Commit 448c3de8 authored by Dave Jiang's avatar Dave Jiang Committed by Vinod Koul
Browse files

dmaengine: idxd: create user driver for wq 'device' 



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 drivers.
Those internal drivers were invisible to userspace. Now, as
/sys/bus/dsa wants to grow support for alternate drivers for a given
device, for example vfio-mdev instead of kernel-internal-dmaengine, a
proper bus device-driver model is needed. The first step in that process
is separating the existing omnibus/implicit "dsa" driver into proper
individual drivers registered on /sys/bus/dsa. Establish the
idxd_user_drv driver that controls the enabling and disabling of the
wq and also register and unregister a char device to allow user space
to mmap the descriptor submission portal.

The cdev related bits are moved to the cdev driver probe/remove and out of
the drv_enabe/disable_wq() calls. These bits are exclusive to the cdev
operation and not part of the generic enable/disable of the wq device.

Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162637467578.744545.10203997610072341376.stgit@djiang5-desk3.ch.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 0cda4f69

drivers/dma/idxd/cdev.c

+53 −0
Original line number Diff line number Diff line
@@ -304,6 +304,59 @@ void idxd_wq_del_cdev(struct idxd_wq *wq) 
	put_device(cdev_dev(idxd_cdev));

}



static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)

{

	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);

	struct idxd_device *idxd = wq->idxd;

	int rc;



	if (idxd->state != IDXD_DEV_ENABLED)

		return -ENXIO;



	mutex_lock(&wq->wq_lock);

	wq->type = IDXD_WQT_USER;

	rc = __drv_enable_wq(wq);

	if (rc < 0)

		goto err;



	rc = idxd_wq_add_cdev(wq);

	if (rc < 0)

		goto err_cdev;



	mutex_unlock(&wq->wq_lock);

	return 0;



err_cdev:

	__drv_disable_wq(wq);

err:

	wq->type = IDXD_WQT_NONE;

	mutex_unlock(&wq->wq_lock);

	return rc;

}



static void idxd_user_drv_remove(struct idxd_dev *idxd_dev)

{

	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);



	mutex_lock(&wq->wq_lock);

	idxd_wq_del_cdev(wq);

	__drv_disable_wq(wq);

	wq->type = IDXD_WQT_NONE;

	mutex_unlock(&wq->wq_lock);

}



static enum idxd_dev_type dev_types[] = {

	IDXD_DEV_WQ,

	IDXD_DEV_NONE,

};



struct idxd_device_driver idxd_user_drv = {

	.probe = idxd_user_drv_probe,

	.remove = idxd_user_drv_remove,

	.name = "user",

	.type = dev_types,

};



int idxd_cdev_register(void)

{

	int rc, i;

drivers/dma/idxd/device.c

+0 −14
Original line number Diff line number Diff line
@@ -1201,19 +1201,8 @@ int __drv_enable_wq(struct idxd_wq *wq) 
	}



	wq->client_count = 0;



	if (is_idxd_wq_cdev(wq)) {

		rc = idxd_wq_add_cdev(wq);

		if (rc < 0) {

			dev_dbg(dev, "wq %d cdev creation failed\n", wq->id);

			goto err_client;

		}

	}



	return 0;



err_client:

	idxd_wq_unmap_portal(wq);

err_map_portal:

	rc = idxd_wq_disable(wq, false);

	if (rc < 0)
@@ -1239,9 +1228,6 @@ void __drv_disable_wq(struct idxd_wq *wq) 


	lockdep_assert_held(&wq->wq_lock);



	if (is_idxd_wq_cdev(wq))

		idxd_wq_del_cdev(wq);



	if (idxd_wq_refcount(wq))

		dev_warn(dev, "Clients has claim on wq %d: %d\n",

			 wq->id, idxd_wq_refcount(wq));

drivers/dma/idxd/idxd.h

+1 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ struct idxd_device_driver { 
extern struct idxd_device_driver dsa_drv;

extern struct idxd_device_driver idxd_drv;

extern struct idxd_device_driver idxd_dmaengine_drv;

extern struct idxd_device_driver idxd_user_drv;



struct idxd_irq_entry {

	struct idxd_device *idxd;

drivers/dma/idxd/init.c

+7 −0
Original line number Diff line number Diff line
@@ -848,6 +848,10 @@ static int __init idxd_init_module(void) 
	if (err < 0)

		goto err_idxd_dmaengine_driver_register;



	err = idxd_driver_register(&idxd_user_drv);

	if (err < 0)

		goto err_idxd_user_driver_register;



	err = idxd_driver_register(&dsa_drv);

	if (err < 0)

		goto err_dsa_driver_register;
@@ -867,6 +871,8 @@ static int __init idxd_init_module(void) 
err_cdev_register:

	idxd_driver_unregister(&dsa_drv);

err_dsa_driver_register:

	idxd_driver_unregister(&idxd_user_drv);

err_idxd_user_driver_register:

	idxd_driver_unregister(&idxd_dmaengine_drv);

err_idxd_dmaengine_driver_register:

	idxd_driver_unregister(&idxd_drv);
@@ -878,6 +884,7 @@ module_init(idxd_init_module); 


static void __exit idxd_exit_module(void)

{

	idxd_driver_unregister(&idxd_user_drv);

	idxd_driver_unregister(&idxd_dmaengine_drv);

	idxd_driver_unregister(&idxd_drv);

	idxd_driver_unregister(&dsa_drv);