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ld_sdmmc.c revision 1.43
      1 /*	$NetBSD: ld_sdmmc.c,v 1.43 2024/01/23 23:13:05 riastradh Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2008 KIYOHARA Takashi
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
     20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
     25  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  *
     28  */
     29 
     30 #include <sys/cdefs.h>
     31 __KERNEL_RCSID(0, "$NetBSD: ld_sdmmc.c,v 1.43 2024/01/23 23:13:05 riastradh Exp $");
     32 
     33 #ifdef _KERNEL_OPT
     34 #include "opt_sdmmc.h"
     35 #endif
     36 
     37 #include <sys/param.h>
     38 #include <sys/types.h>
     39 
     40 #include <sys/buf.h>
     41 #include <sys/bufq.h>
     42 #include <sys/bus.h>
     43 #include <sys/device.h>
     44 #include <sys/disk.h>
     45 #include <sys/disklabel.h>
     46 #include <sys/dkio.h>
     47 #include <sys/endian.h>
     48 #include <sys/kernel.h>
     49 #include <sys/kmem.h>
     50 #include <sys/kthread.h>
     51 #include <sys/module.h>
     52 #include <sys/syslog.h>
     53 #include <sys/systm.h>
     54 
     55 #include <dev/ldvar.h>
     56 
     57 #include <dev/sdmmc/sdmmcvar.h>
     58 
     59 #include "ioconf.h"
     60 
     61 #ifdef LD_SDMMC_DEBUG
     62 #define DPRINTF(s)	printf s
     63 #else
     64 #define DPRINTF(s)	__nothing
     65 #endif
     66 
     67 #define	LD_SDMMC_IORETRIES	5	/* number of retries before giving up */
     68 #define	RECOVERYTIME		hz/2	/* time to wait before retrying a cmd */
     69 
     70 #define	LD_SDMMC_MAXQUEUECNT	4	/* number of queued bio requests */
     71 #define	LD_SDMMC_MAXTASKCNT	8	/* number of tasks in task pool */
     72 
     73 struct ld_sdmmc_softc;
     74 
     75 struct ld_sdmmc_task {
     76 	struct sdmmc_task task;
     77 	struct ld_sdmmc_softc *task_sc;
     78 
     79 	struct buf *task_bp;
     80 	int task_retries; /* number of xfer retry */
     81 	struct callout task_restart_ch;
     82 
     83 	bool task_poll;
     84 	int *task_errorp;
     85 
     86 	TAILQ_ENTRY(ld_sdmmc_task) task_entry;
     87 };
     88 
     89 struct ld_sdmmc_softc {
     90 	struct ld_softc sc_ld;
     91 	int sc_hwunit;
     92 	char *sc_typename;
     93 	struct sdmmc_function *sc_sf;
     94 
     95 	kmutex_t sc_lock;
     96 	kcondvar_t sc_cv;
     97 	TAILQ_HEAD(, ld_sdmmc_task) sc_freeq;
     98 	TAILQ_HEAD(, ld_sdmmc_task) sc_xferq;
     99 	unsigned sc_busy;
    100 	bool sc_dying;
    101 
    102 	struct evcnt sc_ev_discard;	/* discard counter */
    103 	struct evcnt sc_ev_discarderr;	/* discard error counter */
    104 	struct evcnt sc_ev_discardbusy;	/* discard busy counter */
    105 	struct evcnt sc_ev_cachesyncbusy; /* cache sync busy counter */
    106 
    107 	struct ld_sdmmc_task sc_task[LD_SDMMC_MAXTASKCNT];
    108 };
    109 
    110 static int ld_sdmmc_match(device_t, cfdata_t, void *);
    111 static void ld_sdmmc_attach(device_t, device_t, void *);
    112 static int ld_sdmmc_detach(device_t, int);
    113 
    114 static int ld_sdmmc_dump(struct ld_softc *, void *, int, int);
    115 static int ld_sdmmc_start(struct ld_softc *, struct buf *);
    116 static void ld_sdmmc_restart(void *);
    117 static int ld_sdmmc_discard(struct ld_softc *, struct buf *);
    118 static int ld_sdmmc_ioctl(struct ld_softc *, u_long, void *, int32_t, bool);
    119 
    120 static void ld_sdmmc_doattach(void *);
    121 static void ld_sdmmc_dobio(void *);
    122 static void ld_sdmmc_dodiscard(void *);
    123 
    124 CFATTACH_DECL_NEW(ld_sdmmc, sizeof(struct ld_sdmmc_softc),
