drivers/misc/mic/host/mic_fops.c

   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 #include <linux/poll.h>
  22 #include <linux/pci.h>
  23
  24 #include <linux/mic_common.h>
  25 #include "../common/mic_dev.h"
  26 #include "mic_device.h"
  27 #include "mic_fops.h"
  28 #include "mic_virtio.h"
  29
  30 int mic_open(struct inode *inode, struct file *f)
  31 {
  32         struct mic_vdev *mvdev;
  33         struct mic_device *mdev = container_of(inode->i_cdev,
  34                 struct mic_device, cdev);
  35
  36         mvdev = kzalloc(sizeof(*mvdev), GFP_KERNEL);
  37         if (!mvdev)
  38                 return -ENOMEM;
  39
  40         init_waitqueue_head(&mvdev->waitq);
  41         INIT_LIST_HEAD(&mvdev->list);
  42         mvdev->mdev = mdev;
  43         mvdev->virtio_id = -1;
  44
  45         f->private_data = mvdev;
  46         return 0;
  47 }
  48
  49 int mic_release(struct inode *inode, struct file *f)
  50 {
  51         struct mic_vdev *mvdev = (struct mic_vdev *)f->private_data;
  52
  53         if (-1 != mvdev->virtio_id)
  54                 mic_virtio_del_device(mvdev);
  55         f->private_data = NULL;
  56         kfree(mvdev);
  57         return 0;
  58 }
  59
  60 long mic_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
  61 {
  62         struct mic_vdev *mvdev = (struct mic_vdev *)f->private_data;
  63         void __user *argp = (void __user *)arg;
  64         int ret;
  65
  66         switch (cmd) {
  67         case MIC_VIRTIO_ADD_DEVICE:
  68         {
  69                 ret = mic_virtio_add_device(mvdev, argp);
  70                 if (ret < 0) {
  71                         dev_err(mic_dev(mvdev),
  72                                 "%s %d errno ret %d\n",
  73                                 __func__, __LINE__, ret);
  74                         return ret;
  75                 }
  76                 break;
  77         }
  78         case MIC_VIRTIO_COPY_DESC:
  79         {
  80                 struct mic_copy_desc copy;
  81
  82                 ret = mic_vdev_inited(mvdev);
  83                 if (ret)
  84                         return ret;
  85
  86                 if (copy_from_user(&copy, argp, sizeof(copy)))
  87                         return -EFAULT;
  88
  89                 dev_dbg(mic_dev(mvdev),
  90                         "%s %d === iovcnt 0x%x vr_idx 0x%x update_used %d\n",
  91                         __func__, __LINE__, copy.iovcnt, copy.vr_idx,
  92                         copy.update_used);
  93
  94                 ret = mic_virtio_copy_desc(mvdev, &copy);
  95                 if (ret < 0) {
  96                         dev_err(mic_dev(mvdev),
  97                                 "%s %d errno ret %d\n",
  98                                 __func__, __LINE__, ret);
  99                         return ret;
 100                 }
 101                 if (copy_to_user(
 102                         &((struct mic_copy_desc __user *)argp)->out_len,
 103                         &copy.out_len, sizeof(copy.out_len))) {
 104                         dev_err(mic_dev(mvdev), "%s %d errno ret %d\n",
 105                                 __func__, __LINE__, -EFAULT);
 106                         return -EFAULT;
 107                 }
 108                 break;
 109         }
 110         case MIC_VIRTIO_CONFIG_CHANGE:
 111         {
 112                 ret = mic_vdev_inited(mvdev);
 113                 if (ret)
 114                         return ret;
 115
 116                 ret = mic_virtio_config_change(mvdev, argp);
 117                 if (ret < 0) {
 118                         dev_err(mic_dev(mvdev),
 119                                 "%s %d errno ret %d\n",
 120                                 __func__, __LINE__, ret);
 121                         return ret;
 122                 }
 123                 break;
 124         }
 125         default:
 126                 return -ENOIOCTLCMD;
 127         };
 128         return 0;
 129 }
 130
 131 /*
 132  * We return POLLIN | POLLOUT from poll when new buffers are enqueued, and
 133  * not when previously enqueued buffers may be available. This means that
 134  * in the card->host (TX) path, when userspace is unblocked by poll it
 135  * must drain all available descriptors or it can stall.
 136  */
 137 unsigned int mic_poll(struct file *f, poll_table *wait)
 138 {
 139         struct mic_vdev *mvdev = (struct mic_vdev *)f->private_data;
 140         int mask = 0;
 141
 142         poll_wait(f, &mvdev->waitq, wait);
 143
 144         if (mic_vdev_inited(mvdev)) {
 145                 mask = POLLERR;
 146         } else if (mvdev->poll_wake) {
 147                 mvdev->poll_wake = 0;
 148                 mask = POLLIN | POLLOUT;
 149         }
 150
 151         return mask;
 152 }
 153
 154 static inline int
 155 mic_query_offset(struct mic_vdev *mvdev, unsigned long offset,
 156                  unsigned long *size, unsigned long *pa)
 157 {
 158         struct mic_device *mdev = mvdev->mdev;
 159         unsigned long start = MIC_DP_SIZE;
 160         int i;
 161
 162         /*
 163          * MMAP interface is as follows:
 164          * offset                               region
 165          * 0x0                                  virtio device_page
 166          * 0x1000                               first vring
 167          * 0x1000 + size of 1st vring           second vring
 168          * ....
 169          */
 170         if (!offset) {
 171                 *pa = virt_to_phys(mdev->dp);
 172                 *size = MIC_DP_SIZE;
 173                 return 0;
 174         }
 175
 176         for (i = 0; i < mvdev->dd->num_vq; i++) {
 177                 struct mic_vringh *mvr = &mvdev->mvr[i];
 178                 if (offset == start) {
 179                         *pa = virt_to_phys(mvr->vring.va);
 180                         *size = mvr->vring.len;
 181                         return 0;
 182                 }
 183                 start += mvr->vring.len;
 184         }
 185         return -1;
 186 }
 187
 188 /*
 189  * Maps the device page and virtio rings to user space for readonly access.
 190  */
 191 int
 192 mic_mmap(struct file *f, struct vm_area_struct *vma)
 193 {
 194         struct mic_vdev *mvdev = (struct mic_vdev *)f->private_data;
 195         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 196         unsigned long pa, size = vma->vm_end - vma->vm_start, size_rem = size;
 197         int i, err;
 198
 199         err = mic_vdev_inited(mvdev);
 200         if (err)
 201                 return err;
 202
 203         if (vma->vm_flags & VM_WRITE)
 204                 return -EACCES;
 205
 206         while (size_rem) {
 207                 i = mic_query_offset(mvdev, offset, &size, &pa);
 208                 if (i < 0)
 209                         return -EINVAL;
 210                 err = remap_pfn_range(vma, vma->vm_start + offset,
 211                         pa >> PAGE_SHIFT, size, vma->vm_page_prot);
 212                 if (err)
 213                         return err;
 214                 dev_dbg(mic_dev(mvdev),
 215                         "%s %d type %d size 0x%lx off 0x%lx pa 0x%lx vma 0x%lx\n",
 216                         __func__, __LINE__, mvdev->virtio_id, size, offset,
 217                         pa, vma->vm_start + offset);
 218                 size_rem -= size;
 219                 offset += size;
 220         }
 221         return 0;
 222 }