bus/cdx: support plug unplug and dev iterator

This change adds support for plugging and unplugging
CDX devices on AMD CDX bus. Also, CDX dev iterator support
has been added for the CDX bus.

Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Acked-by: Ferruh Yigit <ferruh.yigit@amd.com>
Signed-off-by: 0-day Robot <robot@bytheb.org>

drivers/bus/cdx/bus_cdx_driver.h

@@ -52,6 +52,7 @@ struct rte_cdx_id {
 struct rte_cdx_device {
 	RTE_TAILQ_ENTRY(rte_cdx_device) next;	/**< Next probed CDX device. */
 	struct rte_device device;		/**< Inherit core device */
+	struct rte_cdx_driver *driver;		/**< CDX driver used in probing */
 	char name[RTE_DEV_NAME_MAX_LEN];	/**< Device name */
 	struct rte_cdx_id id;			/**< CDX ID. */
 	struct rte_mem_resource mem_resource[CDX_MAX_RESOURCE];

drivers/bus/cdx/cdx.c

@@ -71,6 +71,7 @@
 #include <rte_eal_paging.h>
 #include <rte_errno.h>
 #include <rte_devargs.h>
+#include <rte_kvargs.h>
 #include <rte_malloc.h>
 #include <rte_vfio.h>
 
@@ -92,6 +93,15 @@
 
 struct rte_cdx_bus rte_cdx_bus;
 
+enum cdx_params {
+	RTE_CDX_PARAM_NAME,
+};
+
+static const char * const cdx_params_keys[] = {
+	[RTE_CDX_PARAM_NAME] = "name",
+	NULL,
+};
+
 /* Add a device to CDX bus */
 static void
 cdx_add_device(struct rte_cdx_device *cdx_dev)
@@ -385,6 +395,7 @@ cdx_probe_one_driver(struct rte_cdx_driver *dr,
 	} else {
 		dev->device.driver = &dr->driver;
 	}
+	dev->driver = dr;
 
 	return ret;
 
@@ -499,6 +510,71 @@ cdx_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
 	return NULL;
 }
 
+/* Remove a device from CDX bus */
+static void
+cdx_remove_device(struct rte_cdx_device *cdx_dev)
+{
+	TAILQ_REMOVE(&rte_cdx_bus.device_list, cdx_dev, next);
+}
+
+/*
+ * If vendor/device ID match, call the remove() function of the
+ * driver.
+ */
+static int
+cdx_detach_dev(struct rte_cdx_device *dev)
+{
+	struct rte_cdx_driver *dr;
+	int ret = 0;
+
+	if (dev == NULL)
+		return -EINVAL;
+
+	dr = dev->driver;
+
+	CDX_BUS_DEBUG("detach device %s using driver: %s",
+		dev->device.name, dr->driver.name);
+
+	if (dr->remove) {
+		ret = dr->remove(dev);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* clear driver structure */
+	dev->driver = NULL;
+	dev->device.driver = NULL;
+
+	rte_cdx_unmap_device(dev);
+
+	rte_intr_instance_free(dev->intr_handle);
+	dev->intr_handle = NULL;
+
+	return 0;
+}
+
+static int
+cdx_plug(struct rte_device *dev)
+{
+	return cdx_probe_all_drivers(RTE_DEV_TO_CDX_DEV(dev));
+}
+
+static int
+cdx_unplug(struct rte_device *dev)
+{
+	struct rte_cdx_device *cdx_dev;
+	int ret;
+
+	cdx_dev = RTE_DEV_TO_CDX_DEV(dev);
+	ret = cdx_detach_dev(cdx_dev);
+	if (ret == 0) {
+		cdx_remove_device(cdx_dev);
+		rte_devargs_remove(dev->devargs);
+		free(cdx_dev);
+	}
+	return ret;
+}
+
 static int
 cdx_dma_map(struct rte_device *dev, void *addr, uint64_t iova, size_t len)
 {
@@ -526,15 +602,61 @@ cdx_get_iommu_class(void)
 	return RTE_IOVA_VA;
 }
 
+static int
+cdx_dev_match(const struct rte_device *dev,
+		const void *_kvlist)
+{
+	const struct rte_kvargs *kvlist = _kvlist;
+	const char *key = cdx_params_keys[RTE_CDX_PARAM_NAME];
+	const char *name;
+
+	/* no kvlist arg, all devices match */
+	if (kvlist == NULL)
+		return 0;
+
+	/* if key is present in kvlist and does not match, filter device */
+	name = rte_kvargs_get(kvlist, key);
+	if (name != NULL && strcmp(name, dev->name))
+		return -1;
+
+	return 0;
+}
+
+static void *
+cdx_dev_iterate(const void *start,
+		const char *str,
+		const struct rte_dev_iterator *it __rte_unused)
+{
+	rte_bus_find_device_t find_device;
+	struct rte_kvargs *kvargs = NULL;
+	struct rte_device *dev;
+
+	if (str != NULL) {
+		kvargs = rte_kvargs_parse(str, cdx_params_keys);
+		if (kvargs == NULL) {
+			CDX_BUS_ERR("cannot parse argument list %s", str);
+			rte_errno = EINVAL;
+			return NULL;
+		}
+	}
+	find_device = rte_cdx_bus.bus.find_device;
+	dev = find_device(start, cdx_dev_match, kvargs);
+	rte_kvargs_free(kvargs);
+	return dev;
+}
+
 struct rte_cdx_bus rte_cdx_bus = {
 	.bus = {
 		.scan = cdx_scan,
 		.probe = cdx_probe,
 		.find_device = cdx_find_device,
+		.plug = cdx_plug,
+		.unplug = cdx_unplug,
 		.parse = cdx_parse,
 		.dma_map = cdx_dma_map,
 		.dma_unmap = cdx_dma_unmap,
 		.get_iommu_class = cdx_get_iommu_class,
+		.dev_iterate = cdx_dev_iterate,
 	},
 	.device_list = TAILQ_HEAD_INITIALIZER(rte_cdx_bus.device_list),
 	.driver_list = TAILQ_HEAD_INITIALIZER(rte_cdx_bus.driver_list),