BTE_MAX_XFER is wrong. It is one greater than the number of cache lines the BTE is actually able to transfer. If you request a transfer of exactly BTE_MAX_XFER size, you trip a very cryptic BUG_ON() which should certainly be made more clear. This patch fixes that constant and also cleans up the BUG_ON()s in arch/ia64/sn/kernel/bte.c to test one condition per line. Signed-off-by: Robin Holt <holt@xxxxxxx> --- Changes since -V1: Base the BTE_LEN_MASK upon a 1UL instead of 1 for correctness. arch/ia64/include/asm/sn/bte.h | 4 ++-- arch/ia64/sn/kernel/bte.c | 7 ++++--- 2 files changed, 6 insertions(+), 5 deletions(-) Index: bte_fixup/arch/ia64/include/asm/sn/bte.h =================================================================== --- bte_fixup.orig/arch/ia64/include/asm/sn/bte.h 2009-02-04 10:37:29.594750841 -0600 +++ bte_fixup/arch/ia64/include/asm/sn/bte.h 2009-02-04 10:40:32.495791608 -0600 @@ -38,8 +38,8 @@ /* BTE status register only supports 16 bits for length field */ #define BTE_LEN_BITS (16) -#define BTE_LEN_MASK ((1 << BTE_LEN_BITS) - 1) -#define BTE_MAX_XFER ((1 << BTE_LEN_BITS) * L1_CACHE_BYTES) +#define BTE_LEN_MASK ((1UL << BTE_LEN_BITS) - 1) +#define BTE_MAX_XFER (BTE_LEN_MASK << L1_CACHE_SHIFT) /* Define hardware */ Index: bte_fixup/arch/ia64/sn/kernel/bte.c =================================================================== --- bte_fixup.orig/arch/ia64/sn/kernel/bte.c 2009-02-04 10:37:30.026753839 -0600 +++ bte_fixup/arch/ia64/sn/kernel/bte.c 2009-02-04 10:40:11.711701203 -0600 @@ -97,9 +97,10 @@ bte_result_t bte_copy(u64 src, u64 dest, return BTE_SUCCESS; } - BUG_ON((len & L1_CACHE_MASK) || - (src & L1_CACHE_MASK) || (dest & L1_CACHE_MASK)); - BUG_ON(!(len < ((BTE_LEN_MASK + 1) << L1_CACHE_SHIFT))); + BUG_ON(len & L1_CACHE_MASK); + BUG_ON(src & L1_CACHE_MASK); + BUG_ON(dest & L1_CACHE_MASK); + BUG_ON(len > BTE_MAX_XFER); /* * Start with interface corresponding to cpu number -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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