drivers/staging/unisys/visorchipset/file.c

   1 /* file.c
   2  *
   3  * Copyright (C) 2010 - 2013 UNISYS CORPORATION
   4  * All rights reserved.
   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 as published by
   8  * the Free Software Foundation; either version 2 of the License, or (at
   9  * your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  14  * NON INFRINGEMENT.  See the GNU General Public License for more
  15  * details.
  16  */
  17
  18 /* This contains the implementation that allows a usermode program to
  19  * communicate with the visorchipset driver using a device/file interface.
  20  */
  21
  22 #include "globals.h"
  23 #include "visorchannel.h"
  24 #include <linux/mm.h>
  25 #include <linux/fs.h>
  26 #include "uisutils.h"
  27 #include "file.h"
  28
  29 #define CURRENT_FILE_PC VISOR_CHIPSET_PC_file_c
  30
  31 static struct cdev Cdev;
  32 static VISORCHANNEL **PControlVm_channel;
  33 static dev_t MajorDev = -1; /**< indicates major num for device */
  34 static BOOL Registered = FALSE;
  35
  36 static int visorchipset_open(struct inode *inode, struct file *file);
  37 static int visorchipset_release(struct inode *inode, struct file *file);
  38 static int visorchipset_mmap(struct file *file, struct vm_area_struct *vma);
  39 #ifdef HAVE_UNLOCKED_IOCTL
  40 long visorchipset_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
  41 #else
  42 int visorchipset_ioctl(struct inode *inode, struct file *file,
  43                        unsigned int cmd, unsigned long arg);
  44 #endif
  45
  46 static const struct file_operations visorchipset_fops = {
  47         .owner = THIS_MODULE,
  48         .open = visorchipset_open,
  49         .read = NULL,
  50         .write = NULL,
  51 #ifdef HAVE_UNLOCKED_IOCTL
  52         .unlocked_ioctl = visorchipset_ioctl,
  53 #else
  54         .ioctl = visorchipset_ioctl,
  55 #endif
  56         .release = visorchipset_release,
  57         .mmap = visorchipset_mmap,
  58 };
  59
  60 int
  61 visorchipset_file_init(dev_t majorDev, VISORCHANNEL **pControlVm_channel)
  62 {
  63         int rc = -1;
  64
  65         PControlVm_channel = pControlVm_channel;
  66         MajorDev = majorDev;
  67         cdev_init(&Cdev, &visorchipset_fops);
  68         Cdev.owner = THIS_MODULE;
  69         if (MAJOR(MajorDev) == 0) {
  70                 /* dynamic major device number registration required */
  71                 if (alloc_chrdev_region(&MajorDev, 0, 1, MYDRVNAME) < 0) {
  72                         ERRDRV("Unable to allocate+register char device %s",
  73                                MYDRVNAME);
  74                         goto Away;
  75                 }
  76                 Registered = TRUE;
  77                 INFODRV("New major number %d registered\n", MAJOR(MajorDev));
  78         } else {
  79                 /* static major device number registration required */
  80                 if (register_chrdev_region(MajorDev, 1, MYDRVNAME) < 0) {
  81                         ERRDRV("Unable to register char device %s", MYDRVNAME);
  82                         goto Away;
  83                 }
  84                 Registered = TRUE;
  85                 INFODRV("Static major number %d registered\n", MAJOR(MajorDev));
  86         }
  87         if (cdev_add(&Cdev, MKDEV(MAJOR(MajorDev), 0), 1) < 0) {
  88                 ERRDRV("failed to create char device: (status=%d)\n", rc);
  89                 goto Away;
  90         }
  91         INFODRV("Registered char device for %s (major=%d)",
  92                 MYDRVNAME, MAJOR(MajorDev));
  93         rc = 0;
  94 Away:
  95         return rc;
  96 }
  97
  98 void
  99 visorchipset_file_cleanup(void)
 100 {
 101         if (Cdev.ops != NULL)
 102                 cdev_del(&Cdev);
 103         Cdev.ops = NULL;
 104         if (Registered) {
 105                 if (MAJOR(MajorDev) >= 0) {
 106                         unregister_chrdev_region(MajorDev, 1);
 107                         MajorDev = MKDEV(0, 0);
 108                 }
 109                 Registered = FALSE;
 110         }
 111 }
 112
 113 static int
 114 visorchipset_open(struct inode *inode, struct file *file)
 115 {
 116         unsigned minor_number = iminor(inode);
 117         int rc = -ENODEV;
 118
 119         DEBUGDRV("%s", __func__);
