xref: /dflybsd-src/sys/dev/disk/ahci/ahci_attach.c (revision 97fecd825dd1a70c628493b90a9b1b1724f151df)
1 /*
2  * Copyright (c) 2006 David Gwynne <dlg@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  *
16  *
17  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
18  *
19  * This code is derived from software contributed to The DragonFly Project
20  * by Matthew Dillon <dillon@backplane.com>
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  *
26  * 1. Redistributions of source code must retain the above copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in
30  *    the documentation and/or other materials provided with the
31  *    distribution.
32  * 3. Neither the name of The DragonFly Project nor the names of its
33  *    contributors may be used to endorse or promote products derived
34  *    from this software without specific, prior written permission.
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
37  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
38  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
39  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
40  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
41  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
42  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
44  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47  * SUCH DAMAGE.
48  *
49  * $OpenBSD: ahci.c,v 1.147 2009/02/16 21:19:07 miod Exp $
50  */
51 
52 #include "ahci.h"
53 
54 static int	ahci_vt8251_attach(device_t);
55 static int	ahci_ati_sb600_attach(device_t);
56 static int	ahci_nvidia_mcp_attach(device_t);
57 static int	ahci_intel_attach(device_t dev);
58 static int	ahci_pci_attach(device_t);
59 static int	ahci_pci_detach(device_t);
60 
61 static const struct ahci_device ahci_devices[] = {
62 	{ PCI_VENDOR_VIATECH,	PCI_PRODUCT_VIATECH_VT8251_SATA,
63 	    ahci_vt8251_attach, ahci_pci_detach, "ViaTech-VT8251-SATA" },
64 	{ PCI_VENDOR_ATI,	PCI_PRODUCT_ATI_SB600_SATA,
65 	    ahci_ati_sb600_attach, ahci_pci_detach, "ATI-SB600-SATA" },
66 	{ PCI_VENDOR_NVIDIA,	PCI_PRODUCT_NVIDIA_MCP65_AHCI_2,
67 	    ahci_nvidia_mcp_attach, ahci_pci_detach, "NVidia-MCP65-SATA" },
68 	{ PCI_VENDOR_NVIDIA,	PCI_PRODUCT_NVIDIA_MCP67_AHCI_1,
69 	    ahci_nvidia_mcp_attach, ahci_pci_detach, "NVidia-MCP67-SATA" },
70 	{ PCI_VENDOR_NVIDIA,	PCI_PRODUCT_NVIDIA_MCP77_AHCI_5,
71 	    ahci_nvidia_mcp_attach, ahci_pci_detach, "NVidia-MCP77-SATA" },
72 	{ PCI_VENDOR_INTEL,	PCI_PRODUCT_INTEL_82801GB_S1,
73 	    ahci_intel_attach, ahci_pci_detach, "Intel ICH7 82801GB-S1" },
74 	{ PCI_VENDOR_INTEL,	PCI_PRODUCT_INTEL_82801GB_AH,
75 	    ahci_intel_attach, ahci_pci_detach, "Intel ICH7 82801GB-AH" },
76 	{ PCI_VENDOR_INTEL,	PCI_PRODUCT_INTEL_82801GB_R1,
77 	    ahci_intel_attach, ahci_pci_detach, "Intel ICH7 82801GB-R1" },
78 	{ PCI_VENDOR_INTEL,	PCI_PRODUCT_INTEL_82801GBM_S1,
79 	    ahci_intel_attach, ahci_pci_detach, "Intel ICH7 82801GBM-S1" },
80 	{ PCI_VENDOR_INTEL,	PCI_PRODUCT_INTEL_82801GBM_AH,
81 	    ahci_intel_attach, ahci_pci_detach, "Intel ICH7 82801GBM-AH" },
82 	{ PCI_VENDOR_INTEL,	PCI_PRODUCT_INTEL_82801GBM_R1,
83 	    ahci_intel_attach, ahci_pci_detach, "Intel ICH7 82801GBM-R1" },
84 	{ 0, 0,
85 	    ahci_pci_attach, ahci_pci_detach, "AHCI-PCI-SATA" }
86 };
87 
88 /*
89  * Match during probe and attach.  The device does not yet have a softc.
90  */
91 const struct ahci_device *
92 ahci_lookup_device(device_t dev)
93 {
94 	const struct ahci_device *ad;
95 	u_int16_t vendor = pci_get_vendor(dev);
96 	u_int16_t product = pci_get_device(dev);
97 	u_int8_t class = pci_get_class(dev);
98 	u_int8_t subclass = pci_get_subclass(dev);
99 	u_int8_t progif = pci_read_config(dev, PCIR_PROGIF, 1);
100 
101 
102 	for (ad = &ahci_devices[0]; ad->ad_vendor; ++ad) {
103 		if (ad->ad_vendor == vendor && ad->ad_product == product)
104 			return (ad);
105 	}
106 
107 	/*
108 	 * Last ad is the default match if the PCI device matches SATA.
