[deliverable/linux.git] / drivers / video / fb_defio.c

/*
 *  linux/drivers/video/fb_defio.c
 *
 *  Copyright (C) 2006 Jaya Kumar
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/list.h>
#include <asm/uaccess.h>

/* to support deferred IO */
#include <linux/rmap.h>
#include <linux/pagemap.h>

/* this is to find and return the vmalloc-ed fb pages */
static struct page* fb_deferred_io_nopage(struct vm_area_struct *vma,
					unsigned long vaddr, int *type)
{
	unsigned long offset;
	struct page *page;
	struct fb_info *info = vma->vm_private_data;
	/* info->screen_base is in System RAM */
	void *screen_base = (void __force *) info->screen_base;

	offset = (vaddr - vma->vm_start) + (vma->vm_pgoff << PAGE_SHIFT);
	if (offset >= info->fix.smem_len)
		return NOPAGE_SIGBUS;

	page = vmalloc_to_page(screen_base + offset);
	if (!page)
		return NOPAGE_OOM;

	get_page(page);
	if (type)
		*type = VM_FAULT_MINOR;
	return page;
}

int fb_deferred_io_fsync(struct file *file, struct dentry *dentry, int datasync)
{
	struct fb_info *info = file->private_data;

	/* Kill off the delayed work */
	cancel_rearming_delayed_work(&info->deferred_work);

	/* Run it immediately */
	return schedule_delayed_work(&info->deferred_work, 0);
}
EXPORT_SYMBOL_GPL(fb_deferred_io_fsync);

/* vm_ops->page_mkwrite handler */
static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
				  struct page *page)
{
	struct fb_info *info = vma->vm_private_data;
	struct fb_deferred_io *fbdefio = info->fbdefio;

	/* this is a callback we get when userspace first tries to
	write to the page. we schedule a workqueue. that workqueue
	will eventually mkclean the touched pages and execute the
	deferred framebuffer IO. then if userspace touches a page
	again, we repeat the same scheme */

	/* protect against the workqueue changing the page list */
	mutex_lock(&fbdefio->lock);
	list_add(&page->lru, &fbdefio->pagelist);
	mutex_unlock(&fbdefio->lock);

	/* come back after delay to process the deferred IO */
	schedule_delayed_work(&info->deferred_work, fbdefio->delay);
	return 0;
}

static struct vm_operations_struct fb_deferred_io_vm_ops = {
	.nopage   	= fb_deferred_io_nopage,
	.page_mkwrite	= fb_deferred_io_mkwrite,
};

static int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
	vma->vm_ops = &fb_deferred_io_vm_ops;
	vma->vm_flags |= ( VM_IO | VM_RESERVED | VM_DONTEXPAND );
	vma->vm_private_data = info;
	return 0;
}

/* workqueue callback */
static void fb_deferred_io_work(struct work_struct *work)
{
	struct fb_info *info = container_of(work, struct fb_info,
						deferred_work.work);
	struct list_head *node, *next;
	struct page *cur;
	struct fb_deferred_io *fbdefio = info->fbdefio;

	/* here we mkclean the pages, then do all deferred IO */
	mutex_lock(&fbdefio->lock);
	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
		lock_page(cur);
		page_mkclean(cur);
		unlock_page(cur);
	}

	/* driver's callback with pagelist */
	fbdefio->deferred_io(info, &fbdefio->pagelist);

	/* clear the list */
	list_for_each_safe(node, next, &fbdefio->pagelist) {
		list_del(node);
	}
	mutex_unlock(&fbdefio->lock);
}

void fb_deferred_io_init(struct fb_info *info)
{
	struct fb_deferred_io *fbdefio = info->fbdefio;

	BUG_ON(!fbdefio);
	mutex_init(&fbdefio->lock);
	info->fbops->fb_mmap = fb_deferred_io_mmap;
	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
	INIT_LIST_HEAD(&fbdefio->pagelist);
	if (fbdefio->delay == 0) /* set a default of 1 s */
		fbdefio->delay = HZ;
}
EXPORT_SYMBOL_GPL(fb_deferred_io_init);

void fb_deferred_io_cleanup(struct fb_info *info)
{
	struct fb_deferred_io *fbdefio = info->fbdefio;

	BUG_ON(!fbdefio);
	cancel_delayed_work(&info->deferred_work);
	flush_scheduled_work();
}
EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);

