangle,
						   protected by dirty_lock */
	spinlock_t		dirty_lock;
	int			nr_pages;
	int			irq;
	struct xenfb_page	*page;
	unsigned long 		*mfns;
	int			update_wanted; /* XENFB_TYPE_UPDATE wanted */
	int			feature_resize; /* XENFB_TYPE_RESIZE ok */
	struct xenfb_resize	resize;		/* protected by resize_lock */
	int			resize_dpy;	/* ditto */
	spinlock_t		resize_lock;

	struct xenbus_device	*xbdev;
};

#define XENFB_DEFAULT_FB_LEN (XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8)

enum { KPARAM_MEM, KPARAM_WIDTH, KPARAM_HEIGHT, KPARAM_CNT };
static int video[KPARAM_CNT] = { 2, XENFB_WIDTH, XENFB_HEIGHT };
module_param_array(video, int, NULL, 0);
MODULE_PARM_DESC(video,
	"Video memory size in MB, width, height in pixels (default 2,800,600)");

static void xenfb_make_preferred_console(void);
static int xenfb_remove(struct xenbus_device *);
static void xenfb_init_shared_page(struct xenfb_info *, struct fb_info *);
static int xenfb_connect_backend(struct xenbus_device *, struct xenfb_info *);
static void xenfb_disconnect_backend(struct xenfb_info *);

static void xenfb_send_event(struct xenfb_info *info,
			     union xenfb_out_event *event)
{
	u32 prod;

	prod = info->page->out_prod;
	/* caller ensures !xenfb_queue_full() */
	mb();			/* ensure ring space available */
	XENFB_OUT_RING_REF(info->page, prod) = *event;
	wmb();			/* ensure ring contents visible */
	info->page->out_prod = prod + 1;

	notify_remote_via_irq(info->irq);
}

static void xenfb_do_update(struct xenfb_info *info,
			    int x, int y, int w, int h)
{
	union xenfb_out_event event;

	memset(&event, 0, sizeof(event));
	event.type = XENFB_TYPE_UPDATE;
	event.update.x = x;
	event.update.y = y;
	event.update.width = w;
	event.update.height = h;

	/* caller ensures !xenfb_queue_full() */
	xenfb_send_event(info, &event);
}

static void xenfb_do_resize(struct xenfb_info *info)
{
	union xenfb_out_event event;

	memset(&event, 0, sizeof(event));
	event.resize = info->resize;

	/* caller ensures !xenfb_queue_full() */
	xenfb_send_event(info, &event);
}

static int xenfb_queue_full(struct xenfb_info *info)
{
	u32 cons, prod;

	prod = info->page->out_prod;
	cons = info->page->out_cons;
	return prod - cons == XENFB_OUT_RING_LEN;
}

static void xenfb_handle_resize_dpy(struct xenfb_info *info)
{
	unsigned long flags;

	spin_lock_irqsave(&info->resize_lock, flags);
	if (info->resize_dpy) {
		if (!xenfb_queue_full(info)) {
			info->resize_dpy = 0;
			xenfb_do_resize(info);
		}
	}
	spin_unlock_irqrestore(&info->resize_lock, flags);
}

static void xenfb_refresh(struct xenfb_info *info,
			  int x1, int y1, int w, int h)
{
	unsigned long flags;
	int x2 = x1 + w - 1;
	int y2 = y1 + h - 1;

	xenfb_handle_resize_dpy(info);

	if (!info->update_wanted)
		return;

	spin_lock_irqsave(&info->dirty_lock, flags);

	/* Combine with dirty rectangle: */
	if (info->y1 < y1)
		y1 = info->y1;
	if (info->y2 > y2)
		y2 = info->y2;
	if (info->x1 < x1)
		x1 = info->x1;
	if (info->x2 > x2)
		x2 = info->x2;

	if (xenfb_queue_full(info)) {
		/* Can't send right now, stash it in the dirty rectangle */
		info->x1 = x1;
		info->x2 = x2;
		info->y1 = y1;
		info->y2 = y2;
		spin_unlock_irqrestore(&info->dirty_lock, flags);
		return;
	}

	/* Clear dirty rectangle: */
	info->x1 = info->y1 = INT_MAX;
	info->x2 = info->y2 = 0;

	spin_unlock_irqrestore(&info->dirty_lock, flags);

	if (x1 <= x2 && y1 <= y2)
		xenfb_do_update(info, x1, y1, x2 - x1 + 1, y2 - y1 + 1);
}

static void xenfb_deferred_io(struct fb_info *fb_info,
			      struct list_head *pagelist)
{
	struct xenfb_info *info = fb_info->par;
	struct page *page;
	unsigned long beg, end;
	int y1, y2, miny, maxy;

	miny = INT_MAX;
	maxy = 0;
	list_for_each_entry(page, pagelist, lru) {
		beg = page->index << PAGE_SHIFT;
		end = beg + PAGE_SIZE - 1;
		y1 = beg / fb_info->fix.line_length;
		y2 = end / fb_info->fix.line_length;
		if (y2 >= fb_info->var.yres)
			y2 = fb_info->var.yres - 1;
		if (miny > y1)
			miny = y1;
		if (maxy < y2)
			maxy = y2;
	}
	xenfb_refresh(info, 0, miny, fb_info->var.xres, maxy - miny + 1);
}

static struct fb_deferred_io xenfb_defio = {
	.delay		= HZ / 20,
	.deferred_io	= xenfb_deferred_io,
};

static int xenfb_setcolreg(unsigned regno, unsigned red, unsigned green,
			   unsigned blue, unsigned transp,
			   struct fb_info *info)
{
	u32 v;

	if (regno > info->cmap.len)
		return 1;

