[nrf fromtree] ipc: pbuf: Provide function for Rx side initialization

Provide a new function for initializing the Rx side,
so users do not need to initialize the pointers by hand
if they did not use PBUF_DEFINE().

Let's also rename pbuf_init() to pbuf_tx_init() to clearly
signify the previous function was only meant to be used
by the Tx side.

Signed-off-by: Alberto Escolar Piedras <[email protected]>
(cherry picked from commit 5dc810e)

Author: aescolar

include/zephyr/ipc/pbuf.h

@@ -152,9 +152,9 @@ struct pbuf {
 	}
 
 /**
- * @brief Initialize the packet buffer.
+ * @brief Initialize the Tx packet buffer.
  *
- * This function initializes the packet buffer based on provided configuration.
+ * This function initializes the Tx packet buffer based on provided configuration.
  * If the configuration is incorrect, the function will return error.
  *
  * It is recommended to use PBUF_DEFINE macro for build time initialization.
@@ -165,7 +165,23 @@ struct pbuf {
  * @retval 0 on success.
  * @retval -EINVAL when the input parameter is incorrect.
  */
-int pbuf_init(struct pbuf *pb);
+int pbuf_tx_init(struct pbuf *pb);
+
+/**
+ * @brief Initialize the Rx packet buffer.
+ *
+ * This function initializes the Rx packet buffer.
+ * If the configuration is incorrect, the function will return error.
+ *
+ * It is recommended to use PBUF_DEFINE macro for build time initialization.
+ *
+ * @param pb	Pointer to the packed buffer containing
+ *		configuration and data. Configuration has to be
+ *		fixed before the initialization.
+ * @retval 0 on success.
+ * @retval -EINVAL when the input parameter is incorrect.
+ */
+int pbuf_rx_init(struct pbuf *pb);
 
 /**
  * @brief Write specified amount of data to the packet buffer.

subsys/ipc/ipc_service/lib/icmsg.c

@@ -270,16 +270,14 @@ int icmsg_open(const struct icmsg_config_t *conf,
 	k_mutex_init(&dev_data->tx_lock);
 #endif
 
-	int ret = pbuf_init(dev_data->tx_pb);
+	int ret = pbuf_tx_init(dev_data->tx_pb);
 
 	if (ret < 0) {
 		__ASSERT(false, "Incorrect configuration");
 		return ret;
 	}
 
-	/* Initialize local copies of rx_pb. */
-	dev_data->rx_pb->data.wr_idx = 0;
-	dev_data->rx_pb->data.rd_idx = 0;
+	(void)pbuf_rx_init(dev_data->rx_pb);
 
 	ret = pbuf_write(dev_data->tx_pb, magic, sizeof(magic));
 

subsys/ipc/ipc_service/lib/pbuf.c

@@ -54,7 +54,7 @@ static int validate_cfg(const struct pbuf_cfg *cfg)
 	return 0;
 }
 
-int pbuf_init(struct pbuf *pb)
+int pbuf_tx_init(struct pbuf *pb)
 {
 	if (validate_cfg(pb->cfg) != 0) {
 		return -EINVAL;
@@ -77,6 +77,18 @@ int pbuf_init(struct pbuf *pb)
 	return 0;
 }
 
+int pbuf_rx_init(struct pbuf *pb)
+{
+	if (validate_cfg(pb->cfg) != 0) {
+		return -EINVAL;
+	}
+	/* Initialize local copy of indexes. */
+	pb->data.wr_idx = 0;
+	pb->data.rd_idx = 0;
+
+	return 0;
+}
+
 int pbuf_write(struct pbuf *pb, const char *data, uint16_t len)
 {
 	if (pb == NULL || len == 0 || data == NULL) {

tests/subsys/ipc/pbuf/src/main.c

@@ -58,7 +58,7 @@ ZTEST(test_pbuf, test_rw)
 		write_buf[i] = i+1;
 	}
 
-	zassert_equal(pbuf_init(&pb), 0);
+	zassert_equal(pbuf_tx_init(&pb), 0);
 
 	/* Write MSGA_SZ bytes packet. */
 	ret = pbuf_write(&pb, write_buf, MSGA_SZ);
@@ -132,9 +132,9 @@ ZTEST(test_pbuf, test_retcodes)
 	};
 
 	/* Initialize buffers. */
-	zassert_equal(pbuf_init(&pb0), 0);
-	zassert_equal(pbuf_init(&pb1), 0);
-	zassert_equal(pbuf_init(&pb2), 0);
+	zassert_equal(pbuf_tx_init(&pb0), 0);
+	zassert_equal(pbuf_tx_init(&pb1), 0);
+	zassert_equal(pbuf_tx_init(&pb2), 0);
 
 	print_pbuf_info(&pb0);
 	print_pbuf_info(&pb1);
@@ -274,7 +274,7 @@ ZTEST(test_pbuf, test_stress)
 		.cfg = &cfg,
 	};
 
-	zassert_equal(pbuf_init(&pb), 0);
+	zassert_equal(pbuf_tx_init(&pb), 0);
 	ctx.pbuf = &pb;
 	ctx.wr_cnt = 0;
 	ctx.rd_cnt = 0;