MODULE_LICENSE("GPL");
Commit	Line	Data
60b59bea JK	1	/*
	2	* linux/drivers/video/fb_defio.c
	3	*
	4	* Copyright (C) 2006 Jaya Kumar
	5	*
	6	* This file is subject to the terms and conditions of the GNU General Public
	7	* License. See the file COPYING in the main directory of this archive
	8	* for more details.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/kernel.h>
	13	#include <linux/errno.h>
	14	#include <linux/string.h>
	15	#include <linux/mm.h>
	16	#include <linux/slab.h>
	17	#include <linux/vmalloc.h>
	18	#include <linux/delay.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/fb.h>
	21	#include <linux/list.h>
	22	#include <asm/uaccess.h>
	23
	24	/* to support deferred IO */
	25	#include <linux/rmap.h>
	26	#include <linux/pagemap.h>
	27
	28	/* this is to find and return the vmalloc-ed fb pages */
	29	static struct page* fb_deferred_io_nopage(struct vm_area_struct *vma,
	30	unsigned long vaddr, int *type)
	31	{
	32	unsigned long offset;
	33	struct page *page;
	34	struct fb_info *info = vma->vm_private_data;
98a1153a AD	35	/* info->screen_base is in System RAM */
98a1153a AD	36	void screen_base = (void __force ) info->screen_base;
60b59bea JK	37
	38	offset = (vaddr - vma->vm_start) + (vma->vm_pgoff << PAGE_SHIFT);
	39	if (offset >= info->fix.smem_len)
	40	return NOPAGE_SIGBUS;
	41
98a1153a	42	page = vmalloc_to_page(screen_base + offset);
60b59bea JK	43	if (!page)
	44	return NOPAGE_OOM;
	45
	46	get_page(page);
	47	if (type)
	48	*type = VM_FAULT_MINOR;
	49	return page;
	50	}
	51
5e841b88 PM	52	int fb_deferred_io_fsync(struct file file, struct dentry dentry, int datasync)
	53	{
	54	struct fb_info *info = file->private_data;
	55
	56	/* Kill off the delayed work */
	57	cancel_rearming_delayed_work(&info->deferred_work);
	58
	59	/* Run it immediately */
	60	return schedule_delayed_work(&info->deferred_work, 0);
	61	}
	62	EXPORT_SYMBOL_GPL(fb_deferred_io_fsync);
	63
60b59bea	64	/* vm_ops->page_mkwrite handler */
7bf1ea33 AB	65	static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
7bf1ea33 AB	66	struct page *page)
60b59bea JK	67	{
	68	struct fb_info *info = vma->vm_private_data;
	69	struct fb_deferred_io *fbdefio = info->fbdefio;
	70
	71	/* this is a callback we get when userspace first tries to
	72	write to the page. we schedule a workqueue. that workqueue
	73	will eventually mkclean the touched pages and execute the
	74	deferred framebuffer IO. then if userspace touches a page
	75	again, we repeat the same scheme */
	76
	77	/* protect against the workqueue changing the page list */
	78	mutex_lock(&fbdefio->lock);
	79	list_add(&page->lru, &fbdefio->pagelist);
	80	mutex_unlock(&fbdefio->lock);
	81
	82	/* come back after delay to process the deferred IO */
	83	schedule_delayed_work(&info->deferred_work, fbdefio->delay);
	84	return 0;
	85	}
	86
	87	static struct vm_operations_struct fb_deferred_io_vm_ops = {
	88	.nopage = fb_deferred_io_nopage,
	89	.page_mkwrite = fb_deferred_io_mkwrite,
	90	};
	91
	92	static int fb_deferred_io_mmap(struct fb_info info, struct vm_area_struct vma)
	93	{
	94	vma->vm_ops = &fb_deferred_io_vm_ops;
	95	vma->vm_flags \|= ( VM_IO \| VM_RESERVED \| VM_DONTEXPAND );
	96	vma->vm_private_data = info;
	97	return 0;
	98	}
	99
	100	/* workqueue callback */
	101	static void fb_deferred_io_work(struct work_struct *work)
	102	{
	103	struct fb_info *info = container_of(work, struct fb_info,
	104	deferred_work.work);
	105	struct list_head node, next;
	106	struct page *cur;
	107	struct fb_deferred_io *fbdefio = info->fbdefio;
	108
	109	/* here we mkclean the pages, then do all deferred IO */
	110	mutex_lock(&fbdefio->lock);
	111	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
	112	lock_page(cur);
	113	page_mkclean(cur);
	114	unlock_page(cur);
	115	}
	116
	117	/* driver's callback with pagelist */
	118	fbdefio->deferred_io(info, &fbdefio->pagelist);
	119
	120	/* clear the list */
	121	list_for_each_safe(node, next, &fbdefio->pagelist) {
	122	list_del(node);
	123	}
	124	mutex_unlock(&fbdefio->lock);
	125	}
	126
	127	void fb_deferred_io_init(struct fb_info *info)
	128	{
	129	struct fb_deferred_io *fbdefio = info->fbdefio;
	130
131	BUG_ON(!fbdefio);
132	mutex_init(&fbdefio->lock);
133	info->fbops->fb_mmap = fb_deferred_io_mmap;
134	INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
135	INIT_LIST_HEAD(&fbdefio->pagelist);
136	if (fbdefio->delay == 0) /* set a default of 1 s */
137	fbdefio->delay = HZ;
138	}
139	EXPORT_SYMBOL_GPL(fb_deferred_io_init);
140
141	void fb_deferred_io_cleanup(struct fb_info *info)
142	{
143	struct fb_deferred_io *fbdefio = info->fbdefio;
144
145	BUG_ON(!fbdefio);
146	cancel_delayed_work(&info->deferred_work);
147	flush_scheduled_work();
148	}
149	EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
150
151	MODULE_LICENSE("GPL");