raw/ioat: add device info function

Add in the "info_get" function to the driver, to allow us to query the
device. This allows us to have the unit test pick up the presence of
supported hardware or not.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Jiayu Hu <jiayu.hu@intel.com>
Tested-by: Harry van Haaren <harry.van.haaren@intel.com>

app/test/test_rawdev.c

@@ -29,6 +29,17 @@ REGISTER_TEST_COMMAND(rawdev_autotest, test_rawdev_selftest_skeleton);
 static int
 test_rawdev_selftest_ioat(void)
 {
+	const int count = rte_rawdev_count();
+	int i;
+
+	for (i = 0; i < count; i++) {
+		struct rte_rawdev_info info = { .dev_private = NULL };
+		if (rte_rawdev_info_get(i, &info) == 0 &&
+				strstr(info.driver_name, "ioat") != NULL)
+			return TEST_SUCCESS;
+	}
+
+	printf("No IOAT rawdev found, skipping tests\n");
 	return TEST_SKIPPED;
 }
 

doc/guides/rawdevs/ioat_rawdev.rst

@@ -83,3 +83,37 @@ parameters need to be passed to create or initialize the device.
 Once probed successfully, the device will appear as a ``rawdev``, that is a
 "raw device type" inside DPDK, and can be accessed using APIs from the
 ``rte_rawdev`` library.
+
+Using IOAT Rawdev Devices
+--------------------------
+
+To use the devices from an application, the rawdev API can be used, along
+with definitions taken from the device-specific header file
+``rte_ioat_rawdev.h``. This header is needed to get the definition of
+structure parameters used by some of the rawdev APIs for IOAT rawdev
+devices, as well as providing key functions for using the device for memory
+copies.
+
+Getting Device Information
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Basic information about each rawdev device can be queried using the
+``rte_rawdev_info_get()`` API. For most applications, this API will be
+needed to verify that the rawdev in question is of the expected type. For
+example, the following code snippet can be used to identify an IOAT
+rawdev device for use by an application:
+
+.. code-block:: C
+
+        for (i = 0; i < count && !found; i++) {
+                struct rte_rawdev_info info = { .dev_private = NULL };
+                found = (rte_rawdev_info_get(i, &info) == 0 &&
+                                strcmp(info.driver_name,
+                                                IOAT_PMD_RAWDEV_NAME_STR) == 0);
+        }
+
+When calling the ``rte_rawdev_info_get()`` API for an IOAT rawdev device,
+the ``dev_private`` field in the ``rte_rawdev_info`` struct should either
+be NULL, or else be set to point to a structure of type
+``rte_ioat_rawdev_config``, in which case the size of the configured device
+input ring will be returned in that structure.

drivers/raw/ioat/ioat_rawdev.c

@@ -34,10 +34,21 @@ static struct rte_pci_driver ioat_pmd_drv;
 #define IOAT_PMD_ERR(fmt, args...)    IOAT_PMD_LOG(ERR, fmt, ## args)
 #define IOAT_PMD_WARN(fmt, args...)   IOAT_PMD_LOG(WARNING, fmt, ## args)
 
+static void
+ioat_dev_info_get(struct rte_rawdev *dev, rte_rawdev_obj_t dev_info)
+{
+	struct rte_ioat_rawdev_config *cfg = dev_info;
+	struct rte_ioat_rawdev *ioat = dev->dev_private;
+
+	if (cfg != NULL)
+		cfg->ring_size = ioat->ring_size;
+}
+
 static int
 ioat_rawdev_create(const char *name, struct rte_pci_device *dev)
 {
 	static const struct rte_rawdev_ops ioat_rawdev_ops = {
+			.dev_info_get = ioat_dev_info_get,
 	};
 
 	struct rte_rawdev *rawdev = NULL;

drivers/raw/ioat/rte_ioat_rawdev.h

@@ -25,6 +25,17 @@
 /** Name used to adjust the log level for this driver */
 #define IOAT_PMD_LOG_NAME "rawdev.ioat"
 
+/**
+ * Configuration structure for an ioat rawdev instance
+ *
+ * This structure is to be passed as the ".dev_private" parameter when
+ * calling the rte_rawdev_get_info() and rte_rawdev_configure() APIs on
+ * an ioat rawdev instance.
+ */
+struct rte_ioat_rawdev_config {
+	unsigned short ring_size;
+};
+
 /**
  * @internal
  * Structure representing a device instance