Re: [RFC 05/19] s390/zcrypt: base implementation of AP matrix device driver

[Tony Krowiak <akrowiak@linux.vnet.ibm.com>]

On 10/16/2017 04:59 AM, Martin Schwidefsky wrote:
> On Fri, 13 Oct 2017 13:38:50 -0400
> Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:
>
>> diff --git a/drivers/s390/crypto/Makefile b/drivers/s390/crypto/Makefile
>> index 87646ca..1983afa 100644
>> --- a/drivers/s390/crypto/Makefile
>> +++ b/drivers/s390/crypto/Makefile
>> @@ -13,4 +13,8 @@ obj-$(CONFIG_ZCRYPT) += zcrypt_pcixcc.o zcrypt_cex2a.o zcrypt_cex4.o
>>
>>   # pkey kernel module
>>   pkey-objs := pkey_api.o
>> -obj-$(CONFIG_PKEY) += pkey.o
>> \ No newline at end of file
>> +obj-$(CONFIG_PKEY) += pkey.o
>> +
>> +# adjunct processor matrix
>> +vfio_ap_matrix-objs := vfio_ap_matrix_drv.o
>> +obj-$(CONFIG_VFIO_AP_MATRIX) += vfio_ap_matrix.o
> With the fix to patch #3 the newline quirk will be gone.
Yes it will.
>
>> diff --git a/drivers/s390/crypto/ap_matrix_bus.c b/drivers/s390/crypto/ap_matrix_bus.c
>> index 4eb1e3c..66bfa54 100644
>> --- a/drivers/s390/crypto/ap_matrix_bus.c
>> +++ b/drivers/s390/crypto/ap_matrix_bus.c
>> @@ -75,10 +75,18 @@ static int ap_matrix_dev_create(void)
>>   	return 0;
>>   }
>>
>> +struct ap_matrix *ap_matrix_get_device(void)
>> +{
>> +	return matrix;
>> +}
>> +EXPORT_SYMBOL(ap_matrix_get_device);
>> +
>>   int __init ap_matrix_init(void)
>>   {
>>   	int ret;
>>
>> +	matrix = NULL;
>> +
>>   	ap_matrix_root_device = root_device_register(AP_MATRIX_BUS_NAME);
>>   	ret = PTR_RET(ap_matrix_root_device);
>>   	if (ret)
> The global variable "matrix" is already NULL at the time ap_matrix_init is
> called. No need to set it again. And I would appreciate if the global
> variable would be named "ap_matrix".
Will make those changes.
>
>> diff --git a/drivers/s390/crypto/ap_matrix_bus.h b/drivers/s390/crypto/ap_matrix_bus.h
>> index 225db4f..c2aff23 100644
>> --- a/drivers/s390/crypto/ap_matrix_bus.h
>> +++ b/drivers/s390/crypto/ap_matrix_bus.h
>> @@ -16,6 +16,6 @@ struct ap_matrix {
>>   	struct device device;
>>   };
>>
>> -int ap_matrix_init(void);
>> +struct ap_matrix *ap_matrix_get_device(void);
>>
>>   #endif /* _AP_MATRIX_BUS_H_ */
>> diff --git a/drivers/s390/crypto/vfio_ap_matrix_drv.c b/drivers/s390/crypto/vfio_ap_matrix_drv.c
>> new file mode 100644
>> index 0000000..760ed56
>> --- /dev/null
>> +++ b/drivers/s390/crypto/vfio_ap_matrix_drv.c
>> @@ -0,0 +1,102 @@
>> +/*
>> + * VFIO based AP Matrix device driver
>> + *
>> + * Copyright IBM Corp. 2017
>> + *
>> + * Author(s): Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/mod_devicetable.h>
>> +#include <linux/slab.h>
>> +
>> +#include "ap_bus.h"
>> +#include "ap_matrix_bus.h"
>> +#include "vfio_ap_matrix_private.h"
>> +
>> +#define VFIO_AP_MATRIX_DRV_NAME "vfio_ap_queue"
>> +
>> +MODULE_AUTHOR("IBM Corporation");
>> +MODULE_DESCRIPTION("AP Matrix device driver, Copyright IBM Corp. 2017");
>> +MODULE_LICENSE("GPL v2");
>> +
>> +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 list */ },
>> +};
>> +
>> +MODULE_DEVICE_TABLE(ap_matrix, ap_queue_ids);
>> +
>> +static struct ap_matrix_driver {
>> +	struct ap_driver ap_drv;
>> +	struct ap_matrix *ap_matrix;
>> +} vfio_ap_matrix_drv;
>> +
>> +static int ap_matrix_queue_dev_probe(struct ap_device *apdev)
>> +{
>> +	struct vfio_ap_queue *vapq;
>> +	struct ap_queue *apq = to_ap_queue(&apdev->device);
>> +	struct ap_matrix *ap_matrix = vfio_ap_matrix_drv.ap_matrix;
>> +
>> +	vapq = kzalloc(sizeof(*vapq), GFP_KERNEL);
>> +	if (!vapq)
>> +		return -ENOMEM;
>> +
>> +	INIT_LIST_HEAD(&vapq->list);
>> +	vapq->queue = apq;
>> +	spin_lock_bh(&ap_matrix->qlock);
>> +	list_add_tail(&vapq->list, &ap_matrix->queues);
>> +	spin_unlock_bh(&ap_matrix->qlock);
>> +
>> +	return 0;
>> +}
>> +
>> +static void ap_matrix_queue_dev_remove(struct ap_device *apdev)
>> +{
>> +	struct vfio_ap_queue *vapq;
>> +	struct ap_queue *apq = to_ap_queue(&apdev->device);
>> +	struct ap_matrix *ap_matrix = vfio_ap_matrix_drv.ap_matrix;
>> +
>> +	vapq = find_vapq(ap_matrix, apq->qid);
>> +
>> +	if (vapq) {
>> +		spin_lock_bh(&ap_matrix->qlock);
>> +		list_del_init(&vapq->list);
>> +		spin_unlock_bh(&ap_matrix->qlock);
>> +		kfree(vapq);
>> +	}
>> +}
> I would opt for a quick exit if find_vapq can not find the device.
