[dpdk-dev] [PATCH v1 09/18] eal/dev: implement device iteration

Gaetan Rivet gaetan.rivet at 6wind.com
Thu Mar 15 18:49:39 CET 2018


Use the iteration hooks in the abstraction layers to perform the
requested filtering on the internal device lists.

Signed-off-by: Gaetan Rivet <gaetan.rivet at 6wind.com>
---
 lib/librte_eal/common/eal_common_dev.c  | 81 +++++++++++++++++++++++++++++++++
 lib/librte_eal/common/include/rte_dev.h | 25 ++++++++++
 lib/librte_eal/rte_eal_version.map      |  1 +
 3 files changed, 107 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
index bdab1423a..159fdcf73 100644
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -303,3 +303,84 @@ rte_dev_iterator_init(struct rte_dev_iterator *it, const char *str)
 	it->cls = cls;
 	return 0;
 }
+
+static int
+class_next_dev_cmp(const struct rte_class *cls,
+		   const void *_it)
+{
+	const struct rte_dev_iterator *cit = _it;
+	struct rte_dev_iterator *it;
+
+	if (cls->dev_iterate == NULL)
+		return 1;
+	/* We need a mutable iterator. */
+	it = (void *)(intptr_t)cit;
+	/* it->clsstr != NULL means a class
+	 * was specified in the devstr.
+	 */
+	if (it->clsstr != NULL && cls != it->cls)
+		return 1;
+	return cls->dev_iterate(it) == NULL;
+}
+
+static int
+bus_next_dev_cmp(const struct rte_bus *bus,
+		 const void *_it)
+{
+	const struct rte_dev_iterator *cit = _it;
+	struct rte_class *cls = NULL;
+	struct rte_dev_iterator *it;
+
+	if (bus->dev_iterate == NULL)
+		return 1;
+	/* We need a mutable iterator. */
+	it = (void *)(intptr_t)cit;
+	/* it->busstr != NULL means a bus
+	 * was specified in the devstr.
+	 */
+	if (it->busstr != NULL && bus != it->bus)
+		return 1;
+	if (it->clsstr == NULL)
+		return bus->dev_iterate(it) == NULL;
+	/* clsstr != NULL */
+	if (it->device == NULL)
+next_dev_on_bus:
+		bus->dev_iterate(it);
+	if (it->device == NULL)
+		return 1;
+	if (it->cls != NULL)
+		cls = TAILQ_PREV(it->cls, rte_class_list, next);
+	cls = rte_class_find(cls, class_next_dev_cmp, it);
+	if (cls != NULL) {
+		it->cls = cls;
+		return 0;
+	}
+	goto next_dev_on_bus;
+}
+__rte_experimental struct rte_device *
+rte_dev_iterator_next(struct rte_dev_iterator *it)
+{
+	struct rte_bus *bus = NULL;
+	int old_errno = rte_errno;
+
+	rte_errno = 0;
+	if (it->busstr == NULL && it->clsstr == NULL) {
+		/* Invalid iterator. */
+		rte_errno = EINVAL;
+		return NULL;
+	}
+	if (it->bus != NULL)
+		bus = TAILQ_PREV(it->bus, rte_bus_list, next);
+	while ((bus = rte_bus_find(bus, bus_next_dev_cmp, it))) {
+		if (it->device != NULL) {
+			it->bus = bus;
+			return it->device;
+		}
+		if (it->busstr != NULL ||
+		    rte_errno != 0)
+			break;
+	}
+	if (rte_errno == 0)
+		rte_errno = old_errno;
+	return NULL;
+}
diff --git a/lib/librte_eal/common/include/rte_dev.h b/lib/librte_eal/common/include/rte_dev.h
index 9b53f0ad3..11a6d786c 100644
--- a/lib/librte_eal/common/include/rte_dev.h
+++ b/lib/librte_eal/common/include/rte_dev.h
@@ -322,6 +322,31 @@ typedef struct rte_device *(*rte_dev_iterate_t)(struct rte_dev_iterator *it);
 int __rte_experimental
 rte_dev_iterator_init(struct rte_dev_iterator *it, const char *str);
 
+/**
+ * Iterates on a device iterator.
+ *
+ * Generates a new rte_device handle corresponding to the next element
+ * in the list described in comprehension by the iterator.
+ *
+ * The next object is returned, and the iterator is updated.
+ *
+ * @param it
+ *   Device iterator handle.
+ *
+ * @return
+ *   An rte_device handle if found.
+ *   NULL if an error occurred (rte_errno is set).
+ *   NULL if no device could be found (rte_errno is not set).
+ */
+struct rte_device * __rte_experimental
+rte_dev_iterator_next(struct rte_dev_iterator *it);
+
+#define RTE_DEV_FOREACH(dev, devstr, it) \
+	for (rte_dev_iterator_init(it, devstr), \
+	     dev = rte_dev_iterator_next(it); \
+	     dev != NULL; \
+	     dev = rte_dev_iterator_next(it))
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index 921da3075..925efcb6d 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -229,6 +229,7 @@ EXPERIMENTAL {
 	rte_mp_request;
 	rte_mp_reply;
 	rte_dev_iterator_init;
+	rte_dev_iterator_next;
 	rte_service_attr_get;
 	rte_service_attr_reset_all;
 	rte_service_component_register;
-- 
2.11.0



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