include/sys/ramdisk.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 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  * Copyright 2015 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
  25  */
  26
  27 #ifndef _SYS_RAMDISK_H
  28 #define _SYS_RAMDISK_H
  29
  30 #include <sys/types.h>
  31 #include <sys/time.h>
  32 #include <sys/vtoc.h>
  33 #include <sys/dkio.h>
  34 #include <sys/vnode.h>
  35
  36 #ifdef  __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /*
  41  * /dev names:
  42  *      /dev/ramdiskctl         - control device
  43  *      /dev/ramdisk/<name>     - block devices
  44  *      /dev/rramdisk/<name>    - character devices
  45  */
  46 #define RD_DRIVER_NAME          "ramdisk"
  47 #define RD_BLOCK_NAME           RD_DRIVER_NAME
  48 #define RD_CHAR_NAME            "r" RD_DRIVER_NAME
  49
  50 #define RD_CTL_NODE             "ctl"
  51 #define RD_CTL_NAME             RD_DRIVER_NAME RD_CTL_NODE
  52
  53 /*
  54  * Minor number 0 is reserved for the controlling device.  All other ramdisks
  55  * are assigned minor numbers 1..rd_max_disks.  The minor number is used as
  56  * an index into the 'rd_devstate' structures.
  57  */
  58 #define RD_CTL_MINOR            0
  59
  60 /*
  61  * Maximum number of ramdisks supported by this driver.
  62  */
  63 #define RD_MAX_DISKS            1024
  64
  65 /*
  66  * Properties exported by the driver.
  67  */
  68 #define NBLOCKS_PROP_NAME       "Nblocks"
  69 #define SIZE_PROP_NAME          "Size"
  70
  71 /*
  72  * Strip any "ramdisk-" prefix from the name of OBP-created ramdisks.
  73  */
  74 #define RD_OBP_PFXSTR           "ramdisk-"
  75 #define RD_OBP_PFXLEN           (sizeof (RD_OBP_PFXSTR) - 1)
  76
  77 #define RD_STRIP_PREFIX(newname, oldname) \
  78         { \
  79                 char    *onm = oldname; \
  80                 newname = strncmp(onm, RD_OBP_PFXSTR, RD_OBP_PFXLEN) == 0 ? \
  81                     (onm + RD_OBP_PFXLEN) : onm; \
  82         }
  83
  84 /*
  85  * Strip any ",raw" suffix from the name of pseudo ramdisk devices.
  86  */
  87 #define RD_STRIP_SUFFIX(name) \
  88         { \
  89                 char    *str = strstr((name), ",raw"); \
  90                 if (str != NULL) \
  91                         *str = '\0'; \
  92         }
  93
  94 /*
  95  * Interface between the ramdisk(7D) driver and ramdiskadm(8).  Use is:
  96  *
  97  *      fd = open("/dev/ramdiskctl", O_RDWR | O_EXCL);
  98  *
  99  * 'ramdiskctl' must be opened exclusively. Access is controlled by permissions
 100  * on the device, which is 0644 by default.  Write-access is required for the
 101  * allocation and deletion of ramdisks, but only read-access is required for
 102  * the remaining ioctls which simply return information.
 103  *
 104  * ioctl usage:
 105  *
 106  *      struct rd_ioctl ri;
 107  *
 108  *      strlcpy(ri.ri_name, "somediskname", sizeof (ri.ri_name));
 109  *      ri.ri_size = somedisksize;
 110  *      ioctl(fd, RD_CREATE_DISK, &ri);
 111  *
 112  *      strlcpy(ri.ri_name, "somediskname", sizeof (ri.ri_name));
 113  *      ioctl(fd, RD_DELETE_DISK, &ri);
 114  *
 115  * (only ramdisks created using the RD_CREATE_DISK ioctl can be deleted
 116  *  by the RD_DELETE_DISK ioctl).
 117  *
 118  * Note that these ioctls are completely private, and only for the use of
 119  * ramdiskadm(8).
