[PATCH 3.13 093/187] bfa: Fix undefined bit shift on big-endian architectures with 32-bit DMA address

Kamal Mostafa
2014-09-15T23:17:39Z

From: Ben Hutchings <ben@decadent.org.uk>

commit 03a6c3ff3282ee9fa893089304d951e0be93a144 upstream.

bfa_swap_words() shifts its argument (assumed to be 64-bit) by 32 bits
each way. In two places the argument type is dma_addr_t, which may be
32-bit, in which case the effect of the bit shift is undefined:

drivers/scsi/bfa/bfa_fcpim.c: In function 'bfa_ioim_send_ioreq':
drivers/scsi/bfa/bfa_fcpim.c:2497:4: warning: left shift count >= width of type [enabled by default]
addr = bfa_sgaddr_le(sg_dma_address(sg));
^
drivers/scsi/bfa/bfa_fcpim.c:2497:4: warning: right shift count >= width of type [enabled by default]
drivers/scsi/bfa/bfa_fcpim.c:2509:4: warning: left shift count >= width of type [enabled by default]
addr = bfa_sgaddr_le(sg_dma_address(sg));
^
drivers/scsi/bfa/bfa_fcpim.c:2509:4: warning: right shift count >= width of type [enabled by default]

Avoid this by adding casts to u64 in bfa_swap_words().

Compile-tested only.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Anil Gurumurthy <anil.gurumurthy@qlogic.com>
Fixes: f16a17507b09 ('[SCSI] bfa: remove all OS wrappers')
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/scsi/bfa/bfa_ioc.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/bfa/bfa_ioc.h b/drivers/scsi/bfa/bfa_ioc.h
index 90814fe..d5b3f66 100644
--- a/drivers/scsi/bfa/bfa_ioc.h
+++ b/drivers/scsi/bfa/bfa_ioc.h
@@ -72,7 +72,7 @@ struct bfa_sge_s {
} while (0)

#define bfa_swap_words(_x) ( \
- ((_x) << 32) | ((_x) >> 32))
+ ((u64)(_x) << 32) | ((u64)(_x) >> 32))

#ifdef __BIG_ENDIAN
#define bfa_sge_to_be(_x)
--
1.9.1