usr/src/uts/common/sys/blkdev.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  23  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25
  26 #ifndef _SYS_BLKDEV_H
  27 #define _SYS_BLKDEV_H
  28
  29 #include <sys/types.h>
  30 #include <sys/ksynch.h>
  31 #include <sys/ddi.h>
  32 #include <sys/sunddi.h>
  33
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37
  38 /*
  39  * This describes a fairly simple block device.  The idea here is that
  40  * these things want to take advantage of the common labelling support,
  41  * but do not need all the capabilities of SCSA.  So we make quite a few
  42  * simplifications:
  43  *
  44  * 1) Device block size is a multiple of 512 bytes.
  45  *
  46  * 2) Non-rotating media.  We assume a simple linear layout.
  47  *
  48  * 3) Fixed queue depth, for each device.  The adapter driver reports
  49  *    the queue depth at registration.  We don't have any form of
  50  *    dynamic flow control.
  51  *
  52  * 4) Negligible power management support.  The framework does not support
  53  *    fine grained power management.  If the adapter driver wants to use
  54  *    such, it will need to manage power on its own.
  55  *
  56  * 5) Suspend/resume support managed by the adapter driver.  We don't
  57  *    support suspend/resume directly.  The adapter device driver will
  58  *    need to manage this on its own behalf.
  59  *
  60  * 6) No request priorities.  Transfers are assumed to execute in
  61  *    roughly FIFO order.  The adapter driver may reorder them, but the
  62  *    submitter has no control over that.
  63  *
  64  * 7) No request cancellation.  Once submitted, the job completes or
  65  *    fails.  It cannot be canceled.
  66  *
  67  * 8) Limited support for removable media.  There is no support for
  68  *    locking bay doors or mechanised media bays.  This could be
  69  *    added, but at present the only such interesting devices are
  70  *    covered by the SCSI disk driver.
  71  */
  72
  73 typedef struct bd_handle *bd_handle_t;
  74 typedef struct bd_xfer bd_xfer_t;
  75 typedef struct bd_drive bd_drive_t;
  76 typedef struct bd_media bd_media_t;
  77 typedef struct bd_ops bd_ops_t;
  78
  79
  80 struct bd_xfer {
  81         /*
  82          * NB: If using DMA the br_ndmac will be non-zero.  Otherwise
  83          * the br_kaddr will be non-NULL.
  84          */
  85         diskaddr_t              x_blkno;
  86         size_t                  x_nblks;
  87         ddi_dma_handle_t        x_dmah;
  88         ddi_dma_cookie_t        x_dmac;
  89         unsigned                x_ndmac;
  90         caddr_t                 x_kaddr;
  91         unsigned                x_flags;
  92 };
  93
  94 #define BD_XFER_POLL            (1U << 0)       /* no interrupts (dump) */
  95
  96 struct bd_drive {
  97         uint32_t                d_qsize;
  98         uint32_t                d_maxxfer;
  99         boolean_t               d_removable;
 100         boolean_t               d_hotpluggable;
 101         int                     d_target;
 102         int                     d_lun;
 103 };
 104
 105 struct bd_media {
 106         /*
 107          * NB: The block size must be a power of two not less than
 108          * DEV_BSIZE (512).  Other values of the block size will
 109          * simply not function and the media will be rejected.
 110          *
 111          * The block size must also divide evenly into the device's
 112          * d_maxxfer field.  If the maxxfer is a power of two larger
 113          * than the block size, then this will automatically be
 114          * satisfied.
 115          */
 116         uint64_t                m_nblks;
 117         uint32_t                m_blksize;
 118         boolean_t               m_readonly;
 119 };
 120
 121 #define BD_INFO_FLAG_REMOVABLE          (1U << 0)
 122 #define BD_INFO_FLAG_HOTPLUGGABLE       (1U << 1)
 123 #define BD_INFO_FLAG_READ_ONLY          (1U << 2)
 124
 125 struct bd_ops {
 126         int     o_version;
 127         void    (*o_drive_info)(void *, bd_drive_t *);
 128         int     (*o_media_info)(void *, bd_media_t *);
 129         int     (*o_devid_init)(void *, dev_info_t *, ddi_devid_t *);
 130         int     (*o_sync_cache)(void *, bd_xfer_t *);
 131         int     (*o_read)(void *, bd_xfer_t *);
 132         int     (*o_write)(void *, bd_xfer_t *);
 133 };
 134
 135 #define BD_OPS_VERSION_0                0
 136
 137 /*
 138  * Note, one handler *per* address.  Drivers with multiple targets at
 139  * different addresses must use separate handles.
 140  */
 141 bd_handle_t     bd_alloc_handle(void *, bd_ops_t *, ddi_dma_attr_t *, int);
 142 void            bd_free_handle(bd_handle_t);
 143 int             bd_attach_handle(dev_info_t *, bd_handle_t);
 144 int             bd_detach_handle(bd_handle_t);
 145 void            bd_state_change(bd_handle_t);
 146 void            bd_xfer_done(bd_xfer_t *, int);
 147 void            bd_mod_init(struct dev_ops *);
 148 void            bd_mod_fini(struct dev_ops *);
 149
 150 #ifdef __cplusplus
 151 }
 152 #endif
 153
 154 #endif  /* _SYS_BLKDEV_H */