[dpdk-dev] [PATCH v4 3/6] ethdev: allow iterating with pure class filter

[Thomas Monjalon <thomas@monjalon.net>]

If no rte_device is given in the iterator,
eth_dev_match() is looking at all ports without any restriction,
except the ethdev kvargs filter.

It allows to iterate with a devargs filter referencing only
some ethdev parameters. The format (from the new devargs syntax) is:
	class=eth,paramY=Y

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 lib/librte_ethdev/rte_class_eth.c |  2 +-
 lib/librte_ethdev/rte_ethdev.c    | 25 ++++++++++++++++++++++---
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/lib/librte_ethdev/rte_class_eth.c b/lib/librte_ethdev/rte_class_eth.c
index c04279ec6..58fed694b 100644
--- a/lib/librte_ethdev/rte_class_eth.c
+++ b/lib/librte_ethdev/rte_class_eth.c
@@ -42,7 +42,7 @@ eth_dev_match(const struct rte_eth_dev *edev,
 
 	if (edev->state == RTE_ETH_DEV_UNUSED)
 		return -1;
-	if (edev->device != arg->device)
+	if (arg->device != NULL && arg->device != edev->device)
 		return -1;
 	if (kvlist == NULL)
 		/* Empty string matches everything. */
diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 73919149a..f195ea917 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -199,10 +199,24 @@ rte_eth_iterator_init(struct rte_dev_iterator *iter, const char *devargs_str)
 	 * The devargs string may use various syntaxes:
 	 *   - 0000:08:00.0,representor=[1-3]
 	 *   - pci:0000:06:00.0,representor=[0,5]
+	 *   - class=eth,mac=00:11:22:33:44:55
 	 * A new syntax is in development (not yet supported):
 	 *   - bus=X,paramX=x/class=Y,paramY=y/driver=Z,paramZ=z
 	 */
 
+	/*
+	 * Handle pure class filter (i.e. without any bus-level argument),
+	 * from future new syntax.
+	 * rte_devargs_parse() is not yet supporting the new syntax,
+	 * that's why this simple case is temporarily parsed here.
+	 */
+#define iter_anybus_str "class=eth,"
+	if (strncmp(devargs_str, iter_anybus_str,
+			strlen(iter_anybus_str)) == 0) {
+		iter->cls_str = devargs_str + strlen(iter_anybus_str);
+		goto end;
+	}
+
 	/* Split bus, device and parameters. */
 	ret = rte_devargs_parse(&devargs, devargs_str);
 	if (ret != 0)
@@ -256,6 +270,7 @@ rte_eth_iterator_init(struct rte_dev_iterator *iter, const char *devargs_str)
 	}
 	iter->bus_str = bus_str;
 
+end:
 	iter->cls = rte_class_find_by_name("eth");
 	return 0;
 
@@ -276,8 +291,10 @@ rte_eth_iterator_next(struct rte_dev_iterator *iter)
 		return RTE_MAX_ETHPORTS;
 
 	do { /* loop to try all matching rte_device */
-		/* If not in middle of rte_eth_dev iteration, */
-		if (iter->class_device == NULL) {
+		/* If not pure ethdev filter and */
+		if (iter->bus != NULL &&
+				/* not in middle of rte_eth_dev iteration, */
+				iter->class_device == NULL) {
 			/* get next rte_device to try. */
 			iter->device = iter->bus->dev_iterate(
 					iter->device, iter->bus_str, iter);
@@ -289,7 +306,7 @@ rte_eth_iterator_next(struct rte_dev_iterator *iter)
 				iter->class_device, iter->cls_str, iter);
 		if (iter->class_device != NULL)
 			return eth_dev_to_id(iter->class_device); /* match */
-	} while (1); /* need to try next rte_device */
+	} while (iter->bus != NULL); /* need to try next rte_device */
 
 	/* No more ethdev port to iterate. */
 	rte_eth_iterator_cleanup(iter);
@@ -299,6 +316,8 @@ rte_eth_iterator_next(struct rte_dev_iterator *iter)
 void __rte_experimental
 rte_eth_iterator_cleanup(struct rte_dev_iterator *iter)
 {
+	if (iter->bus_str == NULL)
+		return; /* nothing to free in pure class filter */
 	free(RTE_CAST_FIELD(iter, bus_str, char *)); /* workaround const */
 	free(RTE_CAST_FIELD(iter, cls_str, char *)); /* workaround const */
 	memset(iter, 0, sizeof(*iter));
-- 
2.19.0