drivers/xen/blktap/blktap.c

   1 /******************************************************************************
   2  * blktap.c
   3  *
   4  * XenLinux virtual block-device tap.
   5  *
   6  * Copyright (c) 2004, Andrew Warfield
   7  *
   8  * Based on the original split block driver:
   9  * Copyright (c) 2003-2004, Keir Fraser & Steve Hand
  10  * Modifications by Mark A. Williamson are (c) Intel Research Cambridge
  11  * Copyright (c) 2004, Christian Limpach
  12  *
  13  * Note that unlike the split block driver code, this driver has been developed
  14  * strictly for Linux 2.6
  15  */
  16
  17 #include "blktap.h"
  18
  19 int __init xlblktap_init(void)
  20 {
  21     ctrl_msg_t               cmsg;
  22     blkif_fe_driver_status_t fe_st;
  23     blkif_be_driver_status_t be_st;
  24
  25     printk(KERN_INFO "Initialising Xen block tap device\n");
  26
  27     DPRINTK("   tap - Backend connection init:\n");
  28
  29
  30     (void)ctrl_if_register_receiver(CMSG_BLKIF_FE, blkif_ctrlif_rx,
  31                                     CALLBACK_IN_BLOCKING_CONTEXT);
  32
  33     /* Send a driver-UP notification to the domain controller. */
  34     cmsg.type      = CMSG_BLKIF_FE;
  35     cmsg.subtype   = CMSG_BLKIF_FE_DRIVER_STATUS;
  36     cmsg.length    = sizeof(blkif_fe_driver_status_t);
  37     fe_st.status   = BLKIF_DRIVER_STATUS_UP;
  38     memcpy(cmsg.msg, &fe_st, sizeof(fe_st));
  39     ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
  40
  41     DPRINTK("   tap - Frontend connection init:\n");
  42
  43     active_reqs_init();
  44     blkif_interface_init();
  45     blkdev_schedule_init();
  46
  47     (void)ctrl_if_register_receiver(CMSG_BLKIF_BE, blkif_ctrlif_rx,
  48                                     CALLBACK_IN_BLOCKING_CONTEXT);
  49
  50     /* Send a driver-UP notification to the domain controller. */
  51     cmsg.type      = CMSG_BLKIF_BE;
  52     cmsg.subtype   = CMSG_BLKIF_BE_DRIVER_STATUS;
  53     cmsg.length    = sizeof(blkif_be_driver_status_t);
  54     be_st.status   = BLKIF_DRIVER_STATUS_UP;
  55     memcpy(cmsg.msg, &be_st, sizeof(be_st));
  56     ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
  57
  58     DPRINTK("   tap - Userland channel init:\n");
  59
  60     blktap_init();
  61
  62     DPRINTK("Blkif tap device initialized.\n");
  63
  64     return 0;
  65 }
  66
  67 #if 0 /* tap doesn't handle suspend/resume */
  68 void blkdev_suspend(void)
  69 {
  70 }
  71
  72 void blkdev_resume(void)
  73 {
  74     ctrl_msg_t               cmsg;
  75     blkif_fe_driver_status_t st;
  76
  77     /* Send a driver-UP notification to the domain controller. */
  78     cmsg.type      = CMSG_BLKIF_FE;
  79     cmsg.subtype   = CMSG_BLKIF_FE_DRIVER_STATUS;
  80     cmsg.length    = sizeof(blkif_fe_driver_status_t);
  81     st.status      = BLKIF_DRIVER_STATUS_UP;
  82     memcpy(cmsg.msg, &st, sizeof(st));
  83     ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
  84 }
  85 #endif
  86
  87 __initcall(xlblktap_init);