drivers/staging/hv/storvsc_api.h

   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
  24
  25 #ifndef _STORVSC_API_H_
  26 #define _STORVSC_API_H_
  27
  28 #include <linux/kernel.h>
  29 #include "vstorage.h"
  30 #include "vmbus_api.h"
  31
  32 /* Defines */
  33 #define STORVSC_RING_BUFFER_SIZE                        (20*PAGE_SIZE)
  34 #define BLKVSC_RING_BUFFER_SIZE                         (20*PAGE_SIZE)
  35
  36 #define STORVSC_MAX_IO_REQUESTS                         128
  37
  38 /*
  39  * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
  40  * reality, the path/target is not used (ie always set to 0) so our
  41  * scsi host adapter essentially has 1 bus with 1 target that contains
  42  * up to 256 luns.
  43  */
  44 #define STORVSC_MAX_LUNS_PER_TARGET                     64
  45 #define STORVSC_MAX_TARGETS                             1
  46 #define STORVSC_MAX_CHANNELS                            1
  47
  48 struct hv_storvsc_request;
  49
  50 /* Matches Windows-end */
  51 enum storvsc_request_type{
  52         WRITE_TYPE,
  53         READ_TYPE,
  54         UNKNOWN_TYPE,
  55 };
  56
  57
  58 struct storvsc_request_extension {
  59         struct hv_storvsc_request *request;
  60         struct hv_device *device;
  61
  62         /* Synchronize the request/response if needed */
  63         struct completion wait_event;
  64
  65         struct vstor_packet vstor_packet;
  66 };
  67
  68 struct hv_storvsc_request {
  69         u32 bus;
  70         u32 target_id;
  71         u32 lun_id;
  72         u8 *cdb;
  73         u32 cdb_len;
  74         u32 status;
  75         u32 bytes_xfer;
  76
  77         unsigned char *sense_buffer;
  78         u32 sense_buffer_size;
  79
  80         void *context;
  81
  82         void (*on_io_completion)(struct hv_storvsc_request *request);
  83
  84         struct storvsc_request_extension extension;
  85
  86         struct hv_multipage_buffer data_buffer;
  87 };
  88
  89 /* Represents the block vsc driver */
  90 struct storvsc_driver_object {
  91         struct hv_driver base;
  92
  93         /* Set by caller (in bytes) */
  94         u32 ring_buffer_size;
  95
  96         /* Maximum # of requests in flight per channel/device */
  97         u32 max_outstanding_req_per_channel;
  98
  99         /* Specific to this driver */
 100         int (*on_io_request)(struct hv_device *device,
 101                            struct hv_storvsc_request *request);
 102 };
 103
 104 struct storvsc_device_info {
 105         unsigned int port_number;
 106         unsigned char path_id;
 107         unsigned char target_id;
 108 };
 109
 110 /* A storvsc device is a device object that contains a vmbus channel */
 111 struct storvsc_device {
 112         struct hv_device *device;
 113
 114         /* 0 indicates the device is being destroyed */
 115         atomic_t ref_count;
 116
 117         atomic_t num_outstanding_req;
 118
 119         /*
 120          * Each unique Port/Path/Target represents 1 channel ie scsi
 121          * controller. In reality, the pathid, targetid is always 0
 122          * and the port is set by us
 123          */
 124         unsigned int port_number;
 125         unsigned char path_id;
 126         unsigned char target_id;
 127
 128         /* Used for vsc/vsp channel reset process */
 129         struct storvsc_request_extension init_request;
 130         struct storvsc_request_extension reset_request;
 131 };
 132
 133
 134 /* Get the stordevice object iff exists and its refcount > 1 */
 135 static inline struct storvsc_device *get_stor_device(struct hv_device *device)
 136 {
 137         struct storvsc_device *stor_device;
 138
 139         stor_device = (struct storvsc_device *)device->ext;
 140         if (stor_device && atomic_read(&stor_device->ref_count) > 1)
 141                 atomic_inc(&stor_device->ref_count);
 142         else
 143                 stor_device = NULL;
 144
 145         return stor_device;
 146 }
 147
 148
 149 static inline void put_stor_device(struct hv_device *device)
 150 {
 151         struct storvsc_device *stor_device;
 152
 153         stor_device = (struct storvsc_device *)device->ext;
 154
 155         atomic_dec(&stor_device->ref_count);
 156 }
 157
 158 static inline struct storvsc_driver_object *hvdr_to_stordr(struct hv_driver *d)
 159 {
 160         return container_of(d, struct storvsc_driver_object, base);
 161 }
 162
 163 /* Interface */
 164
 165 int stor_vsc_on_device_add(struct hv_device *device,
 166                                 void *additional_info);
 167 int stor_vsc_on_device_remove(struct hv_device *device);
 168
 169 int stor_vsc_on_io_request(struct hv_device *device,
 170                                 struct hv_storvsc_request *request);
 171 void stor_vsc_on_cleanup(struct hv_driver *driver);
 172
 173
 174 #endif /* _STORVSC_API_H_ */