This commit was manufactured by cvs2svn to create tag

[linux-2.6.git] / arch / ppc / mm / 44x_mmu.c

diff --git a/arch/ppc/mm/44x_mmu.c b/arch/ppc/mm/44x_mmu.c
index 72f7c0d..a2ab8b0 100644 (file)
--- a/arch/ppc/mm/44x_mmu.c
+++ b/arch/ppc/mm/44x_mmu.c
@@ -55,8 +55,10 @@
 #include <asm/setup.h>
 
 #include "mmu_decl.h"
+#include "mem_pieces.h"
 
 extern char etext[], _stext[];
+extern struct mem_pieces phys_avail;
 
 /* Used by the 44x TLB replacement exception handler.
  * Just needed it declared someplace.
@@ -103,6 +105,16 @@ unsigned long __init mmu_mapin_ram(void)
        unsigned int pinned_tlbs = 1;
        int i;
 
+       /*
+        * If lowmem is not on a pin tlb entry size boundary,
+        * then reserve the last page of system memory. This
+        * eliminates the possibility of a speculative dcache
+        * fetch past the end of system memory that would
+        * result in a machine check exception.
+        */
+       if (total_lowmem | (PPC44x_PIN_SIZE - 1))
+               mem_pieces_remove(&phys_avail, total_lowmem - PAGE_SIZE, PAGE_SIZE, 1);
+
        /* Determine number of entries necessary to cover lowmem */
        pinned_tlbs = (unsigned int)
                (_ALIGN(total_lowmem, PPC44x_PIN_SIZE) >> PPC44x_PIN_SHIFT);