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Date:      Tue, 2 Sep 2014 19:36:18 +0000 (UTC)
From:      Ed Maste <emaste@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org
Subject:   svn commit: r270978 - stable/10/sys/dev/vt/hw/efifb
Message-ID:  <201409021936.s82JaIad017766@svn.freebsd.org>

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Author: emaste
Date: Tue Sep  2 19:36:18 2014
New Revision: 270978
URL: http://svnweb.freebsd.org/changeset/base/270978

Log:
  MFC r268624 by nwhitehorn:
  
    On my Lenovo laptop, the firmware maps the EFI framebuffer with MTRRs
    set to uncacheable. This leads to execrable console performance. Once
    PMAP is up, remap the framebuffer as write-combining. This reduces
    boot time on my laptop by 60% when booting with EFI.

Modified:
  stable/10/sys/dev/vt/hw/efifb/efifb.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/vt/hw/efifb/efifb.c
==============================================================================
--- stable/10/sys/dev/vt/hw/efifb/efifb.c	Tue Sep  2 19:14:33 2014	(r270977)
+++ stable/10/sys/dev/vt/hw/efifb/efifb.c	Tue Sep  2 19:36:18 2014	(r270978)
@@ -53,6 +53,7 @@ __FBSDID("$FreeBSD$");
 
 static vd_init_t vt_efifb_init;
 static vd_probe_t vt_efifb_probe;
+static void vt_efifb_remap(void *efifb_data);
 
 static struct vt_driver vt_efifb_driver = {
 	.vd_name = "efifb",
@@ -68,6 +69,8 @@ static struct vt_driver vt_efifb_driver 
 static struct fb_info local_info;
 VT_DRIVER_DECLARE(vt_efifb, vt_efifb_driver);
 
+SYSINIT(efifb_remap, SI_SUB_KMEM, SI_ORDER_ANY, vt_efifb_remap, &local_info);
+
 static int
 vt_efifb_probe(struct vt_device *vd)
 {
@@ -133,9 +136,9 @@ vt_efifb_init(struct vt_device *vd)
 	info->fb_size = info->fb_height * info->fb_stride;
 	info->fb_pbase = efifb->fb_addr;
 	/*
-	 * We could use pmap_mapdev here except that the kernel pmap
-	 * hasn't been created yet and hence any attempt to lock it will
-	 * fail.
+	 * Use the direct map as a crutch until pmap is available. Once pmap
+	 * is online, the framebuffer will be remapped by vt_efifb_remap()
+	 * using pmap_mapdev_attr().
 	 */
 	info->fb_vbase = PHYS_TO_DMAP(efifb->fb_addr);
 
@@ -163,3 +166,22 @@ vt_efifb_init(struct vt_device *vd)
 
 	return (CN_INTERNAL);
 }
+
+static void
+vt_efifb_remap(void *xinfo)
+{
+	struct fb_info *info = xinfo;
+
+	if (info->fb_pbase == 0)
+		return;
+
+	/*
+	 * Remap as write-combining. This massively improves performance and
+	 * happens very early in kernel initialization, when everything is
+	 * still single-threaded and interrupts are off, so replacing the
+	 * mapping address is safe.
+	 */
+	info->fb_vbase = (intptr_t)pmap_mapdev_attr(info->fb_pbase,
+	    info->fb_size, VM_MEMATTR_WRITE_COMBINING);
+}
+



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