#define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
	red = CNVT_TOHW(red, info->var.red.length);
	green = CNVT_TOHW(green, info->var.green.length);
	blue = CNVT_TOHW(blue, info->var.blue.length);
	transp = CNVT_TOHW(transp, info->var.transp.length);
#undef CNVT_TOHW

	v = (red << info->var.red.offset) |
	    (green << info->var.green.offset) |
	    (blue << info->var.blue.offset);

	switch (info->var.bits_per_pixel) {
	case 16:
	case 24:
	case 32:
		((u32 *)info->pseudo_palette)[regno] = v;
		break;
	}

	return 0;
}

static void xenfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
{
	struct xenfb_info *info = p->par;

	sys_fillrect(p, rect);
	xenfb_refresh(info, rect->dx, rect->dy, rect->width, rect->height);
}

static void xenfb_imageblit(struct fb_info *p, const struct fb_image *image)
{
	struct xenfb_info *info = p->par;

	sys_imageblit(p, image);
	xenfb_refresh(info, image->dx, image->dy, image->width, image->height);
}

static void xenfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
{
	struct xenfb_info *info = p->par;

	sys_copyarea(p, area);
	xenfb_refresh(info, area->dx, area->dy, area->width, area->height);
}

static ssize_t xenfb_write(struct fb_info *p, const char __user *buf,
			size_t count, loff_t *ppos)
{
	struct xenfb_info *info = p->par;
	ssize_t res;

	res = fb_sys_write(p, buf, count, ppos);
	xenfb_refresh(info, 0, 0, info->page->width, info->page->height);
	return res;
}

static int
xenfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct xenfb_info *xenfb_info;
	int required_mem_len;

	xenfb_info = info->par;

	if (!xenfb_info->feature_resize) {
		if (var->xres == video[KPARAM_WIDTH] &&
		    var->yres == video[KPARAM_HEIGHT] &&
		    var->bits_per_pixel == xenfb_info->page->depth) {
			return 0;
		}
		return -EINVAL;
	}

	/* Can't resize past initial width and height */
	if (var->xres > video[KPARAM_WIDTH] || var->yres > video[KPARAM_HEIGHT])
		return -EINVAL;

	required_mem_len = var->xres * var->yres * xenfb_info->page->depth / 8;
	if (var->bits_per_pixel == xenfb_info->page->depth &&
	    var->xres <= info->fix.line_length / (XENFB_DEPTH / 8) &&
	    required_mem_len <= info->fix.smem_len) {
		var->xres_virtual = var->xres;
		var->yres_virtual = var->yres;
		return 0;
	}
	return -EINVAL;
}

static int xenfb_set_par(struct fb_info *info)
{
	struct xenfb_info *xenfb_info;
	unsigned long flags;

	xenfb_info = info->par;

	spin_lock_irqsave(&xenfb_info->resize_lock, flags);
	xenfb_info->resize.type = XENFB_TYPE_RESIZE;
	xenfb_info->resize.width = info->var.xres;
	xenfb_info->resize.height = info->var.yres;
	xenfb_info->resize.stride = info->fix.line_length;
	xenfb_info->resize.depth = info->var.bits_per_pixel;
	xenfb_info->resize.offset = 0;
	xenfb_info->resize_dpy = 1;
	spin_unlock_irqrestore(&xenfb_info->resize_lock, flags);
	return 0;
}

static struct fb_ops xenfb_fb_ops = {
	.owner		= THIS_MODULE,
	.fb_read	= fb_sys_read,
	.fb_write	= xenfb_write,
	.fb_setcolreg	= xenfb_setcolreg,
	.fb_fillrect	= xenfb_fillrect,
	.fb_copyarea	= xenfb_copyarea,
	.fb_imageblit	= xenfb_imageblit,
	.fb_check_var	= xenfb_check_var,
	.fb_set_par     = xenfb_set_par,
};

static irqreturn_t xenfb_event_handler(int rq, void *dev_id)
{
	/*
	 * No in events recognized, simply ignore them all.
	 * If you need to recognize some, see xen-kbdfront's
	 * input_handler() for how to do that.
	 */
	struct xenfb_info *info = dev_id;
	struct xenfb_page *page = info->page;

	if (page->in_cons != page->in_prod) {
		info->page->in_cons = info->page->in_prod;
		notify_remote_via_irq(info->irq);
	}

	/* Flush dirty rectangle: */
	xenfb_refresh(info, INT_MAX, INT_MAX, -INT_MAX, -INT_MAX);

	return IRQ_HANDLED;
}

static int xenfb_probe(struct xenbus_device *dev,
		       const struct xenbus_device_id *id)
{
	struct xenfb_info *info;
	struct fb_info *fb_info;
	int fb_size;
	int val;
	int ret = 0;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (info == NULL) {
		xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
		return -ENOMEM;
	}

	/* Limit kernel param videoram amount to what is in xenstore */
	if (xenbus_scanf(XBT_NIL, dev->otherend, "videoram", "%d", &val) == 1) {
		if (val < video[KPARAM_MEM])
			video[KPARAM_MEM] = val;
	}

	/* If requested res does not fit in available memory, use default */
	fb_size = video[KPARAM_MEM] * 1024 * 1024;
	if (video[KPARAM_WIDTH] * video[KPARAM_HEIGHT] * XENFB_DEPTH / 8
	    > fb_size) {
		video[KPARAM_WIDTH] = XENFB_WIDTH;
		video[KPARAM_HEIGHT] = XENFB_HEIGHT;
		fb_size = XENFB_DEFAULT_FB_LEN;
	}

	dev_set_drvdata(&dev->dev, info);
	info->xbdev = dev;
	info->irq = -1;
	info->x1 = info->y1 = INT_MAX;
	spin_lock_init(&info->dirty_lock);
	spin_lock_init(&info->resize_lock);

	info->fb = vzalloc(fb_size);
	if (info->fb == NULL)
		goto error_nomem;

	info->nr_pages = (fb_size + PAGE_SIZE - 1) >> PAGE_SHIFT;

	info->mfns = vmalloc(sizeof(unsigned long) * info->nr_pages);
	if (!info->mfns)
		goto error_nomem;

	/* set up shared page */
	info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
	if (!info->page)
		goto error_nomem;

	/* abusing framebuffer_alloc() to allocate pseudo_palette */
	fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL);
	if (fb_info == NULL)
		goto error_nomem;

