[dpdk-dev] [PATCH v10 12/27] eal/dev: implement device iteration initialization

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

Parse a device description.
Split this description in their relevant part for each layers.
No dynamic allocation is performed.

Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
---
 lib/Makefile                            |  1 +
 lib/librte_eal/bsdapp/eal/Makefile      |  1 +
 lib/librte_eal/common/eal_common_dev.c  | 55 +++++++++++++++++++++++++
 lib/librte_eal/common/include/rte_dev.h | 24 +++++++++++
 lib/librte_eal/linuxapp/eal/Makefile    |  1 +
 lib/librte_eal/rte_eal_version.map      |  1 +
 6 files changed, 83 insertions(+)

diff --git a/lib/Makefile b/lib/Makefile
index 8a65525cd..afa604e20 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -7,6 +7,7 @@ DIRS-y += librte_compat
 DIRS-$(CONFIG_RTE_LIBRTE_KVARGS) += librte_kvargs
 DEPDIRS-librte_kvargs := librte_compat
 DIRS-$(CONFIG_RTE_LIBRTE_EAL) += librte_eal
+DEPDIRS-librte_eal := librte_kvargs
 DIRS-$(CONFIG_RTE_LIBRTE_PCI) += librte_pci
 DEPDIRS-librte_pci := librte_eal
 DIRS-$(CONFIG_RTE_LIBRTE_RING) += librte_ring
diff --git a/lib/librte_eal/bsdapp/eal/Makefile b/lib/librte_eal/bsdapp/eal/Makefile
index b0a1c880a..67b10ae0d 100644
--- a/lib/librte_eal/bsdapp/eal/Makefile
+++ b/lib/librte_eal/bsdapp/eal/Makefile
@@ -18,6 +18,7 @@ CFLAGS += $(WERROR_FLAGS) -O3
 LDLIBS += -lexecinfo
 LDLIBS += -lpthread
 LDLIBS += -lgcc_s
+LDLIBS += -lrte_kvargs
 
 EXPORT_MAP := ../../rte_eal_version.map
 
diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
index ce4b51469..5b7956d17 100644
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -10,9 +10,12 @@
 
 #include <rte_compat.h>
 #include <rte_bus.h>
+#include <rte_class.h>
 #include <rte_dev.h>
 #include <rte_devargs.h>
 #include <rte_debug.h>
+#include <rte_errno.h>
+#include <rte_kvargs.h>
 #include <rte_log.h>
 #include <rte_spinlock.h>
 #include <rte_malloc.h>
@@ -343,3 +346,55 @@ dev_callback_process(char *device_name, enum rte_dev_event_type event)
 	}
 	rte_spinlock_unlock(&dev_event_lock);
 }
+
+__rte_experimental
+int
+rte_dev_iterator_init(struct rte_dev_iterator *it,
+		      const char *devstr)
+{
+	struct rte_devargs da;
+	struct rte_class *cls = NULL;
+	struct rte_bus *bus = NULL;
+
+	/* Having both busstr and clsstr NULL is illegal,
+	 * marking this iterator as invalid unless
+	 * everything goes well.
+	 */
+	it->busstr = NULL;
+	it->clsstr = NULL;
+
+	da.data = devstr;
+	if (rte_devargs_layers_parse(&da, devstr))
+		goto get_out;
+
+	bus = da.bus;
+	cls = da.cls;
+	/* The string should have at least
+	 * one layer specified.
+	 */
+	if (bus == NULL && cls == NULL) {
+		RTE_LOG(ERR, EAL,
+			"Either bus or class must be specified.\n");
+		rte_errno = EINVAL;
+		goto get_out;
+	}
+	if (bus != NULL && bus->dev_iterate == NULL) {
+		RTE_LOG(ERR, EAL, "Bus %s not supported\n", bus->name);
+		rte_errno = ENOTSUP;
+		goto get_out;
+	}
+	if (cls != NULL && cls->dev_iterate == NULL) {
+		RTE_LOG(ERR, EAL, "Class %s not supported\n", cls->name);
+		rte_errno = ENOTSUP;
+		goto get_out;
+	}
+	it->busstr = da.busstr;
+	it->clsstr = da.clsstr;
+	it->devstr = devstr;
+	it->bus = bus;
+	it->cls = cls;
+	it->device = NULL;
+	it->class_device = NULL;
+get_out:
+	return -rte_errno;
+}
diff --git a/lib/librte_eal/common/include/rte_dev.h b/lib/librte_eal/common/include/rte_dev.h
index 120df729f..7b7bd83bc 100644
--- a/lib/librte_eal/common/include/rte_dev.h
+++ b/lib/librte_eal/common/include/rte_dev.h
@@ -332,6 +332,30 @@ typedef void *(*rte_dev_iterate_t)(const void *start,
 				   const char *devstr,
 				   const struct rte_dev_iterator *it);
 
+/**
+ * Initializes a device iterator.
+ *
+ * This iterator allows accessing a list of devices matching a criteria.
+ * The device matching is made among all buses and classes currently registered,
+ * filtered by the device description given as parameter.
+ *
+ * This function will not allocate any memory. It is safe to stop the
+ * iteration at any moment and let the iterator go out of context.
+ *
+ * @param it
+ *   Device iterator handle.
+ *
+ * @param str
+ *   Device description string.
+ *
+ * @return
+ *   0 on successful initialization.
+ *   <0 on error.
+ */
+__rte_experimental
+int
+rte_dev_iterator_init(struct rte_dev_iterator *it, const char *str);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_eal/linuxapp/eal/Makefile b/lib/librte_eal/linuxapp/eal/Makefile
index babc8617a..885c48110 100644
--- a/lib/librte_eal/linuxapp/eal/Makefile
+++ b/lib/librte_eal/linuxapp/eal/Makefile
@@ -27,6 +27,7 @@ LDLIBS += -lrt
 ifeq ($(CONFIG_RTE_EAL_NUMA_AWARE_HUGEPAGES),y)
 LDLIBS += -lnuma
 endif
+LDLIBS += -lrte_kvargs
 
 # specific to linuxapp exec-env
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) := eal.c
diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index 19d36b4c7..ac04120d6 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -251,6 +251,7 @@ EXPERIMENTAL {
 	rte_dev_event_callback_unregister;
 	rte_dev_event_monitor_start;
 	rte_dev_event_monitor_stop;
+	rte_dev_iterator_init;
 	rte_devargs_add;
 	rte_devargs_dump;
 	rte_devargs_insert;
-- 
2.18.0