[dpdk-dev] [PATCH v2 2/2] eal: fix build issue

[Jerin Jacob]

Some toolchain has fls() definition in string.h as argument type int,
which is conflicting uint32_t argument type.

/export/dpdk.org/lib/librte_eal/common/rte_reciprocal.c:47:19:
error: conflicting types for ‘fls’
 static inline int fls(uint32_t x)
                  ^~~

/opt/marvell-tools-201/aarch64-marvell-elf/include/strings.h:59:6:
note: previous declaration of ‘fls’ was here
 int  fls(int) __pure2;

FreeBSD string.h also has fls() with argument as int type.
https://www.freebsd.org/cgi/man.cgi?query=fls&sektion=3

Fixing the conflict by using rte version of fls.

Fixes: ffe3ec811ef5 ("sched: introduce reciprocal divide")
Fixes: faf2b25c9f80 ("fm10k: support VMDQ in multi-queue configuration")
Cc: stable at dpdk.org

Suggested-by: Thomas Monjalon <thomas at monjalon.net>
Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
---
v2:
- Introduce and use rte version of fls(Thomas Monjalon)
---
 drivers/net/fm10k/fm10k_ethdev.c       | 11 +++--------
 lib/librte_eal/common/rte_reciprocal.c | 17 +----------------
 2 files changed, 4 insertions(+), 24 deletions(-)

diff --git a/drivers/net/fm10k/fm10k_ethdev.c b/drivers/net/fm10k/fm10k_ethdev.c
index c852022dd..85fb6c5cb 100644
--- a/drivers/net/fm10k/fm10k_ethdev.c
+++ b/drivers/net/fm10k/fm10k_ethdev.c
@@ -464,11 +464,6 @@ fm10k_dev_configure(struct rte_eth_dev *dev)
 	return 0;
 }
 
-/* fls = find last set bit = 32 minus the number of leading zeros */
-#ifndef fls
-#define fls(x) (((x) == 0) ? 0 : (32 - __builtin_clz((x))))
-#endif
-
 static void
 fm10k_dev_vmdq_rx_configure(struct rte_eth_dev *dev)
 {
@@ -1030,8 +1025,8 @@ fm10k_dev_dglort_map_configure(struct rte_eth_dev *dev)
 
 	macvlan = FM10K_DEV_PRIVATE_TO_MACVLAN(dev->data->dev_private);
 	nb_queue_pools = macvlan->nb_queue_pools;
-	pool_len = nb_queue_pools ? fls(nb_queue_pools - 1) : 0;
-	rss_len = fls(dev->data->nb_rx_queues - 1) - pool_len;
+	pool_len = nb_queue_pools ? rte_fls_u32(nb_queue_pools - 1) : 0;
+	rss_len = rte_fls_u32(dev->data->nb_rx_queues - 1) - pool_len;
 
 	/* GLORT 0x0-0x3F are used by PF and VMDQ,  0x40-0x7F used by FD */
 	dglortdec = (rss_len << FM10K_DGLORTDEC_RSSLENGTH_SHIFT) | pool_len;
@@ -1042,7 +1037,7 @@ fm10k_dev_dglort_map_configure(struct rte_eth_dev *dev)
 	FM10K_WRITE_REG(hw, FM10K_DGLORTDEC(0), dglortdec);
 
 	/* Flow Director configurations, only queue number is valid. */
-	dglortdec = fls(dev->data->nb_rx_queues - 1);
+	dglortdec = rte_fls_u32(dev->data->nb_rx_queues - 1);
 	dglortmask = (GLORT_FD_MASK << FM10K_DGLORTMAP_MASK_SHIFT) |
 			(hw->mac.dglort_map + GLORT_FD_Q_BASE);
 	FM10K_WRITE_REG(hw, FM10K_DGLORTMAP(1), dglortmask);
diff --git a/lib/librte_eal/common/rte_reciprocal.c b/lib/librte_eal/common/rte_reciprocal.c
index d81b11db6..f017d0c28 100644
--- a/lib/librte_eal/common/rte_reciprocal.c
+++ b/lib/librte_eal/common/rte_reciprocal.c
@@ -41,28 +41,13 @@
 
 #include "rte_reciprocal.h"
 
-/* find largest set bit.
- * portable and slow but does not matter for this usage.
- */
-static inline int fls(uint32_t x)
-{
-	int b;
-
-	for (b = 31; b >= 0; --b) {
-		if (x & (1u << b))
-			return b + 1;
-	}
-
-	return 0;
-}
-
 struct rte_reciprocal rte_reciprocal_value(uint32_t d)
 {
 	struct rte_reciprocal R;
 	uint64_t m;
 	int l;
 
-	l = fls(d - 1);
+	l = rte_fls_u32(d - 1);
 	m = ((1ULL << 32) * ((1ULL << l) - d));
 	m /= d;
 
-- 
2.19.1