	/* complete the abuse: */
	fb_info->pseudo_palette = fb_info->par;
	fb_info->par = info;

	fb_info->screen_base = info->fb;

	fb_info->fbops = &xenfb_fb_ops;
	fb_info->var.xres_virtual = fb_info->var.xres = video[KPARAM_WIDTH];
	fb_info->var.yres_virtual = fb_info->var.yres = video[KPARAM_HEIGHT];
	fb_info->var.bits_per_pixel = XENFB_DEPTH;

	fb_info->var.red = (struct fb_bitfield){16, 8, 0};
	fb_info->var.green = (struct fb_bitfield){8, 8, 0};
	fb_info->var.blue = (struct fb_bitfield){0, 8, 0};

	fb_info->var.activate = FB_ACTIVATE_NOW;
	fb_info->var.height = -1;
	fb_info->var.width = -1;
	fb_info->var.vmode = FB_VMODE_NONINTERLACED;

	fb_info->fix.visual = FB_VISUAL_TRUECOLOR;
	fb_info->fix.line_length = fb_info->var.xres * XENFB_DEPTH / 8;
	fb_info->fix.smem_start = 0;
	fb_info->fix.smem_len = fb_size;
	strcpy(fb_info->fix.id, "xen");
	fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
	fb_info->fix.accel = FB_ACCEL_NONE;

	fb_info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;

	ret = fb_alloc_cmap(&fb_info->cmap, 256, 0);
	if (ret < 0) {
		framebuffer_release(fb_info);
		xenbus_dev_fatal(dev, ret, "fb_alloc_cmap");
		goto error;
	}

	fb_info->fbdefio = &xenfb_defio;
	fb_deferred_io_init(fb_info);

	xenfb_init_shared_page(info, fb_info);

	ret = xenfb_connect_backend(dev, info);
	if (ret < 0) {
		xenbus_dev_fatal(dev, ret, "xenfb_connect_backend");
		goto error_fb;
	}

	ret = register_framebuffer(fb_info);
	if (ret) {
		xenbus_dev_fatal(dev, ret, "register_framebuffer");
		goto error_fb;
	}
	info->fb_info = fb_info;

	xenfb_make_preferred_console();
	return 0;

error_fb:
	fb_deferred_io_cleanup(fb_info);
	fb_dealloc_cmap(&fb_info->cmap);
	framebuffer_release(fb_info);
error_nomem:
	if (!ret) {
		ret = -ENOMEM;
		xenbus_dev_fatal(dev, ret, "allocating device memory");
	}
error:
	xenfb_remove(dev);
	return ret;
}

static void xenfb_make_preferred_console(void)
{
	struct console *c;

	if (console_set_on_cmdline)
		return;

	console_lock();
	for_each_console(c) {
		if (!strcmp(c->name, "tty") && c->index == 0)
			break;
	}
	console_unlock();
	if (c) {
		unregister_console(c);
		c->flags |= CON_CONSDEV;
		c->flags &= ~CON_PRINTBUFFER; /* don't print again */
		register_console(c);
	}
}

static int xenfb_resume(struct xenbus_device *dev)
{
	struct xenfb_info *info = dev_get_drvdata(&dev->dev);

	xenfb_disconnect_backend(info);
	xenfb_init_shared_page(info, info->fb_info);
	return xenfb_connect_backend(dev, info);
}

static int xenfb_remove(struct xenbus_device *dev)
{
	struct xenfb_info *info = dev_get_drvdata(&dev->dev);

	xenfb_disconnect_backend(info);
	if (info->fb_info) {
		fb_deferred_io_cleanup(info->fb_info);
		unregister_framebuffer(info->fb_info);
		fb_dealloc_cmap(&info->fb_info->cmap);
		framebuffer_release(info->fb_info);
	}
	free_page((unsigned long)info->page);
	vfree(info->mfns);
	vfree(info->fb);
	kfree(info);

	return 0;
}

static unsigned long vmalloc_to_mfn(void *address)
{
	return pfn_to_mfn(vmalloc_to_pfn(address));
}

static void xenfb_init_shared_page(struct xenfb_info *info,
				   struct fb_info *fb_info)
{
	int i;
	int epd = PAGE_SIZE / sizeof(info->mfns[0]);

	for (i = 0; i < info->nr_pages; i++)
		info->mfns[i] = vmalloc_to_mfn(info->fb + i * PAGE_SIZE);

	for (i = 0; i * epd < info->nr_pages; i++)
		info->page->pd[i] = vmalloc_to_mfn(&info->mfns[i * epd]);

	info->page->width = fb_info->var.xres;
	info->page->height = fb_info->var.yres;
	info->page->depth = fb_info->var.bits_per_pixel;
	info->page->line_length = fb_info->fix.line_length;
	info->page->mem_length = fb_info->fix.smem_len;
	info->page->in_cons = info->page->in_prod = 0;
	info->page->out_cons = info->page->out_prod = 0;
}

static int xenfb_connect_backend(struct xenbus_device *dev,
				 struct xenfb_info *info)
{
	int ret, evtchn, irq;
	struct xenbus_transaction xbt;

	ret = xenbus_alloc_evtchn(dev, &evtchn);
	if (ret)
		return ret;
	irq = bind_evtchn_to_irqhandler(evtchn, xenfb_event_handler,
					0, dev->devicetype, info);
	if (irq < 0) {
		xenbus_free_evtchn(dev, evtchn);
		xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
		return irq;
	}
 again:
	ret = xenbus_transaction_start(&xbt);
	if (ret) {
		xenbus_dev_fatal(dev, ret, "starting transaction");
		goto unbind_irq;
	}
	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
			    virt_to_mfn(info->page));
	if (ret)
		goto error_xenbus;
	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
			    evtchn);
	if (ret)
		goto error_xenbus;
	ret = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
			    XEN_IO_PROTO_ABI_NATIVE);
	if (ret)
		goto error_xenbus;
	ret = xenbus_printf(xbt, dev->nodename, "feature-update", "1");
	if (ret)
		goto error_xenbus;
	ret = xenbus_transaction_end(xbt, 0);
	if (ret) {
		if (ret == -EAGAIN)
			goto again;
		xenbus_dev_fatal(dev, ret, "completing transaction");
		goto unbind_irq;
	}

	xenbus_switch_state(dev, XenbusStateInitialised);
	info->irq = irq;
	return 0;

 error_xenbus:
	xenbus_transaction_end(xbt, 1);
	xenbus_dev_fatal(dev, ret, "writing xenstore");
 unbind_irq:
	unbind_from_irqhandler(irq, info);
	return ret;
}

static void xenfb_disconnect_backend(struct xenfb_info *info)
{
	/* Prevent xenfb refresh */
	info->update_wanted = 0;
	if (info->irq >= 0)
		unbind_from_irqhandler(info->irq, info);
	info->irq = -1;
}

static void xenfb_backend_changed(struct xenbus_device *dev,
				  enum xenbus_state backend_state)
{
	struct xenfb_info *info = dev_get_drvdata(&dev->dev);
	int val;

	switch (backend_state) {
	case XenbusStateInitialising:
	case XenbusStateInitialised:
	case XenbusStateReconfiguring:
	case XenbusStateReconfigured:
	case XenbusStateUnknown:
		break;

	case XenbusStateInitWait:
InitWait:
		xenbus_switch_state(dev, XenbusStateConnected);
		break;

	case XenbusStateConnected:
		/*
		 * Work around xenbus race condition: If backend goes
		 * through InitWait to Connected fast enough, we can
		 * get Connected twice here.
		 */
		if (dev->state != XenbusStateConnected)
			goto InitWait; /* no InitWait seen yet, fudge it */

