sfc: Merge efx_filter_search() into efx_filter_insert()

efx_filter_search() is only called from efx_filter_insert(), and
neither function is very long.  The following bug fix requires a more
sophisticated search with a third result, which is going to be easier
to implement as part of the same function.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

drivers/net/ethernet/sfc/filter.c

@@ -513,37 +513,6 @@ static bool efx_filter_equal(const struct efx_filter_spec *left,
 	return true;
 }
 
-static int efx_filter_search(struct efx_filter_table *table,
-			     struct efx_filter_spec *spec, u32 key,
-			     unsigned int *depth_required)
-{
-	unsigned hash, incr, filter_idx, depth, depth_max;
-
-	hash = efx_filter_hash(key);
-	incr = efx_filter_increment(key);
-
-	filter_idx = hash & (table->size - 1);
-	depth = 1;
-	depth_max = (spec->priority <= EFX_FILTER_PRI_HINT ?
-		     FILTER_CTL_SRCH_HINT_MAX : FILTER_CTL_SRCH_MAX);
-
-	for (;;) {
-		/* Return success if entry is unused or matches this spec */
-		if (!test_bit(filter_idx, table->used_bitmap) ||
-		    efx_filter_equal(spec, &table->spec[filter_idx])) {
-			*depth_required = depth;
-			return filter_idx;
-		}
-
-		/* Return failure if we reached the maximum search depth */
-		if (depth == depth_max)
-			return -EBUSY;
-
-		filter_idx = (filter_idx + incr) & (table->size - 1);
-		++depth;
-	}
-}
-
 /*
  * Construct/deconstruct external filter IDs.  At least the RX filter
  * IDs must be ordered by matching priority, for RX NFC semantics.
@@ -679,14 +648,33 @@ s32 efx_filter_insert_filter(struct efx_nic *efx, struct efx_filter_spec *spec,
 		spin_lock_bh(&state->lock);
 	} else {
 		u32 key = efx_filter_build(&filter, spec);
+		unsigned int hash = efx_filter_hash(key);
+		unsigned int incr = efx_filter_increment(key);
+		unsigned int depth_max =
+			spec->priority <= EFX_FILTER_PRI_HINT ?
+			FILTER_CTL_SRCH_HINT_MAX : FILTER_CTL_SRCH_MAX;
+
+		filter_idx = hash & (table->size - 1);
+		depth = 1;
 
 		spin_lock_bh(&state->lock);
 
-		rc = efx_filter_search(table, spec, key, &depth);
-		if (rc < 0)
+		for (;;) {
+			if (!test_bit(filter_idx, table->used_bitmap) ||
+			    efx_filter_equal(spec, &table->spec[filter_idx]))
+				break;
+
+			/* Return failure if we reached the maximum search
+			 * depth
+			 */
+			if (depth == depth_max) {
+				rc = -EBUSY;
 				goto out;
-		filter_idx = rc;
-		BUG_ON(filter_idx >= table->size);
+			}
+
+			filter_idx = (filter_idx + incr) & (table->size - 1);
+			++depth;
+		}
 	}
 
 	saved_spec = &table->spec[filter_idx];