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

From: Tony Krowiak
Date: Mon Oct 16 2017 - 11:56:17 EST


On 10/16/2017 04:59 AM, Martin Schwidefsky wrote:
On Fri, 13 Oct 2017 13:38:50 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxx>
+ */
+
+#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@xxxxxxxxxxxxxxxxxx>
+ */
+
+#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_ */