drivers/vfio/platform/vfio_amba.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2013 - Virtual Open Systems
   4  * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/slab.h>
   9 #include <linux/vfio.h>
  10 #include <linux/pm_runtime.h>
  11 #include <linux/amba/bus.h>
  12
  13 #include "vfio_platform_private.h"
  14
  15 #define DRIVER_VERSION  "0.10"
  16 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
  17 #define DRIVER_DESC     "VFIO for AMBA devices - User Level meta-driver"
  18
  19 /* probing devices from the AMBA bus */
  20
  21 static struct resource *get_amba_resource(struct vfio_platform_device *vdev,
  22                                           int i)
  23 {
  24         struct amba_device *adev = (struct amba_device *) vdev->opaque;
  25
  26         if (i == 0)
  27                 return &adev->res;
  28
  29         return NULL;
  30 }
  31
  32 static int get_amba_irq(struct vfio_platform_device *vdev, int i)
  33 {
  34         struct amba_device *adev = (struct amba_device *) vdev->opaque;
  35         int ret = 0;
  36
  37         if (i < AMBA_NR_IRQS)
  38                 ret = adev->irq[i];
  39
  40         /* zero is an unset IRQ for AMBA devices */
  41         return ret ? ret : -ENXIO;
  42 }
  43
  44 static int vfio_amba_init_dev(struct vfio_device *core_vdev)
  45 {
  46         struct vfio_platform_device *vdev =
  47                 container_of(core_vdev, struct vfio_platform_device, vdev);
  48         struct amba_device *adev = to_amba_device(core_vdev->dev);
  49         int ret;
  50
  51         vdev->name = kasprintf(GFP_KERNEL, "vfio-amba-%08x", adev->periphid);
  52         if (!vdev->name)
  53                 return -ENOMEM;
  54
  55         vdev->opaque = (void *) adev;
  56         vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
  57         vdev->get_resource = get_amba_resource;
  58         vdev->get_irq = get_amba_irq;
  59         vdev->reset_required = false;
  60
  61         ret = vfio_platform_init_common(vdev);
  62         if (ret)
  63                 kfree(vdev->name);
  64         return ret;
  65 }
  66
  67 static const struct vfio_device_ops vfio_amba_ops;
  68 static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
  69 {
  70         struct vfio_platform_device *vdev;
  71         int ret;
  72
  73         vdev = vfio_alloc_device(vfio_platform_device, vdev, &adev->dev,
  74                                  &vfio_amba_ops);
  75         if (IS_ERR(vdev))
  76                 return PTR_ERR(vdev);
  77
  78         ret = vfio_register_group_dev(&vdev->vdev);
  79         if (ret)
  80                 goto out_put_vdev;
  81
  82         pm_runtime_enable(&adev->dev);
  83         dev_set_drvdata(&adev->dev, vdev);
  84         return 0;
  85
  86 out_put_vdev:
  87         vfio_put_device(&vdev->vdev);
  88         return ret;
  89 }
  90
  91 static void vfio_amba_release_dev(struct vfio_device *core_vdev)
  92 {
  93         struct vfio_platform_device *vdev =
  94                 container_of(core_vdev, struct vfio_platform_device, vdev);
  95
  96         vfio_platform_release_common(vdev);
  97         kfree(vdev->name);
  98 }
  99
 100 static void vfio_amba_remove(struct amba_device *adev)
 101 {
 102         struct vfio_platform_device *vdev = dev_get_drvdata(&adev->dev);
 103
 104         vfio_unregister_group_dev(&vdev->vdev);
 105         pm_runtime_disable(vdev->device);
 106         vfio_put_device(&vdev->vdev);
 107 }
 108
 109 static const struct vfio_device_ops vfio_amba_ops = {
 110         .name           = "vfio-amba",
 111         .init           = vfio_amba_init_dev,
 112         .release        = vfio_amba_release_dev,
 113         .open_device    = vfio_platform_open_device,
 114         .close_device   = vfio_platform_close_device,
 115         .ioctl          = vfio_platform_ioctl,
 116         .read           = vfio_platform_read,
 117         .write          = vfio_platform_write,
 118         .mmap           = vfio_platform_mmap,
 119         .bind_iommufd   = vfio_iommufd_physical_bind,
 120         .unbind_iommufd = vfio_iommufd_physical_unbind,
 121         .attach_ioas    = vfio_iommufd_physical_attach_ioas,
 122         .detach_ioas    = vfio_iommufd_physical_detach_ioas,
 123 };
 124
 125 static const struct amba_id vfio_amba_ids[] = {
 126         { 0, 0 },
 127 };
 128
 129 MODULE_DEVICE_TABLE(amba, vfio_amba_ids);
 130
 131 static struct amba_driver vfio_amba_driver = {
 132         .probe = vfio_amba_probe,
 133         .remove = vfio_amba_remove,
 134         .id_table = vfio_amba_ids,
 135         .drv = {
 136                 .name = "vfio-amba",
 137         },
 138         .driver_managed_dma = true,
 139 };
 140
 141 module_amba_driver(vfio_amba_driver);
 142
 143 MODULE_VERSION(DRIVER_VERSION);
 144 MODULE_LICENSE("GPL v2");
 145 MODULE_AUTHOR(DRIVER_AUTHOR);
 146 MODULE_DESCRIPTION(DRIVER_DESC);