From patchwork Thu May  9 19:46:26 2013
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
X-Patchwork-Submitter: Andy Lutomirski <luto@amacapital.net>
X-Patchwork-Id: 2545491
Return-Path: <linux-fbdev-owner@vger.kernel.org>
X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org
Delivered-To: patchwork-process-083081@patchwork2.kernel.org
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by patchwork2.kernel.org (Postfix) with ESMTP id D9005DF24C
	for <patchwork-linux-fbdev@patchwork.kernel.org>;
	Thu,  9 May 2013 19:48:14 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753562Ab3EITrI (ORCPT
	<rfc822;patchwork-linux-fbdev@patchwork.kernel.org>);
	Thu, 9 May 2013 15:47:08 -0400
Received: from mail-pa0-f52.google.com ([209.85.220.52]:64478 "EHLO
	mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752982Ab3EITrG (ORCPT
	<rfc822; linux-fbdev@vger.kernel.org>); Thu, 9 May 2013 15:47:06 -0400
Received: by mail-pa0-f52.google.com with SMTP id bg2so2363785pad.39
	for <linux-fbdev@vger.kernel.org>;
	Thu, 09 May 2013 12:47:05 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
	d=google.com; s=20120113;
	h=x-received:from:to:cc:subject:date:message-id:x-mailer:in-reply-to
	:references:in-reply-to:references:x-gm-message-state;
	bh=P+WiS7Kh9+j5XpxoaTF7a0zes56OGCzmbx0ws3c8RZY=;
	b=FfEShE3XjJx9uTGjzwjMU+WvUQAeWlmUJEIzcZ2J1CkBEccLLUWcraW6hbKFtyc223
	mZNmfWSs+Ad5/PQCKo3+D88Opd3XDOWVdOxLlyU3gAIKVV3OOtEY4S7bvGhJo5NrPOC1
	3dPbxd9zsblvaEpf4DqlHEumJaAMLJ5+Fu6FWQ7+vtBvUN9i9lez1GP3VS02qwXsAuxn
	ymtPdbd2lZ9cpey+fTohYS0HCMa+jotJlz6WHexP2O043WR8mf8haFrV0tdMIZVJWsMr
	xI0zDfsGLZBPPfFCOo3+F3K1vEDrYluHRQUmarFgAwF78oBmsgjQMPrYIAscI4W4v3C2
	8SYA==
X-Received: by 10.66.122.97 with SMTP id lr1mr14365414pab.147.1368128825565;
	Thu, 09 May 2013 12:47:05 -0700 (PDT)
Received: from localhost (50-76-60-73-ip-static.hfc.comcastbusiness.net.
	[50.76.60.73]) by mx.google.com with ESMTPSA id
	aj2sm4126693pbc.1.2013.05.09.12.47.04 for <multiple recipients>
	(version=TLSv1.2 cipher=RC4-SHA bits=128/128);
	Thu, 09 May 2013 12:47:04 -0700 (PDT)
From: Andy Lutomirski <luto@amacapital.net>
To: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linux-fbdev@vger.kernel.org
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
	Jerome Glisse <j.glisse@gmail.com>, Alex Deucher <alexdeucher@gmail.com>,
	Dave Airlie <airlied@gmail.com>, Andy Lutomirski <luto@amacapital.net>,
	Michal Januszewski <spock@gentoo.org>
Subject: [RFC/PATCH v2 7/8] uvesafb: Clean up MTRR code
Date: Thu,  9 May 2013 12:46:26 -0700
Message-Id: 
 <9b38320eba51f38d4d646438399313f7932d3a04.1368128020.git.luto@amacapital.net>
X-Mailer: git-send-email 1.8.1.4
In-Reply-To: <cover.1368128020.git.luto@amacapital.net>
References: <cover.1368128020.git.luto@amacapital.net>
In-Reply-To: <cover.1368128020.git.luto@amacapital.net>
References: <cover.1368128020.git.luto@amacapital.net>
X-Gm-Message-State: 
 ALoCoQkgnO6zW/e0/YUx/P8pVCa6hyNG+9Vhn19oEFgi1US20Hxp23nCdW8YhywaLqk7nIXD0YuY
Sender: linux-fbdev-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-fbdev.vger.kernel.org>
X-Mailing-List: linux-fbdev@vger.kernel.org

The old code allowed very strange memory types.  Now it works like
all the other video drivers: ioremap_wc is used unconditionally,
and MTRRs are set if PAT is unavailable (unless MTRR is disabled
by a module parameter).

UC, WB, and WT support is gone.  If there are MTRR conflicts that prevent
addition of a WC MTRR, adding a non-conflicting MTRR is pointless; it's
better to just turn off MTRR support entirely.

