video: fbdev: vesafb: use arch_phys_wc_add()

Author: Luis R. Rodriguez <>

This driver uses the same area for MTRR as for the ioremap_wc(), if
anything it just uses a smaller size in case MTRR reservation fails.
ioremap_wc() API is already used to take advantage of architecture
write-combining when available.

Convert the driver from using the x86 specific MTRR code to
the architecture agnostic arch_phys_wc_add(). arch_phys_wc_add()
will avoid MTRR if write-combining is available.

There are a few motivations for this:

a) Take advantage of PAT when available

b) Help bury MTRR code away, MTRR is architecture specific and on
   x86 its replaced by PAT

c) Help with the goal of eventually using _PAGE_CACHE_UC over
   _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit
   de33c442e titled "x86 PAT: fix performance drop for glx,
   use UC minus for ioremap(), ioremap_nocache() and

The conversion done is expressed by the following Coccinelle
SmPL patch, it additionally required manual intervention to
address all the #ifdery and removal of redundant things which
arch_phys_wc_add() already addresses such as verbose message
about when MTRR fails and doing nothing when we didn't get
an MTRR.

@ mtrr_found @
expression index, base, size;

-index = mtrr_add(base, size, MTRR_TYPE_WRCOMB, 1);
+index = arch_phys_wc_add(base, size);

@ mtrr_rm depends on mtrr_found @
expression mtrr_found.index, mtrr_found.base, mtrr_found.size;

-mtrr_del(index, base, size);

@ mtrr_rm_zero_arg depends on mtrr_found @
expression mtrr_found.index;

-mtrr_del(index, 0, 0);

@ mtrr_rm_fb_info depends on mtrr_found @
struct fb_info *info;
expression mtrr_found.index;

-mtrr_del(index, info->fix.smem_start, info->fix.smem_len);

@ ioremap_replace_nocache depends on mtrr_found @
struct fb_info *info;
expression base, size;

-info->screen_base = ioremap_nocache(base, size);
+info->screen_base = ioremap_wc(base, size);

@ ioremap_replace_default depends on mtrr_found @
struct fb_info *info;
expression base, size;

-info->screen_base = ioremap(base, size);
+info->screen_base = ioremap_wc(base, size);

Generated-by: Coccinelle SmPL
Cc: Toshi Kani 
Cc: Suresh Siddha 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Daniel Vetter 
Cc: Andy Lutomirski 
Cc: Dave Airlie 
Cc: Antonino Daplas 
Cc: Jean-Christophe Plagniol-Villard 
Cc: Rob Clark 
Cc: Jingoo Han 
Cc: Wolfram Sang 
Cc: Tomi Valkeinen 
Signed-off-by: Luis R. Rodriguez 
Signed-off-by: Tomi Valkeinen 
 drivers/video/fbdev/vesafb.c | 29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)
diff --git a/drivers/video/fbdev/vesafb.c b/drivers/video/fbdev/vesafb.c
index 3db3908..528fe91 100644
--- a/drivers/video/fbdev/vesafb.c
+++ b/drivers/video/fbdev/vesafb.c
@@ -19,10 +19,9 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/screen_info.h>
+#include <linux/io.h>
 #include <video/vga.h>
-#include <asm/io.h>
-#include <asm/mtrr.h>
 #define dac_reg	(0x3c8)
 #define dac_val	(0x3c9)
@@ -180,16 +179,10 @@ static int vesafb_setcolreg(unsigned regno, unsigned red, unsigned green,
 static void vesafb_destroy(struct fb_info *info)
 	struct vesafb_par *par = info->par;
-	if (par->wc_cookie >= 0)
-		mtrr_del(par->wc_cookie, 0, 0);
+	arch_phys_wc_del(par->wc_cookie);
 	if (info->screen_base)
 	release_mem_region(info->apertures->ranges[0].base, info->apertures->ranges[0].size);
@@ -420,7 +413,6 @@ static int vesafb_probe(struct platform_device *dev)
 	request_region(0x3c0, 32, "vesafb");
 	if (mtrr == 3) {
 		unsigned int temp_size = size_total;
 		/* Find the largest power-of-two */
@@ -428,18 +420,16 @@ static int vesafb_probe(struct platform_device *dev)
 		/* Try and find a power of two to add */
 		do {
-			par->wc_cookie = mtrr_add(vesafb_fix.smem_start,
-						  temp_size,
-						  MTRR_TYPE_WRCOMB, 1);
+			par->wc_cookie =
+				arch_phys_wc_add(vesafb_fix.smem_start,
+						 temp_size);
 			temp_size >>= 1;
-		} while (temp_size >= PAGE_SIZE && par->wc_cookie == -EINVAL);
+		} while (temp_size >= PAGE_SIZE && par->wc_cookie < 0);
 		info->screen_base = ioremap_wc(vesafb_fix.smem_start, vesafb_fix.smem_len);
 	} else {
 		if (mtrr && mtrr != 3)
 			WARN_ONCE(1, "Only MTRR_TYPE_WRCOMB (3) make sense\n");
 		info->screen_base = ioremap(vesafb_fix.smem_start, vesafb_fix.smem_len);
@@ -477,10 +467,7 @@ static int vesafb_probe(struct platform_device *dev)
 	fb_info(info, "%s frame buffer device\n", info->;
 	return 0;
-	if (par->wc_cookie >= 0)
-		mtrr_del(par->wc_cookie, 0, 0);
+	arch_phys_wc_del(par->wc_cookie);
 	if (info->screen_base)