eal: deprecate and rename bsf64 function

Rename rte_bsf64 to rte_bsf64_safe (this is a "safe" version in
that it prevents undefined behavior by checking if incoming
parameter is zero) and move it to common header.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
Acked-by: Jasvinder Singh <jasvinder.singh@intel.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 34b2823..024f4b2 100644 (file)
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -11,6 +11,11 @@ API and ABI deprecation notices are to be posted here.
 Deprecation Notices
 -------------------
 
+* eal: function ``rte_bsf64`` in ``rte_bitmap.h`` has been renamed to
+  ``rte_bsf64_safe`` and moved to ``rte_common.h``. A new ``rte_bsf64`` function
+  will be added in the next release in ``rte_common.h`` that follows convention
+  set by existing ``rte_bsf32`` function.
+
 * eal: both declaring and identifying devices will be streamlined in v18.11.
   New functions will appear to query a specific port from buses, classes of
   device and device drivers. Device declaration will be made coherent with the

diff --git a/lib/librte_eal/common/include/rte_bitmap.h b/lib/librte_eal/common/include/rte_bitmap.h
index d2ed620..77727c8 100644 (file)
--- a/lib/librte_eal/common/include/rte_bitmap.h
+++ b/lib/librte_eal/common/include/rte_bitmap.h
@@ -93,14 +93,10 @@ __rte_bitmap_index2_set(struct rte_bitmap *bmp)
        bmp->index2 = (((bmp->index1 << RTE_BITMAP_SLAB_BIT_SIZE_LOG2) + bmp->offset1) << RTE_BITMAP_CL_SLAB_SIZE_LOG2);
 }
 
-static inline int
+static inline int __rte_deprecated
 rte_bsf64(uint64_t slab, uint32_t *pos)
 {
-       if (slab == 0)
-               return 0;
-
-       *pos = __builtin_ctzll(slab);
-       return 1;
+       return rte_bsf64_safe(slab, pos);
 }
 
 static inline uint32_t
@@ -408,9 +404,8 @@ __rte_bitmap_scan_search(struct rte_bitmap *bmp)
        value1 = bmp->array1[bmp->index1];
        value1 &= __rte_bitmap_mask1_get(bmp);
 
-       if (rte_bsf64(value1, &bmp->offset1)) {
+       if (rte_bsf64_safe(value1, &bmp->offset1))
                return 1;
-       }
 
        __rte_bitmap_index1_inc(bmp);
        bmp->offset1 = 0;
@@ -419,9 +414,8 @@ __rte_bitmap_scan_search(struct rte_bitmap *bmp)
        for (i = 0; i < bmp->array1_size; i ++, __rte_bitmap_index1_inc(bmp)) {
                value1 = bmp->array1[bmp->index1];
 
-               if (rte_bsf64(value1, &bmp->offset1)) {
+               if (rte_bsf64_safe(value1, &bmp->offset1))
                        return 1;
-               }
        }
 
        return 0;

diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 87f0f63..d115b17 100644 (file)
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -491,6 +491,29 @@ rte_fls_u32(uint32_t x)
        return (x == 0) ? 0 : 32 - __builtin_clz(x);
 }
 
+/**
+ * Searches the input parameter for the least significant set bit
+ * (starting from zero). Safe version (checks for input parameter being zero).
+ *
+ * @warning ``pos`` must be a valid pointer. It is not checked!
+ *
+ * @param v
+ *     The input parameter.
+ * @param pos
+ *     If ``v`` was not 0, this value will contain position of least significant
+ *     bit within the input parameter.
+ * @return
+ *     Returns 0 if ``v`` was 0, otherwise returns 1.
+ */
+static inline int
+rte_bsf64_safe(uint64_t v, uint32_t *pos)
+{
+       if (v == 0)
+               return 0;
+
+       *pos = __builtin_ctzll(v);
+       return 1;
+}
 
 #ifndef offsetof
 /** Return the offset of a field in a structure. */