On Wed, 8 Aug 2018 10:44:18 -0400 Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote: > diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c > new file mode 100644 > index 0000000..d7e39ad > --- /dev/null > +++ b/drivers/s390/crypto/vfio_ap_drv.c > @@ -0,0 +1,115 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * VFIO based AP device driver > + * > + * Copyright IBM Corp. 2018 > + * > + * Author(s): Tony Krowiak <akrowiak@xxxxxxxxxxxxx> > + * Halil Pasic <pasic@xxxxxxxxxxxxx> > + */ > + > +#include <linux/module.h> > +#include <linux/mod_devicetable.h> > +#include <linux/slab.h> > +#include <linux/string.h> > +#include "vfio_ap_private.h" > + > +#define VFIO_AP_ROOT_NAME "vfio_ap" > +#define VFIO_AP_DEV_TYPE_NAME "ap_matrix" > +#define VFIO_AP_DEV_NAME "vfio_ap" > + > +MODULE_AUTHOR("IBM Corporation"); > +MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018"); > +MODULE_LICENSE("GPL v2"); > + > +static struct ap_driver vfio_ap_drv; > + > +static struct device_type vfio_ap_dev_type = { > + .name = VFIO_AP_DEV_TYPE_NAME, > +}; > + > +struct ap_matrix_dev matrix_dev = { > + /* > + * We may add some fops later to implement a more program friendly > + * management interface for vfio_ap_mdev devices. > + */ > + .misc_dev = { > + MISC_DYNAMIC_MINOR, > + VFIO_AP_DEV_NAME, > + } Is there any reason why you embed a struct miscdevice and don't just use it directly? > +}; > + > +/* Only type 10 adapters (CEX4 and later) are supported > + * by the AP matrix device driver > + */ > +static struct ap_device_id ap_queue_ids[] = { > + { .dev_type = AP_DEVICE_TYPE_CEX4, > + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE }, > + { .dev_type = AP_DEVICE_TYPE_CEX5, > + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE }, > + { .dev_type = AP_DEVICE_TYPE_CEX6, > + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE }, > + { /* end of sibling */ }, > +}; > + > +MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids); > + > +static int vfio_ap_queue_dev_probe(struct ap_device *apdev) > +{ > + return 0; > +} > + > +static void vfio_ap_queue_dev_remove(struct ap_device *apdev) > +{ > + /* Nothing to do yet */ > +} > + > +static int vfio_ap_matrix_dev_create(void) > +{ > + int ret; > + > + ret = misc_register(&matrix_dev.misc_dev); > + if (ret) > + return ret; > + > + to_device(&matrix_dev)->type = &vfio_ap_dev_type; > + to_device(&matrix_dev)->driver = &vfio_ap_drv.driver; This looks strange. Why would you want to change the driver for a miscdevice, and that after it already has been registered? This feels like a miscdevice is not the right choice here. > + > + return ret; > +} > + > +static void vfio_ap_matrix_dev_destroy(void) > +{ > + misc_deregister(&matrix_dev.misc_dev); > +} > + > +int __init vfio_ap_init(void) > +{ > + int ret; > + > + ret = vfio_ap_matrix_dev_create(); > + if (ret) > + return ret; > + > + memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv)); > + vfio_ap_drv.probe = vfio_ap_queue_dev_probe; > + vfio_ap_drv.remove = vfio_ap_queue_dev_remove; > + vfio_ap_drv.ids = ap_queue_ids; > + > + ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME); > + if (ret) { > + vfio_ap_matrix_dev_destroy(); > + return ret; > + } > + > + return 0; > +} > + > +void __exit vfio_ap_exit(void) > +{ > + ap_driver_unregister(&vfio_ap_drv); > + vfio_ap_matrix_dev_destroy(); > +} > + > +module_init(vfio_ap_init); > +module_exit(vfio_ap_exit); > diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h > new file mode 100644 > index 0000000..02c878c > --- /dev/null > +++ b/drivers/s390/crypto/vfio_ap_private.h > @@ -0,0 +1,30 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Private data and functions for adjunct processor VFIO matrix driver. > + * > + * Copyright IBM Corp. 2018 > + */ > + > +#ifndef _VFIO_AP_PRIVATE_H_ > +#define _VFIO_AP_PRIVATE_H_ > + > +#include <linux/types.h> > +#include <linux/miscdevice.h> > + > +#include "ap_bus.h" > + > +#define VFIO_AP_MODULE_NAME "vfio_ap" > +#define VFIO_AP_DRV_NAME "vfio_ap" > + > +struct ap_matrix_dev { > + struct miscdevice misc_dev; > +}; > + > +extern struct ap_matrix_dev matrix_dev; > + > +static inline struct device *to_device(struct ap_matrix_dev *matrix_dev) > +{ > + return matrix_dev->misc_dev.this_device; > +} Even if you keep it as a miscdevice, I don't like that function, especially the naming. Frankly, I'd simply drop it. > + > +#endif /* _VFIO_AP_PRIVATE_H_ */