Messages in this thread Patch in this message | | | Date | Tue, 3 Feb 2009 18:40:59 -0600 | From | Robin Holt <> | Subject | [Patch] bte_copy of BTE_MAX_XFER trips BUG_ON. |
| |
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@sgi.com>
---
arch/ia64/include/asm/sn/bte.h | 2 +- arch/ia64/sn/kernel/bte.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-)
Index: bte_max_xfer_fix/arch/ia64/include/asm/sn/bte.h =================================================================== --- bte_max_xfer_fix.orig/arch/ia64/include/asm/sn/bte.h 2009-02-03 18:07:26.000000000 -0600 +++ bte_max_xfer_fix/arch/ia64/include/asm/sn/bte.h 2009-02-03 18:09:38.749729353 -0600 @@ -39,7 +39,7 @@ /* 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_MAX_XFER (BTE_LEN_MASK << L1_CACHE_SHIFT) /* Define hardware */ Index: bte_max_xfer_fix/arch/ia64/sn/kernel/bte.c =================================================================== --- bte_max_xfer_fix.orig/arch/ia64/sn/kernel/bte.c 2009-02-03 18:07:26.000000000 -0600 +++ bte_max_xfer_fix/arch/ia64/sn/kernel/bte.c 2009-02-03 18:15:42.854040475 -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
| |