Apr 22 2015

video: fbdev: matrox: use arch_phys_wc_add() and ioremap_wc() 

Author: Luis R. Rodriguez <mcgrof@suse.com>

This driver uses the same ioremap()'d area for the MTRR.
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, in order to
take advantage of that also ensure the ioremap'd area is requested
as write-combining.

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
   pci_mmap_page_range()")

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);
+arch_phys_wc_del(index);

@ mtrr_rm_zero_arg depends on mtrr_found @
expression mtrr_found.index;
@@

-mtrr_del(index, 0, 0);
+arch_phys_wc_del(index);

@ 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);
+arch_phys_wc_del(index);

@ 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: Jean-Christophe Plagniol-Villard 
Cc: Tomi Valkeinen 
Cc: Rob Clark 
Cc: Daniel Vetter 
Cc: Geert Uytterhoeven 
Cc: Julia Lawall 
Cc: Mikulas Patocka 
Cc: Suresh Siddha 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Andy Lutomirski 
Cc: Dave Airlie 
Cc: Antonino Daplas 
Cc: linux-fbdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez 
Reviewed-by: Dave Airlie 
Signed-off-by: Tomi Valkeinen 

---
 drivers/video/fbdev/matrox/matroxfb_base.c | 36 +++++++++++-------------------
 drivers/video/fbdev/matrox/matroxfb_base.h | 27 +---------------------
 2 files changed, 14 insertions(+), 49 deletions(-)
 
diff --git a/drivers/video/fbdev/matrox/matroxfb_base.c b/drivers/video/fbdev/matrox/matroxfb_base.c
index 2ba4e54..11eb094 100644
--- a/drivers/video/fbdev/matrox/matroxfb_base.c
+++ b/drivers/video/fbdev/matrox/matroxfb_base.c
@@ -370,12 +370,9 @@ static void matroxfb_remove(struct matrox_fb_info *minfo, int dummy)
 	matroxfb_unregister_device(minfo);
 	unregister_framebuffer(&minfo->fbcon);
 	matroxfb_g450_shutdown(minfo);
-#ifdef CONFIG_MTRR
-	if (minfo->mtrr.vram_valid)
-		mtrr_del(minfo->mtrr.vram, minfo->video.base, minfo->video.len);
-#endif
-	mga_iounmap(minfo->mmio.vbase);
-	mga_iounmap(minfo->video.vbase);
+	arch_phys_wc_del(minfo->wc_cookie);
+	iounmap(minfo->mmio.vbase.vaddr);
+	iounmap(minfo->video.vbase.vaddr);
 	release_mem_region(minfo->video.base, minfo->video.len_maximum);
 	release_mem_region(minfo->mmio.base, 16384);
 	kfree(minfo);
@@ -1252,9 +1249,7 @@ static int nobios;			/* "matroxfb:nobios" */
 static int noinit = 1;			/* "matroxfb:init" */
 static int inverse;			/* "matroxfb:inverse" */
 static int sgram;			/* "matroxfb:sgram" */
-#ifdef CONFIG_MTRR
 static int mtrr = 1;			/* "matroxfb:nomtrr" */
-#endif
 static int grayscale;			/* "matroxfb:grayscale" */
 static int dev = -1;			/* "matroxfb:dev:xxxxx" */
 static unsigned int vesa = ~0;		/* "matroxfb:vesa:xxxxx" */
@@ -1713,14 +1708,17 @@ static int initMatrox2(struct matrox_fb_info *minfo, struct board *b)
 	if (mem && (mem < memsize))
 		memsize = mem;
 	err = -ENOMEM;
-	if (mga_ioremap(ctrlptr_phys, 16384, MGA_IOREMAP_MMIO, &minfo->mmio.vbase)) {
+
+	minfo->mmio.vbase.vaddr = ioremap_nocache(ctrlptr_phys, 16384);
+	if (!minfo->mmio.vbase.vaddr) {
 		printk(KERN_ERR "matroxfb: cannot ioremap(%lX, 16384), matroxfb disabled\n", ctrlptr_phys);
 		goto failVideoMR;
 	}
 	minfo->mmio.base = ctrlptr_phys;
 	minfo->mmio.len = 16384;
 	minfo->video.base = video_base_phys;
-	if (mga_ioremap(video_base_phys, memsize, MGA_IOREMAP_FB, &minfo->video.vbase)) {
+	minfo->video.vbase.vaddr = ioremap_wc(video_base_phys, memsize);
+	if (!minfo->video.vbase.vaddr) {
 		printk(KERN_ERR "matroxfb: cannot ioremap(%lX, %d), matroxfb disabled\n",
 			video_base_phys, memsize);
 		goto failCtrlIO;
@@ -1768,13 +1766,9 @@ static int initMatrox2(struct matrox_fb_info *minfo, struct board *b)
 	minfo->video.len_usable = minfo->video.len;
 	if (minfo->video.len_usable > b->base->maxdisplayable)
 		minfo->video.len_usable = b->base->maxdisplayable;
-#ifdef CONFIG_MTRR
-	if (mtrr) {
-		minfo->mtrr.vram = mtrr_add(video_base_phys, minfo->video.len, MTRR_TYPE_WRCOMB, 1);
-		minfo->mtrr.vram_valid = 1;
-		printk(KERN_INFO "matroxfb: MTRR's turned on\n");
-	}
-#endif	/* CONFIG_MTRR */
+	if (mtrr)
+		minfo->wc_cookie = arch_phys_wc_add(video_base_phys,
+						    minfo->video.len);
 
