Commit e5e0a65c authored Mar 28, 2016 by Alexey Brodkin Committed by Vineet Gupta Apr 07, 2016

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>

parent 732dc97b

arch/arc/include/asm/fb.h

0 → 100644

+19 −0

Original line number	Diff line number	Diff line
		#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_ */

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