[PATCH v2 4/4] fbdev: defio: Move pageref array to struct fb_deferred_io_state

[Thomas Zimmermann <tzimmermann@suse.de>]

The pageref array stores all pageref structures for a device's defio
helpers. Move it into struct fb_deferred_io_state to not expose it to
drivers.

v2:
- use kvzalloc_objs()

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/fbdev/core/fb_defio.c | 55 ++++++++++++++---------------
 include/linux/fb.h                  |  2 --
 2 files changed, 27 insertions(+), 30 deletions(-)

diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index 35ac13727da1..a12dd25ab697 100644
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -41,28 +41,46 @@ struct fb_deferred_io_state {
 	/* fields protected by lock */
 	struct fb_info *info;
 	struct list_head pagereflist; /* list of pagerefs for touched pages */
+	unsigned long npagerefs;
+	struct fb_deferred_io_pageref *pagerefs;
 };
 
-static struct fb_deferred_io_state *fb_deferred_io_state_alloc(void)
+static struct fb_deferred_io_state *fb_deferred_io_state_alloc(unsigned long len)
 {
 	struct fb_deferred_io_state *fbdefio_state;
+	struct fb_deferred_io_pageref *pagerefs;
+	unsigned long npagerefs;
 
 	fbdefio_state = kzalloc_obj(*fbdefio_state);
 	if (!fbdefio_state)
 		return NULL;
 
+	npagerefs = DIV_ROUND_UP(len, PAGE_SIZE);
+
+	/* alloc a page ref for each page of the display memory */
+	pagerefs = kvzalloc_objs(*pagerefs, npagerefs);
+	if (!pagerefs)
+		goto err_kfree;
+	fbdefio_state->npagerefs = npagerefs;
+	fbdefio_state->pagerefs = pagerefs;
+
 	kref_init(&fbdefio_state->ref);
 	mutex_init(&fbdefio_state->lock);
 
 	INIT_LIST_HEAD(&fbdefio_state->pagereflist);
 
 	return fbdefio_state;
+
+err_kfree:
+	kfree(fbdefio_state);
+	return NULL;
 }
 
 static void fb_deferred_io_state_release(struct fb_deferred_io_state *fbdefio_state)
 {
 	WARN_ON(!list_empty(&fbdefio_state->pagereflist));
 	mutex_destroy(&fbdefio_state->lock);
+	kvfree(fbdefio_state->pagerefs);
 
 	kfree(fbdefio_state);
 }
@@ -125,18 +143,19 @@ static struct page *fb_deferred_io_get_page(struct fb_info *info, unsigned long
 	return page;
 }
 
-static struct fb_deferred_io_pageref *fb_deferred_io_pageref_lookup(struct fb_info *info,
-								    unsigned long offset,
-								    struct page *page)
+static struct fb_deferred_io_pageref *
+fb_deferred_io_pageref_lookup(struct fb_deferred_io_state *fbdefio_state, unsigned long offset,
+			      struct page *page)
 {
+	struct fb_info *info = fbdefio_state->info;
 	unsigned long pgoff = offset >> PAGE_SHIFT;
 	struct fb_deferred_io_pageref *pageref;
 
-	if (fb_WARN_ON_ONCE(info, pgoff >= info->npagerefs))
+	if (fb_WARN_ON_ONCE(info, pgoff >= fbdefio_state->npagerefs))
 		return NULL; /* incorrect allocation size */
 
 	/* 1:1 mapping between pageref and page offset */
-	pageref = &info->pagerefs[pgoff];
+	pageref = &fbdefio_state->pagerefs[pgoff];
 
 	if (pageref->page)
 		goto out;
@@ -160,7 +179,7 @@ static struct fb_deferred_io_pageref *fb_deferred_io_pageref_get(struct fb_info
 	struct list_head *pos = &fbdefio_state->pagereflist;
 	struct fb_deferred_io_pageref *pageref, *cur;
 
-	pageref = fb_deferred_io_pageref_lookup(info, offset, page);
+	pageref = fb_deferred_io_pageref_lookup(fbdefio_state, offset, page);
 	if (!pageref)
 		return NULL;
 
@@ -397,16 +416,13 @@ int fb_deferred_io_init(struct fb_info *info)
 {
 	struct fb_deferred_io *fbdefio = info->fbdefio;
 	struct fb_deferred_io_state *fbdefio_state;
-	struct fb_deferred_io_pageref *pagerefs;
-	unsigned long npagerefs;
-	int ret;
 
 	BUG_ON(!fbdefio);
 
 	if (WARN_ON(!info->fix.smem_len))
 		return -EINVAL;
 
-	fbdefio_state = fb_deferred_io_state_alloc();
+	fbdefio_state = fb_deferred_io_state_alloc(info->fix.smem_len);
 	if (!fbdefio_state)
 		return -ENOMEM;
 	fbdefio_state->info = info;
@@ -415,24 +431,9 @@ int fb_deferred_io_init(struct fb_info *info)
 	if (fbdefio->delay == 0) /* set a default of 1 s */
 		fbdefio->delay = HZ;
 
-	npagerefs = DIV_ROUND_UP(info->fix.smem_len, PAGE_SIZE);
-
-	/* alloc a page ref for each page of the display memory */
-	pagerefs = kvzalloc_objs(*pagerefs, npagerefs);
-	if (!pagerefs) {
-		ret = -ENOMEM;
-		goto err;
-	}
-	info->npagerefs = npagerefs;
-	info->pagerefs = pagerefs;
-
 	info->fbdefio_state = fbdefio_state;
 
 	return 0;
-
-err:
-	fb_deferred_io_state_release(fbdefio_state);
-	return ret;
 }
 EXPORT_SYMBOL_GPL(fb_deferred_io_init);
 
@@ -475,7 +476,5 @@ void fb_deferred_io_cleanup(struct fb_info *info)
 	mutex_unlock(&fbdefio_state->lock);
 
 	fb_deferred_io_state_put(fbdefio_state);
-
-	kvfree(info->pagerefs);
 }
 EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 2791777f3a50..b27943719fab 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -482,8 +482,6 @@ struct fb_info {
 
 #ifdef CONFIG_FB_DEFERRED_IO
 	struct delayed_work deferred_work;
-	unsigned long npagerefs;
-	struct fb_deferred_io_pageref *pagerefs;
 	struct fb_deferred_io *fbdefio;
 	struct fb_deferred_io_state *fbdefio_state;
 #endif
-- 
2.52.0