Incorrect word calculation in some configs

Ben Dooks
2004-09-20T23:40:08Z

There seems to be a problem with map_words() if there are
types longer than `unsigned long` enabled at the same time
as anything shorted than an `unsigned long`

Tested on an EB2410ITX (ARM9 SoC)
Patch against 2.6.9-rc2 patched with 19th September CVS

Signed-off-by: Ben Dooks <ben-mtd@fluff.org>

--- linux-2.6.9-rc2-bk6-mtd20040919/include/linux/mtd/map.h 2004-09-20 13:02:46.000000000 +0100
+++ linux-2.6.9-rc2-bk6-mtd20040919-work/include/linux/mtd/map.h 2004-09-21 00:25:47.000000000 +0100
@@ -56,6 +56,11 @@
#define map_bankwidth_is_4(map) (0)
#endif

+/* ensure we never evaluate anything shorted than an unsigned long
+ * to zero, and ensure we'll never miss the end of an comparison (bjd) */
+
+#define map_calc_words(map) ((map_bankwidth(map) + (sizeof(unsigned long)-1))/ sizeof(unsigned long))
+
#ifdef CONFIG_MTD_MAP_BANK_WIDTH_8
# ifdef map_bankwidth
# undef map_bankwidth
@@ -64,12 +69,12 @@
# undef map_bankwidth_is_large
# define map_bankwidth_is_large(map) (map_bankwidth(map) > BITS_PER_LONG/8)
# undef map_words
-# define map_words(map) (map_bankwidth(map) / sizeof(unsigned long))
+# define map_words(map) map_calc_words(map)
# endif
# else
# define map_bankwidth(map) 8
# define map_bankwidth_is_large(map) (BITS_PER_LONG < 64)
-# define map_words(map) (map_bankwidth(map) / sizeof(unsigned long))
+# define map_words(map) map_calc_words(map)
# endif
#define map_bankwidth_is_8(map) (map_bankwidth(map) == 8)
#undef MAX_MAP_BANKWIDTH
@@ -85,11 +90,11 @@
# undef map_bankwidth_is_large
# define map_bankwidth_is_large(map) (map_bankwidth(map) > BITS_PER_LONG/8)
# undef map_words
-# define map_words(map) (map_bankwidth(map) / sizeof(unsigned long))
+# define map_words(map) map_calc_words(map)
# else
# define map_bankwidth(map) 16
# define map_bankwidth_is_large(map) (1)
-# define map_words(map) (map_bankwidth(map) / sizeof(unsigned long))
+# define map_words(map) map_calc_words(map)
# endif
#define map_bankwidth_is_16(map) (map_bankwidth(map) == 16)
#undef MAX_MAP_BANKWIDTH
@@ -105,11 +110,11 @@
# undef map_bankwidth_is_large
# define map_bankwidth_is_large(map) (map_bankwidth(map) > BITS_PER_LONG/8)
# undef map_words
-# define map_words(map) (map_bankwidth(map) / sizeof(unsigned long))
+# define map_words(map) map_calc_words(map)
# else
# define map_bankwidth(map) 32
# define map_bankwidth_is_large(map) (1)
-# define map_words(map) (map_bankwidth(map) / sizeof(unsigned long))
+# define map_words(map) map_calc_words(map)
# endif
#define map_bankwidth_is_32(map) (map_bankwidth(map) == 32)
#undef MAX_MAP_BANKWIDTH