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 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * smbios(7D) driver 31 * 32 * This pseudo-driver makes available a snapshot of the system's SMBIOS image 33 * that can be accessed using libsmbios. Clients may access a snapshot using 34 * either read(2) or mmap(2). The driver returns the SMBIOS entry point data 35 * followed by the SMBIOS structure table. The entry point has its 'staddr' 36 * field set to indicate the byte offset of the structure table. The driver 37 * uses the common SMBIOS API defined in <sys/smbios.h> to access the image. 38 * 39 * At present, the kernel takes a single snapshot of SMBIOS at boot time and 40 * stores a handle for this snapshot in 'ksmbios'. To keep track of driver 41 * opens, we simply compare-and-swap this handle into an 'smb_clones' array. 42 * Future x86 systems may need to support dynamic SMBIOS updates: when that 43 * happens the SMBIOS API can be extended to support reference counting and 44 * handles for different snapshots can be stored in smb_clones[]. 45 */ 46 47 #include <sys/smbios.h> 48 #include <sys/sysmacros.h> 49 #include <sys/cmn_err.h> 50 #include <sys/vmsystm.h> 51 #include <vm/seg_vn.h> 52 #include <sys/ddi.h> 53 #include <sys/sunddi.h> 54 #include <sys/modctl.h> 55 #include <sys/conf.h> 56 #include <sys/stat.h> 57 58 typedef struct smb_clone { 59 smbios_hdl_t *c_hdl; 60 size_t c_eplen; 61 size_t c_stlen; 62 } smb_clone_t; 63 64 static dev_info_t *smb_devi; 65 static smb_clone_t *smb_clones; 66 static int smb_nclones; 67 68 /*ARGSUSED*/ 69 static int 70 smb_open(dev_t *dp, int flag, int otyp, cred_t *cred) 71 { 72 minor_t c; 73 74 if (ksmbios == NULL) 75 return (ENXIO); 76 77 /* 78 * Locate and reserve a clone structure. We skip clone 0 as that is 79 * the real minor number, and we assign a new minor to each clone. 80 */ 81 for (c = 1; c < smb_nclones; c++) { 82 if (casptr(&smb_clones[c].c_hdl, NULL, ksmbios) == NULL) 83 break; 84 } 85 86 if (c >= smb_nclones) 87 return (EAGAIN); 88 89 smb_clones[c].c_eplen = P2ROUNDUP(sizeof (smbios_entry_t), 16); 90 smb_clones[c].c_stlen = smbios_buflen(smb_clones[c].c_hdl); 91 92 *dp = makedevice(getemajor(*dp), c); 93 94 (void) ddi_prop_update_int(*dp, smb_devi, "size", 95 smb_clones[c].c_eplen + smb_clones[c].c_stlen); 96 97 return (0); 98 } 99 100 /*ARGSUSED*/ 101 static int 102 smb_close(dev_t dev, int flag, int otyp, cred_t *cred) 103 { 104 (void) ddi_prop_remove(dev, smb_devi, "size"); 105 smb_clones[getminor(dev)].c_hdl = NULL; 106 return (0); 107 } 108 109 /* 110 * Common code to copy out the SMBIOS snapshot used for both read and mmap. 111 * The caller must validate uio_offset for us since semantics differ there. 112 * The copy is done in two stages, either of which can be skipped based on the 113 * offset and length: first we copy the entry point, with 'staddr' recalculated 114 * to indicate the offset of the data buffer, and second we copy the table. 115 */ 116 static int 117 smb_uiomove(smb_clone_t *cp, uio_t *uio) 118 { 119 off_t off = uio->uio_offset; 120 size_t len = uio->uio_resid; 121 int err = 0; 122 123 if (off + len > cp->c_eplen + cp->c_stlen) 124 len = cp->c_eplen + cp->c_stlen - off; 125 126 if (off < cp->c_eplen) { 127 smbios_entry_t *ep = kmem_zalloc(cp->c_eplen, KM_SLEEP); 128 size_t eprlen = MIN(len, cp->c_eplen - off); 129 130 smbios_info_smbios(cp->c_hdl, ep); 131 ep->smbe_staddr = (uint32_t)cp->c_eplen; 132 smbios_checksum(cp->c_hdl, ep); 133 134 err = uiomove((char *)ep + off, eprlen, UIO_READ, uio); 135 kmem_free(ep, cp->c_eplen); 136 137 off += eprlen; 138 len -= eprlen; 139 } 140 141 if (err == 0 && off >= cp->c_eplen) { 142 char *buf = (char *)smbios_buf(cp->c_hdl); 143 size_t bufoff = off - cp->c_eplen; 144 145 err = uiomove(buf + bufoff, 146 MIN(len, cp->c_stlen - bufoff), UIO_READ, uio); 147 } 148 149 return (err); 150 } 151 152 /*ARGSUSED*/ 153 static int 154 smb_read(dev_t