    125     ld_sdmmc_match, ld_sdmmc_attach, ld_sdmmc_detach, NULL);
    126 
    127 static struct ld_sdmmc_task *
    128 ld_sdmmc_task_get(struct ld_sdmmc_softc *sc)
    129 {
    130 	struct ld_sdmmc_task *task;
    131 
    132 	KASSERT(mutex_owned(&sc->sc_lock));
    133 
    134 	if (sc->sc_dying || (task = TAILQ_FIRST(&sc->sc_freeq)) == NULL)
    135 		return NULL;
    136 	TAILQ_REMOVE(&sc->sc_freeq, task, task_entry);
    137 	TAILQ_INSERT_TAIL(&sc->sc_xferq, task, task_entry);
    138 	KASSERT(task->task_bp == NULL);
    139 	KASSERT(task->task_errorp == NULL);
    140 
    141 	return task;
    142 }
    143 
    144 static void
    145 ld_sdmmc_task_put(struct ld_sdmmc_softc *sc, struct ld_sdmmc_task *task)
    146 {
    147 
    148 	KASSERT(mutex_owned(&sc->sc_lock));
    149 
    150 	TAILQ_REMOVE(&sc->sc_xferq, task, task_entry);
    151 	TAILQ_INSERT_TAIL(&sc->sc_freeq, task, task_entry);
    152 	task->task_bp = NULL;
    153 	task->task_errorp = NULL;
    154 }
    155 
    156 static void
    157 ld_sdmmc_task_cancel(struct ld_sdmmc_softc *sc, struct ld_sdmmc_task *task)
    158 {
    159 	struct buf *bp;
    160 	int *errorp;
    161 
    162 	KASSERT(mutex_owned(&sc->sc_lock));
    163 	KASSERT(sc->sc_dying);
    164 
    165 	/*
    166 	 * Either the callout or the task may be pending, but not both.
    167 	 * First, determine whether the callout is pending.
    168 	 */
    169 	if (callout_pending(&task->task_restart_ch) ||
    170 	    callout_invoking(&task->task_restart_ch)) {
    171 		/*
    172 		 * The callout either is pending, or just started but
    173 		 * is waiting for us to release the lock.  At this
    174 		 * point, it will notice sc->sc_dying and give up, so
    175 		 * just wait for it to complete and then we will
    176 		 * release everything.
    177 		 */
    178 		callout_halt(&task->task_restart_ch, &sc->sc_lock);
    179 	} else {
    180 		/*
    181 		 * If the callout is running, it has just scheduled, so
    182 		 * after we wait for the callout to finish running, the
    183 		 * task is either pending or running.  If the task is
    184 		 * already running, it will notice sc->sc_dying and
    185 		 * give up; otherwise we have to release everything.
    186 		 */
    187 		callout_halt(&task->task_restart_ch, &sc->sc_lock);
    188 		if (!sdmmc_del_task(sc->sc_sf->sc, &task->task, &sc->sc_lock))
    189 			return; /* task already started, let it clean up */
    190 	}
    191 
    192 	/*
    193 	 * It is our responsibility to clean up.  Move it from xferq
    194 	 * back to freeq and make sure to notify anyone waiting that
    195 	 * it's finished.
    196 	 */
    197 	bp = task->task_bp;
    198 	errorp = task->task_errorp;
    199 	ld_sdmmc_task_put(sc, task);
    200 
    201 	/*
    202 	 * If the task was for an asynchronous I/O xfer, fail the I/O
    203 	 * xfer, with the softc lock dropped since this is a callback
    204 	 * into arbitrary other subsystems.
    205 	 */
    206 	if (bp) {
    207 		mutex_exit(&sc->sc_lock);
    208 		/*
    209 		 * XXX We assume that the same sequence works for bio
    210 		 * and discard -- that lddiscardend is just the same as
    211 		 * setting bp->b_resid = bp->b_bcount in the event of
    212 		 * error and then calling lddone.
    213 		 */
    214 		bp->b_error = ENXIO;
    215 		bp->b_resid = bp->b_bcount;
    216 		lddone(&sc->sc_ld, bp);
    217 		mutex_enter(&sc->sc_lock);
    218 	}
    219 
    220 	/*
    221 	 * If the task was for a synchronous operation (cachesync),
    222 	 * then just set the error indicator and wake up the waiter.
