Hi Thomas,
On Thu, Apr 6, 2023 at 4:30 PM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
Generic implementations of fb_pgprotect() and fb_is_primary_device()
have been in the source code for a long time. Prepare the header file
to make use of them.
Improve the code by using an inline function for fb_pgprotect()
and by removing include statements. The default mode set by
fb_pgprotect() is now writecombine, which is what most platforms
want.
Symbols are protected by preprocessor guards. Architectures that
provide a symbol need to define a preprocessor token of the same
name and value. Otherwise the header file will provide a generic
implementation. This pattern has been taken from <asm/io.h>.
v2:
* use writecombine mappings by default (Arnd)
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Thanks for your patch!
--- a/include/asm-generic/fb.h
+++ b/include/asm-generic/fb.h
@@ -1,13 +1,32 @@
/* SPDX-License-Identifier: GPL-2.0 */
+
#ifndef __ASM_GENERIC_FB_H_
#define __ASM_GENERIC_FB_H_
-#include <linux/fb.h>
-#define fb_pgprotect(...) do {} while (0)
+/*
+ * Only include this header file from your architecture's <asm/fb.h>.
+ */
+
+#include <asm/page.h>
+
+struct fb_info;
+struct file;
+
+#ifndef fb_pgprotect
+#define fb_pgprotect fb_pgprotect
+static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
+ unsigned long off)
Does this affect any noMMU platforms that relied on fb_pgprotect()
doing nothing before?
Perhaps the body below should be protected by "#ifdef CONFIG_MMU"?
+{
+ vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
Shouldn't this use the pgprot_val() wrapper?
+}
+#endif
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
