This is a note to let you know that I've just added the patch titled
fbdev: Rename pagelist to pagereflist for deferred I/O
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fbdev-rename-pagelist-to-pagereflist-for-deferred-i-.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6706769caf4a001397cc1c5dde6b8010fb77c24a
Author: Thomas Zimmermann <tzimmermann@xxxxxxx>
Date: Fri Apr 29 12:08:33 2022 +0200
fbdev: Rename pagelist to pagereflist for deferred I/O
[ Upstream commit e80eec1b871a2acb8f5c92db4c237e9ae6dd322b ]
Rename various instances of pagelist to pagereflist. The list now
stores pageref structures, so the new name is more appropriate.
In their write-back helpers, several fbdev drivers refer to the
pageref list in struct fb_deferred_io instead of using the one
supplied as argument to the function. Convert them over to the
supplied one. It's the same instance, so no change of behavior
occurs.
v4:
* fix commit message (Javier)
Suggested-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-5-tzimmermann@xxxxxxx
Stable-dep-of: 33cd6ea9c067 ("fbdev: flush deferred IO before closing")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 888ec6135544..82960d5d4e73 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -683,13 +683,12 @@ static void drm_fb_helper_damage(struct fb_info *info, u32 x, u32 y,
/**
* drm_fb_helper_deferred_io() - fbdev deferred_io callback function
* @info: fb_info struct pointer
- * @pagelist: list of mmap framebuffer pages that have to be flushed
+ * @pagereflist: list of mmap framebuffer pages that have to be flushed
*
* This function is used as the &fb_deferred_io.deferred_io
* callback function for flushing the fbdev mmap writes.
*/
-void drm_fb_helper_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
unsigned long start, end, min, max;
struct fb_deferred_io_pageref *pageref;
@@ -697,7 +696,7 @@ void drm_fb_helper_deferred_io(struct fb_info *info,
min = ULONG_MAX;
max = 0;
- list_for_each_entry(pageref, pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
start = pageref->offset;
end = start + PAGE_SIZE - 1;
min = min(min, start);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
index 1f20e3c958ef..79b08e927f76 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
@@ -316,8 +316,7 @@ static int vmw_fb_pan_display(struct fb_var_screeninfo *var,
return 0;
}
-static void vmw_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+static void vmw_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
struct vmw_fb_par *par = info->par;
unsigned long start, end, min, max;
@@ -327,7 +326,7 @@ static void vmw_deferred_io(struct fb_info *info,
min = ULONG_MAX;
max = 0;
- list_for_each_entry(pageref, pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
struct page *page = pageref->page;
start = page->index << PAGE_SHIFT;
end = start + PAGE_SIZE - 1;
diff --git a/drivers/hid/hid-picolcd_fb.c b/drivers/hid/hid-picolcd_fb.c
index 33c102a60992..8a0d1365cd72 100644
--- a/drivers/hid/hid-picolcd_fb.c
+++ b/drivers/hid/hid-picolcd_fb.c
@@ -432,7 +432,7 @@ static const struct fb_ops picolcdfb_ops = {
/* Callback from deferred IO workqueue */
-static void picolcd_fb_deferred_io(struct fb_info *info, struct list_head *pagelist)
+static void picolcd_fb_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
picolcd_fb_update(info);
}
diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index 5c52b5ff9f51..7aec35ae5cd5 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -322,7 +322,7 @@ static void fbtft_mkdirty(struct fb_info *info, int y, int height)