109 	 */
110 	if (class == PCIC_STORAGE && subclass == PCIS_STORAGE_SATA &&
111 	    progif == PCIP_STORAGE_SATA_AHCI_1_0) {
112 		return (ad);
113 	}
114 
115 	return (NULL);
116 }
117 
118 /*
119  * Attach functions.  They all eventually fall through to ahci_pci_attach().
120  */
121 static int
122 ahci_vt8251_attach(device_t dev)
123 {
124 	struct ahci_softc *sc = device_get_softc(dev);
125 
126 	sc->sc_flags |= AHCI_F_NO_NCQ;
127 	return (ahci_pci_attach(dev));
128 }
129 
130 static int
131 ahci_ati_sb600_attach(device_t dev)
132 {
133 	struct ahci_softc *sc = device_get_softc(dev);
134 	pcireg_t magic;
135 	u_int8_t subclass = pci_get_subclass(dev);
136 	u_int8_t revid;
137 
138 	if (subclass == PCIS_STORAGE_IDE) {
139 		revid = pci_read_config(dev, PCIR_REVID, 1);
140 		magic = pci_read_config(dev, AHCI_PCI_ATI_SB600_MAGIC, 4);
141 		pci_write_config(dev, AHCI_PCI_ATI_SB600_MAGIC,
142 				 magic | AHCI_PCI_ATI_SB600_LOCKED, 4);
143 		pci_write_config(dev, PCIR_REVID,
144 				 (PCIC_STORAGE << 24) |
145 				 (PCIS_STORAGE_SATA << 16) |
146 				 (PCIP_STORAGE_SATA_AHCI_1_0 << 8) |
147 				 revid, 4);
148 		pci_write_config(dev, AHCI_PCI_ATI_SB600_MAGIC, magic, 4);
149 	}
150 
151 	sc->sc_flags |= AHCI_F_IGN_FR;
152 	return (ahci_pci_attach(dev));
153 }
154 
155 static int
156 ahci_nvidia_mcp_attach(device_t dev)
157 {
158 	struct ahci_softc *sc = device_get_softc(dev);
159 
160 	sc->sc_flags |= AHCI_F_IGN_FR;
161 	return (ahci_pci_attach(dev));
162 }
163 
164 /*
165  * Do some hocus pocus.  Probably more then just the Intel ICH7 parts need
166  * this.  It depends on whether the BIOS sets the chip up properly for
167  * AHCI operation.
168  */
169 static int
170 ahci_intel_attach(device_t dev)
171 {
172 	pci_write_config(dev, 0x92, pci_read_config(dev, 0x92, 2) | 0x0F, 2);
173 	return (ahci_pci_attach(dev));
174 }
175 
176 static int
177 ahci_pci_attach(device_t dev)
178 {
179 	struct ahci_softc *sc = device_get_softc(dev);
180 	struct ahci_port *ap;
181 	const char *gen;
182 	u_int32_t cap, pi, reg;
183 	bus_addr_t addr;
184 	int i;
185 	int error;
186 	const char *revision;
187 
188 	if (pci_read_config(dev, PCIR_COMMAND, 2) & 0x0400) {
189 		device_printf(dev, "BIOS disabled PCI interrupt, "
190 				   "re-enabling\n");
191 		pci_write_config(dev, PCIR_COMMAND,
192 			pci_read_config(dev, PCIR_COMMAND, 2) & ~0x0400, 2);
193 	}
194 
195 
196 	/*
197 	 * Map the AHCI controller's IRQ and BAR(5) (hardware registers)
198 	 */
199 	sc->sc_dev = dev;
200 	sc->sc_rid_irq = AHCI_IRQ_RID;
201 	sc->sc_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->sc_rid_irq,
202 					    RF_SHAREABLE | RF_ACTIVE);
203 	if (sc->sc_irq == NULL) {
204 		device_printf(dev, "unable to map interrupt\n");
205 		ahci_pci_detach(dev);
206 		return (ENXIO);
207 	}
208 
209 	/*
210 	 * When mapping the register window store the tag and handle
211 	 * separately so we can use the tag with per-port bus handle
212 	 * sub-spaces.