		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
				 "request-update", "%d", &val) < 0)
			val = 0;
		if (val)
			info->update_wanted = 1;

		if (xenbus_scanf(XBT_NIL, dev->otherend,
				 "feature-resize", "%d", &val) < 0)
			val = 0;
		info->feature_resize = val;
		break;

	case XenbusStateClosed:
		if (dev->state == XenbusStateClosed)
			break;
		/* Missed the backend's CLOSING state -- fallthrough */
	case XenbusStateClosing:
		xenbus_frontend_closed(dev);
		break;
	}
}

static const struct xenbus_device_id xenfb_ids[] = {
	{ "vfb" },
	{ "" }
};

static DEFINE_XENBUS_DRIVER(xenfb, ,
	.probe = xenfb_probe,
	.remove = xenfb_remove,
	.resume = xenfb_resume,
	.otherend_changed = xenfb_backend_changed,
);

static int __init xenfb_init(void)
{
	if (!xen_pv_domain())
		return -ENODEV;

	/* Nothing to do if running in dom0. */
	if (xen_initial_domain())
		return -ENODEV;

	return xenbus_register_frontend(&xenfb_driver);
}

static void __exit xenfb_cleanup(void)
{
	xenbus_unregister_driver(&xenfb_driver);
}

module_init(xenfb_init);
module_exit(xenfb_cleanup);

