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

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

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
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_ */
-- 
1.7.1