As an added bonus, any MTRR added is freed on unload.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
 Documentation/fb/uvesafb.txt | 16 ++++------
 drivers/video/uvesafb.c      | 70 +++++++++++---------------------------------
 include/video/uvesafb.h      |  1 +
 3 files changed, 23 insertions(+), 64 deletions(-)

diff --git a/Documentation/fb/uvesafb.txt b/Documentation/fb/uvesafb.txt
index eefdd91..f6362d8 100644
--- a/Documentation/fb/uvesafb.txt
+++ b/Documentation/fb/uvesafb.txt
@@ -81,17 +81,11 @@ pmipal  Use the protected mode interface for palette changes.
 
 mtrr:n  Setup memory type range registers for the framebuffer
         where n:
-              0 - disabled (equivalent to nomtrr) (default)
-              1 - uncachable
-              2 - write-back
-              3 - write-combining
-              4 - write-through
-
-        If you see the following in dmesg, choose the type that matches
-        the old one.  In this example, use "mtrr:2".
-...
-mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining
-...
+              0 - disabled (equivalent to nomtrr)
+              3 - write-combining (default)
+
+	Values other than 0 and 3 will result in a warning and will be
+	treated just like 3.
 
 nomtrr  Do not use memory type range registers.
 
diff --git a/drivers/video/uvesafb.c b/drivers/video/uvesafb.c
index d428445..8701f96 100644
--- a/drivers/video/uvesafb.c
+++ b/drivers/video/uvesafb.c
@@ -24,9 +24,6 @@
 #ifdef CONFIG_X86
 #include <video/vga.h>
 #endif
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
 #include "edid.h"
 
 static struct cb_id uvesafb_cn_id = {
@@ -1540,67 +1537,30 @@ static void uvesafb_init_info(struct fb_info *info, struct vbe_mode_ib *mode)
 
 static void uvesafb_init_mtrr(struct fb_info *info)
 {
-#ifdef CONFIG_MTRR
+	struct uvesafb_par *par = info->par;
+
 	if (mtrr && !(info->fix.smem_start & (PAGE_SIZE - 1))) {
 		int temp_size = info->fix.smem_len;
-		unsigned int type = 0;
 
-		switch (mtrr) {
-		case 1:
-			type = MTRR_TYPE_UNCACHABLE;
-			break;
-		case 2:
-			type = MTRR_TYPE_WRBACK;
-			break;
-		case 3:
-			type = MTRR_TYPE_WRCOMB;
-			break;
-		case 4:
-			type = MTRR_TYPE_WRTHROUGH;
-			break;
-		default:
-			type = 0;
-			break;
-		}
+		int rc;
 
-		if (type) {
-			int rc;
+		/* Find the largest power-of-two */
+		temp_size = roundup_pow_of_two(temp_size);
 
-			/* Find the largest power-of-two */
-			temp_size = roundup_pow_of_two(temp_size);
+		/* Try and find a power of two to add */
+		do {
+			rc = arch_phys_wc_add(info->fix.smem_start, temp_size);
+			temp_size >>= 1;
+		} while (temp_size >= PAGE_SIZE && rc == -EINVAL);
 
-			/* Try and find a power of two to add */
-			do {
-				rc = mtrr_add(info->fix.smem_start,
-					      temp_size, type, 1);
-				temp_size >>= 1;
-			} while (temp_size >= PAGE_SIZE && rc == -EINVAL);
-		}
+		if (rc >= 0)
+			par->mtrr_handle = rc;
 	}
-#endif /* CONFIG_MTRR */
 }
 
 static void uvesafb_ioremap(struct fb_info *info)
 {
-#ifdef CONFIG_X86
-	switch (mtrr) {
-	case 1: /* uncachable */
-		info->screen_base = ioremap_nocache(info->fix.smem_start, info->fix.smem_len);
-		break;
-	case 2: /* write-back */
-		info->screen_base = ioremap_cache(info->fix.smem_start, info->fix.smem_len);
-		break;
-	case 3: /* write-combining */
-		info->screen_base = ioremap_wc(info->fix.smem_start, info->fix.smem_len);
-		break;
-	case 4: /* write-through */
-	default:
-		info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
-		break;
-	}
-#else
-	info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
-#endif /* CONFIG_X86 */
+	info->screen_base = ioremap_wc(info->fix.smem_start, info->fix.smem_len);
 }
 
 static ssize_t uvesafb_show_vbe_ver(struct device *dev,
@@ -1851,6 +1811,7 @@ static int uvesafb_remove(struct platform_device *dev)
 		unregister_framebuffer(info);
 		release_region(0x3c0, 32);
 		iounmap(info->screen_base);
+		arch_phys_wc_del(par->mtrr_handle);
 		release_mem_region(info->fix.smem_start, info->fix.smem_len);
 		fb_destroy_modedb(info->monspecs.modedb);
 		fb_dealloc_cmap(&info->cmap);
@@ -1930,6 +1891,9 @@ static int uvesafb_setup(char *options)
 		}
 	}
 
+	if (mtrr != 3 && mtrr != 1)
+		pr_warn("uvesafb: mtrr should be set to 0 or 3; %d is unsupported", mtrr);
+
 	return 0;
 }
 #endif /* !MODULE */
diff --git a/include/video/uvesafb.h b/include/video/uvesafb.h
index 1a91850..30f5362 100644
--- a/include/video/uvesafb.h
+++ b/include/video/uvesafb.h
@@ -134,6 +134,7 @@ struct uvesafb_par {
 
 	int mode_idx;
 	struct vbe_crtc_ib crtc;
+	int mtrr_handle;
 };
 
 #endif /* _UVESAFB_H */