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Commit e4dcff1f authored by Markus Armbruster's avatar Markus Armbruster Committed by Thomas Gleixner
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xen pvfb: Dynamic mode support (screen resizing) 

The pvfb backend indicates dynamic mode support by creating node
feature_resize with a non-zero value in its xenstore directory.
xen-fbfront sends a resize notification event on mode change.  Fully
backwards compatible both ways.

Framebuffer size and initial resolution can be controlled through
kernel parameter xen_fbfront.video.  The backend enforces a separate
size limit, which it advertises in node videoram in its xenstore
directory.

xen-kbdfront gets the maximum screen resolution from nodes width and
height in the backend's xenstore directory instead of hardcoding it.

Additional goodie: support for larger framebuffers (512M on a 64-bit
system with 4K pages).

Changing the number of bits per pixels dynamically is not supported,
yet.

Ported from
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/92f7b3144f41
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/bfc040135633



Signed-off-by: default avatarPat Campbell <plc@novell.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent f4ad1ebd

drivers/input/xen-kbdfront.c

+10 −0
Original line number Diff line number Diff line
@@ -300,6 +300,16 @@ static void xenkbd_backend_changed(struct xenbus_device *dev, 
		 */

		if (dev->state != XenbusStateConnected)

			goto InitWait; /* no InitWait seen yet, fudge it */



		/* Set input abs params to match backend screen res */

		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,

				 "width", "%d", &val) > 0)

			input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);



		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,

				 "height", "%d", &val) > 0)

			input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);



		break;



	case XenbusStateClosing:

drivers/video/xen-fbfront.c

+154 −29
Original line number Diff line number Diff line
@@ -43,23 +43,47 @@ struct xenfb_info { 
	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;

};



static u32 xenfb_mem_len = XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8;

#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 *);

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;

	u32 prod;



	memset(&event, 0, sizeof(event));

	event.type = XENFB_TYPE_UPDATE;
@@ -68,14 +92,19 @@ static void xenfb_do_update(struct xenfb_info *info, 
	event.update.width = w;

	event.update.height = h;



	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;

	xenfb_send_event(info, &event);

}



	notify_remote_via_irq(info->irq);

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)
@@ -87,12 +116,28 @@ static int xenfb_queue_full(struct xenfb_info *info) 
	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 y2 = y1 + h - 1;

	int x2 = x1 + w - 1;

	int y2 = y1 + h - 1;



	xenfb_handle_resize_dpy(info);



	if (!info->update_wanted)

		return;
@@ -225,6 +270,57 @@ static ssize_t xenfb_write(struct fb_info *p, const char __user *buf, 
	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,
@@ -233,6 +329,8 @@ static struct fb_ops xenfb_fb_ops = { 
	.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)
@@ -261,6 +359,8 @@ static int __devinit xenfb_probe(struct xenbus_device *dev, 
{

	struct xenfb_info *info;

	struct fb_info *fb_info;

	int fb_size;

	int val;

	int ret;



	info = kzalloc(sizeof(*info), GFP_KERNEL);
@@ -268,18 +368,35 @@ static int __devinit xenfb_probe(struct xenbus_device *dev, 
		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->dev.driver_data = 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 = vmalloc(xenfb_mem_len);

	info->fb = vmalloc(fb_size);

	if (info->fb == NULL)

		goto error_nomem;

	memset(info->fb, 0, xenfb_mem_len);

	memset(info->fb, 0, fb_size);



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

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



	info->mfns = vmalloc(sizeof(unsigned long) * info->nr_pages);

	if (!info->mfns)
@@ -290,8 +407,6 @@ static int __devinit xenfb_probe(struct xenbus_device *dev, 
	if (!info->page)

		goto error_nomem;



	xenfb_init_shared_page(info);



	/* abusing framebuffer_alloc() to allocate pseudo_palette */

	fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL);

	if (fb_info == NULL)
@@ -304,9 +419,9 @@ static int __devinit xenfb_probe(struct xenbus_device *dev, 
	fb_info->screen_base = info->fb;



	fb_info->fbops = &xenfb_fb_ops;

	fb_info->var.xres_virtual = fb_info->var.xres = info->page->width;

	fb_info->var.yres_virtual = fb_info->var.yres = info->page->height;

	fb_info->var.bits_per_pixel = info->page->depth;