MODULE_DESCRIPTION("Xen virtual framebuffer device frontend");
MODULE_LICENSE("GPL");
MODULE_ALIAS("xen:vfb");
Commit	Line	Data
4ee36dc0 MA	1	/*
	2	* Xen para-virtual frame buffer device
	3	*
	4	* Copyright (C) 2005-2006 Anthony Liguori <[email protected]>
	5	* Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <[email protected]>
	6	*
	7	* Based on linux/drivers/video/q40fb.c
	8	*
	9	* This file is subject to the terms and conditions of the GNU General Public
	10	* License. See the file COPYING in the main directory of this archive for
	11	* more details.
	12	*/
	13
	14	/*
	15	* TODO:
	16	*
	17	* Switch to grant tables when they become capable of dealing with the
	18	* frame buffer.
	19	*/
	20
9e124fe1	21	#include <linux/console.h>
4ee36dc0 MA	22	#include <linux/kernel.h>
	23	#include <linux/errno.h>
	24	#include <linux/fb.h>
	25	#include <linux/module.h>
5a0e3ad6	26	#include <linux/slab.h>
4ee36dc0 MA	27	#include <linux/vmalloc.h>
4ee36dc0 MA	28	#include <linux/mm.h>
1ccbf534	29
4ee36dc0	30	#include <asm/xen/hypervisor.h>
1ccbf534 JF	31
1ccbf534 JF	32	#include <xen/xen.h>
4ee36dc0 MA	33	#include <xen/events.h>
	34	#include <xen/page.h>
	35	#include <xen/interface/io/fbif.h>
	36	#include <xen/interface/io/protocols.h>
	37	#include <xen/xenbus.h>
	38
	39	struct xenfb_info {
	40	unsigned char *fb;
	41	struct fb_info *fb_info;
	42	int x1, y1, x2, y2; /* dirty rectangle,
	43	protected by dirty_lock */
	44	spinlock_t dirty_lock;
	45	int nr_pages;
	46	int irq;
	47	struct xenfb_page *page;
	48	unsigned long *mfns;
	49	int update_wanted; /* XENFB_TYPE_UPDATE wanted */
e4dcff1f MA	50	int feature_resize; /* XENFB_TYPE_RESIZE ok */
	51	struct xenfb_resize resize; /* protected by resize_lock */
	52	int resize_dpy; /* ditto */
	53	spinlock_t resize_lock;
4ee36dc0 MA	54
	55	struct xenbus_device *xbdev;
	56	};
	57
e4dcff1f MA	58	#define XENFB_DEFAULT_FB_LEN (XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8)
	59
	60	enum { KPARAM_MEM, KPARAM_WIDTH, KPARAM_HEIGHT, KPARAM_CNT };
	61	static int video[KPARAM_CNT] = { 2, XENFB_WIDTH, XENFB_HEIGHT };
	62	module_param_array(video, int, NULL, 0);
	63	MODULE_PARM_DESC(video,
	64	"Video memory size in MB, width, height in pixels (default 2,800,600)");
4ee36dc0	65
9e124fe1	66	static void xenfb_make_preferred_console(void);
4ee36dc0	67	static int xenfb_remove(struct xenbus_device *);
e4dcff1f	68	static void xenfb_init_shared_page(struct xenfb_info , struct fb_info );
4ee36dc0 MA	69	static int xenfb_connect_backend(struct xenbus_device , struct xenfb_info );
	70	static void xenfb_disconnect_backend(struct xenfb_info *);
	71
e4dcff1f MA	72	static void xenfb_send_event(struct xenfb_info *info,
	73	union xenfb_out_event *event)
	74	{
	75	u32 prod;
	76
	77	prod = info->page->out_prod;
	78	/* caller ensures !xenfb_queue_full() */
	79	mb(); /* ensure ring space available */
	80	XENFB_OUT_RING_REF(info->page, prod) = *event;
	81	wmb(); /* ensure ring contents visible */
	82	info->page->out_prod = prod + 1;
	83
	84	notify_remote_via_irq(info->irq);
	85	}
	86
4ee36dc0 MA	87	static void xenfb_do_update(struct xenfb_info *info,
	88	int x, int y, int w, int h)
	89	{
	90	union xenfb_out_event event;
4ee36dc0	91
f4ad1ebd	92	memset(&event, 0, sizeof(event));
4ee36dc0 MA	93	event.type = XENFB_TYPE_UPDATE;
	94	event.update.x = x;
	95	event.update.y = y;
	96	event.update.width = w;
	97	event.update.height = h;
	98
4ee36dc0	99	/* caller ensures !xenfb_queue_full() */
e4dcff1f MA	100	xenfb_send_event(info, &event);
e4dcff1f MA	101	}
4ee36dc0	102
e4dcff1f MA	103	static void xenfb_do_resize(struct xenfb_info *info)
	104	{
	105	union xenfb_out_event event;
	106
	107	memset(&event, 0, sizeof(event));
	108	event.resize = info->resize;
	109
	110	/* caller ensures !xenfb_queue_full() */
	111	xenfb_send_event(info, &event);
4ee36dc0 MA	112	}
	113
	114	static int xenfb_queue_full(struct xenfb_info *info)
	115	{
	116	u32 cons, prod;
	117
	118	prod = info->page->out_prod;
	119	cons = info->page->out_cons;
	120	return prod - cons == XENFB_OUT_RING_LEN;
	121	}
	122
e4dcff1f MA	123	static void xenfb_handle_resize_dpy(struct xenfb_info *info)
	124	{
	125	unsigned long flags;
	126
	127	spin_lock_irqsave(&info->resize_lock, flags);
	128	if (info->resize_dpy) {
	129	if (!xenfb_queue_full(info)) {
	130	info->resize_dpy = 0;
	131	xenfb_do_resize(info);
	132	}
	133	}
	134	spin_unlock_irqrestore(&info->resize_lock, flags);
	135	}
	136
4ee36dc0 MA	137	static void xenfb_refresh(struct xenfb_info *info,
	138	int x1, int y1, int w, int h)
	139	{
	140	unsigned long flags;
4ee36dc0	141	int x2 = x1 + w - 1;
e4dcff1f MA	142	int y2 = y1 + h - 1;
	143
	144	xenfb_handle_resize_dpy(info);
4ee36dc0 MA	145
	146	if (!info->update_wanted)
	147	return;
	148
	149	spin_lock_irqsave(&info->dirty_lock, flags);
	150
	151	/* Combine with dirty rectangle: */
	152	if (info->y1 < y1)
	153	y1 = info->y1;
	154	if (info->y2 > y2)
	155	y2 = info->y2;
	156	if (info->x1 < x1)
	157	x1 = info->x1;
	158	if (info->x2 > x2)
	159	x2 = info->x2;
	160
	161	if (xenfb_queue_full(info)) {
	162	/* Can't send right now, stash it in the dirty rectangle */
	163	info->x1 = x1;
	164	info->x2 = x2;
	165	info->y1 = y1;
	166	info->y2 = y2;
	167	spin_unlock_irqrestore(&info->dirty_lock, flags);
	168	return;
	169	}
	170
	171	/* Clear dirty rectangle: */
	172	info->x1 = info->y1 = INT_MAX;
	173	info->x2 = info->y2 = 0;
	174
	175	spin_unlock_irqrestore(&info->dirty_lock, flags);
	176
	177	if (x1 <= x2 && y1 <= y2)
	178	xenfb_do_update(info, x1, y1, x2 - x1 + 1, y2 - y1 + 1);
	179	}
