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  * @vr_mutex: Mutex for synchronizing access to the VRING.
  50  * @buf: Temporary kernel buffer used to copy in/out data
  51  * from/to the card via DMA.
  52  * @buf_da: dma address of buf.
  53  * @mvdev: Back pointer to MIC virtio device for vringh_notify(..).
  54  * @head: The VRINGH head index address passed to vringh_getdesc_kern(..).
  55  */
  56 struct mic_vringh {
  57         struct mic_vring vring;
  58         struct vringh vrh;
  59         struct vringh_kiov riov;
  60         struct vringh_kiov wiov;
  61         struct mutex vr_mutex;
  62         void *buf;
  63         dma_addr_t buf_da;
  64         struct mic_vdev *mvdev;
  65         u16 head;
  66 };
  67
  68 /**
  69  * struct mic_vdev - Host information for a card Virtio device.
  70  *
  71  * @virtio_id - Virtio device id.
  72  * @waitq - Waitqueue to allow ring3 apps to poll.
  73  * @mdev - Back pointer to host MIC device.
  74  * @poll_wake - Used for waking up threads blocked in poll.
  75  * @out_bytes - Debug stats for number of bytes copied from host to card.
  76  * @in_bytes - Debug stats for number of bytes copied from card to host.
  77  * @out_bytes_dma - Debug stats for number of bytes copied from host to card
  78  * using DMA.
  79  * @in_bytes_dma - Debug stats for number of bytes copied from card to host
  80  * using DMA.
  81  * @tx_len_unaligned - Debug stats for number of bytes copied to the card where
  82  * the transfer length did not have the required DMA alignment.
  83  * @tx_dst_unaligned - Debug stats for number of bytes copied where the
  84  * destination address on the card did not have the required DMA alignment.
  85  * @mvr - Store per VRING data structures.
  86  * @virtio_bh_work - Work struct used to schedule virtio bottom half handling.
  87  * @dd - Virtio device descriptor.
  88  * @dc - Virtio device control fields.
  89  * @list - List of Virtio devices.
  90  * @virtio_db - The doorbell used by the card to interrupt the host.
  91  * @virtio_cookie - The cookie returned while requesting interrupts.
  92  */
  93 struct mic_vdev {
  94         int virtio_id;
  95         wait_queue_head_t waitq;
  96         struct mic_device *mdev;
  97         int poll_wake;
  98         unsigned long out_bytes;
  99         unsigned long in_bytes;
 100         unsigned long out_bytes_dma;
 101         unsigned long in_bytes_dma;
 102         unsigned long tx_len_unaligned;
 103         unsigned long tx_dst_unaligned;
 104         struct mic_vringh mvr[MIC_MAX_VRINGS];
 105         struct work_struct virtio_bh_work;
 106         struct mic_device_desc *dd;
 107         struct mic_device_ctrl *dc;
 108         struct list_head list;
 109         int virtio_db;
 110         struct mic_irq *virtio_cookie;
 111 };
 112
 113 void mic_virtio_uninit(struct mic_device *mdev);
 114 int mic_virtio_add_device(struct mic_vdev *mvdev,
 115                         void __user *argp);
 116 void mic_virtio_del_device(struct mic_vdev *mvdev);
 117 int mic_virtio_config_change(struct mic_vdev *mvdev,
 118                         void __user *argp);
 119 int mic_virtio_copy_desc(struct mic_vdev *mvdev,
 120         struct mic_copy_desc *request);
 121 void mic_virtio_reset_devices(struct mic_device *mdev);
 122 void mic_bh_handler(struct work_struct *work);
 123
 124 /* Helper API to obtain the MIC PCIe device */
 125 static inline struct device *mic_dev(struct mic_vdev *mvdev)
 126 {
 127         return mvdev->mdev->sdev->parent;
 128 }
 129
 130 /* Helper API to check if a virtio device is initialized */
 131 static inline int mic_vdev_inited(struct mic_vdev *mvdev)
 132 {
 133         /* Device has not been created yet */
 134         if (!mvdev->dd || !mvdev->dd->type) {
 135                 dev_err(mic_dev(mvdev), "%s %d err %d\n",
 136                         __func__, __LINE__, -EINVAL);
 137                 return -EINVAL;
 138         }
 139
 140         /* Device has been removed/deleted */
 141         if (mvdev->dd->type == -1) {
 142                 dev_err(mic_dev(mvdev), "%s %d err %d\n",
 143                         __func__, __LINE__, -ENODEV);
 144                 return -ENODEV;
 145         }
 146
 147         return 0;
 148 }
 149
 150 /* Helper API to check if a virtio device is running */
 151 static inline bool mic_vdevup(struct mic_vdev *mvdev)
 152 {
 153         return !!mvdev->dd->status;
 154 }
 155 #endif