    223 	 */
    224 	if (errorp) {
    225 		*errorp = ENXIO;
    226 		cv_broadcast(&sc->sc_cv);
    227 	}
    228 }
    229 
    230 /* ARGSUSED */
    231 static int
    232 ld_sdmmc_match(device_t parent, cfdata_t match, void *aux)
    233 {
    234 	struct sdmmc_softc *sdmsc = device_private(parent);
    235 
    236 	if (ISSET(sdmsc->sc_flags, SMF_MEM_MODE))
    237 		return 1;
    238 	return 0;
    239 }
    240 
    241 /* ARGSUSED */
    242 static void
    243 ld_sdmmc_attach(device_t parent, device_t self, void *aux)
    244 {
    245 	struct ld_sdmmc_softc *sc = device_private(self);
    246 	struct sdmmc_attach_args *sa = aux;
    247 	struct ld_softc *ld = &sc->sc_ld;
    248 	struct ld_sdmmc_task *task;
    249 	struct lwp *lwp;
    250 	const char *cardtype;
    251 	int i;
    252 
    253 	ld->sc_dv = self;
    254 
    255 	aprint_normal(": <0x%02x:0x%04x:%s:0x%02x:0x%08x:0x%03x>\n",
    256 	    sa->sf->cid.mid, sa->sf->cid.oid, sa->sf->cid.pnm,
    257 	    sa->sf->cid.rev, sa->sf->cid.psn, sa->sf->cid.mdt);
    258 	aprint_naive("\n");
    259 
    260 	if (ISSET(sa->sf->sc->sc_flags, SMF_SD_MODE)) {
    261 		cardtype = "SD card";
    262 	} else {
    263 		cardtype = "MMC";
    264 	}
    265 	sc->sc_typename = kmem_asprintf("%s 0x%02x:0x%04x:%s",
    266 	    cardtype, sa->sf->cid.mid, sa->sf->cid.oid, sa->sf->cid.pnm);
    267 
    268 	evcnt_attach_dynamic(&sc->sc_ev_discard, EVCNT_TYPE_MISC,
    269 	    NULL, device_xname(self), "sdmmc discard count");
    270 	evcnt_attach_dynamic(&sc->sc_ev_discarderr, EVCNT_TYPE_MISC,
    271 	    NULL, device_xname(self), "sdmmc discard errors");
    272 	evcnt_attach_dynamic(&sc->sc_ev_discardbusy, EVCNT_TYPE_MISC,
    273 	    NULL, device_xname(self), "sdmmc discard busy");
    274 
    275 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_SDMMC);
    276 	cv_init(&sc->sc_cv, "ldsdmmc");
    277 	TAILQ_INIT(&sc->sc_freeq);
    278 	TAILQ_INIT(&sc->sc_xferq);
    279 	sc->sc_dying = false;
    280 
    281 	const int ntask = __arraycount(sc->sc_task);
    282 	for (i = 0; i < ntask; i++) {
    283 		task = &sc->sc_task[i];
    284 		task->task_sc = sc;
    285 		callout_init(&task->task_restart_ch, CALLOUT_MPSAFE);
    286 		TAILQ_INSERT_TAIL(&sc->sc_freeq, task, task_entry);
    287 	}
    288 
    289 	sc->sc_hwunit = 0;	/* always 0? */
    290 	sc->sc_sf = sa->sf;
    291 
    292 	ld->sc_flags = LDF_ENABLED | LDF_MPSAFE;
    293 	ld->sc_secperunit = sc->sc_sf->csd.capacity;
    294 	ld->sc_secsize = SDMMC_SECTOR_SIZE;
    295 	ld->sc_maxxfer = MAXPHYS;
    296 	ld->sc_maxqueuecnt = LD_SDMMC_MAXQUEUECNT;
    297 	ld->sc_dump = ld_sdmmc_dump;
    298 	ld->sc_start = ld_sdmmc_start;
    299 	ld->sc_discard = ld_sdmmc_discard;
    300 	ld->sc_ioctl = ld_sdmmc_ioctl;
    301 	ld->sc_typename = sc->sc_typename;
    302 
    303 	/*
    304 	 * Defer attachment of ld + disk subsystem to a thread.
