[PATCH][MIPS] fix divide by zero error in build_clear_page and build_copy_page

[Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>]

Fix divide by zero error in build_clear_page() and build_copy_page()

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>

diff -pruN -X /home/yuasa/Memo/dontdiff linux-orig/arch/mips/mm/page.c 
linux/arch/mips/mm/page.c
--- linux-orig/arch/mips/mm/page.c      2008-05-07 10:28:03.732151097 +0900
+++ linux/arch/mips/mm/page.c   2008-05-07 23:27:00.212977534 +0900
@@ -310,8 +310,8 @@ void __cpuinit build_clear_page(void)
        if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
                uasm_i_lui(&buf, AT, 0xa000);
 
-       off = min(8, pref_bias_clear_store / cache_line_size) *
-             cache_line_size;
+       off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
+                               * cache_line_size : 0;
        while (off) {
                build_clear_pref(&buf, -off);
                off -= cache_line_size;
@@ -454,12 +454,14 @@ void __cpuinit build_copy_page(void)
        if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
                uasm_i_lui(&buf, AT, 0xa000);
 
-       off = min(8, pref_bias_copy_load / cache_line_size) * cache_line_size;
+       off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
+                               cache_line_size : 0;
        while (off) {
                build_copy_load_pref(&buf, -off);
                off -= cache_line_size;
        }
-       off = min(8, pref_bias_copy_store / cache_line_size) * cache_line_size;
+       off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
+                               cache_line_size : 0;
        while (off) {
                build_copy_store_pref(&buf, -off);
                off -= cache_line_size;