drivers/vfio/platform/vfio_amba.c

   1 /*
   2  * Copyright (C) 2013 - Virtual Open Systems
   3  * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/vfio.h>
  18 #include <linux/amba/bus.h>
  19
  20 #include "vfio_platform_private.h"
  21
  22 #define DRIVER_VERSION  "0.10"
  23 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
  24 #define DRIVER_DESC     "VFIO for AMBA devices - User Level meta-driver"
  25
  26 /* probing devices from the AMBA bus */
  27
  28 static struct resource *get_amba_resource(struct vfio_platform_device *vdev,
  29                                           int i)
  30 {
  31         struct amba_device *adev = (struct amba_device *) vdev->opaque;
  32
  33         if (i == 0)
  34                 return &adev->res;
  35
  36         return NULL;
  37 }
  38
  39 static int get_amba_irq(struct vfio_platform_device *vdev, int i)
  40 {
  41         struct amba_device *adev = (struct amba_device *) vdev->opaque;
  42         int ret = 0;
  43
  44         if (i < AMBA_NR_IRQS)
  45                 ret = adev->irq[i];
  46
  47         /* zero is an unset IRQ for AMBA devices */
  48         return ret ? ret : -ENXIO;
  49 }
  50
  51 static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
  52 {
  53         struct vfio_platform_device *vdev;
  54         int ret;
  55
  56         vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
  57         if (!vdev)
  58                 return -ENOMEM;
  59
  60         vdev->name = kasprintf(GFP_KERNEL, "vfio-amba-%08x", adev->periphid);
  61         if (!vdev->name) {
  62                 kfree(vdev);
  63                 return -ENOMEM;
  64         }
  65
  66         vdev->opaque = (void *) adev;
  67         vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
  68         vdev->get_resource = get_amba_resource;
  69         vdev->get_irq = get_amba_irq;
  70         vdev->parent_module = THIS_MODULE;
  71         vdev->reset_required = false;
  72
  73         ret = vfio_platform_probe_common(vdev, &adev->dev);
  74         if (ret) {
  75                 kfree(vdev->name);
  76                 kfree(vdev);
  77         }
  78
  79         return ret;
  80 }
  81
  82 static int vfio_amba_remove(struct amba_device *adev)
  83 {
  84         struct vfio_platform_device *vdev;
  85
  86         vdev = vfio_platform_remove_common(&adev->dev);
  87         if (vdev) {
  88                 kfree(vdev->name);
  89                 kfree(vdev);
  90                 return 0;
  91         }
  92
  93         return -EINVAL;
  94 }
  95
  96 static const struct amba_id pl330_ids[] = {
  97         { 0, 0 },
  98 };
  99
 100 MODULE_DEVICE_TABLE(amba, pl330_ids);
 101
 102 static struct amba_driver vfio_amba_driver = {
 103         .probe = vfio_amba_probe,
 104         .remove = vfio_amba_remove,
 105         .id_table = pl330_ids,
 106         .drv = {
 107                 .name = "vfio-amba",
 108                 .owner = THIS_MODULE,
 109         },
 110 };
 111
 112 module_amba_driver(vfio_amba_driver);
 113
 114 MODULE_VERSION(DRIVER_VERSION);
 115 MODULE_LICENSE("GPL v2");
 116 MODULE_AUTHOR(DRIVER_AUTHOR);
 117 MODULE_DESCRIPTION(DRIVER_DESC);