schedule_delayed_work(&info->deferred_work, fbdefio->delay);
}
-static void fbtft_deferred_io(struct fb_info *info, struct list_head *pagelist)
+static void fbtft_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
struct fbtft_par *par = info->par;
unsigned int dirty_lines_start, dirty_lines_end;
@@ -340,7 +340,7 @@ static void fbtft_deferred_io(struct fb_info *info, struct list_head *pagelist)
spin_unlock(&par->dirty_lock);
/* Mark display lines as dirty */
- list_for_each_entry(pageref, pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
struct page *page = pageref->page;
count++;
index = page->index << PAGE_SHIFT;
@@ -654,9 +654,9 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
fbops->fb_setcolreg = fbtft_fb_setcolreg;
fbops->fb_blank = fbtft_fb_blank;
- fbdefio->delay = HZ / fps;
- fbdefio->sort_pagelist = true;
- fbdefio->deferred_io = fbtft_deferred_io;
+ fbdefio->delay = HZ / fps;
+ fbdefio->sort_pagereflist = true;
+ fbdefio->deferred_io = fbtft_deferred_io;
fb_deferred_io_init(info);
snprintf(info->fix.id, sizeof(info->fix.id), "%s", dev->driver->name);
diff --git a/drivers/video/fbdev/broadsheetfb.c b/drivers/video/fbdev/broadsheetfb.c
index 2ca753d27f76..8b953d20ccdc 100644
--- a/drivers/video/fbdev/broadsheetfb.c
+++ b/drivers/video/fbdev/broadsheetfb.c
@@ -929,13 +929,11 @@ static void broadsheetfb_dpy_update(struct broadsheetfb_par *par)
}
/* this is called back from the deferred io workqueue */
-static void broadsheetfb_dpy_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+static void broadsheetfb_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
u16 y1 = 0, h = 0;
int prev_index = -1;
struct fb_deferred_io_pageref *pageref;
- struct fb_deferred_io *fbdefio = info->fbdefio;
int h_inc;
u16 yres = info->var.yres;
u16 xres = info->var.xres;
@@ -944,7 +942,7 @@ static void broadsheetfb_dpy_deferred_io(struct fb_info *info,
h_inc = DIV_ROUND_UP(PAGE_SIZE , xres);
/* walk the written page list and swizzle the data */
- list_for_each_entry(pageref, &fbdefio->pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
struct page *cur = pageref->page;
if (prev_index < 0) {
/* just starting so assign first page */
@@ -1059,9 +1057,9 @@ static const struct fb_ops broadsheetfb_ops = {
};
static struct fb_deferred_io broadsheetfb_defio = {
- .delay = HZ/4,
- .sort_pagelist = true,
- .deferred_io = broadsheetfb_dpy_deferred_io,
+ .delay = HZ/4,
+ .sort_pagereflist = true,
+ .deferred_io = broadsheetfb_dpy_deferred_io,
};
static int broadsheetfb_probe(struct platform_device *dev)
diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index a79af3b5faf3..5faeca61d3dd 100644
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -41,7 +41,7 @@ static struct fb_deferred_io_pageref *fb_deferred_io_pageref_get(struct fb_info
struct page *page)
{
struct fb_deferred_io *fbdefio = info->fbdefio;
- struct list_head *pos = &fbdefio->pagelist;
+ struct list_head *pos = &fbdefio->pagereflist;
unsigned long pgoff = offset >> PAGE_SHIFT;
struct fb_deferred_io_pageref *pageref, *cur;
@@ -63,7 +63,7 @@ static struct fb_deferred_io_pageref *fb_deferred_io_pageref_get(struct fb_info
pageref->page = page;
pageref->offset = pgoff << PAGE_SHIFT;
- if (unlikely(fbdefio->sort_pagelist)) {
+ if (unlikely(fbdefio->sort_pagereflist)) {
/*
* We loop through the list of pagerefs before adding in
* order to keep the pagerefs sorted. This has significant
@@ -71,7 +71,7 @@ static struct fb_deferred_io_pageref *fb_deferred_io_pageref_get(struct fb_info
* pages. If possible, drivers should try to work with
* unsorted page lists instead.
