From: Ingo Molnar <mingo@elte.hu>
Subject: Limit MAXMEM on 64bit
Patch-Mainline: Yes

on 64-bit x86 the physical memory limit is controlled by the sparsemem
bits - which are 44 bits right now. But MAXMEM (the max pfn number
e820 parsing will allow to enter our sizing routines) is set to
0x00003fffffffffff, i.e. 46 bits - that's too large because it overlaps
into the vmalloc range.

So couple MAXMEM to MAX_PHYSMEM_BITS, and add a comment that the
maximum of MAX_PHYSMEM_BITS is 45 bits.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Hannes Reinecke <hare@suse.de>

Index: linux-2.6.27-SLE11_BRANCH/include/asm-x86/pgtable_64.h
===================================================================
--- linux-2.6.27-SLE11_BRANCH.orig/include/asm-x86/pgtable_64.h
+++ linux-2.6.27-SLE11_BRANCH/include/asm-x86/pgtable_64.h
@@ -146,7 +146,7 @@ static inline void native_pgd_clear(pgd_
 #define PGDIR_MASK	(~(PGDIR_SIZE - 1))
 
 
-#define MAXMEM		 _AC(0x00003fffffffffff, UL)
+#define MAXMEM		 _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
 #define VMALLOC_START    _AC(0xffffc20000000000, UL)
 #define VMALLOC_END      _AC(0xffffe1ffffffffff, UL)
 #define VMEMMAP_START	 _AC(0xffffe20000000000, UL)
Index: linux-2.6.27-SLE11_BRANCH/include/asm-x86/sparsemem.h
===================================================================
--- linux-2.6.27-SLE11_BRANCH.orig/include/asm-x86/sparsemem.h
+++ linux-2.6.27-SLE11_BRANCH/include/asm-x86/sparsemem.h
@@ -27,7 +27,7 @@
 #else /* CONFIG_X86_32 */
 # define SECTION_SIZE_BITS	27 /* matt - 128 is convenient right now */
 # define MAX_PHYSADDR_BITS	44
-# define MAX_PHYSMEM_BITS	44
+# define MAX_PHYSMEM_BITS	44 /* Can be max 45 bits */
 #endif
 
 #endif /* CONFIG_SPARSEMEM */