 	if (!minfo->devflags.novga)
 		request_region(0x3C0, 32, "matrox");
@@ -1943,9 +1937,9 @@ static int initMatrox2(struct matrox_fb_info *minfo, struct board *b)
 	return 0;
 failVideoIO:;
 	matroxfb_g450_shutdown(minfo);
-	mga_iounmap(minfo->video.vbase);
+	iounmap(minfo->video.vbase.vaddr);
 failCtrlIO:;
-	mga_iounmap(minfo->mmio.vbase);
+	iounmap(minfo->mmio.vbase.vaddr);
 failVideoMR:;
 	release_mem_region(video_base_phys, minfo->video.len_maximum);
 failCtrlMR:;
@@ -2439,10 +2433,8 @@ static int __init matroxfb_setup(char *options) {
 				nobios = !value;
 			else if (!strcmp(this_opt, "init"))
 				noinit = !value;
-#ifdef CONFIG_MTRR
 			else if (!strcmp(this_opt, "mtrr"))
 				mtrr = value;
-#endif
 			else if (!strcmp(this_opt, "inv24"))
 				inv24 = value;
 			else if (!strcmp(this_opt, "cross4MB"))
@@ -2511,10 +2503,8 @@ module_param(noinit, int, 0);
 MODULE_PARM_DESC(noinit, "Disables W/SG/SD-RAM and bus interface initialization (0 or 1=do not initialize) (default=0)");
 module_param(memtype, int, 0);
 MODULE_PARM_DESC(memtype, "Memory type for G200/G400 (see Documentation/fb/matroxfb.txt for explanation) (default=3 for G200, 0 for G400)");
-#ifdef CONFIG_MTRR
 module_param(mtrr, int, 0);
 MODULE_PARM_DESC(mtrr, "This speeds up video memory accesses (0=disabled or 1) (default=1)");
-#endif
 module_param(sgram, int, 0);
 MODULE_PARM_DESC(sgram, "Indicates that G100/G200/G400 has SGRAM memory (0=SDRAM, 1=SGRAM) (default=0)");
 module_param(inv24, int, 0);
diff --git a/drivers/video/fbdev/matrox/matroxfb_base.h b/drivers/video/fbdev/matrox/matroxfb_base.h
index 89a8a89a..09b02cd 100644
--- a/drivers/video/fbdev/matrox/matroxfb_base.h
+++ b/drivers/video/fbdev/matrox/matroxfb_base.h
@@ -44,9 +44,6 @@
 
 #include <asm/io.h>
 #include <asm/unaligned.h>
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
 
 #if defined(CONFIG_PPC_PMAC)
 #include <asm/prom.h>
@@ -187,23 +184,6 @@ static inline void __iomem* vaddr_va(vaddr_t va) {
 	return va.vaddr;
 }
 
-#define MGA_IOREMAP_NORMAL	0
-#define MGA_IOREMAP_NOCACHE	1
-
-#define MGA_IOREMAP_FB		MGA_IOREMAP_NOCACHE
-#define MGA_IOREMAP_MMIO	MGA_IOREMAP_NOCACHE
-static inline int mga_ioremap(unsigned long phys, unsigned long size, int flags, vaddr_t* virt) {
-	if (flags & MGA_IOREMAP_NOCACHE)
-		virt->vaddr = ioremap_nocache(phys, size);
-	else
-		virt->vaddr = ioremap(phys, size);
-	return (virt->vaddr == NULL); /* 0, !0... 0, error_code in future */
-}
-
-static inline void mga_iounmap(vaddr_t va) {
-	iounmap(va.vaddr);
-}
-
 struct my_timming {
 	unsigned int pixclock;
 	int mnp;
@@ -449,12 +429,7 @@ struct matrox_fb_info {
 		int		plnwt;
 		int		srcorg;
 			      } capable;
-#ifdef CONFIG_MTRR
-	struct {
-		int		vram;
-		int		vram_valid;
-			      } mtrr;
-#endif
+	int			wc_cookie;
 	struct {
 		int		precise_width;
 		int		mga_24bpp_fix;

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