    305 	 *
    306 	 * This is necessary because wedge autodiscover needs to
    307 	 * open and call into the ld driver, which could deadlock
    308 	 * when the sdmmc driver isn't ready in early bootstrap.
    309 	 *
    310 	 * Don't mark thread as MPSAFE to keep aprint output sane.
    311 	 */
    312 	config_pending_incr(self);
    313 	if (kthread_create(PRI_NONE, 0, NULL,
    314 	    ld_sdmmc_doattach, sc, &lwp, "%sattach", device_xname(self))) {
    315 		aprint_error_dev(self, "couldn't create thread\n");
    316 	}
    317 }
    318 
    319 static void
    320 ld_sdmmc_doattach(void *arg)
    321 {
    322 	struct ld_sdmmc_softc *sc = (struct ld_sdmmc_softc *)arg;
    323 	struct ld_softc *ld = &sc->sc_ld;
    324 	struct sdmmc_softc *ssc = device_private(device_parent(ld->sc_dv));
    325 	const u_int cache_size = sc->sc_sf->ext_csd.cache_size;
    326 	char buf[sizeof("9999 KB")];
    327 
    328 	ldattach(ld, BUFQ_DISK_DEFAULT_STRAT);
    329 	aprint_normal_dev(ld->sc_dv, "%d-bit width,", sc->sc_sf->width);
    330 	if (ssc->sc_transfer_mode != NULL)
    331 		aprint_normal(" %s,", ssc->sc_transfer_mode);
    332 	if (cache_size > 0) {
    333 		format_bytes(buf, sizeof(buf), cache_size);
    334 		aprint_normal(" %s cache%s,", buf,
    335 		    ISSET(sc->sc_sf->flags, SFF_CACHE_ENABLED) ? "" :
    336 		    " (disabled)");
    337 	}
    338 	if ((ssc->sc_busclk / 1000) != 0)
    339 		aprint_normal(" %u.%03u MHz\n",
    340 		    ssc->sc_busclk / 1000, ssc->sc_busclk % 1000);
    341 	else
    342 		aprint_normal(" %u KHz\n", ssc->sc_busclk % 1000);
    343 	config_pending_decr(ld->sc_dv);
    344 	kthread_exit(0);
    345 }
    346 
    347 static int
    348 ld_sdmmc_detach(device_t dev, int flags)
    349 {
    350 	struct ld_sdmmc_softc *sc = device_private(dev);
    351 	struct ld_softc *ld = &sc->sc_ld;
    352 	struct ld_sdmmc_task *task;
    353 	int error, i;
    354 
    355 	/*
    356 	 * Block new xfers, or fail if the disk is still open and the
    357 	 * detach isn't forced.  After this point, we are committed to
    358 	 * detaching.
    359 	 */
    360 	error = ldbegindetach(ld, flags);
    361 	if (error)
    362 		return error;
    363 
    364 	/*
    365 	 * Abort all pending tasks, and wait for all pending waiters to
    366 	 * notice that we're gone.
    367 	 */
    368 	mutex_enter(&sc->sc_lock);
    369 	sc->sc_dying = true;
    370 	while ((task = TAILQ_FIRST(&sc->sc_xferq)) != NULL)
    371 		ld_sdmmc_task_cancel(sc, task);
    372 	while (sc->sc_busy)
    373 		cv_wait(&sc->sc_cv, &sc->sc_lock);
    374 	mutex_exit(&sc->sc_lock);
    375 
    376 	/* Done!  Destroy the disk.  */
    377 	ldenddetach(ld);
    378 
    379 	KASSERT(TAILQ_EMPTY(&sc->sc_xferq));
    380 
    381 	for (i = 0; i < __arraycount(sc->sc_task); i++)
    382 		callout_destroy(&sc->sc_task[i].task_restart_ch);
    383 
    384 	cv_destroy(&sc->sc_cv);
    385 	mutex_destroy(&sc->sc_lock);
    386 
    387 	evcnt_detach(&sc->sc_ev_discard);
    388 	evcnt_detach(&sc->sc_ev_discarderr);
    389 	evcnt_detach(&sc->sc_ev_discardbusy);
    390 	kmem_free(sc->sc_typename, strlen(sc->sc_typename) + 1);
    391 
    392 	return 0;
    393 }
    394 
    395 static int
    396 ld_sdmmc_start(struct ld_softc *ld, struct buf *bp)
    397 {
    398 	struct ld_sdmmc_softc *sc = device_private(ld->sc_dv);