 120         if (minor_number != 0)
 121                 goto Away;
 122         file->private_data = NULL;
 123         rc = 0;
 124 Away:
 125         if (rc < 0)
 126                 ERRDRV("%s minor=%d failed", __func__, minor_number);
 127         return rc;
 128 }
 129
 130 static int
 131 visorchipset_release(struct inode *inode, struct file *file)
 132 {
 133         DEBUGDRV("%s", __func__);
 134         return 0;
 135 }
 136
 137 static int
 138 visorchipset_mmap(struct file *file, struct vm_area_struct *vma)
 139 {
 140         ulong physAddr = 0;
 141         ulong offset = vma->vm_pgoff << PAGE_SHIFT;
 142         GUEST_PHYSICAL_ADDRESS addr = 0;
 143
 144         /* sv_enable_dfp(); */
 145         DEBUGDRV("%s", __func__);
 146         if (offset & (PAGE_SIZE - 1)) {
 147                 ERRDRV("%s virtual address NOT page-aligned!", __func__);
 148                 return -ENXIO;  /* need aligned offsets */
 149         }
 150         switch (offset) {
 151         case VISORCHIPSET_MMAP_CONTROLCHANOFFSET:
 152                 vma->vm_flags |= VM_IO;
 153                 if (*PControlVm_channel == NULL) {
 154                         ERRDRV("%s no controlvm channel yet", __func__);
 155                         return -ENXIO;
 156                 }
 157                 visorchannel_read(*PControlVm_channel,
 158                                   offsetof(ULTRA_CONTROLVM_CHANNEL_PROTOCOL,
 159                                            gpControlChannel), &addr,
 160                                   sizeof(addr));
 161                 if (addr == 0) {
 162                         ERRDRV("%s control channel address is 0", __func__);
 163                         return -ENXIO;
 164                 }
 165                 physAddr = (ulong) (addr);
 166                 DEBUGDRV("mapping physical address = 0x%lx", physAddr);
 167                 if (remap_pfn_range(vma, vma->vm_start,
 168                                     physAddr >> PAGE_SHIFT,
 169                                     vma->vm_end - vma->vm_start,
 170                                     /*pgprot_noncached */
 171                                     (vma->vm_page_prot))) {
 172                         ERRDRV("%s remap_pfn_range failed", __func__);
 173                         return -EAGAIN;
 174                 }
 175                 break;
 176         default:
 177                 return -ENOSYS;
 178         }
 179         DEBUGDRV("%s success!", __func__);
 180         return 0;
 181 }
 182
 183 #ifdef HAVE_UNLOCKED_IOCTL
 184 long
 185 visorchipset_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 186 #else
 187 int
 188 visorchipset_ioctl(struct inode *inode, struct file *file,
 189                    unsigned int cmd, unsigned long arg)
 190 #endif
 191 {
 192         int rc = SUCCESS;
 193         s64 adjustment;
 194         s64 vrtc_offset;
 195         DBGINF("entered visorchipset_ioctl, cmd=%d", cmd);
 196         switch (cmd) {
 197         case VMCALL_QUERY_GUEST_VIRTUAL_TIME_OFFSET:
 198                 /* get the physical rtc offset */
 199                 vrtc_offset = Issue_VMCALL_QUERY_GUEST_VIRTUAL_TIME_OFFSET();
 200                 if (copy_to_user
 201                     ((void __user *)arg, &vrtc_offset, sizeof(vrtc_offset))) {
 202                         rc = -EFAULT;
 203                         goto Away;
 204                 }
 205                 DBGINF("insde visorchipset_ioctl, cmd=%d, vrtc_offset=%lld",
 206                        cmd, vrtc_offset);
 207                 break;
 208         case VMCALL_UPDATE_PHYSICAL_TIME:
 209                 if (copy_from_user
 210                     (&adjustment, (void __user *)arg, sizeof(adjustment))) {
 211                         rc = -EFAULT;
 212                         goto Away;
 213                 }
 214                 DBGINF("insde visorchipset_ioctl, cmd=%d, adjustment=%lld", cmd,
 215                        adjustment);
 216                 rc = Issue_VMCALL_UPDATE_PHYSICAL_TIME(adjustment);
 217                 break;
 218         default:
 219                 LOGERR("visorchipset_ioctl received invalid command");
 220                 rc = -EFAULT;
 221                 break;
 222         }
 223 Away:
 224         DBGINF("exiting %d!", rc);
 225         return rc;
 226 }