[dpdk-dev] [PATCH v4 1/9] bus: add bus iterator to find a particular bus

[Gaetan Rivet <gaetan.rivet@6wind.com>]

From: Jan Blunck <jblunck@infradead.org>

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
---
 lib/librte_eal/bsdapp/eal/rte_eal_version.map   |  1 +
 lib/librte_eal/common/eal_common_bus.c          | 20 ++++++++++++
 lib/librte_eal/common/include/rte_bus.h         | 41 +++++++++++++++++++++++++
 lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
 4 files changed, 63 insertions(+)

diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
index 2e48a73..ed09ab2 100644
--- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
@@ -162,6 +162,7 @@ DPDK_17.02 {
 DPDK_17.05 {
 	global:
 
+	rte_bus_find;
 	rte_cpu_is_supported;
 	rte_log_dump;
 	rte_log_register;
diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
index 8f9baf8..4619eb2 100644
--- a/lib/librte_eal/common/eal_common_bus.c
+++ b/lib/librte_eal/common/eal_common_bus.c
@@ -145,3 +145,23 @@ rte_bus_dump(FILE *f)
 		}
 	}
 }
+
+struct rte_bus *
+rte_bus_find(rte_bus_cmp_t cmp,
+	     const void *data,
+	     const struct rte_bus *start)
+{
+	struct rte_bus *bus = NULL;
+	int started = start == NULL;
+
+	TAILQ_FOREACH(bus, &rte_bus_list, next) {
+		if (!started) {
+			if (bus == start)
+				started = 1;
+			continue;
+		}
+		if (cmp(bus, data) == 0)
+			break;
+	}
+	return bus;
+}
diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
index 5f47b82..3e26d4b 100644
--- a/lib/librte_eal/common/include/rte_bus.h
+++ b/lib/librte_eal/common/include/rte_bus.h
@@ -141,6 +141,47 @@ int rte_bus_probe(void);
 void rte_bus_dump(FILE *f);
 
 /**
+ * Bus comparison function.
+ *
+ * @param bus
+ *	Bus under test.
+ *
+ * @param data
+ *	Data to compare against.
+ *
+ * @return
+ *	0 if the bus matches the data.
+ *	!0 if the bus does not match.
+ *	<0 if ordering is possible and the bus is lower than the data.
+ *	>0 if ordering is possible and the bus is greater than the data.
+ */
+typedef int (*rte_bus_cmp_t)(const struct rte_bus *bus, const void *data);
+
+/**
+ * Bus iterator to find a particular bus.
+ *
+ * If the callback returns zero this function will stop iterating over
+ * any more buses.
+ * If the start parameter is non-NULL, the comparison will only be determined
+ * past this element.
+ *
+ * @param cmp
+ *	Comparison function.
+ *
+ * @param data
+ *	 Data to pass to cmp callback
+ *
+ * @param start
+ *	Starting point for the iteration.
+ *
+ * @return
+ *	 A pointer to a rte_bus structure or NULL in case no bus matches
+ */
+struct rte_bus *rte_bus_find(rte_bus_cmp_t cmp,
+			     const void *data,
+			     const struct rte_bus *start);
+
+/**
  * Helper for Bus registration.
  * The constructor has higher priority than PMD constructors.
  */
diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
index 670bab3..6efa517 100644
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -166,6 +166,7 @@ DPDK_17.02 {
 DPDK_17.05 {
 	global:
 
+	rte_bus_find;
 	rte_cpu_is_supported;
 	rte_intr_free_epoll_fd;
 	rte_log_dump;
-- 
2.1.4