dmaengine: idxd: move dsa_drv support to compatible mode

The original architecture of /sys/bus/dsa invented a scheme whereby
a single entry in the list of bus drivers, /sys/bus/drivers/dsa,
handled all device types and internally routed them to different
different drivers. Those internal drivers were invisible to
userspace.

With the idxd driver transitioned to a proper bus device-driver model,
the legacy behavior needs to be preserved due to it being exposed to
user space via sysfs. Create a compat driver to provide the legacy
behavior for /sys/bus/dsa/drivers/dsa. This should satisfy user
tool accel-config v3.2 or ealier where this behavior is expected.
If the distro has a newer accel-config then the legacy mode does
not need to be enabled.

When the compat driver binds the device (i.e. dsa0) to the dsa driver,
it will be bound to the new idxd_drv. The wq device (i.e. wq0.0) will
be bound to either the dmaengine_drv or the user_drv. The dsa_drv
becomes a routing mechansim for the new drivers. It will not support
additional external drivers that are implemented later.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162637468705.744545.4399080971745974435.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 0 insertions, 40 deletions

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 633f4947ed32..b883e9f16e7f 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -16,46 +16,6 @@ static char *idxd_wq_type_names[] = {
 	[IDXD_WQT_USER]		= "user",
 };
 
-static int idxd_dsa_drv_probe(struct idxd_dev *idxd_dev)
-{
-	if (is_idxd_dev(idxd_dev))
-		return idxd_device_drv_probe(idxd_dev);
-
-	if (is_idxd_wq_dev(idxd_dev)) {
-		struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
-
-		return drv_enable_wq(wq);
-	}
-
-	return -ENODEV;
-}
-
-static void idxd_dsa_drv_remove(struct idxd_dev *idxd_dev)
-{
-	if (is_idxd_dev(idxd_dev)) {
-		idxd_device_drv_remove(idxd_dev);
-		return;
-	}
-
-	if (is_idxd_wq_dev(idxd_dev)) {
-		struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
-
-		drv_disable_wq(wq);
-		return;
-	}
-}
-
-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 */
 static ssize_t engine_group_id_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)