    399 	struct ld_sdmmc_task *task;
    400 	int error;
    401 
    402 	mutex_enter(&sc->sc_lock);
    403 	if ((task = ld_sdmmc_task_get(sc)) == NULL) {
    404 		error = EAGAIN;
    405 		goto out;
    406 	}
    407 
    408 	task->task_bp = bp;
    409 	task->task_retries = 0;
    410 	sdmmc_init_task(&task->task, ld_sdmmc_dobio, task);
    411 
    412 	sdmmc_add_task(sc->sc_sf->sc, &task->task);
    413 
    414 	/* Success!  The xfer is now queued.  */
    415 	error = 0;
    416 
    417 out:	mutex_exit(&sc->sc_lock);
    418 	return error;
    419 }
    420 
    421 static void
    422 ld_sdmmc_restart(void *arg)
    423 {
    424 	struct ld_sdmmc_task *task = (struct ld_sdmmc_task *)arg;
    425 	struct ld_sdmmc_softc *sc = task->task_sc;
    426 	struct buf *bp = task->task_bp;
    427 
    428 	bp->b_resid = bp->b_bcount;
    429 
    430 	mutex_enter(&sc->sc_lock);
    431 	callout_ack(&task->task_restart_ch);
    432 	if (!sc->sc_dying)
    433 		sdmmc_add_task(sc->sc_sf->sc, &task->task);
    434 	mutex_exit(&sc->sc_lock);
    435 }
    436 
    437 static void
    438 ld_sdmmc_dobio(void *arg)
    439 {
    440 	struct ld_sdmmc_task *task = (struct ld_sdmmc_task *)arg;
    441 	struct ld_sdmmc_softc *sc = task->task_sc;
    442 	struct buf *bp = task->task_bp;
    443 	int error;
    444 
    445 	/*
    446 	 * I/O operation
    447 	 */
    448 	DPRINTF(("%s: I/O operation (dir=%s, blkno=0x%jx, bcnt=0x%x)\n",
    449 	    device_xname(sc->sc_ld.sc_dv), bp->b_flags & B_READ ? "IN" : "OUT",
    450 	    bp->b_rawblkno, bp->b_bcount));
    451 
    452 	/* is everything done in terms of blocks? */
    453 	if (bp->b_rawblkno >= sc->sc_sf->csd.capacity) {
    454 		/* trying to read or write past end of device */
    455 		aprint_error_dev(sc->sc_ld.sc_dv,
    456 		    "blkno 0x%" PRIu64 " exceeds capacity %d\n",
    457 		    bp->b_rawblkno, sc->sc_sf->csd.capacity);
    458 		bp->b_error = EINVAL;
    459 		bp->b_resid = bp->b_bcount;
    460 
    461 		goto done;
    462 	}
    463 
    464 	if (bp->b_flags & B_READ)
    465 		error = sdmmc_mem_read_block(sc->sc_sf, bp->b_rawblkno,
    466 		    bp->b_data, bp->b_bcount);
    467 	else
    468 		error = sdmmc_mem_write_block(sc->sc_sf, bp->b_rawblkno,
    469 		    bp->b_data, bp->b_bcount);
    470 	if (error) {
    471 		if (task->task_retries < LD_SDMMC_IORETRIES) {
    472 			struct dk_softc *dksc = &sc->sc_ld.sc_dksc;
    473 			struct cfdriver *cd = device_cfdriver(dksc->sc_dev);
    474 
    475 			diskerr(bp, cd->cd_name, "error", LOG_PRINTF, 0,
    476 				dksc->sc_dkdev.dk_label);
    477 			printf(", retrying\n");
    478 			task->task_retries++;
    479 			mutex_enter(&sc->sc_lock);
    480 			if (sc->sc_dying) {
    481 				bp->b_resid = bp->b_bcount;
    482 				bp->b_error = error;
    483 				goto done_locked;
    484 			} else {
    485 				callout_reset(&task->task_restart_ch,
    486 				    RECOVERYTIME, ld_sdmmc_restart, task);
    487 			}
    488 			mutex_exit(&sc->sc_lock);
    489 			return;
    490 		}
    491 		bp->b_error = error;
    492 		bp->b_resid = bp->b_bcount;
    493 	} else {
    494 		bp->b_resid = 0;
    495 	}
    496 
    497 done:
    498 	/* Dissociate the task from the I/O xfer and release it.  */
    499 	mutex_enter(&sc->sc_lock);
    500 done_locked:
    501 	ld_sdmmc_task_put(sc, task);
    502 	mutex_exit(&sc->sc_lock);
    503 
