drivers/misc/mic/host/mic_virtio.h

   1 /*
   2  * Intel MIC Platform Software Stack (MPSS)
   3  *
   4  * Copyright(c) 2013 Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 2, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * The full GNU General Public License is included in this distribution in
  16  * the file called "COPYING".
  17  *
  18  * Intel MIC Host driver.
  19  *
  20  */
  21 #ifndef MIC_VIRTIO_H
  22 #define MIC_VIRTIO_H
  23
  24 #include <linux/virtio_config.h>
  25 #include <linux/mic_ioctl.h>
  26
  27 /*
  28  * Note on endianness.
  29  * 1. Host can be both BE or LE
  30  * 2. Guest/card is LE. Host uses le_to_cpu to access desc/avail
  31  *    rings and ioreadXX/iowriteXX to access used ring.
  32  * 3. Device page exposed by host to guest contains LE values. Guest
  33  *    accesses these using ioreadXX/iowriteXX etc. This way in general we
  34  *    obey the virtio spec according to which guest works with native
  35  *    endianness and host is aware of guest endianness and does all
  36  *    required endianness conversion.
  37  * 4. Data provided from user space to guest (in ADD_DEVICE and
  38  *    CONFIG_CHANGE ioctl's) is not interpreted by the driver and should be
  39  *    in guest endianness.
  40  */
  41
  42 /**
  43  * struct mic_vringh - Virtio ring host information.
  44  *
  45  * @vring: The MIC vring used for setting up user space mappings.
  46  * @vrh: The host VRINGH used for accessing the card vrings.
  47  * @riov: The VRINGH read kernel IOV.
  48  * @wiov: The VRINGH write kernel IOV.
  49  * @head: The VRINGH head index address passed to vringh_getdesc_kern(..).
  50  * @vr_mutex: Mutex for synchronizing access to the VRING.
  51  * @mvdev: Back pointer to MIC virtio device for vringh_notify(..).
  52  */
  53 struct mic_vringh {
  54         struct mic_vring vring;
  55         struct vringh vrh;
  56         struct vringh_kiov riov;
  57         struct vringh_kiov wiov;
  58         u16 head;
  59         struct mutex vr_mutex;
  60         struct mic_vdev *mvdev;
  61 };
  62
  63 /**
  64  * struct mic_vdev - Host information for a card Virtio device.
  65  *
  66  * @virtio_id - Virtio device id.
  67  * @waitq - Waitqueue to allow ring3 apps to poll.
  68  * @mdev - Back pointer to host MIC device.
  69  * @poll_wake - Used for waking up threads blocked in poll.
  70  * @out_bytes - Debug stats for number of bytes copied from host to card.
  71  * @in_bytes - Debug stats for number of bytes copied from card to host.
  72  * @mvr - Store per VRING data structures.
  73  * @virtio_bh_work - Work struct used to schedule virtio bottom half handling.
  74  * @dd - Virtio device descriptor.
  75  * @dc - Virtio device control fields.
  76  * @list - List of Virtio devices.
  77  * @virtio_db - The doorbell used by the card to interrupt the host.
  78  * @virtio_cookie - The cookie returned while requesting interrupts.
  79  */
  80 struct mic_vdev {
  81         int virtio_id;
  82         wait_queue_head_t waitq;
  83         struct mic_device *mdev;
  84         int poll_wake;
  85         unsigned long out_bytes;
  86         unsigned long in_bytes;
  87         struct mic_vringh mvr[MIC_MAX_VRINGS];
  88         struct work_struct virtio_bh_work;
  89         struct mic_device_desc *dd;
  90         struct mic_device_ctrl *dc;
  91         struct list_head list;
  92         int virtio_db;
  93         struct mic_irq *virtio_cookie;
  94 };
  95
  96 void mic_virtio_uninit(struct mic_device *mdev);
  97 int mic_virtio_add_device(struct mic_vdev *mvdev,
  98                         void __user *argp);
  99 void mic_virtio_del_device(struct mic_vdev *mvdev);
 100 int mic_virtio_config_change(struct mic_vdev *mvdev,
 101                         void __user *argp);
 102 int mic_virtio_copy_desc(struct mic_vdev *mvdev,
 103         struct mic_copy_desc *request);
 104 void mic_virtio_reset_devices(struct mic_device *mdev);
 105 void mic_bh_handler(struct work_struct *work);
 106
 107 /* Helper API to obtain the MIC PCIe device */
 108 static inline struct device *mic_dev(struct mic_vdev *mvdev)
 109 {
 110         return mvdev->mdev->sdev->parent;
 111 }
 112
 113 /* Helper API to check if a virtio device is initialized */
 114 static inline int mic_vdev_inited(struct mic_vdev *mvdev)
 115 {
 116         /* Device has not been created yet */
 117         if (!mvdev->dd || !mvdev->dd->type) {
 118                 dev_err(mic_dev(mvdev), "%s %d err %d\n",
 119                         __func__, __LINE__, -EINVAL);
 120                 return -EINVAL;
 121         }
 122
 123         /* Device has been removed/deleted */
 124         if (mvdev->dd->type == -1) {
 125                 dev_err(mic_dev(mvdev), "%s %d err %d\n",
 126                         __func__, __LINE__, -ENODEV);
 127                 return -ENODEV;
 128         }
 129
 130         return 0;
 131 }
 132
 133 /* Helper API to check if a virtio device is running */
 134 static inline bool mic_vdevup(struct mic_vdev *mvdev)
 135 {
 136         return !!mvdev->dd->status;
 137 }
 138 #endif