*/
- list_for_each_entry(cur, &info->fbdefio->pagelist, list) {
+ list_for_each_entry(cur, &fbdefio->pagereflist, list) {
if (cur->offset > pageref->offset)
break;
}
@@ -163,7 +163,7 @@ static vm_fault_t fb_deferred_io_mkwrite(struct vm_fault *vmf)
mutex_lock(&fbdefio->lock);
/* first write in this cycle, notify the driver */
- if (fbdefio->first_io && list_empty(&fbdefio->pagelist))
+ if (fbdefio->first_io && list_empty(&fbdefio->pagereflist))
fbdefio->first_io(info);
pageref = fb_deferred_io_pageref_get(info, offset, page);
@@ -228,18 +228,18 @@ static void fb_deferred_io_work(struct work_struct *work)
/* here we mkclean the pages, then do all deferred IO */
mutex_lock(&fbdefio->lock);
- list_for_each_entry(pageref, &fbdefio->pagelist, list) {
+ list_for_each_entry(pageref, &fbdefio->pagereflist, list) {
struct page *cur = pageref->page;
lock_page(cur);
page_mkclean(cur);
unlock_page(cur);
}
- /* driver's callback with pagelist */
- fbdefio->deferred_io(info, &fbdefio->pagelist);
+ /* driver's callback with pagereflist */
+ fbdefio->deferred_io(info, &fbdefio->pagereflist);
/* clear the list */
- list_for_each_entry_safe(pageref, next, &fbdefio->pagelist, list)
+ list_for_each_entry_safe(pageref, next, &fbdefio->pagereflist, list)
fb_deferred_io_pageref_put(pageref, info);
mutex_unlock(&fbdefio->lock);
@@ -259,7 +259,7 @@ int fb_deferred_io_init(struct fb_info *info)
mutex_init(&fbdefio->lock);
INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
- INIT_LIST_HEAD(&fbdefio->pagelist);
+ INIT_LIST_HEAD(&fbdefio->pagereflist);
if (fbdefio->delay == 0) /* set a default of 1 s */
fbdefio->delay = HZ;
diff --git a/drivers/video/fbdev/hecubafb.c b/drivers/video/fbdev/hecubafb.c
index 00d77105161a..bd6b0dec414b 100644
--- a/drivers/video/fbdev/hecubafb.c
+++ b/drivers/video/fbdev/hecubafb.c
@@ -115,8 +115,7 @@ static void hecubafb_dpy_update(struct hecubafb_par *par)
}
/* this is called back from the deferred io workqueue */
-static void hecubafb_dpy_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+static void hecubafb_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
hecubafb_dpy_update(info->par);
}
diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
index 704ba7ee13c6..6a881cfd7f5c 100644
--- a/drivers/video/fbdev/hyperv_fb.c
+++ b/drivers/video/fbdev/hyperv_fb.c
@@ -420,8 +420,7 @@ static void hvfb_docopy(struct hvfb_par *par,
}
/* Deferred IO callback */
-static void synthvid_deferred_io(struct fb_info *p,
- struct list_head *pagelist)
+static void synthvid_deferred_io(struct fb_info *p, struct list_head *pagereflist)
{
struct hvfb_par *par = p->par;
struct fb_deferred_io_pageref *pageref;
@@ -437,7 +436,7 @@ static void synthvid_deferred_io(struct fb_info *p,
* in synthvid_update function by clamping the y2
* value to yres.
*/
- list_for_each_entry(pageref, pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
struct page *page = pageref->page;
start = page->index << PAGE_SHIFT;
end = start + PAGE_SIZE - 1;
diff --git a/drivers/video/fbdev/metronomefb.c b/drivers/video/fbdev/metronomefb.c
index 74672539ee7b..b8df0bb7cabc 100644
--- a/drivers/video/fbdev/metronomefb.c
+++ b/drivers/video/fbdev/metronomefb.c
@@ -465,16 +465,14 @@ static u16 metronomefb_dpy_update_page(struct metronomefb_par *par, int index)
}
/* this is called back from the deferred io workqueue */
-static void metronomefb_dpy_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+static void metronomefb_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
u16 cksum;
struct fb_deferred_io_pageref *pageref;
- struct fb_deferred_io *fbdefio = info->fbdefio;
struct metronomefb_par *par = info->par;
/* walk the written page list and swizzle the data */
- list_for_each_entry(pageref, &fbdefio->pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
struct page *cur = pageref->page;
cksum = metronomefb_dpy_update_page(par,
(cur->index << PAGE_SHIFT));
@@ -568,9 +566,9 @@ static const struct fb_ops metronomefb_ops = {
};
static struct fb_deferred_io metronomefb_defio = {
- .delay = HZ,
- .sort_pagelist = true,
- .deferred_io = metronomefb_dpy_deferred_io,
+ .delay = HZ,
+ .sort_pagereflist = true,
+ .deferred_io = metronomefb_dpy_deferred_io,
};
static int metronomefb_probe(struct platform_device *dev)
diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c b/drivers/video/fbdev/sh_mobile_lcdcfb.c
index b6b5ce3505c0..e33c016c5428 100644
--- a/drivers/video/fbdev/sh_mobile_lcdcfb.c
+++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c
@@ -435,8 +435,7 @@ static struct sh_mobile_lcdc_sys_bus_ops sh_mobile_lcdc_sys_bus_ops = {
.read_data = lcdc_sys_read_data,
};
-static int sh_mobile_lcdc_sginit(struct fb_info *info,
- struct list_head *pagelist)
+static int sh_mobile_lcdc_sginit(struct fb_info *info, struct list_head *pagereflist)
{
struct sh_mobile_lcdc_chan *ch = info->par;
unsigned int nr_pages_max = ch->fb_size >> PAGE_SHIFT;
@@ -445,7 +444,7 @@ static int sh_mobile_lcdc_sginit(struct fb_info *info,
sg_init_table(ch->sglist, nr_pages_max);
- list_for_each_entry(pageref, pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
struct page *page = pageref->page;
sg_set_page(&ch->sglist[nr_pages++], page, PAGE_SIZE, 0);
}
@@ -453,8 +452,7 @@ static int sh_mobile_lcdc_sginit(struct fb_info *info,
return nr_pages;
}
-static void sh_mobile_lcdc_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+static void sh_mobile_lcdc_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
struct sh_mobile_lcdc_chan *ch = info->par;
const struct sh_mobile_lcdc_panel_cfg *panel = &ch->cfg->panel_cfg;
@@ -463,7 +461,7 @@ static void sh_mobile_lcdc_deferred_io(struct fb_info *info,
sh_mobile_lcdc_clk_on(ch->lcdc);
/*
- * It's possible to get here without anything on the pagelist via
+ * It's possible to get here without anything on the pagereflist via
* sh_mobile_lcdc_deferred_io_touch() or via a userspace fsync()
* invocation. In the former case, the acceleration routines are
* stepped in to when using the framebuffer console causing the
@@ -473,12 +471,12 @@ static void sh_mobile_lcdc_deferred_io(struct fb_info *info,
* acceleration routines have their own methods for writing in
* that still need to be updated.
*
- * The fsync() and empty pagelist case could be optimized for,
+ * The fsync() and empty pagereflist case could be optimized for,
* but we don't bother, as any application exhibiting such
* behaviour is fundamentally broken anyways.
*/
- if (!list_empty(pagelist)) {
- unsigned int nr_pages = sh_mobile_lcdc_sginit(info, pagelist);
+ if (!list_empty(pagereflist)) {
+ unsigned int nr_pages = sh_mobile_lcdc_sginit(info, pagereflist);
/* trigger panel update */
dma_map_sg(ch->lcdc->dev, ch->sglist, nr_pages, DMA_TO_DEVICE);
diff --git a/drivers/video/fbdev/smscufx.c b/drivers/video/fbdev/smscufx.c
index bf3d151abd6f..14e4e106d26b 100644
--- a/drivers/video/fbdev/smscufx.c
+++ b/drivers/video/fbdev/smscufx.c
@@ -953,12 +953,10 @@ static void ufx_ops_fillrect(struct fb_info *info,
* Touching ANY framebuffer memory that triggers a page fault
* in fb_defio will cause a deadlock, when it also tries to
* grab the same mutex. */
-static void ufx_dpy_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+static void ufx_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
- struct fb_deferred_io_pageref *pageref;
- struct fb_deferred_io *fbdefio = info->fbdefio;
struct ufx_data *dev = info->par;
+ struct fb_deferred_io_pageref *pageref;
if (!fb_defio)
return;
@@ -967,7 +965,7 @@ static void ufx_dpy_deferred_io(struct fb_info *info,
return;
/* walk the written page list and render each to device */
- list_for_each_entry(pageref, &fbdefio->pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
/* create a rectangle of full screen width that encloses the
* entire dirty framebuffer page */
struct page *cur = pageref->page;
diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index 1e2f71c2f8a8..7acf7c0b263e 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -370,8 +370,7 @@ static const struct fb_ops ssd1307fb_ops = {
.fb_imageblit = ssd1307fb_imageblit,
};
-static void ssd1307fb_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+static void ssd1307fb_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
ssd1307fb_update_display(info->par);
}
diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c
index c187163fe580..12bd5a7318e1 100644
--- a/drivers/video/fbdev/udlfb.c
+++ b/drivers/video/fbdev/udlfb.c
@@ -780,11 +780,9 @@ static void dlfb_ops_fillrect(struct fb_info *info,
* in fb_defio will cause a deadlock, when it also tries to
* grab the same mutex.
