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