Commit 1ecbc7dd authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

fbdev/deferred-io: Always call get_page() for framebuffer pages 



Unconditionally call get_page() after looking up a page from the
framebuffer memory. Guarantees that we always hold a reference.

This change also refactors the code such that it can support a
driver-supplied get_page helper. This will be useful for DRM's
fbdev emulation.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240419083331.7761-7-tzimmermann@suse.de
parent dcaefc82

drivers/video/fbdev/core/fb_defio.c

+5 −4
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ 
#include <linux/rmap.h>

#include <linux/pagemap.h>



static struct page *fb_deferred_io_page(struct fb_info *info, unsigned long offs)

static struct page *fb_deferred_io_get_page(struct fb_info *info, unsigned long offs)

{

	const void *screen_buffer = info->screen_buffer;

	struct page *page = NULL;
@@ -33,6 +33,9 @@ static struct page *fb_deferred_io_page(struct fb_info *info, unsigned long offs 
	else if (info->fix.smem_start)

		page = pfn_to_page((info->fix.smem_start + offs) >> PAGE_SHIFT);



	if (page)

		get_page(page);



	return page;

}
@@ -129,12 +132,10 @@ static vm_fault_t fb_deferred_io_fault(struct vm_fault *vmf) 
	if (offset >= info->fix.smem_len)

		return VM_FAULT_SIGBUS;



	page = fb_deferred_io_page(info, offset);

	page = fb_deferred_io_get_page(info, offset);

	if (!page)

		return VM_FAULT_SIGBUS;



	get_page(page);



	if (vmf->vma->vm_file)

		page->mapping = vmf->vma->vm_file->f_mapping;

	else