> The un-indent the actual remove code.
Okay, will do.
>
>> +
>> +int __init ap_matrix_init(void)
>> +{
>> +
>> +	int ret;
>> +
>> +	vfio_ap_matrix_drv.ap_matrix = ap_matrix_get_device();
>> +	if (!vfio_ap_matrix_drv.ap_matrix)
>> +		return -ENODEV;
>> +
>> +	vfio_ap_matrix_drv.ap_drv.probe = ap_matrix_queue_dev_probe;
>> +	vfio_ap_matrix_drv.ap_drv.remove = ap_matrix_queue_dev_remove;
>> +	vfio_ap_matrix_drv.ap_drv.ids = ap_queue_ids;
>> +
>> +	ret = ap_driver_register(&vfio_ap_matrix_drv.ap_drv,
>> +				 THIS_MODULE, VFIO_AP_MATRIX_DRV_NAME);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return ret;
>> +}
>> +
>> +void __exit ap_matrix_exit(void)
>> +{
>> +	ap_driver_unregister(&vfio_ap_matrix_drv.ap_drv);
>> +}
>> +
>> +module_init(ap_matrix_init);
>> +module_exit(ap_matrix_exit);
>> diff --git a/drivers/s390/crypto/vfio_ap_matrix_private.h b/drivers/s390/crypto/vfio_ap_matrix_private.h
>> new file mode 100644
>> index 0000000..11c5e02
>> --- /dev/null
>> +++ b/drivers/s390/crypto/vfio_ap_matrix_private.h
>> @@ -0,0 +1,47 @@
>> +/*
>> + * Private data and functions for adjunct processor VFIO matrix driver.
>> + *
>> + * Copyright IBM Corp. 2016
>> + * Author(s): Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>> + */
>> +
>> +#ifndef _VFIO_AP_PRIVATE_H_
>> +#define _VFIO_AP_PRIVATE_H_
>> +
>> +#include <linux/types.h>
>> +
>> +#include "ap_bus.h"
>> +#include "ap_matrix_bus.h"
>> +
>> +#define VFIO_AP_MATRIX_MODULE_NAME "vfio_ap_matrix"
>> +
>> +struct vfio_ap_queue {
>> +	struct ap_queue *queue;
>> +	struct list_head list;
>> +};
>> +
>> +static inline struct vfio_ap_queue *to_vapq(struct ap_device *ap_dev)
>> +{
>> +	struct ap_queue *ap_queue = to_ap_queue(&ap_dev->device);
>> +	struct vfio_ap_queue *vapq;
>> +
>> +	vapq = container_of(&ap_queue, struct vfio_ap_queue, queue);
>> +
>> +	return vapq;
>> +}
> This can be shortened a bit
>
> 	return container_of(&ap_queue, struct vfio_ap_queue, queue);
Okay, will do.
>
>> +
>> +static inline struct vfio_ap_queue *find_vapq(struct ap_matrix *ap_matrix,
>> +					      ap_qid_t qid)
>> +{
>> +	struct vfio_ap_queue *vapq;
>> +
>> +	if (!list_empty(&ap_matrix->queues)) {
>> +		list_for_each_entry(vapq, &ap_matrix->queues, list)
>> +			if (vapq->queue->qid == qid)
>> +				return vapq;
>> +	}
>> +
>> +	return NULL;
>> +}
>> +
>> +#endif /* _VFIO_AP_PRIVATE_H_ */
>