From: Keir Fraser <keir.fraser@citrix.com>
Date: Fri, 5 Dec 2008 13:06:57 +0000 (+0000)
Subject: minios: Clip memory not usable by Mini-OS (above 1GB)
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14026^2~67
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=7e60fdf5b1f934061f26ec514b6dfecb83d7d46b;p=xen.git

minios: Clip memory not usable by Mini-OS (above 1GB)

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
---

diff --git a/extras/mini-os/arch/x86/mm.c b/extras/mini-os/arch/x86/mm.c
index b1c0084fe7..07b6da8d1e 100644
--- a/extras/mini-os/arch/x86/mm.c
+++ b/extras/mini-os/arch/x86/mm.c
@@ -420,7 +420,9 @@ static unsigned long demand_map_area_start;
 #define DEMAND_MAP_PAGES ((2ULL << 30) / PAGE_SIZE)
 #endif
 
-#ifdef HAVE_LIBC
+#ifndef HAVE_LIBC
+#define HEAP_PAGES 0
+#else
 unsigned long heap, brk, heap_mapped, heap_end;
 #ifdef __x86_64__
 #define HEAP_PAGES ((128ULL << 30) / PAGE_SIZE)
@@ -591,7 +593,7 @@ void arch_init_p2m(unsigned long max_pfn)
 void arch_init_mm(unsigned long* start_pfn_p, unsigned long* max_pfn_p)
 {
 
-    unsigned long start_pfn, max_pfn;
+    unsigned long start_pfn, max_pfn, virt_pfns;
 
     printk("  _text:        %p\n", &_text);
     printk("  _etext:       %p\n", &_etext);
@@ -604,7 +606,12 @@ void arch_init_mm(unsigned long* start_pfn_p, unsigned long* max_pfn_p)
     start_pfn = PFN_UP(to_phys(start_info.pt_base)) + 
                 start_info.nr_pt_frames + 3;
     max_pfn = start_info.nr_pages;
-   
+
+    /* We need room for demand mapping and heap, clip available memory */
+    virt_pfns = DEMAND_MAP_PAGES + HEAP_PAGES;
+    if (max_pfn + virt_pfns + 1 < max_pfn)
+        max_pfn = -(virt_pfns + 1);
+
     printk("  start_pfn:    %lx\n", start_pfn);
     printk("  max_pfn:      %lx\n", max_pfn);