linux-kernel - [RFC PATCH 11/11] x86, fbdev: Cleanup PWT/PCD bit manipulation in fbdev

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Date:	Tue, 15 Jul 2014 13:34:44 -0600
From:	Toshi Kani <toshi.kani@...com>
To:	hpa@...or.com, tglx@...utronix.de, mingo@...hat.com,
	akpm@...ux-foundation.org, arnd@...db.de, konrad.wilk@...cle.com,
	plagnioj@...osoft.com, tomi.valkeinen@...com
Cc:	linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	stefan.bader@...onical.com, luto@...capital.net, airlied@...il.com,
	bp@...en8.de, Toshi Kani <toshi.kani@...com>
Subject: [RFC PATCH 11/11] x86, fbdev: Cleanup PWT/PCD bit manipulation in fbdev

This patch cleans up the PWT & PCD bit manipulation in fbdev,
and uses _PAGE_CACHE_<type> macros, instead.  This keeps the
fbdev code independent from the PAT slot assignment.

Signed-off-by: Toshi Kani <toshi.kani@...com>
---
 arch/x86/include/asm/fb.h                 |    3 ++-
 drivers/video/fbdev/gbefb.c               |    3 ++-
 drivers/video/fbdev/vermilion/vermilion.c |    4 ++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/fb.h b/arch/x86/include/asm/fb.h
index 2519d06..05fa937 100644
--- a/arch/x86/include/asm/fb.h
+++ b/arch/x86/include/asm/fb.h
@@ -9,7 +9,8 @@ static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
 				unsigned long off)
 {
 	if (boot_cpu_data.x86 > 3)
-		pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
+		vma->vm_page_prot = pgprot_set_cache(vma->vm_page_prot,
+						     _PAGE_CACHE_UC_MINUS);
 }
 
 extern int fb_is_primary_device(struct fb_info *info);
diff --git a/drivers/video/fbdev/gbefb.c b/drivers/video/fbdev/gbefb.c
index 4aa56ba..4af9ec7 100644
--- a/drivers/video/fbdev/gbefb.c
+++ b/drivers/video/fbdev/gbefb.c
@@ -54,7 +54,8 @@ struct gbefb_par {
 #endif
 #endif
 #ifdef CONFIG_X86
-#define pgprot_fb(_prot) ((_prot) | _PAGE_PCD)
+/* NOTE: use _PAGE_CACHE_WT if desired */
+#define pgprot_fb(_prot) (((_prot) & ~_PAGE_CACHE_MASK) | _PAGE_CACHE_UC_MINUS)
 #endif
 
 /*
diff --git a/drivers/video/fbdev/vermilion/vermilion.c b/drivers/video/fbdev/vermilion/vermilion.c
index 048a666..6a7c744 100644
--- a/drivers/video/fbdev/vermilion/vermilion.c
+++ b/drivers/video/fbdev/vermilion/vermilion.c
@@ -1009,8 +1009,8 @@ static int vmlfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 	if (ret)
 		return -EINVAL;
 
-	pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
-	pgprot_val(vma->vm_page_prot) &= ~_PAGE_PWT;
+	vma->vm_page_prot = pgprot_set_cache(vma->vm_page_prot,
+					     _PAGE_CACHE_UC_MINUS);
 
 	return vm_iomap_memory(vma, vinfo->vram_start,
 			vinfo->vram_contig_size);
--
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