Extend alock API with entries_count method

Right now alock assumes that number of locks taken will equal number of
core lines. This is not the case in pio, where only parts of metadata
are under locks. If pio request overlaps locked and not-locked metadata
section it will have different core lines number and awaited locks
number. To remedy this discrepancy additional method which gets count of
locks that will be taken/waited on is added to alock API.

Signed-off-by: Jan Musial <jan.musial@intel.com>

src/concurrency/ocf_pio_concurrency.c

@@ -1,5 +1,5 @@
 /*
- * Copyright(c) 2021 Intel Corporation
+ * Copyright(c) 2021-2022 Intel Corporation
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -136,9 +136,26 @@ err:
 	return ret;
 }
 
+static uint32_t ocf_pio_lock_get_entries_count(struct ocf_alock *alock,
+		struct ocf_request *req)
+{
+	uint32_t i, count = 0;
+	ocf_cache_line_t entry;
+
+	for (i = 0; i < req->core_line_count; i++) {
+		entry = ocf_pio_lock_get_entry(alock, req, i);
+		if (entry == OUT_OF_RANGE)
+			continue;
+		count++;
+	}
+
+	return count;
+}
+
 static struct ocf_alock_lock_cbs ocf_pio_conc_cbs = {
 		.lock_entries_fast = ocf_pio_lock_fast,
-		.lock_entries_slow = ocf_pio_lock_slow
+		.lock_entries_slow = ocf_pio_lock_slow,
+		.get_entries_count = ocf_pio_lock_get_entries_count
 };
 
 int ocf_pio_async_lock(struct ocf_alock *alock, struct ocf_request *req,