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 63883a892120e125be75db301e1c49322c1c7a71..74832837025032dcd0f4ee21a665b3a59612b701 100644 (file)
--- a/Documentation/fb/deferred_io.txt
+++ b/Documentation/fb/deferred_io.txt
@@ -7,10 +7,10 @@ IO. The following example may be a useful explanation of how one such setup
 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 a0c5d9d90d741499e5cdb6087d138337c494b3e9..0f8cfb988c901a7f45314387149a759d8b252929 100644 (file)
--- 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 @@ static struct page* fb_deferred_io_nopage(struct vm_area_struct *vma,
        /* 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 int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
 }
 
 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,
 };