From: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Date: Mon, 28 Mar 2016 11:36:38 +0000 (+0300)
Subject: arc: Add our own implementation of fb_pgprotect()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e5e0a65cd20a7a892a87e6bd73bdc3d83726d725;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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>
---

diff --git a/arch/arc/include/asm/fb.h b/arch/arc/include/asm/fb.h
new file mode 100644
index 000000000000..bd3f68c9ddfc
--- /dev/null
+++ b/arch/arc/include/asm/fb.h
@@ -0,0 +1,19 @@
+#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_ */