[dpdk-dev] [PATCH v2 24/26] net/ena: fix GENMASK_ULL macro

Michal Krawczyk mk at semihalf.com
Mon Jun 4 14:09:52 CEST 2018


From: Rafal Kozik <rk at semihalf.com>

When use GENMASK_ULL(63,0) left shift by 64 bits is performed.
Shifting by number greater or equal then word length
is undefined operation and failed on some platforms.

Fixes: 9ba7981ec992 ("ena: add communication layer for DPDK")

Signed-off-by: Rafal Kozik <rk at semihalf.com>
Acked-by: Michal Krawczyk <mk at semihalf.com>
---
 drivers/net/ena/base/ena_plat_dpdk.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ena/base/ena_plat_dpdk.h b/drivers/net/ena/base/ena_plat_dpdk.h
index 22d7a9cb1..8a04e84b9 100644
--- a/drivers/net/ena/base/ena_plat_dpdk.h
+++ b/drivers/net/ena/base/ena_plat_dpdk.h
@@ -116,11 +116,13 @@ typedef uint64_t dma_addr_t;
 #define ENA_MIN16(x, y) RTE_MIN((x), (y))
 #define ENA_MIN8(x, y) RTE_MIN((x), (y))
 
+#define BITS_PER_LONG_LONG (__SIZEOF_LONG_LONG__ * 8)
 #define U64_C(x) x ## ULL
 #define BIT(nr)         (1UL << (nr))
 #define BITS_PER_LONG	(__SIZEOF_LONG__ * 8)
 #define GENMASK(h, l)	(((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
-#define GENMASK_ULL(h, l) (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l))
+#define GENMASK_ULL(h, l) (((~0ULL) - (1ULL << (l)) + 1) & \
+			  (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
 
 #ifdef RTE_LIBRTE_ENA_COM_DEBUG
 #define ena_trc_dbg(format, arg...)					\
-- 
2.14.1



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