[dpdk-dev] [PATCH v10 13/27] eal/dev: implement device iteration

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

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@6wind.com>
---
 lib/librte_eal/common/eal_common_dev.c  | 168 ++++++++++++++++++++++++
 lib/librte_eal/common/include/rte_dev.h |  26 ++++
 lib/librte_eal/rte_eal_version.map      |   1 +
 3 files changed, 195 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
index 5b7956d17..3d486a841 100644
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -45,6 +45,28 @@ static struct dev_event_cb_list dev_event_cbs;
 /* spinlock for device callbacks */
 static rte_spinlock_t dev_event_lock = RTE_SPINLOCK_INITIALIZER;
 
+struct dev_next_ctx {
+	struct rte_dev_iterator *it;
+	const char *busstr;
+	const char *clsstr;
+};
+
+#define CTX(it, busstr, clsstr) \
+	(&(const struct dev_next_ctx){ \
+		.it = it, \
+		.busstr = busstr, \
+		.clsstr = clsstr, \
+	})
+
+#define ITCTX(ptr) \
+	(((struct dev_next_ctx *)(intptr_t)ptr)->it)
+
+#define BUSCTX(ptr) \
+	(((struct dev_next_ctx *)(intptr_t)ptr)->busstr)
+
+#define CLSCTX(ptr) \
+	(((struct dev_next_ctx *)(intptr_t)ptr)->clsstr)
+
 static int cmp_detached_dev_name(const struct rte_device *dev,
 	const void *_name)
 {
@@ -398,3 +420,149 @@ rte_dev_iterator_init(struct rte_dev_iterator *it,
 get_out:
 	return -rte_errno;
 }
+
+static char *
+dev_str_sane_copy(const char *str)
+{
+	size_t end;
+	char *copy;
+
+	end = strcspn(str, ",/");
+	if (str[end] == ',') {
+		copy = strdup(&str[end + 1]);
+	} else {
+		/* '/' or '\0' */
+		copy = strdup("");
+	}
+	if (copy == NULL) {
+		rte_errno = ENOMEM;
+	} else {
+		char *slash;
+
+		slash = strchr(copy, '/');
+		if (slash != NULL)
+			slash[0] = '\0';
+	}
+	return copy;
+}
+
+static int
+class_next_dev_cmp(const struct rte_class *cls,
+		   const void *ctx)
+{
+	struct rte_dev_iterator *it;
+	const char *clsstr = NULL;
+	void *dev;
+
+	if (cls->dev_iterate == NULL)
+		return 1;
+	it = ITCTX(ctx);
+	clsstr = CLSCTX(ctx);
+	dev = it->class_device;
+	/* it->clsstr != NULL means a class
+	 * was specified in the devstr.
+	 */
+	if (it->clsstr != NULL && cls != it->cls)
+		return 1;
+	/* If an error occurred previously,
+	 * no need to test further.
+	 */
+	if (rte_errno != 0)
+		return -1;
+	dev = cls->dev_iterate(dev, clsstr, it);
+	it->class_device = dev;
+	return dev == NULL;
+}
+
+static int
+bus_next_dev_cmp(const struct rte_bus *bus,
+		 const void *ctx)
+{
+	struct rte_device *dev = NULL;
+	struct rte_class *cls = NULL;
+	struct rte_dev_iterator *it;
+	const char *busstr = NULL;
+
+	if (bus->dev_iterate == NULL)
+		return 1;
+	it = ITCTX(ctx);
+	busstr = BUSCTX(ctx);
+	dev = it->device;
+	/* it->busstr != NULL means a bus
+	 * was specified in the devstr.
+	 */
+	if (it->busstr != NULL && bus != it->bus)
+		return 1;
+	/* If an error occurred previously,
+	 * no need to test further.
+	 */
+	if (rte_errno != 0)
+		return -1;
+	if (it->clsstr == NULL) {
+		dev = bus->dev_iterate(dev, busstr, it);
+		goto end;
+	}
+	/* clsstr != NULL */
+	if (dev == NULL) {
+next_dev_on_bus:
+		dev = bus->dev_iterate(dev, busstr, it);
+		it->device = dev;
+	}
+	if (dev == 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, ctx);
+	if (cls != NULL) {
+		it->cls = cls;
+		goto end;
+	}
+	goto next_dev_on_bus;
+end:
+	it->device = dev;
+	return dev == NULL;
+}
+__rte_experimental
+struct rte_device *
+rte_dev_iterator_next(struct rte_dev_iterator *it)
+{
+	struct rte_bus *bus = NULL;
+	int old_errno = rte_errno;
+	char *busstr = NULL;
+	char *clsstr = NULL;
+
+	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);
+	if (it->busstr != NULL) {
+		busstr = dev_str_sane_copy(it->busstr);
+		if (busstr == NULL)
+			goto out;
+	}
+	if (it->clsstr != NULL) {
+		clsstr = dev_str_sane_copy(it->clsstr);
+		if (clsstr == NULL)
+			goto out;
+	}
+	while ((bus = rte_bus_find(bus, bus_next_dev_cmp,
+				   CTX(it, busstr, clsstr)))) {
+		if (it->device != NULL) {
+			it->bus = bus;
+			goto out;
+		}
+		if (it->busstr != NULL ||
+		    rte_errno != 0)
+			break;
+	}
+	if (rte_errno == 0)
+		rte_errno = old_errno;
+out:
+	free(busstr);
+	free(clsstr);
+	return it->device;
+}
diff --git a/lib/librte_eal/common/include/rte_dev.h b/lib/librte_eal/common/include/rte_dev.h
index 7b7bd83bc..1553c0970 100644
--- a/lib/librte_eal/common/include/rte_dev.h
+++ b/lib/librte_eal/common/include/rte_dev.h
@@ -356,6 +356,32 @@ __rte_experimental
 int
 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).
+ */
+__rte_experimental
+struct rte_device *
+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 ac04120d6..4cd5ab3df 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -252,6 +252,7 @@ EXPERIMENTAL {
 	rte_dev_event_monitor_start;
 	rte_dev_event_monitor_stop;
 	rte_dev_iterator_init;
+	rte_dev_iterator_next;
 	rte_devargs_add;
 	rte_devargs_dump;
 	rte_devargs_insert;
-- 
2.18.0