	180
	181	static void xenfb_deferred_io(struct fb_info *fb_info,
	182	struct list_head *pagelist)
	183	{
	184	struct xenfb_info *info = fb_info->par;
	185	struct page *page;
	186	unsigned long beg, end;
	187	int y1, y2, miny, maxy;
	188
	189	miny = INT_MAX;
	190	maxy = 0;
	191	list_for_each_entry(page, pagelist, lru) {
	192	beg = page->index << PAGE_SHIFT;
	193	end = beg + PAGE_SIZE - 1;
	194	y1 = beg / fb_info->fix.line_length;
	195	y2 = end / fb_info->fix.line_length;
	196	if (y2 >= fb_info->var.yres)
	197	y2 = fb_info->var.yres - 1;
	198	if (miny > y1)
	199	miny = y1;
	200	if (maxy < y2)
	201	maxy = y2;
	202	}
	203	xenfb_refresh(info, 0, miny, fb_info->var.xres, maxy - miny + 1);
	204	}
	205
	206	static struct fb_deferred_io xenfb_defio = {
	207	.delay = HZ / 20,
	208	.deferred_io = xenfb_deferred_io,
209	};
210
211	static int xenfb_setcolreg(unsigned regno, unsigned red, unsigned green,
212	unsigned blue, unsigned transp,
213	struct fb_info *info)
214	{
215	u32 v;
216
217	if (regno > info->cmap.len)
218	return 1;
219
220	#define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
221	red = CNVT_TOHW(red, info->var.red.length);
222	green = CNVT_TOHW(green, info->var.green.length);
223	blue = CNVT_TOHW(blue, info->var.blue.length);
224	transp = CNVT_TOHW(transp, info->var.transp.length);
225	#undef CNVT_TOHW
226
227	v = (red << info->var.red.offset) \|
228	(green << info->var.green.offset) \|
229	(blue << info->var.blue.offset);
230
231	switch (info->var.bits_per_pixel) {
232	case 16:
233	case 24:
234	case 32:
235	((u32 *)info->pseudo_palette)[regno] = v;
236	break;
237	}
238
239	return 0;
240	}
241
242	static void xenfb_fillrect(struct fb_info p, const struct fb_fillrect rect)
243	{
244	struct xenfb_info *info = p->par;
245
246	sys_fillrect(p, rect);
247	xenfb_refresh(info, rect->dx, rect->dy, rect->width, rect->height);
248	}
249
250	static void xenfb_imageblit(struct fb_info p, const struct fb_image image)
251	{
252	struct xenfb_info *info = p->par;
253
254	sys_imageblit(p, image);
255	xenfb_refresh(info, image->dx, image->dy, image->width, image->height);
256	}
257
258	static void xenfb_copyarea(struct fb_info p, const struct fb_copyarea area)
259	{
260	struct xenfb_info *info = p->par;
261
262	sys_copyarea(p, area);
263	xenfb_refresh(info, area->dx, area->dy, area->width, area->height);
264	}
265
266	static ssize_t xenfb_write(struct fb_info p, const char __user buf,
267	size_t count, loff_t *ppos)
268	{
269	struct xenfb_info *info = p->par;
270	ssize_t res;
271
272	res = fb_sys_write(p, buf, count, ppos);
273	xenfb_refresh(info, 0, 0, info->page->width, info->page->height);
274	return res;
275	}
276
e4dcff1f MA	277	static int
	278	xenfb_check_var(struct fb_var_screeninfo var, struct fb_info info)
	279	{
	280	struct xenfb_info *xenfb_info;
	281	int required_mem_len;
	282
	283	xenfb_info = info->par;
	284
	285	if (!xenfb_info->feature_resize) {
	286	if (var->xres == video[KPARAM_WIDTH] &&
	287	var->yres == video[KPARAM_HEIGHT] &&
	288	var->bits_per_pixel == xenfb_info->page->depth) {
	289	return 0;
	290	}
	291	return -EINVAL;
	292	}
	293
	294	/* Can't resize past initial width and height */
	295	if (var->xres > video[KPARAM_WIDTH] \|\| var->yres > video[KPARAM_HEIGHT])
	296	return -EINVAL;
	297
	298	required_mem_len = var->xres * var->yres * xenfb_info->page->depth / 8;
	299	if (var->bits_per_pixel == xenfb_info->page->depth &&
	300	var->xres <= info->fix.line_length / (XENFB_DEPTH / 8) &&
	301	required_mem_len <= info->fix.smem_len) {
	302	var->xres_virtual = var->xres;
	303	var->yres_virtual = var->yres;
	304	return 0;
	305	}
	306	return -EINVAL;
	307	}
	308
	309	static int xenfb_set_par(struct fb_info *info)
	310	{
	311	struct xenfb_info *xenfb_info;
	312	unsigned long flags;
	313
	314	xenfb_info = info->par;
	315
	316	spin_lock_irqsave(&xenfb_info->resize_lock, flags);
	317	xenfb_info->resize.type = XENFB_TYPE_RESIZE;
	318	xenfb_info->resize.width = info->var.xres;
	319	xenfb_info->resize.height = info->var.yres;
	320	xenfb_info->resize.stride = info->fix.line_length;
	321	xenfb_info->resize.depth = info->var.bits_per_pixel;
	322	xenfb_info->resize.offset = 0;
	323	xenfb_info->resize_dpy = 1;
	324	spin_unlock_irqrestore(&xenfb_info->resize_lock, flags);
	325	return 0;
	326	}
	327
4ee36dc0 MA	328	static struct fb_ops xenfb_fb_ops = {
	329	.owner = THIS_MODULE,
	330	.fb_read = fb_sys_read,
	331	.fb_write = xenfb_write,
	332	.fb_setcolreg = xenfb_setcolreg,
	333	.fb_fillrect = xenfb_fillrect,
	334	.fb_copyarea = xenfb_copyarea,
	335	.fb_imageblit = xenfb_imageblit,
e4dcff1f MA	336	.fb_check_var = xenfb_check_var,
e4dcff1f MA	337	.fb_set_par = xenfb_set_par,
4ee36dc0 MA	338	};
	339
	340	static irqreturn_t xenfb_event_handler(int rq, void *dev_id)
	341	{
	342	/*
	343	* No in events recognized, simply ignore them all.
	344	* If you need to recognize some, see xen-kbdfront's
	345	* input_handler() for how to do that.
	346	*/
	347	struct xenfb_info *info = dev_id;
	348	struct xenfb_page *page = info->page;
	349
	350	if (page->in_cons != page->in_prod) {
	351	info->page->in_cons = info->page->in_prod;
	352	notify_remote_via_irq(info->irq);
	353	}
	354
	355	/* Flush dirty rectangle: */
	356	xenfb_refresh(info, INT_MAX, INT_MAX, -INT_MAX, -INT_MAX);
	357
	358	return IRQ_HANDLED;
	359	}
	360
48c68c4f GKH	361	static int xenfb_probe(struct xenbus_device *dev,
48c68c4f GKH	362	const struct xenbus_device_id *id)
4ee36dc0 MA	363	{
	364	struct xenfb_info *info;
	365	struct fb_info *fb_info;
e4dcff1f MA	366	int fb_size;
