[dpdk-dev] [PATCH v3 2/8] devargs: introduce removal function

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

Hotplug support introduces the possibility of removing devices from the
system. Allocated resources must be freed.

Extend the rte_devargs API to allow freeing allocated resources.

This API is experimental and bound to change. It is currently designed
as a symetrical to rte_eal_devargs_add(), but the latter will evolve
shortly anyway.

Its DEVTYPE parameter is currently only used to specify scan policies,
and those will evolve in the next release. This evolution should
rationalize the rte_devargs API.

As such, the proposed API here is not the most convenient, but is
taylored to follow the current design and integrate easily with its main
use within rte_eal_hotplug_* functions.

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_devargs.c      | 19 +++++++++++++++++++
 lib/librte_eal/common/include/rte_devargs.h     | 18 ++++++++++++++++++
 lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
 4 files changed, 39 insertions(+)

diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
index 381f895..40cd523 100644
--- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
@@ -207,6 +207,7 @@ EXPERIMENTAL {
 	global:
 
 	rte_eal_devargs_parse;
+	rte_eal_devargs_remove;
 	rte_eal_hotplug_add;
 	rte_eal_hotplug_remove;
 
diff --git a/lib/librte_eal/common/eal_common_devargs.c b/lib/librte_eal/common/eal_common_devargs.c
index 49d43a3..bcdee13 100644
--- a/lib/librte_eal/common/eal_common_devargs.c
+++ b/lib/librte_eal/common/eal_common_devargs.c
@@ -41,6 +41,7 @@
 #include <string.h>
 
 #include <rte_devargs.h>
+#include <rte_tailq.h>
 #include "eal_private.h"
 
 /** Global list of user devices */
@@ -182,6 +183,24 @@ rte_eal_devargs_add(enum rte_devtype devtype, const char *devargs_str)
 	return -1;
 }
 
+int
+rte_eal_devargs_remove(const char *busname, const char *devname)
+{
+	struct rte_devargs *d;
+	void *tmp;
+
+	TAILQ_FOREACH_SAFE(d, &devargs_list, next, tmp) {
+		if (strcmp(d->bus->name, busname) == 0 &&
+		    strcmp(d->name, devname) == 0) {
+			TAILQ_REMOVE(&devargs_list, d, next);
+			free(d->args);
+			free(d);
+			return 0;
+		}
+	}
+	return 1;
+}
+
 /* count the number of devices of a specified type */
 unsigned int
 rte_eal_devargs_type_count(enum rte_devtype devtype)
diff --git a/lib/librte_eal/common/include/rte_devargs.h b/lib/librte_eal/common/include/rte_devargs.h
index a0427cd..36453b6 100644
--- a/lib/librte_eal/common/include/rte_devargs.h
+++ b/lib/librte_eal/common/include/rte_devargs.h
@@ -163,6 +163,24 @@ rte_eal_devargs_parse(const char *dev,
 int rte_eal_devargs_add(enum rte_devtype devtype, const char *devargs_str);
 
 /**
+ * Remove a device from the user device list.
+ * Its resources are freed.
+ * If the devargs cannot be found, nothing happens.
+ *
+ * @param busname
+ *   bus name of the devargs to remove.
+ *
+ * @param devname
+ *   device name of the devargs to remove.
+ *
+ * @return
+ *   0 on success.
+ *   <0 on error.
+ *   >0 if the devargs was not within the user device list.
+ */
+int rte_eal_devargs_remove(const char *busname, const char *devname);
+
+/**
  * Count the number of user devices of a specified type
  *
  * @param devtype
diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
index 0f9e009..a8ee349 100644
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -212,6 +212,7 @@ EXPERIMENTAL {
 	global:
 
 	rte_eal_devargs_parse;
+	rte_eal_devargs_remove;
 	rte_eal_hotplug_add;
 	rte_eal_hotplug_remove;
 
-- 
2.1.4