[MIPS] Malta: Handle byteswapping hardare bug in big endian mode.

    
The SOC-it system controller running in big endian mode might forget
byteswapping when DMAing to the last word of physical memory.  Fixed by
ignoring the last page of memory.
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/mips/mips-boards/generic/memory.c b/arch/mips/mips-boards/generic/memory.c
index bc4d093685bb..fd492562584a 100644
--- a/arch/mips/mips-boards/generic/memory.c
+++ b/arch/mips/mips-boards/generic/memory.c
@@ -76,6 +76,15 @@ struct prom_pmemblock * __init prom_getmdesc(void)
                         memsize = simple_strtol(memsize_str, NULL, 0);
                 }
         }
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+        /*
+         * SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
+         * word of physical memory
+         */
+        memsize -= PAGE_SIZE;
+#endif
+
         memset(mdesc, 0, sizeof(mdesc));
 
         mdesc[0].type = yamon_dontuse;