1/*- 2 * Copyright (c) 2012 Robert N. M. Watson 3 * All rights reserved. 4 * 5 * This software was developed by SRI International and the University of 6 * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237) 7 * ("CTSRD"), as part of the DARPA CRASH research programme. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31#include <sys/cdefs.h> 32__FBSDID("$FreeBSD: releng/10.3/sys/dev/altera/sdcard/altera_sdcard.c 257445 2013-10-31 13:47:39Z brooks $"); 33 34#include "opt_altera_sdcard.h" 35 36#include <sys/param.h> 37#include <sys/bus.h> 38#include <sys/condvar.h> 39#include <sys/conf.h> 40#include <sys/bio.h> 41#include <sys/kernel.h> 42#include <sys/lock.h> 43#include <sys/malloc.h> 44#include <sys/module.h> 45#include <sys/mutex.h> 46#include <sys/rman.h> 47#include <sys/systm.h> 48#include <sys/taskqueue.h> 49 50#include <machine/bus.h> 51#include <machine/resource.h> 52 53#include <geom/geom_disk.h> 54 55#include <dev/altera/sdcard/altera_sdcard.h> 56 57/* 58 * Device driver for the Altera University Program Secure Data Card IP Core, 59 * as described in the similarly named SOPC Builder IP Core specification. 60 * This soft core is not a full SD host controller interface (SDHCI) but 61 * instead provides a set of memory mapped registers and memory buffer that 62 * mildly abstract the SD Card protocol, but without providing DMA or 63 * interrupts. However, it does hide the details of voltage and 64 * communications negotiation. This driver implements disk(9), but due to the 65 * lack of interrupt support, must rely on timer-driven polling to determine 66 * when I/Os have completed. 67 * 68 * TODO: 69 * 70 * 1. Implement DISKFLAG_CANDELETE / SD Card sector erase support. 71 * 2. Implement d_ident from SD Card CID serial number field. 72 * 3. Handle read-only SD Cards. 73 * 4. Tune timeouts based on real-world SD Card speeds. 74 */ 75devclass_t altera_sdcard_devclass; 76 77void 78altera_sdcard_attach(struct altera_sdcard_softc *sc) 79{ 80 81 ALTERA_SDCARD_LOCK_INIT(sc); 82 ALTERA_SDCARD_CONDVAR_INIT(sc); 83 sc->as_disk = NULL; 84 bioq_init(&sc->as_bioq); 85 sc->as_currentbio = NULL; 86 sc->as_state = ALTERA_SDCARD_STATE_NOCARD; 87 sc->as_taskqueue = taskqueue_create("altera_sdcardc taskq", M_WAITOK, 88 taskqueue_thread_enqueue, &sc->as_taskqueue); 89 taskqueue_start_threads(&sc->as_taskqueue, 1, PI_DISK, 90 "altera_sdcardc%d taskqueue", sc->as_unit); 91 TIMEOUT_TASK_INIT(sc->as_taskqueue, &sc->as_task, 0, 92 altera_sdcard_task, sc); 93 94 /* 95 * Kick off timer-driven processing with a manual poll so that we 96 * synchronously detect an already-inserted SD Card during the boot or 97 * other driver attach point. 98 */ 99 altera_sdcard_task(sc, 1); 100} 101 102void 103altera_sdcard_detach(struct altera_sdcard_softc *sc) 104{ 105 106 KASSERT(sc->as_taskqueue != NULL, ("%s: taskqueue not present", 107 __func__)); 108 109 /* 110 * Winding down the driver on detach is a bit complex. Update the 111 * flags to indicate that a detach has been requested, and then wait 112 * for in-progress I/O to wind down before continuing. 113 */ 114 ALTERA_SDCARD_LOCK(sc); 115 sc->as_flags |= ALTERA_SDCARD_FLAG_DETACHREQ; 116 while (sc->as_state != ALTERA_SDCARD_STATE_DETACHED) 117 ALTERA_SDCARD_CONDVAR_WAIT(sc); 118 ALTERA_SDCARD_UNLOCK(sc); 119 120 /* 121 * Now wait for the possibly still executing taskqueue to drain. In 122 * principle no more events will be scheduled as we've transitioned to 123 * a detached state, but there might still be a request in execution. 124 */ 125 while (taskqueue_cancel_timeout(sc->as_taskqueue, &sc->as_task, NULL)) 126 taskqueue_drain_timeout(sc->as_taskqueue, &sc->as_task); 127 128 /* 129 * Simulate a disk removal if one is present to deal with any pending 130 * or queued I/O. 131 */ 132 if (sc->as_disk != NULL) 133 altera_sdcard_disk_remove(sc); 134 KASSERT(bioq_first(&sc->as_bioq) == NULL, 135 ("%s: non-empty bioq", __func__)); 136 137 /* 138 * Free any remaining allocated resources. 