    504 	lddone(&sc->sc_ld, bp);
    505 }
    506 
    507 static int
    508 ld_sdmmc_dump(struct ld_softc *ld, void *data, int blkno, int blkcnt)
    509 {
    510 	struct ld_sdmmc_softc *sc = device_private(ld->sc_dv);
    511 
    512 	return sdmmc_mem_write_block(sc->sc_sf, blkno, data,
    513 	    blkcnt * ld->sc_secsize);
    514 }
    515 
    516 static void
    517 ld_sdmmc_dodiscard(void *arg)
    518 {
    519 	struct ld_sdmmc_task *task = arg;
    520 	struct ld_sdmmc_softc *sc = task->task_sc;
    521 	struct buf *bp = task->task_bp;
    522 	uint32_t sblkno, nblks;
    523 	int error;
    524 
    525 	/* first and last block to erase */
    526 	sblkno = bp->b_rawblkno;
    527 	nblks  = howmany(bp->b_bcount, sc->sc_ld.sc_secsize);
    528 
    529 	/* An error from discard is non-fatal */
    530 	error = sdmmc_mem_discard(sc->sc_sf, sblkno, sblkno + nblks - 1);
    531 
    532 	/* Count error or success and release the task.  */
    533 	mutex_enter(&sc->sc_lock);
    534 	if (error)
    535 		sc->sc_ev_discarderr.ev_count++;
    536 	else
    537 		sc->sc_ev_discard.ev_count++;
    538 	ld_sdmmc_task_put(sc, task);
    539 	mutex_exit(&sc->sc_lock);
    540 
    541 	/* Record the error and notify the xfer of completion.  */
    542 	if (error)
    543 		bp->b_error = error;
    544 	lddiscardend(&sc->sc_ld, bp);
    545 }
    546 
    547 static int
    548 ld_sdmmc_discard(struct ld_softc *ld, struct buf *bp)
    549 {
    550 	struct ld_sdmmc_softc *sc = device_private(ld->sc_dv);
    551 	struct ld_sdmmc_task *task;
    552 	int error;
    553 
    554 	mutex_enter(&sc->sc_lock);
    555 
    556 	/* Acquire a free task, or drop the request altogether.  */
    557 	if ((task = ld_sdmmc_task_get(sc)) == NULL) {
    558 		sc->sc_ev_discardbusy.ev_count++;
    559 		error = EBUSY;
    560 		goto out;
    561 	}
    562 
    563 	/* Set up the task and schedule it.  */
    564 	task->task_bp = bp;
    565 	sdmmc_init_task(&task->task, ld_sdmmc_dodiscard, task);
    566 
    567 	sdmmc_add_task(sc->sc_sf->sc, &task->task);
    568 
    569 	/* Success!  The request is queued.  */
    570 	error = 0;
    571 
    572 out:	mutex_exit(&sc->sc_lock);
    573 	return error;
    574 }
    575 
    576 static void
    577 ld_sdmmc_docachesync(void *arg)
    578 {
    579 	struct ld_sdmmc_task *task = arg;
    580 	struct ld_sdmmc_softc *sc = task->task_sc;
    581 	int error;
    582 
    583 	/* Flush the cache.  */
    584 	error = sdmmc_mem_flush_cache(sc->sc_sf, task->task_poll);
    585 
    586 	mutex_enter(&sc->sc_lock);
    587 
    588 	/* Notify the other thread that we're done; pass on the error.  */
    589 	*task->task_errorp = error;
    590 	cv_broadcast(&sc->sc_cv);
    591 
    592 	/* Release the task.  */
    593 	ld_sdmmc_task_put(sc, task);
    594 
    595 	mutex_exit(&sc->sc_lock);
    596 }
    597 
    598 static int
    599 ld_sdmmc_cachesync(struct ld_softc *ld, bool poll)
    600 {
    601 	struct ld_sdmmc_softc *sc = device_private(ld->sc_dv);
    602 	struct sdmmc_softc *sdmmc = device_private(device_parent(ld->sc_dv));
    603 	struct ld_sdmmc_task *task;
    604 	int error = -1;
    605 
    606 	/*
    607 	 * If we come here through the sdmmc discovery task, we can't
    608 	 * wait for a new task because the new task can't even begin
    609 	 * until the sdmmc discovery task has completed.