e4dcff1f MA	367	int val;
a7a97c63	368	int ret = 0;
4ee36dc0 MA	369
	370	info = kzalloc(sizeof(*info), GFP_KERNEL);
	371	if (info == NULL) {
	372	xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
	373	return -ENOMEM;
	374	}
e4dcff1f MA	375
	376	/* Limit kernel param videoram amount to what is in xenstore */
	377	if (xenbus_scanf(XBT_NIL, dev->otherend, "videoram", "%d", &val) == 1) {
	378	if (val < video[KPARAM_MEM])
	379	video[KPARAM_MEM] = val;
	380	}
	381
	382	/* If requested res does not fit in available memory, use default */
	383	fb_size = video[KPARAM_MEM] * 1024 * 1024;
	384	if (video[KPARAM_WIDTH] * video[KPARAM_HEIGHT] * XENFB_DEPTH / 8
	385	> fb_size) {
	386	video[KPARAM_WIDTH] = XENFB_WIDTH;
	387	video[KPARAM_HEIGHT] = XENFB_HEIGHT;
	388	fb_size = XENFB_DEFAULT_FB_LEN;
	389	}
	390
1b713e00	391	dev_set_drvdata(&dev->dev, info);
4ee36dc0 MA	392	info->xbdev = dev;
	393	info->irq = -1;
	394	info->x1 = info->y1 = INT_MAX;
	395	spin_lock_init(&info->dirty_lock);
e4dcff1f	396	spin_lock_init(&info->resize_lock);
4ee36dc0	397
1b86d775	398	info->fb = vzalloc(fb_size);
4ee36dc0 MA	399	if (info->fb == NULL)
4ee36dc0 MA	400	goto error_nomem;
4ee36dc0	401
e4dcff1f	402	info->nr_pages = (fb_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
4ee36dc0 MA	403
	404	info->mfns = vmalloc(sizeof(unsigned long) * info->nr_pages);
	405	if (!info->mfns)
	406	goto error_nomem;
	407
	408	/* set up shared page */
	409	info->page = (void *)__get_free_page(GFP_KERNEL \| __GFP_ZERO);
	410	if (!info->page)
	411	goto error_nomem;
	412
4ee36dc0 MA	413	/* abusing framebuffer_alloc() to allocate pseudo_palette */
	414	fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL);
	415	if (fb_info == NULL)
	416	goto error_nomem;
	417
	418	/* complete the abuse: */
	419	fb_info->pseudo_palette = fb_info->par;
	420	fb_info->par = info;
	421
	422	fb_info->screen_base = info->fb;
	423
	424	fb_info->fbops = &xenfb_fb_ops;
e4dcff1f MA	425	fb_info->var.xres_virtual = fb_info->var.xres = video[KPARAM_WIDTH];
	426	fb_info->var.yres_virtual = fb_info->var.yres = video[KPARAM_HEIGHT];
	427	fb_info->var.bits_per_pixel = XENFB_DEPTH;
4ee36dc0 MA	428
	429	fb_info->var.red = (struct fb_bitfield){16, 8, 0};
	430	fb_info->var.green = (struct fb_bitfield){8, 8, 0};
	431	fb_info->var.blue = (struct fb_bitfield){0, 8, 0};
	432
	433	fb_info->var.activate = FB_ACTIVATE_NOW;
	434	fb_info->var.height = -1;
	435	fb_info->var.width = -1;
	436	fb_info->var.vmode = FB_VMODE_NONINTERLACED;
	437
	438	fb_info->fix.visual = FB_VISUAL_TRUECOLOR;
e4dcff1f	439	fb_info->fix.line_length = fb_info->var.xres * XENFB_DEPTH / 8;
4ee36dc0	440	fb_info->fix.smem_start = 0;
e4dcff1f	441	fb_info->fix.smem_len = fb_size;
4ee36dc0 MA	442	strcpy(fb_info->fix.id, "xen");
	443	fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
	444	fb_info->fix.accel = FB_ACCEL_NONE;
	445
df11303c	446	fb_info->flags = FBINFO_FLAG_DEFAULT \| FBINFO_VIRTFB;
4ee36dc0 MA	447
	448	ret = fb_alloc_cmap(&fb_info->cmap, 256, 0);
	449	if (ret < 0) {
	450	framebuffer_release(fb_info);
	451	xenbus_dev_fatal(dev, ret, "fb_alloc_cmap");
	452	goto error;
	453	}
	454
	455	fb_info->fbdefio = &xenfb_defio;
	456	fb_deferred_io_init(fb_info);
	457
e4dcff1f MA	458	xenfb_init_shared_page(info, fb_info);
e4dcff1f MA	459
0a80fb10	460	ret = xenfb_connect_backend(dev, info);
a7a97c63 JL	461	if (ret < 0) {
	462	xenbus_dev_fatal(dev, ret, "xenfb_connect_backend");
	463	goto error_fb;
	464	}
0a80fb10	465
4ee36dc0 MA	466	ret = register_framebuffer(fb_info);
4ee36dc0 MA	467	if (ret) {
4ee36dc0	468	xenbus_dev_fatal(dev, ret, "register_framebuffer");
a7a97c63	469	goto error_fb;
4ee36dc0 MA	470	}
	471	info->fb_info = fb_info;
	472
9e124fe1	473	xenfb_make_preferred_console();
4ee36dc0 MA	474	return 0;
4ee36dc0 MA	475
a7a97c63 JL	476	error_fb:
	477	fb_deferred_io_cleanup(fb_info);
	478	fb_dealloc_cmap(&fb_info->cmap);
	479	framebuffer_release(fb_info);
	480	error_nomem:
	481	if (!ret) {
	482	ret = -ENOMEM;
	483	xenbus_dev_fatal(dev, ret, "allocating device memory");
	484	}
	485	error:
4ee36dc0 MA	486	xenfb_remove(dev);
	487	return ret;
	488	}
	489
48c68c4f	490	static void xenfb_make_preferred_console(void)
9e124fe1 MA	491	{
	492	struct console *c;
	493
	494	if (console_set_on_cmdline)
	495	return;
	496
ac751efa	497	console_lock();
281e6605	498	for_each_console(c) {
9e124fe1 MA	499	if (!strcmp(c->name, "tty") && c->index == 0)
	500	break;
	501	}
ac751efa	502	console_unlock();
9e124fe1 MA	503	if (c) {
	504	unregister_console(c);
	505	c->flags \|= CON_CONSDEV;
	506	c->flags &= ~CON_PRINTBUFFER; /* don't print again */
	507	register_console(c);
	508	}
	509	}
	510
4ee36dc0 MA	511	static int xenfb_resume(struct xenbus_device *dev)
4ee36dc0 MA	512	{
1b713e00	513	struct xenfb_info *info = dev_get_drvdata(&dev->dev);
4ee36dc0 MA	514
4ee36dc0 MA	515	xenfb_disconnect_backend(info);
e4dcff1f	516	xenfb_init_shared_page(info, info->fb_info);
4ee36dc0 MA	517	return xenfb_connect_backend(dev, info);
	518	}
	519
	520	static int xenfb_remove(struct xenbus_device *dev)
	521	{
1b713e00	522	struct xenfb_info *info = dev_get_drvdata(&dev->dev);
4ee36dc0 MA	523
	524	xenfb_disconnect_backend(info);
	525	if (info->fb_info) {
	526	fb_deferred_io_cleanup(info->fb_info);
	527	unregister_framebuffer(info->fb_info);
	528	fb_dealloc_cmap(&info->fb_info->cmap);
	529	framebuffer_release(info->fb_info);
	530	}
	531	free_page((unsigned long)info->page);
	532	vfree(info->mfns);
	533	vfree(info->fb);
	534	kfree(info);
	535
	536	return 0;
	537	}
	538
	539	static unsigned long vmalloc_to_mfn(void *address)