139 */ 140 taskqueue_free(sc->as_taskqueue); 141 sc->as_taskqueue = NULL; 142 ALTERA_SDCARD_CONDVAR_DESTROY(sc); 143 ALTERA_SDCARD_LOCK_DESTROY(sc); 144} 145 146/* 147 * Set up and start the next I/O. Transition to the I/O state, but allow the 148 * caller to schedule the next timeout, as this may be called either from an 149 * initial attach context, or from the task queue, which requires different 150 * behaviour. 151 */ 152static void 153altera_sdcard_nextio(struct altera_sdcard_softc *sc) 154{ 155 struct bio *bp; 156 157 ALTERA_SDCARD_LOCK_ASSERT(sc); 158 KASSERT(sc->as_currentbio == NULL, 159 ("%s: bio already active", __func__)); 160 161 bp = bioq_takefirst(&sc->as_bioq); 162 if (bp == NULL) 163 panic("%s: bioq empty", __func__); 164 altera_sdcard_io_start(sc, bp); 165 sc->as_state = ALTERA_SDCARD_STATE_IO; 166} 167 168static void 169altera_sdcard_task_nocard(struct altera_sdcard_softc *sc) 170{ 171 172 ALTERA_SDCARD_LOCK_ASSERT(sc); 173 174 /* 175 * Handle device driver detach. 176 */ 177 if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) { 178 sc->as_state = ALTERA_SDCARD_STATE_DETACHED; 179 return; 180 } 181 182 /* 183 * If there is no card insertion, remain in NOCARD. 184 */ 185 if (!(altera_sdcard_read_asr(sc) & ALTERA_SDCARD_ASR_CARDPRESENT)) 186 return; 187 188 /* 189 * Read the CSD -- it may contain values that the driver can't handle, 190 * either because of an unsupported version/feature, or because the 191 * card is misbehaving. This triggers a transition to 192 * ALTERA_SDCARD_STATE_BADCARD. We rely on the CSD read to print a 193 * banner about how the card is problematic, since it has more 194 * information. The bad card state allows us to print that banner 195 * once rather than each time we notice the card is there, and still 196 * bad. 197 */ 198 if (altera_sdcard_read_csd(sc) != 0) { 199 sc->as_state = ALTERA_SDCARD_STATE_BADCARD; 200 return; 201 } 202 203 /* 204 * Process card insertion and upgrade to the IDLE state. 205 */ 206 altera_sdcard_disk_insert(sc); 207 sc->as_state = ALTERA_SDCARD_STATE_IDLE; 208} 209 210static void 211altera_sdcard_task_badcard(struct altera_sdcard_softc *sc) 212{ 213 214 ALTERA_SDCARD_LOCK_ASSERT(sc); 215 216 /* 217 * Handle device driver detach. 218 */ 219 if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) { 220 sc->as_state = ALTERA_SDCARD_STATE_DETACHED; 221 return; 222 } 223 224 /* 225 * Handle safe card removal -- no teardown is required, just a state 226 * transition. 227 */ 228 if (!(altera_sdcard_read_asr(sc) & ALTERA_SDCARD_ASR_CARDPRESENT)) 229 sc->as_state = ALTERA_SDCARD_STATE_NOCARD; 230} 231 232static void 233altera_sdcard_task_idle(struct altera_sdcard_softc *sc) 234{ 235 236 ALTERA_SDCARD_LOCK_ASSERT(sc); 237 238 /* 239 * Handle device driver detach. 240 */ 241 if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) { 242 sc->as_state = ALTERA_SDCARD_STATE_DETACHED; 243 return; 244 } 245 246 /* 247 * Handle safe card removal. 248 */ 249 if (!(altera_sdcard_read_asr(sc) & ALTERA_SDCARD_ASR_CARDPRESENT)) { 250 altera_sdcard_disk_remove(sc); 251 sc->as_state = ALTERA_SDCARD_STATE_NOCARD; 252 } 253} 254 255static void 256altera_sdcard_task_io(struct altera_sdcard_softc *sc) 257{ 258 uint16_t asr; 259 260 ALTERA_SDCARD_LOCK_ASSERT(sc); 261 KASSERT(sc->as_currentbio != NULL, ("%s: no current I/O", __func__)); 262 263#ifdef ALTERA_SDCARD_FAST_SIM 264recheck: 265#endif 266 asr = altera_sdcard_read_asr(sc); 267 268 /* 269 * Check for unexpected card removal during an I/O. 270 */ 271 if (!