213 	 */
214 	sc->sc_rid_regs = PCIR_BAR(5);
215 	sc->sc_regs = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
216 					     &sc->sc_rid_regs, RF_ACTIVE);
217 	if (sc->sc_regs == NULL) {
218 		device_printf(dev, "unable to map registers\n");
219 		ahci_pci_detach(dev);
220 		return (ENXIO);
221 	}
222 	sc->sc_iot = rman_get_bustag(sc->sc_regs);
223 	sc->sc_ioh = rman_get_bushandle(sc->sc_regs);
224 
225 	/*
226 	 * Initialize the chipset and then set the interrupt vector up
227 	 */
228 	error = ahci_init(sc);
229 	if (error) {
230 		ahci_pci_detach(dev);
231 		return (ENXIO);
232 	}
233 
234 	/*
235 	 * Get the AHCI capabilities and max number of concurrent
236 	 * command tags and set up the DMA tags.
237 	 */
238 	cap = ahci_read(sc, AHCI_REG_CAP);
239 	if (sc->sc_flags & AHCI_F_NO_NCQ)
240 		cap &= ~AHCI_REG_CAP_SNCQ;
241 	sc->sc_cap = cap;
242 
243 	/*
244 	 * We assume at least 4 commands.
245 	 */
246 	sc->sc_ncmds = AHCI_REG_CAP_NCS(cap);
247 	if (sc->sc_ncmds < 4) {
248 		device_printf(dev, "NCS must probe a value >= 4\n");
249 		ahci_pci_detach(dev);
250 		return (ENXIO);
251 	}
252 
253 	addr = (cap & AHCI_REG_CAP_S64A) ?
254 		BUS_SPACE_MAXADDR : BUS_SPACE_MAXADDR_32BIT;
255 
256 	/*
257 	 * DMA tags for allocation of DMA memory buffers, lists, and so
258 	 * forth.  These are typically per-port.
259 	 */
260 	error = 0;
261 	error += bus_dma_tag_create(
262 			NULL,				/* parent tag */
263 			256,				/* alignment */
264 			PAGE_SIZE,			/* boundary */
265 			addr,				/* loaddr? */
266 			BUS_SPACE_MAXADDR,		/* hiaddr */
267 			NULL,				/* filter */
268 			NULL,				/* filterarg */
269 			sizeof(struct ahci_rfis),	/* [max]size */
270 			1,				/* maxsegs */
271 			sizeof(struct ahci_rfis),	/* maxsegsz */
272 			0,				/* flags */
273 			&sc->sc_tag_rfis);		/* return tag */
274 
275 	error += bus_dma_tag_create(
276 			NULL,				/* parent tag */
277 			32,				/* alignment */
278 			4096 * 1024,			/* boundary */
279 			addr,				/* loaddr? */
280 			BUS_SPACE_MAXADDR,		/* hiaddr */
281 			NULL,				/* filter */
282 			NULL,				/* filterarg */
283 			sc->sc_ncmds * sizeof(struct ahci_cmd_hdr),
284 			1,				/* maxsegs */
285 			sc->sc_ncmds * sizeof(struct ahci_cmd_hdr),
286 			0,				/* flags */
287 			&sc->sc_tag_cmdh);		/* return tag */
288 
289 	/*
290 	 * NOTE: ahci_cmd_table is sized to a power of 2
291 	 */
292 	error += bus_dma_tag_create(
293 			NULL,				/* parent tag */
294 			sizeof(struct ahci_cmd_table),	/* alignment */
295 			4096 * 1024,			/* boundary */
296 			addr,				/* loaddr? */
297 			BUS_SPACE_MAXADDR,		/* hiaddr */
298 			NULL,				/* filter */
299 			NULL,				/* filterarg */
300 			sc->sc_ncmds * sizeof(struct ahci_cmd_table),
301 			1,				/* maxsegs */
302 			sc->sc_ncmds * sizeof(struct ahci_cmd_table),
303 			0,				/* flags */
304 			&sc->sc_tag_cmdt);		/* return tag */
305 
306 	/*
307 	 * The data tag is used for later dmamaps and not immediately
308 	 * allocated.
