fb: defio nopage
Convert fb defio from nopage to fault.
Switch from OOM to SIGBUS if the resource is not available.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/fb/deferred_io.txt b/Documentation/fb/deferred_io.txt
index 63883a8..7483283 100644
--- a/Documentation/fb/deferred_io.txt
+++ b/Documentation/fb/deferred_io.txt
@@ -7,10 +7,10 @@
works:
- userspace app like Xfbdev mmaps framebuffer
-- deferred IO and driver sets up nopage and page_mkwrite handlers
+- deferred IO and driver sets up fault and page_mkwrite handlers
- userspace app tries to write to mmaped vaddress
-- we get pagefault and reach nopage handler
-- nopage handler finds and returns physical page
+- we get pagefault and reach fault handler
+- fault handler finds and returns physical page
- we get page_mkwrite where we add this page to a list
- schedule a workqueue task to be run after a delay
- app continues writing to that page with no additional cost. this is
diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c
index a0c5d9d..0f8cfb9 100644
--- a/drivers/video/fb_defio.c
+++ b/drivers/video/fb_defio.c
@@ -25,8 +25,8 @@
#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)
+static int fb_deferred_io_fault(struct vm_area_struct *vma,
+ struct vm_fault *vmf)
{
unsigned long offset;
struct page *page;
@@ -34,18 +34,17 @@
/* 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);
+ offset = vmf->pgoff << PAGE_SHIFT;
if (offset >= info->fix.smem_len)
- return NOPAGE_SIGBUS;
+ return VM_FAULT_SIGBUS;
page = vmalloc_to_page(screen_base + offset);
if (!page)
- return NOPAGE_OOM;
+ return VM_FAULT_SIGBUS;
get_page(page);
- if (type)
- *type = VM_FAULT_MINOR;
- return page;
+ vmf->page = page;
+ return 0;
}
int fb_deferred_io_fsync(struct file *file, struct dentry *dentry, int datasync)
@@ -84,7 +83,7 @@
}
static struct vm_operations_struct fb_deferred_io_vm_ops = {
- .nopage = fb_deferred_io_nopage,
+ .fault = fb_deferred_io_fault,
.page_mkwrite = fb_deferred_io_mkwrite,
};