drivers/s390/crypto/vfio_ap_drv.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * VFIO based AP device driver
   4  *
   5  * Copyright IBM Corp. 2018
   6  *
   7  * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/mod_devicetable.h>
  12 #include <linux/slab.h>
  13 #include <linux/string.h>
  14 #include <asm/facility.h>
  15 #include "vfio_ap_private.h"
  16
  17 #define VFIO_AP_ROOT_NAME "vfio_ap"
  18 #define VFIO_AP_DEV_NAME "matrix"
  19
  20 MODULE_AUTHOR("IBM Corporation");
  21 MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
  22 MODULE_LICENSE("GPL v2");
  23
  24 static struct ap_driver vfio_ap_drv;
  25
  26 struct ap_matrix_dev *matrix_dev;
  27
  28 /* Only type 10 adapters (CEX4 and later) are supported
  29  * by the AP matrix device driver
  30  */
  31 static struct ap_device_id ap_queue_ids[] = {
  32         { .dev_type = AP_DEVICE_TYPE_CEX4,
  33           .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
  34         { .dev_type = AP_DEVICE_TYPE_CEX5,
  35           .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
  36         { .dev_type = AP_DEVICE_TYPE_CEX6,
  37           .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
  38         { /* end of sibling */ },
  39 };
  40
  41 MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
  42
  43 static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
  44 {
  45         return 0;
  46 }
  47
  48 static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
  49 {
  50         /* Nothing to do yet */
  51 }
  52
  53 static void vfio_ap_matrix_dev_release(struct device *dev)
  54 {
  55         struct ap_matrix_dev *matrix_dev = dev_get_drvdata(dev);
  56
  57         kfree(matrix_dev);
  58 }
  59
  60 static int matrix_bus_match(struct device *dev, struct device_driver *drv)
  61 {
  62         return 1;
  63 }
  64
  65 static struct bus_type matrix_bus = {
  66         .name = "matrix",
  67         .match = &matrix_bus_match,
  68 };
  69
  70 static struct device_driver matrix_driver = {
  71         .name = "vfio_ap",
  72         .bus = &matrix_bus,
  73         .suppress_bind_attrs = true,
  74 };
  75
  76 static int vfio_ap_matrix_dev_create(void)
  77 {
  78         int ret;
  79         struct device *root_device;
  80
  81         root_device = root_device_register(VFIO_AP_ROOT_NAME);
  82         if (IS_ERR(root_device))
  83                 return PTR_ERR(root_device);
  84
  85         ret = bus_register(&matrix_bus);
  86         if (ret)
  87                 goto bus_register_err;
  88
  89         matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
  90         if (!matrix_dev) {
  91                 ret = -ENOMEM;
  92                 goto matrix_alloc_err;
  93         }
  94
  95         /* Fill in config info via PQAP(QCI), if available */
  96         if (test_facility(12)) {
  97                 ret = ap_qci(&matrix_dev->info);
  98                 if (ret)
  99                         goto matrix_alloc_err;
 100         }
 101
 102         mutex_init(&matrix_dev->lock);
 103         INIT_LIST_HEAD(&matrix_dev->mdev_list);
 104
 105         dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
 106         matrix_dev->device.parent = root_device;
 107         matrix_dev->device.bus = &matrix_bus;
 108         matrix_dev->device.release = vfio_ap_matrix_dev_release;
 109         matrix_dev->vfio_ap_drv = &vfio_ap_drv;
 110
 111         ret = device_register(&matrix_dev->device);
 112         if (ret)
 113                 goto matrix_reg_err;
 114
 115         ret = driver_register(&matrix_driver);
 116         if (ret)
 117                 goto matrix_drv_err;
 118
 119         return 0;
 120
 121 matrix_drv_err:
 122         device_unregister(&matrix_dev->device);
 123 matrix_reg_err:
 124         put_device(&matrix_dev->device);
 125 matrix_alloc_err:
 126         bus_unregister(&matrix_bus);
 127 bus_register_err:
 128         root_device_unregister(root_device);
 129         return ret;
 130 }
 131
 132 static void vfio_ap_matrix_dev_destroy(void)
 133 {
 134         struct device *root_device = matrix_dev->device.parent;
 135
 136         driver_unregister(&matrix_driver);
 137         device_unregister(&matrix_dev->device);
 138         bus_unregister(&matrix_bus);
 139         root_device_unregister(root_device);
 140 }
 141
 142 static int __init vfio_ap_init(void)
 143 {
 144         int ret;
 145
 146         /* If there are no AP instructions, there is nothing to pass through. */
 147         if (!ap_instructions_available())
 148                 return -ENODEV;
 149
 150         ret = vfio_ap_matrix_dev_create();
 151         if (ret)
 152                 return ret;
 153
 154         memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
 155         vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
 156         vfio_ap_drv.remove = vfio_ap_queue_dev_remove;
 157         vfio_ap_drv.ids = ap_queue_ids;
 158
 159         ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
 160         if (ret) {
 161                 vfio_ap_matrix_dev_destroy();
 162                 return ret;
 163         }
 164
 165         ret = vfio_ap_mdev_register();
 166         if (ret) {
 167                 ap_driver_unregister(&vfio_ap_drv);
 168                 vfio_ap_matrix_dev_destroy();
 169
 170                 return ret;
 171         }
 172
 173         return 0;
 174 }
 175
 176 static void __exit vfio_ap_exit(void)
 177 {
 178         vfio_ap_mdev_unregister();
 179         ap_driver_unregister(&vfio_ap_drv);
 180         vfio_ap_matrix_dev_destroy();
 181 }
 182
 183 module_init(vfio_ap_init);
 184 module_exit(vfio_ap_exit);