309 	 */
310 	error += bus_dma_tag_create(
311 			NULL,				/* parent tag */
312 			4,				/* alignment */
313 			0,				/* boundary */
314 			addr,				/* loaddr? */
315 			BUS_SPACE_MAXADDR,		/* hiaddr */
316 			NULL,				/* filter */
317 			NULL,				/* filterarg */
318 			4096 * 1024,			/* maxiosize */
319 			AHCI_MAX_PRDT,			/* maxsegs */
320 			65536,				/* maxsegsz */
321 			0,				/* flags */
322 			&sc->sc_tag_data);		/* return tag */
323 
324 	if (error) {
325 		device_printf(dev, "unable to create dma tags\n");
326 		ahci_pci_detach(dev);
327 		return (ENXIO);
328 	}
329 
330 	switch (cap & AHCI_REG_CAP_ISS) {
331 	case AHCI_REG_CAP_ISS_G1:
332 		gen = "1 (1.5Gbps)";
333 		break;
334 	case AHCI_REG_CAP_ISS_G1_2:
335 		gen = "1 (1.5Gbps) and 2 (3Gbps)";
336 		break;
337 	default:
338 		gen = "unknown";
339 		break;
340 	}
341 
342 	/* check the revision */
343 	reg = ahci_read(sc, AHCI_REG_VS);
344 	switch (reg) {
345 	case AHCI_REG_VS_0_95:
346 		revision = "AHCI 0.95";
347 		break;
348 	case AHCI_REG_VS_1_0:
349 		revision = "AHCI 1.0";
350 		break;
351 	case AHCI_REG_VS_1_1:
352 		revision = "AHCI 1.1";
353 		break;
354 	case AHCI_REG_VS_1_2:
355 		revision = "AHCI 1.2";
356 		break;
357 	default:
358 		device_printf(sc->sc_dev,
359 			      "Warning: Unknown AHCI revision 0x%08x\n", reg);
360 		revision = "AHCI <unknown>";
361 		break;
362 	}
363 
364 	device_printf(dev,
365 		      "%s capabilities 0x%b, %d ports, %d tags/port, gen %s\n",
366 		      revision,
367 		      cap, AHCI_FMT_CAP,
368 		      AHCI_REG_CAP_NP(cap), sc->sc_ncmds, gen);
369 
370 	pi = ahci_read(sc, AHCI_REG_PI);
371 	DPRINTF(AHCI_D_VERBOSE, "%s: ports implemented: 0x%08x\n",
372 	    DEVNAME(sc), pi);
373 
374 #ifdef AHCI_COALESCE
375 	/* Naive coalescing support - enable for all ports. */
376 	if (cap & AHCI_REG_CAP_CCCS) {
377 		u_int16_t		ccc_timeout = 20;
378 		u_int8_t		ccc_numcomplete = 12;
379 		u_int32_t		ccc_ctl;
380 
381 		/* disable coalescing during reconfiguration. */
382 		ccc_ctl = ahci_read(sc, AHCI_REG_CCC_CTL);
383 		ccc_ctl &= ~0x00000001;
384 		ahci_write(sc, AHCI_REG_CCC_CTL, ccc_ctl);
385 
386 		sc->sc_ccc_mask = 1 << AHCI_REG_CCC_CTL_INT(ccc_ctl);
387 		if (pi & sc->sc_ccc_mask) {
388 			/* A conflict with the implemented port list? */
389 			printf("%s: coalescing interrupt/implemented port list "
390 			    "conflict, PI: %08x, ccc_mask: %08x\n",
391 			    DEVNAME(sc), pi, sc->sc_ccc_mask);
392 			sc->sc_ccc_mask = 0;
393 			goto noccc;
394 		}
395 
396 		/* ahci_port_start will enable each port when it starts. */
397 		sc->sc_ccc_ports = pi;
398 		sc->sc_ccc_ports_cur = 0;
399 
400 		/* program thresholds and enable overall coalescing. */
401 		ccc_ctl &= ~0xffffff00;
402 		ccc_ctl |= (ccc_timeout << 16) | (ccc_numcomplete << 8);
403 		ahci_write(sc, AHCI_REG_CCC_CTL, ccc_ctl);
404 		ahci_write(sc, AHCI_REG_CCC_PORTS, 0);
405 		ahci_write(sc, AHCI_REG_CCC_CTL, ccc_ctl | 1);
406 	}
407 noccc:
408 #endif
409 	/*
410 	 * Allocate per-port resources
411 	 *
412 	 * Ignore attach errors, leave the port intact for
413 	 * rescan and continue the loop.
414 	 *
415 	 * All ports are attached in parallel but the CAM scan-bus
416 	 * is held up until all ports are attached so we get a deterministic
417 	 * order.
418 	 */
419 	for (i = 0; error == 0 && i < AHCI_MAX_PORTS; i++) {
420 		if ((pi & (1 << i)) == 0) {
421 			/* dont allocate stuff if the port isnt implemented */
422 			continue;
423 		}
424 		error = ahci_port_alloc(sc, i);
425 	}
426 
427 	/*
428 	 * Setup the interrupt vector and enable interrupts.  Note that
429 	 * since the irq may be shared we do not set it up until we are
430 	 * ready to go.
