source: trunk/packages/xen-3.1/xen-3.1/patches/linux-2.6.18/fixaddr-top.patch @ 34

arch/i386/mm/pgtable.c

@@ -12 +12 @@
 #include <linux/slab.h>
 #include <linux/pagemap.h>
 #include <linux/spinlock.h>
+#include <linux/module.h>
 
 #include <asm/system.h>
 #include <asm/pgtable.h>
@@ -137 +138 @@
         __flush_tlb_one(vaddr);
 }
 
+static int nr_fixmaps = 0;
+unsigned long __FIXADDR_TOP = 0xfffff000;
+EXPORT_SYMBOL(__FIXADDR_TOP);
+
 void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
 {
         unsigned long address = __fix_to_virt(idx);
@@ -146 +151 @@
                 return;
         }
         set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
+        nr_fixmaps++;
+}
+
+void set_fixaddr_top(unsigned long top)
+{
+        BUG_ON(nr_fixmaps > 0);
+        __FIXADDR_TOP = top - PAGE_SIZE;
 }
 
 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)

include/asm-i386/fixmap.h

@@ -19 +19 @@
  * Leave one empty page between vmalloc'ed areas and
  * the start of the fixmap.
  */
-#define __FIXADDR_TOP   0xfffff000
+extern unsigned long __FIXADDR_TOP;
 
 #ifndef __ASSEMBLY__
 #include <linux/kernel.h>
@@ -94 +94 @@
 extern void __set_fixmap (enum fixed_addresses idx,
                                         unsigned long phys, pgprot_t flags);
 
+extern void set_fixaddr_top(unsigned long top);
+
 #define set_fixmap(idx, phys) \
                 __set_fixmap(idx, phys, PAGE_KERNEL)
 /*

include/asm-i386/page.h

@@ -122 +122 @@
 
 #define PAGE_OFFSET             ((unsigned long)__PAGE_OFFSET)
 #define VMALLOC_RESERVE         ((unsigned long)__VMALLOC_RESERVE)
-#define MAXMEM                  (-__PAGE_OFFSET-__VMALLOC_RESERVE)
+#define MAXMEM                  (__FIXADDR_TOP-__PAGE_OFFSET-__VMALLOC_RESERVE)
 #define __pa(x)                 ((unsigned long)(x)-PAGE_OFFSET)
 #define __va(x)                 ((void *)((unsigned long)(x)+PAGE_OFFSET))
 #define pfn_to_kaddr(pfn)      __va((pfn) << PAGE_SHIFT)