[src/trunk]: src/sys/arch/arm/arm32 Deal with 2GB of ram or memory ending at ...

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/eaee8879fce7
branches:  trunk
changeset: 808074:eaee8879fce7
user:      matt <matt%NetBSD.org@localhost>
date:      Mon May 04 00:44:12 2015 +0000

description:
Deal with 2GB of ram or memory ending at or above 4GB.

diffstat:

 sys/arch/arm/arm32/arm32_kvminit.c |  31 ++++++++++++++++++++++++++++---
 1 files changed, 28 insertions(+), 3 deletions(-)

diffs (61 lines):

diff -r 59ce67321857 -r eaee8879fce7 sys/arch/arm/arm32/arm32_kvminit.c
--- a/sys/arch/arm/arm32/arm32_kvminit.c        Mon May 04 00:41:42 2015 +0000
+++ b/sys/arch/arm/arm32/arm32_kvminit.c        Mon May 04 00:44:12 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: arm32_kvminit.c,v 1.32 2014/10/29 14:14:14 skrll Exp $ */
+/*     $NetBSD: arm32_kvminit.c,v 1.33 2015/05/04 00:44:12 matt Exp $  */
 
 /*
  * Copyright (c) 2002, 2003, 2005  Genetec Corporation.  All rights reserved.
@@ -124,7 +124,7 @@
 #include "opt_multiprocessor.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: arm32_kvminit.c,v 1.32 2014/10/29 14:14:14 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: arm32_kvminit.c,v 1.33 2015/05/04 00:44:12 matt Exp $");
 
 #include <sys/param.h>
 #include <sys/device.h>
@@ -191,6 +191,16 @@
 
        physical_start = bmi->bmi_start = memstart;
        physical_end = bmi->bmi_end = memstart + memsize;
+#ifndef ARM_HAS_LPAE
+       if (physical_end == 0) {
+               physical_end = -PAGE_SIZE;
+               memsize -= PAGE_SIZE;
+#ifdef VERBOSE_INIT_ARM
+               printf("%s: memsize shrunk by a page to avoid ending at 4GB\n",
+                   __func__);
+#endif
+       }
+#endif
        physmem = memsize / PAGE_SIZE;
 
        /*
@@ -225,9 +235,24 @@
 #if defined(ARM_MMU_EXTENDED) && defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS)
                pv->pv_va = pmap_directbase;
 #else
+               /*
+                * If there's lots of memory the kernel could be placed far
+                * from the start of RAM.  If that's the case, don't map the
+                * RAM that would have virtual addresses below KERNEL_BASE.
+                */
+               if (pv->pv_pa < KERN_VTOPHYS(bmi, KERNEL_BASE)) {
+                       psize_t size = KERN_VTOPHYS(bmi, KERNEL_BASE) - pv->pv_pa;
+                       bmi->bmi_freepages += size / PAGE_SIZE;
+#ifdef VERBOSE_INIT_ARM
+                       printf("%s: adding %lu free pages: [%#lx..%#lx]\n",
+                           __func__, size / PAGE_SIZE, pv->pv_va,
+                           pv->pv_pa + size - 1);
+#endif
+                       pv->pv_pa = KERN_VTOPHYS(bmi, KERNEL_BASE);
+               }
                pv->pv_va = KERNEL_BASE;
 #endif
-               pv->pv_size = bmi->bmi_kernelstart - bmi->bmi_start;
+               pv->pv_size = bmi->bmi_kernelstart - pv->pv_pa;
                bmi->bmi_freepages += pv->pv_size / PAGE_SIZE;
 #ifdef VERBOSE_INIT_ARM
                printf("%s: adding %lu free pages: [%#lx..%#lx] (VA %#lx)\n",