[PATCH 02/16] dmaengine: idxd: add external module driver support for dsa_bus_type

[Tom Zanussi]

From: Dave Jiang <dave.jiang@xxxxxxxxx>

Add support to allow an external driver to be registered to the
dsa_bus_type and also auto-loaded.

Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
---
 drivers/dma/idxd/bus.c  | 6 ++++++
 drivers/dma/idxd/idxd.h | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/drivers/dma/idxd/bus.c b/drivers/dma/idxd/bus.c
index 6f84621053c6..0c9e689a2e77 100644
--- a/drivers/dma/idxd/bus.c
+++ b/drivers/dma/idxd/bus.c
@@ -67,11 +67,17 @@ static void idxd_config_bus_remove(struct device *dev)
 	idxd_drv->remove(idxd_dev);
 }
 
+static int idxd_bus_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	return add_uevent_var(env, "MODALIAS=" IDXD_DEVICES_MODALIAS_FMT, 0);
+}
+
 struct bus_type dsa_bus_type = {
 	.name = "dsa",
 	.match = idxd_config_bus_match,
 	.probe = idxd_config_bus_probe,
 	.remove = idxd_config_bus_remove,
+	.uevent = idxd_bus_uevent,
 };
 EXPORT_SYMBOL_GPL(dsa_bus_type);
 
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 505118fc19de..719f9f1662ad 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -587,6 +587,9 @@ static inline int idxd_wq_driver_name_match(struct idxd_wq *wq, struct device *d
 	return (strncmp(wq->driver_name, dev->driver->name, strlen(dev->driver->name)) == 0);
 }
 
+#define MODULE_ALIAS_IDXD_DEVICE(type) MODULE_ALIAS("idxd:t" __stringify(type) "*")
+#define IDXD_DEVICES_MODALIAS_FMT "idxd:t%d"
+
 int __must_check __idxd_driver_register(struct idxd_device_driver *idxd_drv,
 					struct module *module, const char *mod_name);
 #define idxd_driver_register(driver) \
-- 
2.34.1