[PATCH v3 04/10] bus: add bus helper iterator to find a particular device

[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          | 25 +++++++++++++++++++++++++
 lib/librte_eal/common/include/rte_bus.h         | 23 +++++++++++++++++++++++
 lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
 4 files changed, 50 insertions(+)

diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
index f1a0765..21640d6 100644
--- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
@@ -164,6 +164,7 @@ DPDK_17.05 {
 
 	rte_bus_find;
 	rte_bus_find_by_device;
+	rte_bus_find_device;
 	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 42f1076..451884f 100644
--- a/lib/librte_eal/common/eal_common_bus.c
+++ b/lib/librte_eal/common/eal_common_bus.c
@@ -180,3 +180,28 @@ struct rte_bus *rte_bus_find_by_device(const struct rte_device *dev)
 {
 	return rte_bus_find(bus_find_device, (const void *)dev);
 }
+
+struct rte_device *
+rte_bus_find_device(const struct rte_device *start,
+		    rte_dev_cmp_t cmp, const void *data)
+{
+	struct rte_bus *bus;
+	struct rte_device *dev = NULL;
+	int start_seen = 0;
+
+	TAILQ_FOREACH(bus, &rte_bus_list, next) {
+		if (!bus->find_device)
+			continue;
+		if (!!start ^ start_seen) {
+			dev = bus->find_device(cmp_rte_device, start);
+			if (dev)
+				start_seen = 1;
+			else
+				continue;
+		}
+		dev = bus->find_device(cmp, data);
+		if (dev)
+			break;
+	}
+	return dev;
+}
diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
index b3bc6e8..eba407d 100644
--- a/lib/librte_eal/common/include/rte_bus.h
+++ b/lib/librte_eal/common/include/rte_bus.h
@@ -182,6 +182,29 @@ typedef int (*rte_bus_cmp_t)(const struct rte_bus *bus, const void *data);
 struct rte_bus *rte_bus_find(rte_bus_cmp_t cmp, const void *data);
 
 /**
+ * Bus iterator to find a particular device.
+ *
+ * If the callback returns non-zero this function will stop iterating over any
+ * more buses and devices. To continue a search the device of a previous search
+ * is passed via the start parameters.
+ *
+ * @param start
+ *	 Start device of the iteration.
+ *
+ * @param cmp
+ *	 Callback function to check device.
+ *
+ * @param data
+ *	 Data to pass to match callback.
+ *
+ * @return
+ *	 A pointer to a rte_bus structure or NULL in case no bus matches.
+ */
+struct rte_device *
+rte_bus_find_device(const struct rte_device *start,
+		    rte_dev_cmp_t cmp, const void *data);
+
+/**
  * Find the registered bus for a particular device.
  */
 struct rte_bus *rte_bus_find_by_device(const struct rte_device *dev);
diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
index 6f77222..e0a056d 100644
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -168,6 +168,7 @@ DPDK_17.05 {
 
 	rte_bus_find;
 	rte_bus_find_by_device;
+	rte_bus_find_device;
 	rte_cpu_is_supported;
 	rte_intr_free_epoll_fd;
 	rte_log_dump;
-- 
2.1.4