	540	{
	541	return pfn_to_mfn(vmalloc_to_pfn(address));
	542	}
	543
e4dcff1f MA	544	static void xenfb_init_shared_page(struct xenfb_info *info,
e4dcff1f MA	545	struct fb_info *fb_info)
4ee36dc0 MA	546	{
4ee36dc0 MA	547	int i;
e4dcff1f	548	int epd = PAGE_SIZE / sizeof(info->mfns[0]);
4ee36dc0 MA	549
	550	for (i = 0; i < info->nr_pages; i++)
	551	info->mfns[i] = vmalloc_to_mfn(info->fb + i * PAGE_SIZE);
	552
e4dcff1f MA	553	for (i = 0; i * epd < info->nr_pages; i++)
	554	info->page->pd[i] = vmalloc_to_mfn(&info->mfns[i * epd]);
	555
	556	info->page->width = fb_info->var.xres;
	557	info->page->height = fb_info->var.yres;
	558	info->page->depth = fb_info->var.bits_per_pixel;
	559	info->page->line_length = fb_info->fix.line_length;
	560	info->page->mem_length = fb_info->fix.smem_len;
4ee36dc0 MA	561	info->page->in_cons = info->page->in_prod = 0;
	562	info->page->out_cons = info->page->out_prod = 0;
	563	}
	564
	565	static int xenfb_connect_backend(struct xenbus_device *dev,
	566	struct xenfb_info *info)
	567	{
fc550e95	568	int ret, evtchn, irq;
4ee36dc0 MA	569	struct xenbus_transaction xbt;
	570
	571	ret = xenbus_alloc_evtchn(dev, &evtchn);
	572	if (ret)
	573	return ret;
fc550e95	574	irq = bind_evtchn_to_irqhandler(evtchn, xenfb_event_handler,
4ee36dc0	575	0, dev->devicetype, info);
fc550e95	576	if (irq < 0) {
4ee36dc0 MA	577	xenbus_free_evtchn(dev, evtchn);
4ee36dc0 MA	578	xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
fc550e95	579	return irq;
4ee36dc0	580	}
4ee36dc0 MA	581	again:
	582	ret = xenbus_transaction_start(&xbt);
	583	if (ret) {
	584	xenbus_dev_fatal(dev, ret, "starting transaction");
fc550e95	585	goto unbind_irq;
4ee36dc0 MA	586	}
	587	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
	588	virt_to_mfn(info->page));
	589	if (ret)
	590	goto error_xenbus;
	591	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
	592	evtchn);
	593	if (ret)
	594	goto error_xenbus;
	595	ret = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
	596	XEN_IO_PROTO_ABI_NATIVE);
	597	if (ret)
	598	goto error_xenbus;
	599	ret = xenbus_printf(xbt, dev->nodename, "feature-update", "1");
	600	if (ret)
	601	goto error_xenbus;
	602	ret = xenbus_transaction_end(xbt, 0);
	603	if (ret) {
	604	if (ret == -EAGAIN)
	605	goto again;
	606	xenbus_dev_fatal(dev, ret, "completing transaction");
fc550e95	607	goto unbind_irq;
4ee36dc0 MA	608	}
	609
	610	xenbus_switch_state(dev, XenbusStateInitialised);
fc550e95	611	info->irq = irq;
4ee36dc0 MA	612	return 0;
	613
	614	error_xenbus:
	615	xenbus_transaction_end(xbt, 1);
	616	xenbus_dev_fatal(dev, ret, "writing xenstore");
fc550e95 JJ	617	unbind_irq:
fc550e95 JJ	618	unbind_from_irqhandler(irq, info);
4ee36dc0 MA	619	return ret;
	620	}
	621
	622	static void xenfb_disconnect_backend(struct xenfb_info *info)
	623	{
731f3ab6 JJ	624	/* Prevent xenfb refresh */
731f3ab6 JJ	625	info->update_wanted = 0;
4ee36dc0 MA	626	if (info->irq >= 0)
	627	unbind_from_irqhandler(info->irq, info);
	628	info->irq = -1;
	629	}
	630
	631	static void xenfb_backend_changed(struct xenbus_device *dev,
	632	enum xenbus_state backend_state)
	633	{
1b713e00	634	struct xenfb_info *info = dev_get_drvdata(&dev->dev);
4ee36dc0 MA	635	int val;
	636
	637	switch (backend_state) {
	638	case XenbusStateInitialising:
	639	case XenbusStateInitialised:
b78c9512 NI	640	case XenbusStateReconfiguring:
b78c9512 NI	641	case XenbusStateReconfigured:
4ee36dc0	642	case XenbusStateUnknown:
4ee36dc0 MA	643	break;
	644
	645	case XenbusStateInitWait:
	646	InitWait:
	647	xenbus_switch_state(dev, XenbusStateConnected);
	648	break;
	649
	650	case XenbusStateConnected:
	651	/*
	652	* Work around xenbus race condition: If backend goes
	653	* through InitWait to Connected fast enough, we can
	654	* get Connected twice here.
	655	*/
	656	if (dev->state != XenbusStateConnected)
	657	goto InitWait; /* no InitWait seen yet, fudge it */
	658
	659	if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
	660	"request-update", "%d", &val) < 0)
	661	val = 0;
	662	if (val)
	663	info->update_wanted = 1;
e4dcff1f MA	664
	665	if (xenbus_scanf(XBT_NIL, dev->otherend,
	666	"feature-resize", "%d", &val) < 0)
	667	val = 0;
	668	info->feature_resize = val;
4ee36dc0 MA	669	break;
4ee36dc0 MA	670
01bc825f DV	671	case XenbusStateClosed:
	672	if (dev->state == XenbusStateClosed)
	673	break;
	674	/* Missed the backend's CLOSING state -- fallthrough */
4ee36dc0 MA	675	case XenbusStateClosing:
	676	xenbus_frontend_closed(dev);
	677	break;
	678	}
	679	}
	680
73db144b	681	static const struct xenbus_device_id xenfb_ids[] = {
4ee36dc0 MA	682	{ "vfb" },
	683	{ "" }
	684	};
	685
73db144b	686	static DEFINE_XENBUS_DRIVER(xenfb, ,
4ee36dc0 MA	687	.probe = xenfb_probe,
	688	.remove = xenfb_remove,
	689	.resume = xenfb_resume,
	690	.otherend_changed = xenfb_backend_changed,
73db144b	691	);
4ee36dc0 MA	692
	693	static int __init xenfb_init(void)
	694	{
bee6ab53	695	if (!xen_pv_domain())
4ee36dc0 MA	696	return -ENODEV;
	697
	698	/* Nothing to do if running in dom0. */
6e833587	699	if (xen_initial_domain())
4ee36dc0 MA	700	return -ENODEV;
4ee36dc0 MA	701
ffb78a26	702	return xenbus_register_frontend(&xenfb_driver);
4ee36dc0 MA	703	}
	704
	705	static void __exit xenfb_cleanup(void)
	706	{
ffb78a26	707	xenbus_unregister_driver(&xenfb_driver);
4ee36dc0 MA	708	}
	709
	710	module_init(xenfb_init);
	711	module_exit(xenfb_cleanup);
	712
1e892c95	713	MODULE_DESCRIPTION("Xen virtual framebuffer device frontend");
4ee36dc0	714	MODULE_LICENSE("GPL");
1e892c95	715	MODULE_ALIAS("xen:vfb");