drivers/staging/hv/blkvsc.c

   1 /*
   2  *
   3  * Copyright (c) 2009, Microsoft Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA 02111-1307 USA.
  17  *
  18  * Authors:
  19  *   Haiyang Zhang <haiyangz@microsoft.com>
  20  *   Hank Janssen  <hjanssen@microsoft.com>
  21  *
  22  */
  23 #include <linux/kernel.h>
  24 #include <linux/mm.h>
  25 #include "hv_api.h"
  26 #include "storvsc.c"
  27
  28 static const char *g_blk_driver_name = "blkvsc";
  29
  30 /* {32412632-86cb-44a2-9b5c-50d1417354f5} */
  31 static const struct hv_guid g_blk_device_type = {
  32         .data = {
  33                 0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
  34                 0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5
  35         }
  36 };
  37
  38 static int blk_vsc_on_device_add(struct hv_device *device, void *additional_info)
  39 {
  40         struct storvsc_device_info *device_info;
  41         int ret = 0;
  42
  43         device_info = (struct storvsc_device_info *)additional_info;
  44
  45         ret = stor_vsc_on_device_add(device, additional_info);
  46         if (ret != 0)
  47                 return ret;
  48
  49         /*
  50          * We need to use the device instance guid to set the path and target
  51          * id. For IDE devices, the device instance id is formatted as
  52          * <bus id> * - <device id> - 8899 - 000000000000.
  53          */
  54         device_info->path_id = device->dev_instance.data[3] << 24 |
  55                              device->dev_instance.data[2] << 16 |
  56                              device->dev_instance.data[1] << 8  |
  57                              device->dev_instance.data[0];
  58
  59         device_info->target_id = device->dev_instance.data[5] << 8 |
  60                                device->dev_instance.data[4];
  61
  62         return ret;
  63 }
  64
  65 int blk_vsc_initialize(struct hv_driver *driver)
  66 {
  67         struct storvsc_driver_object *stor_driver;
  68         int ret = 0;
  69
  70         stor_driver = (struct storvsc_driver_object *)driver;
  71
  72         /* Make sure we are at least 2 pages since 1 page is used for control */
  73         /* ASSERT(stor_driver->RingBufferSize >= (PAGE_SIZE << 1)); */
  74
  75         driver->name = g_blk_driver_name;
  76         memcpy(&driver->dev_type, &g_blk_device_type, sizeof(struct hv_guid));
  77
  78         stor_driver->request_ext_size = sizeof(struct storvsc_request_extension);
  79
  80         /*
  81          * Divide the ring buffer data size (which is 1 page less than the ring
  82          * buffer size since that page is reserved for the ring buffer indices)
  83          * by the max request size (which is
  84          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
  85          */
  86         stor_driver->max_outstanding_req_per_channel =
  87                 ((stor_driver->ring_buffer_size - PAGE_SIZE) /
  88                   ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
  89                            sizeof(struct vstor_packet) + sizeof(u64),
  90                            sizeof(u64)));
  91
  92         DPRINT_INFO(BLKVSC, "max io outstd %u",
  93                     stor_driver->max_outstanding_req_per_channel);
  94
  95         /* Setup the dispatch table */
  96         stor_driver->base.dev_add = blk_vsc_on_device_add;
  97         stor_driver->base.dev_rm = stor_vsc_on_device_remove;
  98         stor_driver->base.cleanup = stor_vsc_on_cleanup;
  99         stor_driver->on_io_request = stor_vsc_on_io_request;
 100
 101         return ret;
 102 }