kernel-fxtec-pro1x/arch/arc/include/asm/fb.h
Alexey Brodkin e5e0a65cd2 arc: Add our own implementation of fb_pgprotect()
During mmaping of frame-buffer pages to user-space
fb_protect() is called to set proper page settings.

In case of ARC we need to mark pages that are mmaped to
user as uncached because of 2 reasons:
 * Huge amount of data if passing through data cache will
   thrash cache a lot making cache almost useless for other
   less traffic hungry processes.
 * Data written by user in FB will be immediately available for
   hardware (such as PGU etc) without requirements to flush data
   cache regularly.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-04-07 14:59:09 +05:30

19 lines
372 B
C

#ifndef _ASM_FB_H_
#define _ASM_FB_H_
#include <linux/fb.h>
#include <linux/fs.h>
#include <asm/page.h>
static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
unsigned long off)
{
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
}
static inline int fb_is_primary_device(struct fb_info *info)
{
return 0;
}
#endif /* _ASM_FB_H_ */