[dpdk-dev] [PATCH v1 1/7] ethdev: expose flow API error helper

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

rte_flow_error_set() is a convenient helper to initialize error objects.

Since there is no fundamental reason to prevent applications from using it,
expose it through the public interface after modifying its return value
from positive to negative. This is done for consistency with the rest of
the public interface.

Documentation is updated accordingly.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
---
 doc/guides/prog_guide/rte_flow.rst | 23 +++++++++++++++++---
 drivers/net/mlx4/mlx4_flow.c       |  6 +++---
 drivers/net/tap/tap_flow.c         |  2 +-
 lib/librte_ether/rte_flow.c        | 30 +++++++++++++-------------
 lib/librte_ether/rte_flow.h        | 36 +++++++++++++++++++++++++++++++
 lib/librte_ether/rte_flow_driver.h | 38 ---------------------------------
 6 files changed, 75 insertions(+), 60 deletions(-)

diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index 662a912..565a809 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -1678,6 +1678,25 @@ freed by the application, however its pointer can be considered valid only
 as long as its associated DPDK port remains configured. Closing the
 underlying device or unloading the PMD invalidates it.
 
+Helpers
+-------
+
+Error initializer
+~~~~~~~~~~~~~~~~~
+
+.. code-block:: c
+
+   static inline int
+   rte_flow_error_set(struct rte_flow_error *error,
+                      int code,
+                      enum rte_flow_error_type type,
+                      const void *cause,
+                      const char *message);
+
+This function initializes ``error`` (if non-NULL) with the provided
+parameters and sets ``rte_errno`` to ``code``. A negative error ``code`` is
+then returned.
+
 Caveats
 -------
 
@@ -1743,13 +1762,11 @@ the legacy filtering framework, which should eventually disappear.
   whatsoever). They only make sure these callbacks are non-NULL or return
   the ``ENOSYS`` (function not supported) error.
 
-This interface additionally defines the following helper functions:
+This interface additionally defines the following helper function:
 
 - ``rte_flow_ops_get()``: get generic flow operations structure from a
   port.
 
-- ``rte_flow_error_set()``: initialize generic flow error structure.
-
 More will be added over time.
 
 Device compatibility
diff --git a/drivers/net/mlx4/mlx4_flow.c b/drivers/net/mlx4/mlx4_flow.c
index 0885a91..018843b 100644
--- a/drivers/net/mlx4/mlx4_flow.c
+++ b/drivers/net/mlx4/mlx4_flow.c
@@ -955,9 +955,9 @@ mlx4_flow_isolate(struct rte_eth_dev *dev,
 		mlx4_mac_addr_del(priv);
 	} else if (mlx4_mac_addr_add(priv) < 0) {
 		priv->isolated = 1;
-		return -rte_flow_error_set(error, rte_errno,
-					   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-					   NULL, "cannot leave isolated mode");
+		return rte_flow_error_set(error, rte_errno,
+					  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+					  NULL, "cannot leave isolated mode");
 	}
 	return 0;
 }
diff --git a/drivers/net/tap/tap_flow.c b/drivers/net/tap/tap_flow.c
index eefa868..a790946 100644
--- a/drivers/net/tap/tap_flow.c
+++ b/drivers/net/tap/tap_flow.c
@@ -1447,7 +1447,7 @@ tap_flow_isolate(struct rte_eth_dev *dev,
 	return 0;
 error:
 	pmd->flow_isolate = 0;
-	return -rte_flow_error_set(
+	return rte_flow_error_set(
 		error, ENOTSUP, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
 		"TC rule creation failed");
 }
diff --git a/lib/librte_ether/rte_flow.c b/lib/librte_ether/rte_flow.c
index 2001fbb..34ce516 100644
--- a/lib/librte_ether/rte_flow.c
+++ b/lib/librte_ether/rte_flow.c
@@ -145,9 +145,9 @@ rte_flow_validate(uint8_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->validate))
 		return ops->validate(dev, attr, pattern, actions, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /* Create a flow rule on a given port. */
@@ -183,9 +183,9 @@ rte_flow_destroy(uint8_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->destroy))
 		return ops->destroy(dev, flow, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /* Destroy all flow rules associated with a port. */
@@ -200,9 +200,9 @@ rte_flow_flush(uint8_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->flush))
 		return ops->flush(dev, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /* Query an existing flow rule. */
@@ -220,9 +220,9 @@ rte_flow_query(uint8_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->query))
 		return ops->query(dev, flow, action, data, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /* Restrict ingress traffic to the defined flow rules. */
@@ -238,9 +238,9 @@ rte_flow_isolate(uint8_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->isolate))
 		return ops->isolate(dev, set, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /** Compute storage space needed by item specification. */
diff --git a/lib/librte_ether/rte_flow.h b/lib/librte_ether/rte_flow.h
index bba6169..ec42f02 100644
--- a/lib/librte_ether/rte_flow.h
+++ b/lib/librte_ether/rte_flow.h
@@ -43,6 +43,7 @@
  */
 
