bus: add iterator to find a bus

This helper allows to iterate over all registered buses and find one
matching data used as parameter.

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>

diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
index 2e48a73..edf9d7d 100644 (file)
--- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
@@ -193,3 +193,10 @@ DPDK_17.05 {
        vfio_get_group_no;
 
 } DPDK_17.02;
+
+DPDK_17.08 {
+       global:
+
+       rte_bus_find;
+
+} DPDK_17.05;

diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
index 8f9baf8..3094daa 100644 (file)
--- a/lib/librte_eal/common/eal_common_bus.c
+++ b/lib/librte_eal/common/eal_common_bus.c
@@ -145,3 +145,22 @@ rte_bus_dump(FILE *f)
                }
        }
 }
+
+struct rte_bus *
+rte_bus_find(const struct rte_bus *start, rte_bus_cmp_t cmp,
+            const void *data)
+{
+       struct rte_bus *bus = NULL;
+       bool start_found = !start;
+
+       TAILQ_FOREACH(bus, &rte_bus_list, next) {
+               if (!start_found) {
+                       if (bus == start)
+                               start_found = 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..c52b65b 100644 (file)
--- a/lib/librte_eal/common/include/rte_bus.h
+++ b/lib/librte_eal/common/include/rte_bus.h
@@ -140,6 +140,48 @@ 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.
+ *
+ * This function compares each registered bus to find one that matches
+ * the data passed as parameter.
+ *
+ * If the comparison function returns zero this function will stop iterating
+ * over any more buses. To continue a search the bus of a previous search can
+ * be passed via the start parameter.
+ *
+ * @param start
+ *     Starting point for the iteration.
+ *
+ * @param cmp
+ *     Comparison function.
+ *
+ * @param data
+ *      Data to pass to comparison function.
+ *
+ * @return
+ *      A pointer to a rte_bus structure or NULL in case no bus matches
+ */
+struct rte_bus *rte_bus_find(const struct rte_bus *start, rte_bus_cmp_t cmp,
+                            const void *data);
+
 /**
  * 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..944416e 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -198,3 +198,10 @@ DPDK_17.05 {
        vfio_get_group_no;
 
 } DPDK_17.02;
+
+DPDK_17.08 {
+       global:
+
+       rte_bus_find;
+
+} DPDK_17.05;