[PATCH 01/05] video: deferred io sys helpers - core V2

[Magnus Damm <magnus.damm@gmail.com>]

From: Magnus Damm <damm@igel.co.jp>

Add shared sys helpers to the deferred io code. Instead of duplicating
the code in each driver we can keep it in one place. This saves a
few lines. The new helper functions make use of the deferred io delay.
While at it, keep track of the dirty area to allow partial screen update.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 Changes since V1
 - Remove sysdelay
 - Fix dirty area calculation

 drivers/video/Kconfig    |    4 ++
 drivers/video/fb_defio.c |   77 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fb.h       |   12 +++++++
 3 files changed, 93 insertions(+)

--- 0001/drivers/video/Kconfig
+++ work/drivers/video/Kconfig	2008-12-24 15:31:14.000000000 +0900
@@ -179,6 +179,10 @@ config FB_SYS_FOPS
 config FB_DEFERRED_IO
 	bool
 	depends on FB
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select FB_SYS_FOPS
 
 config FB_HECUBA
 	tristate
--- 0001/drivers/video/fb_defio.c
+++ work/drivers/video/fb_defio.c	2008-12-24 16:24:01.000000000 +0900
@@ -83,6 +83,38 @@ int fb_deferred_io_fsync(struct file *fi
 }
 EXPORT_SYMBOL_GPL(fb_deferred_io_fsync);
 
+static void fb_deferred_io_touch(struct fb_info *info,
+				 int dx, int dy, int width, int height)
+{
+	struct fb_deferred_io *fbdefio = info->fbdefio;
+	int x, y, ex, ey;
+
+	/* Skip if deferred io is complied-in but disabled on this fbdev */
+	if (!fbdefio)
+		return;
+
+	/* Remember area to redraw and expand if necessary */
+	if (fbdefio->dx != -1) {
+		x = min_t(int, dx, fbdefio->dx);
+		y = min_t(int, dy, fbdefio->dy);
+		ex = max_t(int, dx + width, fbdefio->dx + fbdefio->width);
+		ey = max_t(int, dy + height, fbdefio->dy + fbdefio->height);
+
+		dx = x;
+		dy = y;
+		width = ex - x;
+		height = ey - y;
+	}
+
+	fbdefio->dx = dx;
+	fbdefio->dy = dy;
+	fbdefio->width = width;
+	fbdefio->height = height;
+
+	/* come back after delay to process the deferred IO */
+	schedule_delayed_work(&info->deferred_work, fbdefio->delay);
+}
+
 /* vm_ops->page_mkwrite handler */
 static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
 				  struct page *page)
@@ -172,9 +204,53 @@ static void fb_deferred_io_work(struct w
 	list_for_each_safe(node, next, &fbdefio->pagelist) {
 		list_del(node);
 	}
+
+	/* reset sys operations state */
+	fbdefio->dx = -1;
+
 	mutex_unlock(&fbdefio->lock);
 }
 
+ssize_t fb_deferred_io_read(struct fb_info *info, char __user *buf,
+			    size_t count, loff_t *ppos)
+{
+	return fb_sys_read(info, buf, count, ppos);
+}
+EXPORT_SYMBOL_GPL(fb_deferred_io_read);
+
+ssize_t fb_deferred_io_write(struct fb_info *info, const char __user *buf,
+			     size_t count, loff_t *ppos)
+{
+	int ret = fb_sys_write(info, buf, count, ppos);
+
+	if (ret > 0)
+		fb_deferred_io_touch(info, 0, 0, INT_MAX, INT_MAX);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fb_deferred_io_write);
+
+void fb_deferred_io_fillrect(struct fb_info *info, const struct fb_fillrect *r)
+{
+	sys_fillrect(info, r);
+	fb_deferred_io_touch(info, r->dx, r->dy, r->width, r->height);
+}
+EXPORT_SYMBOL_GPL(fb_deferred_io_fillrect);
+
+void fb_deferred_io_copyarea(struct fb_info *info, const struct fb_copyarea *a)
+{
+	sys_copyarea(info, a);
+	fb_deferred_io_touch(info, a->dx, a->dy, a->width, a->height);
+}
+EXPORT_SYMBOL_GPL(fb_deferred_io_copyarea);
+
+void fb_deferred_io_imageblit(struct fb_info *info, const struct fb_image *i)
+{
+	sys_imageblit(info, i);
+	fb_deferred_io_touch(info, i->dx, i->dy, i->width, i->height);
+}
+EXPORT_SYMBOL_GPL(fb_deferred_io_imageblit);
+
 void fb_deferred_io_init(struct fb_info *info)
 {
 	struct fb_deferred_io *fbdefio = info->fbdefio;
@@ -184,6 +260,7 @@ void fb_deferred_io_init(struct fb_info 
 	info->fbops->fb_mmap = fb_deferred_io_mmap;
 	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
 	INIT_LIST_HEAD(&fbdefio->pagelist);
+	fbdefio->dx = -1;
 	if (fbdefio->delay == 0) /* set a default of 1 s */
 		fbdefio->delay = HZ;
 }
--- 0001/include/linux/fb.h
+++ work/include/linux/fb.h	2008-12-24 16:20:57.000000000 +0900
@@ -589,6 +589,7 @@ struct fb_deferred_io {
 	unsigned long delay;
 	struct mutex lock; /* mutex that protects the page list */
 	struct list_head pagelist; /* list of touched pages */
+	int dx, dy, width, height; /* modified area, excluding pages */
 	/* callback */
 	void (*deferred_io)(struct fb_info *info, struct list_head *pagelist);
 };
@@ -983,6 +984,17 @@ extern void fb_deferred_io_open(struct f
 extern void fb_deferred_io_cleanup(struct fb_info *info);
 extern int fb_deferred_io_fsync(struct file *file, struct dentry *dentry,
 				int datasync);
+extern ssize_t fb_deferred_io_read(struct fb_info *info, char __user *buf,
+				   size_t count, loff_t *ppos);
+extern ssize_t fb_deferred_io_write(struct fb_info *info,
+				    const char __user *buf,
+				    size_t count, loff_t *ppos);
+extern void fb_deferred_io_fillrect(struct fb_info *info,
+				    const struct fb_fillrect *rect);
+extern void fb_deferred_io_copyarea(struct fb_info *info,
+				    const struct fb_copyarea *area);
+extern void fb_deferred_io_imageblit(struct fb_info *info,
+				     const struct fb_image *image);
 
 static inline bool fb_be_math(struct fb_info *info)
 {