From 60b59beafba875aef6d378078bce0baf2287ae14 Mon Sep 17 00:00:00 2001 From: Jaya Kumar Date: Tue, 8 May 2007 00:37:37 -0700 Subject: fbdev: mm: Deferred IO support This implements deferred IO support in fbdev. Deferred IO is a way to delay and repurpose IO. This implementation is done using mm's page_mkwrite and page_mkclean hooks in order to detect, delay and then rewrite IO. This functionality is used by hecubafb. [adaplas] This is useful for graphics hardware with no directly addressable/mappable framebuffer. Implementing this will allow the "framebuffer" to be accesible from user space via mmap(). Signed-off-by: Jaya Kumar Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/fb.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include') diff --git a/include/linux/fb.h b/include/linux/fb.h index be913ec8716..8a8255b94b6 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -561,6 +561,16 @@ struct fb_pixmap { void (*readio) (struct fb_info *info, void *dst, void __iomem *src, unsigned int size); }; +#ifdef CONFIG_FB_DEFERRED_IO +struct fb_deferred_io { + /* delay between mkwrite and deferred handler */ + unsigned long delay; + struct mutex lock; /* mutex that protects the page list */ + struct list_head pagelist; /* list of touched pages */ + /* callback */ + void (*deferred_io)(struct fb_info *info, struct list_head *pagelist); +}; +#endif /* * Frame buffer operations @@ -778,6 +788,10 @@ struct fb_info { struct mutex bl_curve_mutex; u8 bl_curve[FB_BACKLIGHT_LEVELS]; #endif +#ifdef CONFIG_FB_DEFERRED_IO + struct delayed_work deferred_work; + struct fb_deferred_io *fbdefio; +#endif struct fb_ops *fbops; struct device *device; /* This is the parent */ @@ -913,6 +927,12 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, } } +#ifdef CONFIG_FB_DEFERRED_IO +/* drivers/video/fb_defio.c */ +extern void fb_deferred_io_init(struct fb_info *info); +extern void fb_deferred_io_cleanup(struct fb_info *info); +#endif + /* drivers/video/fbsysfs.c */ extern struct fb_info *framebuffer_alloc(size_t size, struct device *dev); extern void framebuffer_release(struct fb_info *info); -- cgit v1.2.3