	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};
@@ -318,9 +433,9 @@ static int __devinit xenfb_probe(struct xenbus_device *dev, 
	fb_info->var.vmode = FB_VMODE_NONINTERLACED;



	fb_info->fix.visual = FB_VISUAL_TRUECOLOR;

	fb_info->fix.line_length = info->page->line_length;

	fb_info->fix.line_length = fb_info->var.xres * XENFB_DEPTH / 8;

	fb_info->fix.smem_start = 0;

	fb_info->fix.smem_len = xenfb_mem_len;

	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;
@@ -337,6 +452,8 @@ static int __devinit xenfb_probe(struct xenbus_device *dev, 
	fb_info->fbdefio = &xenfb_defio;

	fb_deferred_io_init(fb_info);



	xenfb_init_shared_page(info, fb_info);



	ret = register_framebuffer(fb_info);

	if (ret) {

		fb_deferred_io_cleanup(fb_info);
@@ -389,7 +506,7 @@ static int xenfb_resume(struct xenbus_device *dev) 
	struct xenfb_info *info = dev->dev.driver_data;



	xenfb_disconnect_backend(info);

	xenfb_init_shared_page(info);

	xenfb_init_shared_page(info, info->fb_info);

	return xenfb_connect_backend(dev, info);

}
@@ -417,20 +534,23 @@ 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)

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);



	info->page->pd[0] = vmalloc_to_mfn(info->mfns);

	info->page->pd[1] = 0;

	info->page->width = XENFB_WIDTH;

	info->page->height = XENFB_HEIGHT;

	info->page->depth = XENFB_DEPTH;

	info->page->line_length = (info->page->depth / 8) * info->page->width;

	info->page->mem_length = xenfb_mem_len;

	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;

}
@@ -530,6 +650,11 @@ static void xenfb_backend_changed(struct xenbus_device *dev, 
			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 XenbusStateClosing:

include/xen/interface/io/fbif.h

+24 −5
Original line number Diff line number Diff line
@@ -49,11 +49,27 @@ struct xenfb_update { 
	int32_t height;		/* rect height */

};



/*

 * Framebuffer resize notification event

 * Capable backend sets feature-resize in xenstore.

 */

#define XENFB_TYPE_RESIZE 3



struct xenfb_resize {

	uint8_t type;		/* XENFB_TYPE_RESIZE */

	int32_t width;		/* width in pixels */

	int32_t height;		/* height in pixels */

	int32_t stride;		/* stride in bytes */

	int32_t depth;		/* depth in bits */

	int32_t offset;		/* start offset within framebuffer */

};



#define XENFB_OUT_EVENT_SIZE 40



union xenfb_out_event {

	uint8_t type;

	struct xenfb_update update;

	struct xenfb_resize resize;

	char pad[XENFB_OUT_EVENT_SIZE];

};
@@ -105,15 +121,18 @@ struct xenfb_page { 
	 * Each directory page holds PAGE_SIZE / sizeof(*pd)

	 * framebuffer pages, and can thus map up to PAGE_SIZE *

	 * PAGE_SIZE / sizeof(*pd) bytes.  With PAGE_SIZE == 4096 and

	 * sizeof(unsigned long) == 4, that's 4 Megs.  Two directory

	 * pages should be enough for a while.

	 * sizeof(unsigned long) == 4/8, that's 4 Megs 32 bit and 2

	 * Megs 64 bit.  256 directories give enough room for a 512

	 * Meg framebuffer with a max resolution of 12,800x10,240.

	 * Should be enough for a while with room leftover for

	 * expansion.

	 */

	unsigned long pd[2];

	unsigned long pd[256];

};



/*

 * Wart: xenkbd needs to know resolution.  Put it here until a better

 * solution is found, but don't leak it to the backend.

 * Wart: xenkbd needs to know default resolution.  Put it here until a

 * better solution is found, but don't leak it to the backend.

 */

#ifdef __KERNEL__

#define XENFB_WIDTH 800