src/patches/suse-2.6.27.25/patches.fixes/sparsemem-maxmem-fix

   1 From: Ingo Molnar <mingo@elte.hu>
   2 Subject: Limit MAXMEM on 64bit
   3 Patch-Mainline: Yes
   4
   5 on 64-bit x86 the physical memory limit is controlled by the sparsemem
   6 bits - which are 44 bits right now. But MAXMEM (the max pfn number
   7 e820 parsing will allow to enter our sizing routines) is set to
   8 0x00003fffffffffff, i.e. 46 bits - that's too large because it overlaps
   9 into the vmalloc range.
  10
  11 So couple MAXMEM to MAX_PHYSMEM_BITS, and add a comment that the
  12 maximum of MAX_PHYSMEM_BITS is 45 bits.
  13
  14 Signed-off-by: Ingo Molnar <mingo@elte.hu>
  15 Signed-off-by: Hannes Reinecke <hare@suse.de>
  16
  17 Index: linux-2.6.27-SLE11_BRANCH/include/asm-x86/pgtable_64.h
  18 ===================================================================
  19 --- linux-2.6.27-SLE11_BRANCH.orig/include/asm-x86/pgtable_64.h
  20 +++ linux-2.6.27-SLE11_BRANCH/include/asm-x86/pgtable_64.h
  21 @@ -146,7 +146,7 @@ static inline void native_pgd_clear(pgd_
  22  #define PGDIR_MASK     (~(PGDIR_SIZE - 1))
  23
  24
  25 -#define MAXMEM          _AC(0x00003fffffffffff, UL)
  26 +#define MAXMEM          _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
  27  #define VMALLOC_START    _AC(0xffffc20000000000, UL)
  28  #define VMALLOC_END      _AC(0xffffe1ffffffffff, UL)
  29  #define VMEMMAP_START   _AC(0xffffe20000000000, UL)
  30 Index: linux-2.6.27-SLE11_BRANCH/include/asm-x86/sparsemem.h
  31 ===================================================================
  32 --- linux-2.6.27-SLE11_BRANCH.orig/include/asm-x86/sparsemem.h
  33 +++ linux-2.6.27-SLE11_BRANCH/include/asm-x86/sparsemem.h
  34 @@ -27,7 +27,7 @@
  35  #else /* CONFIG_X86_32 */
  36  # define SECTION_SIZE_BITS     27 /* matt - 128 is convenient right now */
  37  # define MAX_PHYSADDR_BITS     44
  38 -# define MAX_PHYSMEM_BITS      44
  39 +# define MAX_PHYSMEM_BITS      44 /* Can be max 45 bits */
  40  #endif
  41
  42  #endif /* CONFIG_SPARSEMEM */