mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
![Magnus Damm](/assets/img/avatar_default.png)
Extend the deferred io code from only supporting vmalloc()ed frame buffer memory to support both vmalloc()ed and physically contiguous frame buffer memory. The sh_mobile_lcdcfb hardware does not support scatter gather so we need physically contiguous memory to back our frame buffer. Signed-off-by: Magnus Damm <damm@igel.co.jp> Acked-by: Jaya Kumar <jayakumar.lkml@gmail.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
221 lines
5.6 KiB
C
221 lines
5.6 KiB
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>
|
|
|
|
/* to support deferred IO */
|
|
#include <linux/rmap.h>
|
|
#include <linux/pagemap.h>
|
|
|
|
struct page *fb_deferred_io_page(struct fb_info *info, unsigned long offs)
|
|
{
|
|
void *screen_base = (void __force *) info->screen_base;
|
|
struct page *page;
|
|
|
|
if (is_vmalloc_addr(screen_base + offs))
|
|
page = vmalloc_to_page(screen_base + offs);
|
|
else
|
|
page = pfn_to_page((info->fix.smem_start + offs) >> PAGE_SHIFT);
|
|
|
|
return page;
|
|
}
|
|
|
|
/* this is to find and return the vmalloc-ed fb pages */
|
|
static int fb_deferred_io_fault(struct vm_area_struct *vma,
|
|
struct vm_fault *vmf)
|
|
{
|
|
unsigned long offset;
|
|
struct page *page;
|
|
struct fb_info *info = vma->vm_private_data;
|
|
|
|
offset = vmf->pgoff << PAGE_SHIFT;
|
|
if (offset >= info->fix.smem_len)
|
|
return VM_FAULT_SIGBUS;
|
|
|
|
page = fb_deferred_io_page(info, offset);
|
|
if (!page)
|
|
return VM_FAULT_SIGBUS;
|
|
|
|
get_page(page);
|
|
|
|
if (vma->vm_file)
|
|
page->mapping = vma->vm_file->f_mapping;
|
|
else
|
|
printk(KERN_ERR "no mapping available\n");
|
|
|
|
BUG_ON(!page->mapping);
|
|
page->index = vmf->pgoff;
|
|
|
|
vmf->page = page;
|
|
return 0;
|
|
}
|
|
|
|
int fb_deferred_io_fsync(struct file *file, struct dentry *dentry, int datasync)
|
|
{
|
|
struct fb_info *info = file->private_data;
|
|
|
|
/* Skip if deferred io is complied-in but disabled on this fbdev */
|
|
if (!info->fbdefio)
|
|
return 0;
|
|
|
|
/* 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;
|
|
struct page *cur;
|
|
|
|
/* 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);
|
|
|
|
/* we loop through the pagelist before adding in order
|
|
to keep the pagelist sorted */
|
|
list_for_each_entry(cur, &fbdefio->pagelist, lru) {
|
|
/* this check is to catch the case where a new
|
|
process could start writing to the same page
|
|
through a new pte. this new access can cause the
|
|
mkwrite even when the original ps's pte is marked
|
|
writable */
|
|
if (unlikely(cur == page))
|
|
goto page_already_added;
|
|
else if (cur->index > page->index)
|
|
break;
|
|
}
|
|
|
|
list_add_tail(&page->lru, &cur->lru);
|
|
|
|
page_already_added:
|
|
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 = {
|
|
.fault = fb_deferred_io_fault,
|
|
.page_mkwrite = fb_deferred_io_mkwrite,
|
|
};
|
|
|
|
static int fb_deferred_io_set_page_dirty(struct page *page)
|
|
{
|
|
if (!PageDirty(page))
|
|
SetPageDirty(page);
|
|
return 0;
|
|
}
|
|
|
|
static const struct address_space_operations fb_deferred_io_aops = {
|
|
.set_page_dirty = fb_deferred_io_set_page_dirty,
|
|
};
|
|
|
|
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_open(struct fb_info *info,
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
file->f_mapping->a_ops = &fb_deferred_io_aops;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fb_deferred_io_open);
|
|
|
|
void fb_deferred_io_cleanup(struct fb_info *info)
|
|
{
|
|
struct fb_deferred_io *fbdefio = info->fbdefio;
|
|
struct page *page;
|
|
int i;
|
|
|
|
BUG_ON(!fbdefio);
|
|
cancel_delayed_work(&info->deferred_work);
|
|
flush_scheduled_work();
|
|
|
|
/* clear out the mapping that we setup */
|
|
for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) {
|
|
page = fb_deferred_io_page(info, i);
|
|
page->mapping = NULL;
|
|
}
|
|
|
|
info->fbops->fb_mmap = NULL;
|
|
mutex_destroy(&fbdefio->lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
|
|
|
|
MODULE_LICENSE("GPL");
|