[PATCH v2 13/18] dmaengine: idxd: add type to driver in order to allow device matching

[Dave Jiang <dave.jiang@intel.com>]

Add an array of support device types to the idxd_device_driver
definition in order to enable simple matching of device type to a
given driver. The deprecated / omnibus dsa_drv driver specifies
IDXD_DEV_NONE as its only role is to service legacy userspace (old
accel-config) directed bind requests and route them to them the proper
driver. It need not attach to a device when the bus is autoprobed. The
accel-config tooling is being updated to drop its dependency on this
deprecated bind scheme.

Reviewed-by: Dan Willliams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/dma/idxd/idxd.h  |    1 +
 drivers/dma/idxd/init.c  |    5 +++++
 drivers/dma/idxd/sysfs.c |   16 +++++++++++++++-
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index d44ee136c223..822afd3a397c 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -51,6 +51,7 @@ enum idxd_type {
 
 struct idxd_device_driver {
 	const char *name;
+	enum idxd_dev_type *type;
 	int (*probe)(struct idxd_dev *idxd_dev);
 	void (*remove)(struct idxd_dev *idxd_dev);
 	struct device_driver drv;
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index ada75bb7e71f..d45ccf4862f2 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -869,6 +869,11 @@ int __idxd_driver_register(struct idxd_device_driver *idxd_drv, struct module *o
 {
 	struct device_driver *drv = &idxd_drv->drv;
 
+	if (!idxd_drv->type) {
+		pr_debug("driver type not set (%ps)\n", __builtin_return_address(0));
+		return -EINVAL;
+	}
+
 	drv->name = idxd_drv->name;
 	drv->bus = &dsa_bus_type;
 	drv->owner = owner;
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 1a6c9cf16a40..500d6c64a1b0 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -19,9 +19,18 @@ static char *idxd_wq_type_names[] = {
 static int idxd_config_bus_match(struct device *dev,
 				 struct device_driver *drv)
 {
+	struct idxd_device_driver *idxd_drv =
+		container_of(drv, struct idxd_device_driver, drv);
 	struct idxd_dev *idxd_dev = confdev_to_idxd_dev(dev);
+	int i = 0;
+
+	while (idxd_drv->type[i] != IDXD_DEV_NONE) {
+		if (idxd_dev->type == idxd_drv->type[i])
+			return 1;
+		i++;
+	}
 
-	return (is_idxd_dev(idxd_dev) || is_idxd_wq_dev(idxd_dev));
+	return 0;
 }
 
 static int idxd_config_bus_probe(struct device *dev)
@@ -79,10 +88,15 @@ static void idxd_dsa_drv_remove(struct idxd_dev *idxd_dev)
 	}
 }
 
+static enum idxd_dev_type dev_types[] = {
+	IDXD_DEV_NONE,
+};
+
 struct idxd_device_driver dsa_drv = {
 	.name = "dsa",
 	.probe = idxd_dsa_drv_probe,
 	.remove = idxd_dsa_drv_remove,
+	.type = dev_types,
 };
 
 /* IDXD engine attributes */