*/
-static void dlfb_dpy_deferred_io(struct fb_info *info,
- struct list_head *pagelist)
+static void dlfb_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist)
{
struct fb_deferred_io_pageref *pageref;
- struct fb_deferred_io *fbdefio = info->fbdefio;
struct dlfb_data *dlfb = info->par;
struct urb *urb;
char *cmd;
@@ -810,7 +808,7 @@ static void dlfb_dpy_deferred_io(struct fb_info *info,
cmd = urb->transfer_buffer;
/* walk the written page list and render each to device */
- list_for_each_entry(pageref, &fbdefio->pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
struct page *cur = pageref->page;
if (dlfb_render_hline(dlfb, &urb, (char *) info->fix.smem_start,
@@ -983,7 +981,7 @@ static int dlfb_ops_open(struct fb_info *info, int user)
if (fbdefio) {
fbdefio->delay = DL_DEFIO_WRITE_DELAY;
- fbdefio->sort_pagelist = true;
+ fbdefio->sort_pagereflist = true;
fbdefio->deferred_io = dlfb_dpy_deferred_io;
}
diff --git a/drivers/video/fbdev/xen-fbfront.c b/drivers/video/fbdev/xen-fbfront.c
index 00d9502ee25a..37e3f226f78c 100644
--- a/drivers/video/fbdev/xen-fbfront.c
+++ b/drivers/video/fbdev/xen-fbfront.c
@@ -181,8 +181,7 @@ static void xenfb_refresh(struct xenfb_info *info,
xenfb_do_update(info, x1, y1, x2 - x1 + 1, y2 - y1 + 1);
}
-static void xenfb_deferred_io(struct fb_info *fb_info,
- struct list_head *pagelist)
+static void xenfb_deferred_io(struct fb_info *fb_info, struct list_head *pagereflist)
{
struct xenfb_info *info = fb_info->par;
struct fb_deferred_io_pageref *pageref;
@@ -191,7 +190,7 @@ static void xenfb_deferred_io(struct fb_info *fb_info,
miny = INT_MAX;
maxy = 0;
- list_for_each_entry(pageref, pagelist, list) {
+ list_for_each_entry(pageref, pagereflist, list) {
struct page *page = pageref->page;
beg = page->index << PAGE_SHIFT;
end = beg + PAGE_SIZE - 1;
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 3af4624368d8..329607ca65c0 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -229,8 +229,7 @@ void drm_fb_helper_fill_info(struct fb_info *info,
struct drm_fb_helper *fb_helper,
struct drm_fb_helper_surface_size *sizes);
-void drm_fb_helper_deferred_io(struct fb_info *info,
- struct list_head *pagelist);
+void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
size_t count, loff_t *ppos);
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 768de6534a82..b322d30f6225 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -211,9 +211,9 @@ struct fb_deferred_io_pageref {
struct fb_deferred_io {
/* delay between mkwrite and deferred handler */
unsigned long delay;
- bool sort_pagelist; /* sort pagelist by offset */
- struct mutex lock; /* mutex that protects the page list */
- struct list_head pagelist; /* list of touched pages */
+ bool sort_pagereflist; /* sort pagelist by offset */
+ struct mutex lock; /* mutex that protects the pageref list */
+ struct list_head pagereflist; /* list of pagerefs for touched pages */
/* callback */
void (*first_io)(struct fb_info *info);
void (*deferred_io)(struct fb_info *info, struct list_head *pagelist);
