Date: Mon, 14 Jul 2014 17:42:22 +0000 (UTC) From: Nathan Whitehorn <nwhitehorn@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r268624 - head/sys/dev/vt/hw/efifb Message-ID: <201407141742.s6EHgMNt094168@svn.freebsd.org>
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Author: nwhitehorn Date: Mon Jul 14 17:42:22 2014 New Revision: 268624 URL: http://svnweb.freebsd.org/changeset/base/268624 Log: 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. MFC after: 2 weeks Modified: head/sys/dev/vt/hw/efifb/efifb.c Modified: head/sys/dev/vt/hw/efifb/efifb.c ============================================================================== --- head/sys/dev/vt/hw/efifb/efifb.c Mon Jul 14 17:16:09 2014 (r268623) +++ head/sys/dev/vt/hw/efifb/efifb.c Mon Jul 14 17:42:22 2014 (r268624) @@ -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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