 #include <rte_arp.h>
+#include <rte_errno.h>
 #include <rte_ether.h>
 #include <rte_icmp.h>
 #include <rte_ip.h>
@@ -1270,6 +1271,41 @@ int
 rte_flow_isolate(uint8_t port_id, int set, struct rte_flow_error *error);
 
 /**
+ * Initialize flow error structure.
+ *
+ * @param[out] error
+ *   Pointer to flow error structure (may be NULL).
+ * @param code
+ *   Related error code (rte_errno).
+ * @param type
+ *   Cause field and error types.
+ * @param cause
+ *   Object responsible for the error.
+ * @param message
+ *   Human-readable error message.
+ *
+ * @return
+ *   Negative error code (errno value) and rte_errno is set.
+ */
+static inline int
+rte_flow_error_set(struct rte_flow_error *error,
+		   int code,
+		   enum rte_flow_error_type type,
+		   const void *cause,
+		   const char *message)
+{
+	if (error) {
+		*error = (struct rte_flow_error){
+			.type = type,
+			.cause = cause,
+			.message = message,
+		};
+	}
+	rte_errno = code;
+	return -code;
+}
+
+/**
  * Generic flow representation.
  *
  * This form is sufficient to describe an rte_flow independently from any
diff --git a/lib/librte_ether/rte_flow_driver.h b/lib/librte_ether/rte_flow_driver.h
index 4d95391..ea92fe7 100644
--- a/lib/librte_ether/rte_flow_driver.h
+++ b/lib/librte_ether/rte_flow_driver.h
@@ -45,7 +45,6 @@
 
 #include <stdint.h>
 
-#include <rte_errno.h>
 #include "rte_ethdev.h"
 #include "rte_flow.h"
 
@@ -128,43 +127,6 @@ struct rte_flow_ops {
 };
 
 /**
- * Initialize generic flow error structure.
- *
- * This function also sets rte_errno to a given value.
- *
- * @param[out] error
- *   Pointer to flow error structure (may be NULL).
- * @param code
- *   Related error code (rte_errno).
- * @param type
- *   Cause field and error types.
- * @param cause
- *   Object responsible for the error.
- * @param message
- *   Human-readable error message.
- *
- * @return
- *   Error code.
- */
-static inline int
-rte_flow_error_set(struct rte_flow_error *error,
-		   int code,
-		   enum rte_flow_error_type type,
-		   const void *cause,
-		   const char *message)
-{
-	if (error) {
-		*error = (struct rte_flow_error){
-			.type = type,
-			.cause = cause,
-			.message = message,
-		};
-	}
-	rte_errno = code;
-	return code;
-}
-
-/**
  * Get generic flow operations structure from a port.
  *
  * @param port_id
-- 
2.1.4