Re: [RFC 03/19] s390/zcrypt: new AP matrix bus

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

On 10/16/2017 04:47 AM, Martin Schwidefsky wrote:
> On Fri, 13 Oct 2017 13:38:48 -0400
> Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:
>
>> Introduces an AP matrix bus. The sysfs location of the
>> AP matrix bus is:
>>
>> /sys/bus/ap_matrix
>>
>> The AP matrix bus will create an AP matrix device that will
>> hold the AP queues reserved for use by KVM guests.
>>
>> Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>> ---
>>   MAINTAINERS                         |    8 +++++
>>   drivers/s390/crypto/Makefile        |    4 +-
>>   drivers/s390/crypto/ap_matrix_bus.c |   52 +++++++++++++++++++++++++++++++++++
>>   drivers/s390/crypto/ap_matrix_bus.h |   15 ++++++++++
>>   4 files changed, 77 insertions(+), 2 deletions(-)
>>   create mode 100644 drivers/s390/crypto/ap_matrix_bus.c
>>   create mode 100644 drivers/s390/crypto/ap_matrix_bus.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index ef23cf5..cbd6f7c 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -11711,6 +11711,14 @@ W:	http://www.ibm.com/developerworks/linux/linux390/
>>   S:	Supported
>>   F:	drivers/s390/crypto/
>>
>> +S390 VFIO AP MATRIX DRIVER
>> +M:	Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>> +L:	linux-s390@vger.kernel.org
>> +W:	http://www.ibm.com/developerworks/linux/linux390/
>> +S:	Supported
>> +F:	drivers/s390/crypto/ap_matrix_bus.h
>> +F:	drivers/s390/crypto/ap_matrix_bus.c
>> +
>>   S390 ZFCP DRIVER
>>   M:	Steffen Maier <maier@linux.vnet.ibm.com>
>>   M:	Benjamin Block <bblock@linux.vnet.ibm.com>
>> diff --git a/drivers/s390/crypto/Makefile b/drivers/s390/crypto/Makefile
>> index be36f10..87646ca 100644
>> --- a/drivers/s390/crypto/Makefile
>> +++ b/drivers/s390/crypto/Makefile
>> @@ -2,7 +2,7 @@
>>   # S/390 crypto devices
>>   #
>>
>> -ap-objs := ap_bus.o ap_card.o ap_queue.o
>> +ap-objs := ap_bus.o ap_card.o ap_queue.o ap_matrix_bus.o
>>   obj-$(subst m,y,$(CONFIG_ZCRYPT)) += ap.o
>>   # zcrypt_api.o and zcrypt_msgtype*.o depend on ap.o
>>   zcrypt-objs := zcrypt_api.o zcrypt_card.o zcrypt_queue.o
>> @@ -13,4 +13,4 @@ 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
>> +obj-$(CONFIG_PKEY) += pkey.o
>> \ No newline at end of file
> Try to avoid this newline hunk please. It is removed again with patch #5.
Will do.
>
>> diff --git a/drivers/s390/crypto/ap_matrix_bus.c b/drivers/s390/crypto/ap_matrix_bus.c
>> new file mode 100644
>> index 0000000..fbae175
>> --- /dev/null
>> +++ b/drivers/s390/crypto/ap_matrix_bus.c
>> @@ -0,0 +1,52 @@
>> +/*
>> + * Copyright IBM Corp. 2017
>> + * Author(s): Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>> + *
>> + * Adjunct processor matrix bus.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/device.h>
>> +#include <asm/ap.h>
>> +
>> +#include "ap_matrix_bus.h"
>> +
>> +MODULE_AUTHOR("Tony Krowiak <akrowiak@linux.vnet.ibm.com");
>> +MODULE_DESCRIPTION("AP Matrix, Copyright IBM Corp. 2017");
>> +MODULE_LICENSE("GPL v2");
>> +
>> +#define AP_MATRIX_BUS_NAME "ap_matrix"
>> +
>> +static struct device *ap_matrix_root_device;
>> +
>> +static struct bus_type ap_matrix_bus_type = {
>> +	.name = AP_MATRIX_BUS_NAME,
>> +};
>> +
>> +int __init ap_matrix_init(void)
>> +{
>> +	int ret;
>> +
>> +	ap_matrix_root_device = root_device_register(AP_MATRIX_BUS_NAME);
>> +	ret = PTR_RET(ap_matrix_root_device);
>> +	if (ret)
>> +		goto done;
>> +
>> +	ret = bus_register(&ap_matrix_bus_type);
>> +	if (ret)
>> +		goto bus_reg_err;
>> +
>> +	return 0;
>> +
>> +bus_reg_err:
>> +	root_device_unregister(ap_matrix_root_device);
>> +
>> +done:
>> +	return ret;
>> +}
>> +device_initcall(ap_matrix_init);
>> diff --git a/drivers/s390/crypto/ap_matrix_bus.h b/drivers/s390/crypto/ap_matrix_bus.h
>> new file mode 100644
>> index 0000000..58e116f
>> --- /dev/null
>> +++ b/drivers/s390/crypto/ap_matrix_bus.h
>> @@ -0,0 +1,15 @@
>> +/*
>> + * Adjunct processor matrix bus header file
>> + *
>> + * Copyright IBM Corp. 2017
>> + * Author(s): Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>> + *
>> + * Adjunct processor bus header file.
>> + */
>> +
>> +#ifndef _AP_MATRIX_BUS_H_
>> +#define _AP_MATRIX_BUS_H_
>> +
>> +int ap_matrix_init(void);
>> +
>> +#endif /* _AP_MATRIX_BUS_H_ */
> While I understand the approach to split the patches into meaningful
> parts, there is always a balance between too coarse and too fine granular.
>
> I would merge patch #3, patch #4 and parts of patch #5 that affect
> ap_matrix_bus.c & ap_matrix_bus.h.
Will do.
>
>