dev, uio_t *uio, cred_t *cred) 155 { 156 smb_clone_t *cp = &smb_clones[getminor(dev)]; 157 158 if (uio->uio_offset < 0 || 159 uio->uio_offset >= cp->c_eplen + cp->c_stlen) 160 return (0); 161 162 return (smb_uiomove(cp, uio)); 163 } 164 165 /*ARGSUSED*/ 166 static int 167 smb_segmap(dev_t dev, off_t off, struct as *as, caddr_t *addrp, off_t len, 168 uint_t prot, uint_t maxprot, uint_t flags, cred_t *cred) 169 { 170 smb_clone_t *cp = &smb_clones[getminor(dev)]; 171 172 size_t alen = P2ROUNDUP(len, PAGESIZE); 173 caddr_t addr = NULL; 174 175 iovec_t iov; 176 uio_t uio; 177 int err; 178 179 if (len <= 0 || (flags & MAP_FIXED)) 180 return (EINVAL); 181 182 if ((prot & PROT_WRITE) && (flags & MAP_SHARED)) 183 return (EACCES); 184 185 if (off < 0 || off + len < off || off + len > cp->c_eplen + cp->c_stlen) 186 return (ENXIO); 187 188 as_rangelock(as); 189 map_addr(&addr, alen, 0, 1, 0); 190 191 if (addr != NULL) 192 err = as_map(as, addr, alen, segvn_create, zfod_argsp); 193 else 194 err = ENOMEM; 195 196 as_rangeunlock(as); 197 *addrp = addr; 198 199 if (err != 0) 200 return (err); 201 202 iov.iov_base = addr; 203 iov.iov_len = len; 204 205 bzero(&uio, sizeof (uio_t)); 206 uio.uio_iov = &iov; 207 uio.uio_iovcnt = 1; 208 uio.uio_offset = off; 209 uio.uio_segflg = UIO_USERSPACE; 210 uio.uio_extflg = UIO_COPY_DEFAULT; 211 uio.uio_resid = len; 212 213 if ((err = smb_uiomove(cp, &uio)) != 0) 214 (void) as_unmap(as, addr, alen); 215 216 return (err); 217 } 218 219 /*ARGSUSED*/ 220 static int 221 smb_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result) 222 { 223 switch (infocmd) { 224 case DDI_INFO_DEVT2DEVINFO: 225 *result = smb_devi; 226 return (DDI_SUCCESS); 227 case DDI_INFO_DEVT2INSTANCE: 228 *result = 0; 229 return (DDI_SUCCESS); 230 } 231 return (DDI_FAILURE); 232 } 233 234 static int 235 smb_attach(dev_info_t *devi, ddi_attach_cmd_t cmd) 236 { 237 if (cmd != DDI_ATTACH) 238 return (DDI_FAILURE); 239 240 if (ddi_create_minor_node(devi, "smbios", 241 S_IFCHR, 0, DDI_PSEUDO, 0) == DDI_FAILURE) { 242 ddi_remove_minor_node(devi, NULL); 243 return (DDI_FAILURE); 244 } 245 246 smb_devi = devi; 247 return (DDI_SUCCESS); 248 } 249 250 static int 251 smb_detach(dev_info_t *devi, ddi_detach_cmd_t cmd) 252 { 253 if (cmd != DDI_DETACH) 254 return (DDI_FAILURE); 255 256 ddi_remove_minor_node(devi, NULL); 257 return (DDI_SUCCESS); 258 } 259 260 static struct cb_ops smb_cb_ops = { 261 smb_open, /* open */ 262 smb_close, /* close */ 263 nodev, /* strategy */ 264 nodev, /* print */ 265 nodev, /* dump */ 266 smb_read, /* read */ 267 nodev, /* write */ 268 nodev, /* ioctl */ 269 nodev, /* devmap */ 270 nodev, /* mmap */ 271 smb_segmap, /* segmap */ 272 nochpoll, /* poll */ 273 ddi_prop_op, /* prop_op */ 274 NULL, /* streamtab */ 275 D_NEW | D_MP /* flags */ 276 }; 277 278 static struct dev_ops smb_ops = { 279 DEVO_REV, /* rev */ 280 0, /* refcnt */ 281 smb_info, /* info */ 282 nulldev, /* identify */ 283 nulldev, /* probe */ 284 smb_attach, /* attach */ 285 smb_detach, /* detach */ 286 nodev, /* reset */ 287 &smb_cb_ops, /* cb ops */ 288 NULL /* bus ops */ 289 }; 290 291 static struct modldrv modldrv = { 292 &mod_driverops, "System Management BIOS driver", &smb_ops, 293 }; 294 295 static struct modlinkage modlinkage = { 296 MODREV_1, { (void *)&modldrv } 297 }; 298 299 int 300 _init(void) 301 { 302 int err; 303 304 if (smb_nclones <= 0) 305 smb_nclones = maxusers; 306 307 smb_clones = kmem_zalloc(sizeof (smb_clone_t) * smb_nclones, KM_SLEEP); 308 309 if ((err = mod_install(&modlinkage)) != 0) 310 kmem_free(smb_clones, sizeof (smb_clone_t) * smb_nclones); 311 312 return (err); 313 } 314 315 int 316 _fini(void) 317 { 318 int err; 319 320 if ((err = mod_remove(&modlinkage)) == 0) 321 kmem_free(smb_clones, sizeof (smb_clone_t) * smb_nclones); 322 323 return (err); 324 } 325 326 int 327 _info(struct modinfo *mip) 328 { 329 return (mod_info(&modlinkage, mip)); 330 } 331