 120  */
 121 #define RD_IOC_BASE             (('R' << 16) | ('D' << 8))
 122
 123 #define RD_CREATE_DISK          (RD_IOC_BASE | 0x01)
 124 #define RD_DELETE_DISK          (RD_IOC_BASE | 0x02)
 125
 126 #define RD_NAME_LEN             32      /* Max length of ramdisk name */
 127 #define RD_NAME_PAD             7       /* Pad ri_name to 8-bytes */
 128
 129 struct rd_ioctl {
 130         char            ri_name[RD_NAME_LEN + 1];
 131         char            _ri_pad[RD_NAME_PAD];
 132         uint64_t        ri_size;
 133 };
 134
 135 #if defined(_KERNEL)
 136
 137 /*
 138  * We limit the maximum number of active ramdisk devices to 32, tuneable
 139  * up to a maximum of 1023.  Minor 0 is always reserved for the controlling
 140  * device.  You can change this by setting a value for 'max_disks' in
 141  * ramdisk.conf.
 142  */
 143 #define RD_DFLT_DISKS   32
 144
 145 /*
 146  * The maximum amount of memory that can be consumed before starving the
 147  * kernel depends loosely on the number of cpus, the speed of those cpus,
 148  * and other hardware characteristics, and is thus highly machine-dependent.
 149  * The default value of 'rd_percent_physmem' is 25% of physical memory,
 150  * but this can be changed by setting a value for 'percent_physmem' in
 151  * ramdisk.conf.
 152  */
 153 #define RD_DEFAULT_PERCENT_PHYSMEM      25
 154
 155 /*
 156  * Maximum size of a physical transfer?
 157  */
 158 #define RD_DEFAULT_MAXPHYS      (63 * 1024)     /* '126b' */
 159
 160 /*
 161  * A physical OBP-created ramdisk consists of one or more physical address
 162  * ranges; these are described by the 'existing' property, whose value
 163  * is a (corresponding) number of {phys,size} pairs.
 164  *
 165  * A virtual OBP-created ramdisk consists of exactly one virtual address
 166  * range; this is described by the 'address' and 'size' properties.
 167  */
 168 #define OBP_EXISTING_PROP_NAME  "existing"
 169 #define OBP_ADDRESS_PROP_NAME   "address"
 170 #define OBP_SIZE_PROP_NAME      "size"
 171
 172 #define RD_EXISTING_PROP_NAME   "existing"      /* for x86 */
 173
 174 typedef struct {
 175         uint64_t        phys;                   /* Phys addr of range */
 176         uint64_t        size;                   /* Size of range */
 177 } rd_existing_t;
 178
 179 struct rd_ops;
 180
 181 /*
 182  * The entire state of each ramdisk device.  The rd_dip field will reference
 183  * the actual devinfo for real OBP-created ramdisks, or the generic devinfo
 184  * 'rd_dip' for pseudo ramdisk devices.
 185  */
 186 typedef struct rd_devstate {
 187         kmutex_t        rd_device_lock;         /* Per device lock */
 188         char            rd_name[RD_NAME_LEN + 1];
 189         dev_info_t      *rd_dip;                /* My devinfo handle */
 190         minor_t         rd_minor;               /* Full minor number */
 191         size_t          rd_size;                /* Size in bytes */
 192
 193         const struct rd_ops     *rd_ops;
 194
 195         /*
 196          * {rd_nexisting, rd_existing} and {rd_npages, rd_ppa} are
 197          * mutually exclusive; the former describe an physical OBP-created
 198          * ramdisk, the latter a 'pseudo' ramdisk.
 199          */
 200         uint_t          rd_nexisting;           /* # 'existing' structs */
 201         rd_existing_t   *rd_existing;
 202         pgcnt_t         rd_npages;              /* # physical pages */
 203         page_t          **rd_ppa;
 204
 205         /*
 206          * The virtual address passed in when the ramdisk was created.  This
 207          * is only used by virtual OBP-created ramdisks.
 208          */
 209         caddr_t         rd_obp_virt;
 210
 211         /*
 212          * Fields to count opens/closes of the ramdisk.
 213          */
 214         uint32_t        rd_blk_open;
 215         uint32_t        rd_chr_open;
 216         uint32_t        rd_lyr_open_cnt;
 217         /*
 218          * Fields to maintain a faked geometry of the disk.
 219          */
 220         struct dk_geom  rd_dkg;
 221         struct vtoc     rd_vtoc;
 222         struct dk_cinfo rd_ci;
 223         /*
 224          * Kstat stuff.
 225          */
 226         kmutex_t        rd_kstat_lock;
 227         kstat_t         *rd_kstat;
 228 } rd_devstate_t;
 229
 230 extern int      is_pseudo_device(dev_info_t *);
 231
 232 #endif
 233
 234 #ifdef  __cplusplus
 235 }
 236 #endif
 237
 238 #endif  /* _SYS_RAMDISK_H */