(asr & ALTERA_SDCARD_ASR_CARDPRESENT)) { 272 altera_sdcard_disk_remove(sc); 273 if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) 274 sc->as_state = ALTERA_SDCARD_STATE_DETACHED; 275 else 276 sc->as_state = ALTERA_SDCARD_STATE_NOCARD; 277 return; 278 } 279 280 /* 281 * If the I/O isn't complete, remain in the IO state without further 282 * action, even if DETACHREQ is in flight. 283 */ 284 if (asr & ALTERA_SDCARD_ASR_CMDINPROGRESS) 285 return; 286 287 /* 288 * Handle various forms of I/O completion, successful and otherwise. 289 * The I/O layer may restart the transaction if an error occurred, in 290 * which case remain in the IO state and reschedule. 291 */ 292 if (!altera_sdcard_io_complete(sc, asr)) 293 return; 294 295 /* 296 * Now that I/O is complete, process detach requests in preference to 297 * starting new I/O. 298 */ 299 if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) { 300 sc->as_state = ALTERA_SDCARD_STATE_DETACHED; 301 return; 302 } 303 304 /* 305 * Finally, either start the next I/O or transition to the IDLE state. 306 */ 307 if (bioq_first(&sc->as_bioq) != NULL) { 308 altera_sdcard_nextio(sc); 309#ifdef ALTERA_SDCARD_FAST_SIM 310 goto recheck; 311#endif 312 } else 313 sc->as_state = ALTERA_SDCARD_STATE_IDLE; 314} 315 316static void 317altera_sdcard_task_rechedule(struct altera_sdcard_softc *sc) 318{ 319 int interval; 320 321 /* 322 * Reschedule based on new state. Or not, if detaching the device 323 * driver. Treat a bad card as though it were no card at all. 324 */ 325 switch (sc->as_state) { 326 case ALTERA_SDCARD_STATE_NOCARD: 327 case ALTERA_SDCARD_STATE_BADCARD: 328 interval = ALTERA_SDCARD_TIMEOUT_NOCARD; 329 break; 330 331 case ALTERA_SDCARD_STATE_IDLE: 332 interval = ALTERA_SDCARD_TIMEOUT_IDLE; 333 break; 334 335 case ALTERA_SDCARD_STATE_IO: 336 if (sc->as_flags & ALTERA_SDCARD_FLAG_IOERROR) 337 interval = ALTERA_SDCARD_TIMEOUT_IOERROR; 338 else 339 interval = ALTERA_SDCARD_TIMEOUT_IO; 340 break; 341 342 default: 343 panic("%s: invalid exit state %d", __func__, sc->as_state); 344 } 345 taskqueue_enqueue_timeout(sc->as_taskqueue, &sc->as_task, interval); 346} 347 348/* 349 * Because the Altera SD Card IP Core doesn't support interrupts, we do all 350 * asynchronous work from a timeout. Poll at two different rates -- an 351 * infrequent check for card insertion status changes, and a frequent one for 352 * I/O completion. The task should never start in DETACHED, as that would 353 * imply that a previous instance failed to cancel rather than reschedule. 354 */ 355void 356altera_sdcard_task(void *arg, int pending) 357{ 358 struct altera_sdcard_softc *sc; 359 360 sc = arg; 361 KASSERT(sc->as_state != ALTERA_SDCARD_STATE_DETACHED, 362 ("%s: already in detached", __func__)); 363 364 ALTERA_SDCARD_LOCK(sc); 365 switch (sc->as_state) { 366 case ALTERA_SDCARD_STATE_NOCARD: 367 altera_sdcard_task_nocard(sc); 368 break; 369 370 case ALTERA_SDCARD_STATE_BADCARD: 371 altera_sdcard_task_badcard(sc); 372 break; 373 374 case ALTERA_SDCARD_STATE_IDLE: 375 altera_sdcard_task_idle(sc); 376 break; 377 378 case ALTERA_SDCARD_STATE_IO: 379 altera_sdcard_task_io(sc); 380 break; 381 382 default: 383 panic("%s: invalid enter state %d", __func__, sc->as_state); 384 } 385 386 /* 387 * If we have transitioned to DETACHED, signal the detach thread and 388 * cancel the timeout-driven task. Otherwise reschedule on an 389 * appropriate timeout. 390 */ 391 if (sc->as_state == ALTERA_SDCARD_STATE_DETACHED) 392 ALTERA_SDCARD_CONDVAR_SIGNAL(sc); 393 else 394 altera_sdcard_task_rechedule(sc); 395 ALTERA_SDCARD_UNLOCK(sc); 396} 397 398void 399altera_sdcard_start(struct altera_sdcard_softc *sc) 400{ 401 402 ALTERA_SDCARD_LOCK_ASSERT(sc); 403 404 KASSERT(sc->as_state == ALTERA_SDCARD_STATE_IDLE, 405 ("%s: starting when not IDLE", __func__)); 406 407 taskqueue_cancel_timeout(sc->as_taskqueue, &sc->as_task, NULL); 408 altera_sdcard_nextio(sc); 409#ifdef ALTERA_SDCARD_FAST_SIM 410 altera_sdcard_task_io(sc); 411#endif 412 altera_sdcard_task_rechedule(sc); 413} 414