    610 	 *
    611 	 * XXX This is wrong, because there may already be queued I/O
    612 	 * tasks ahead of us.  Fixing this properly requires doing
    613 	 * discovery in a separate thread.  But this should avoid the
    614 	 * deadlock of PR kern/57870 (https://gnats.NetBSD.org/57870)
    615 	 * until we do split that up.
    616 	 */
    617 	if (curlwp == sdmmc->sc_tskq_lwp)
    618 		return sdmmc_mem_flush_cache(sc->sc_sf, poll);
    619 
    620 	mutex_enter(&sc->sc_lock);
    621 
    622 	/* Acquire a free task, or fail with EBUSY.  */
    623 	if ((task = ld_sdmmc_task_get(sc)) == NULL) {
    624 		sc->sc_ev_cachesyncbusy.ev_count++;
    625 		error = EBUSY;
    626 		goto out;
    627 	}
    628 
    629 	/* Set up the task and schedule it.  */
    630 	task->task_poll = poll;
    631 	task->task_errorp = &error;
    632 	sdmmc_init_task(&task->task, ld_sdmmc_docachesync, task);
    633 
    634 	sdmmc_add_task(sc->sc_sf->sc, &task->task);
    635 
    636 	/*
    637 	 * Wait for the task to complete.  If the device is yanked,
    638 	 * detach will notify us.  Keep the busy count up until we're
    639 	 * done waiting so that the softc doesn't go away until we're
    640 	 * done.
    641 	 */
    642 	sc->sc_busy++;
    643 	KASSERT(sc->sc_busy <= LD_SDMMC_MAXTASKCNT);
    644 	while (error == -1)
    645 		cv_wait(&sc->sc_cv, &sc->sc_lock);
    646 	if (--sc->sc_busy == 0)
    647 		cv_broadcast(&sc->sc_cv);
    648 
    649 out:	mutex_exit(&sc->sc_lock);
    650 	return error;
    651 }
    652 
    653 static int
    654 ld_sdmmc_ioctl(struct ld_softc *ld, u_long cmd, void *addr, int32_t flag,
    655     bool poll)
    656 {
    657 
    658 	switch (cmd) {
    659 	case DIOCCACHESYNC:
    660 		return ld_sdmmc_cachesync(ld, poll);
    661 	default:
    662 		return EPASSTHROUGH;
    663 	}
    664 }
    665 
    666 MODULE(MODULE_CLASS_DRIVER, ld_sdmmc, "ld");
    667 
    668 #ifdef _MODULE
    669 /*
    670  * XXX Don't allow ioconf.c to redefine the "struct cfdriver ld_cd"
    671  * XXX it will be defined in the common-code module
    672  */
    673 #undef  CFDRIVER_DECL
    674 #define CFDRIVER_DECL(name, class, attr)
    675 #include "ioconf.c"
    676 #endif
    677 
    678 static int
    679 ld_sdmmc_modcmd(modcmd_t cmd, void *opaque)
    680 {
    681 #ifdef _MODULE
    682 	/*
    683 	 * We ignore the cfdriver_vec[] that ioconf provides, since
    684 	 * the cfdrivers are attached already.
    685 	 */
    686 	static struct cfdriver * const no_cfdriver_vec[] = { NULL };
    687 #endif
    688 	int error = 0;
    689 
    690 #ifdef _MODULE
    691 	switch (cmd) {
    692 	case MODULE_CMD_INIT:
    693 		error = config_init_component(no_cfdriver_vec,
    694 		    cfattach_ioconf_ld_sdmmc, cfdata_ioconf_ld_sdmmc);
    695 		break;
    696 	case MODULE_CMD_FINI:
    697 		error = config_fini_component(no_cfdriver_vec,
    698 		    cfattach_ioconf_ld_sdmmc, cfdata_ioconf_ld_sdmmc);
    699 		break;
    700 	default:
    701 		error = ENOTTY;
    702 		break;
    703 	}
    704 #endif
    705 
    706 	return error;
    707 }
    708