431 	 */
432 	if (error == 0) {
433 		error = bus_setup_intr(dev, sc->sc_irq, 0, ahci_intr, sc,
434 				       &sc->sc_irq_handle, NULL);
435 	}
436 
437 	if (error) {
438 		device_printf(dev, "unable to install interrupt\n");
439 		ahci_pci_detach(dev);
440 		return (ENXIO);
441 	}
442 
443 	/*
444 	 * Master interrupt enable, and call ahci_intr() in case we race
445 	 * our AHCI_F_INT_GOOD flag.
446 	 */
447 	crit_enter();
448 	ahci_write(sc, AHCI_REG_GHC, AHCI_REG_GHC_AE | AHCI_REG_GHC_IE);
449 	sc->sc_flags |= AHCI_F_INT_GOOD;
450 	crit_exit();
451 	ahci_intr(sc);
452 
453 	/*
454 	 * All ports are probing in parallel.  Wait for them to finish
455 	 * and then issue the cam attachment and bus scan serially so
456 	 * the 'da' assignments are deterministic.
457 	 */
458 	for (i = 0; i < AHCI_MAX_PORTS; i++) {
459 		if ((ap = sc->sc_ports[i]) != NULL) {
460 			while (ap->ap_signal & AP_SIGF_INIT)
461 				tsleep(&ap->ap_signal, 0, "ahprb1", hz);
462 			ahci_os_lock_port(ap);
463 			if (ahci_cam_attach(ap) == 0) {
464 				ahci_cam_changed(ap, NULL, -1);
465 				ahci_os_unlock_port(ap);
466 				while ((ap->ap_flags & AP_F_SCAN_COMPLETED) == 0) {
467 					tsleep(&ap->ap_flags, 0, "ahprb2", hz);
468 				}
469 			} else {
470 				ahci_os_unlock_port(ap);
471 			}
472 		}
473 	}
474 
475 	return(0);
476 }
477 
478 /*
479  * Device unload / detachment
480  */
481 static int
482 ahci_pci_detach(device_t dev)
483 {
484 	struct ahci_softc *sc = device_get_softc(dev);
485 	struct ahci_port *ap;
486 	int	i;
487 
488 	/*
489 	 * Disable the controller and de-register the interrupt, if any.
490 	 *
491 	 * XXX interlock last interrupt?
492 	 */
493 	sc->sc_flags &= ~AHCI_F_INT_GOOD;
494 	if (sc->sc_regs)
495 		ahci_write(sc, AHCI_REG_GHC, 0);
496 
497 	if (sc->sc_irq_handle) {
498 		bus_teardown_intr(dev, sc->sc_irq, sc->sc_irq_handle);
499 		sc->sc_irq_handle = NULL;
500 	}
501 
502 	/*
503 	 * Free port structures and DMA memory
504 	 */
505 	for (i = 0; i < AHCI_MAX_PORTS; i++) {
506 		ap = sc->sc_ports[i];
507 		if (ap) {
508 			ahci_cam_detach(ap);
509 			ahci_port_free(sc, i);
510 		}
511 	}
512 
513 	/*
514 	 * Clean up the bus space
515 	 */
516 	if (sc->sc_irq) {
517 		bus_release_resource(dev, SYS_RES_IRQ,
518 				     sc->sc_rid_irq, sc->sc_irq);
519 		sc->sc_irq = NULL;
520 	}
521 	if (sc->sc_regs) {
522 		bus_release_resource(dev, SYS_RES_MEMORY,
523 				     sc->sc_rid_regs, sc->sc_regs);
524 		sc->sc_regs = NULL;
525 	}
526 
527 	if (sc->sc_tag_rfis) {
528 		bus_dma_tag_destroy(sc->sc_tag_rfis);
529 		sc->sc_tag_rfis = NULL;
530 	}
531 	if (sc->sc_tag_cmdh) {
532 		bus_dma_tag_destroy(sc->sc_tag_cmdh);
533 		sc->sc_tag_cmdh = NULL;
534 	}
535 	if (sc->sc_tag_cmdt) {
536 		bus_dma_tag_destroy(sc->sc_tag_cmdt);
537 		sc->sc_tag_cmdt = NULL;
538 	}
539 	if (sc->sc_tag_data) {
540 		bus_dma_tag_destroy(sc->sc_tag_data);
541 		sc->sc_tag_data = NULL;
542 	}
543 
544 	return (0);
545 }
546