xref: /dragonfly/sys/dev/raid/amr/amr_pci.c (revision 6b5c5d0d)
1 /*-
2  * Copyright (c) 1999,2000 Michael Smith
3  * Copyright (c) 2000 BSDi
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * Copyright (c) 2002 Eric Moore
28  * Copyright (c) 2002 LSI Logic Corporation
29  * All rights reserved.
30  *
31  * Redistribution and use in source and binary forms, with or without
32  * modification, are permitted provided that the following conditions
33  * are met:
34  * 1. Redistributions of source code must retain the above copyright
35  *    notice, this list of conditions and the following disclaimer.
36  * 2. Redistributions in binary form must reproduce the above copyright
37  *    notice, this list of conditions and the following disclaimer in the
38  *    documentation and/or other materials provided with the distribution.
39  * 3. The party using or redistributing the source code and binary forms
40  *    agrees to the disclaimer below and the terms and conditions set forth
41  *    herein.
42  *
43  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53  * SUCH DAMAGE.
54  *
55  *	$FreeBSD: src/sys/dev/amr/amr_pci.c,v 1.1.2.9 2002/12/20 15:12:04 emoore Exp $
56  *	$DragonFly: src/sys/dev/raid/amr/amr_pci.c,v 1.9 2006/12/22 23:26:23 swildner Exp $
57  */
58 
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/kernel.h>
62 
63 #include "amr_compat.h"
64 #include <sys/bus.h>
65 #include <sys/conf.h>
66 #include <sys/devicestat.h>
67 #include <sys/disk.h>
68 #include <sys/rman.h>
69 
70 #include <bus/pci/pcireg.h>
71 #include <bus/pci/pcivar.h>
72 
73 #include "amrio.h"
74 #include "amrreg.h"
75 #include "amrvar.h"
76 
77 static int		amr_pci_probe(device_t dev);
78 static int		amr_pci_attach(device_t dev);
79 static int              amr_pci_detach(device_t dev);
80 static int              amr_pci_shutdown(device_t dev);
81 static int              amr_pci_suspend(device_t dev);
82 static int              amr_pci_resume(device_t dev);
83 static void		amr_pci_intr(void *arg);
84 static void		amr_pci_free(struct amr_softc *sc);
85 static void		amr_sglist_map_helper(void *arg, bus_dma_segment_t *segs, int nseg, int error);
86 static int		amr_sglist_map(struct amr_softc *sc);
87 static void		amr_setup_mbox_helper(void *arg, bus_dma_segment_t *segs, int nseg, int error);
88 static int		amr_setup_mbox(struct amr_softc *sc);
89 
90 static device_method_t amr_methods[] = {
91     /* Device interface */
92     DEVMETHOD(device_probe,	amr_pci_probe),
93     DEVMETHOD(device_attach,	amr_pci_attach),
94     DEVMETHOD(device_detach,	amr_pci_detach),
95     DEVMETHOD(device_shutdown,	amr_pci_shutdown),
96     DEVMETHOD(device_suspend,	amr_pci_suspend),
97     DEVMETHOD(device_resume,	amr_pci_resume),
98 
99     DEVMETHOD(bus_print_child,	bus_generic_print_child),
100     DEVMETHOD(bus_driver_added,	bus_generic_driver_added),
101     { 0, 0 }
102 };
103 
104 static driver_t amr_pci_driver = {
105 	"amr",
106 	amr_methods,
107 	sizeof(struct amr_softc)
108 };
109 
110 static devclass_t	amr_devclass;
111 DRIVER_MODULE(amr, pci, amr_pci_driver, amr_devclass, 0, 0);
112 
113 static struct
114 {
115     int		vendor;
116     int		device;
117     int		flag;
118 #define PROBE_SIGNATURE	(1<<0)
119 } amr_device_ids[] = {
120     {0x101e, 0x9010, 0},
121     {0x101e, 0x9060, 0},
122     {0x8086, 0x1960, PROBE_SIGNATURE},/* generic i960RD, check for signature */
123     {0x101e, 0x1960, 0},
124     {0x1000, 0x1960, PROBE_SIGNATURE},
125     {0x1000, 0x0407, 0},
126     {0x1028, 0x000e, PROBE_SIGNATURE}, /* perc4/di i960 */
127     {0x1028, 0x000f, 0}, /* perc4/di Verde*/
128     {0, 0, 0}
129 };
130 
131 static int
132 amr_pci_probe(device_t dev)
133 {
134     int		i, sig;
135 
136     debug_called(1);
137 
138     for (i = 0; amr_device_ids[i].vendor != 0; i++) {
139 	if ((pci_get_vendor(dev) == amr_device_ids[i].vendor) &&
140 	    (pci_get_device(dev) == amr_device_ids[i].device)) {
141 
142 	    /* do we need to test for a signature? */
143 	    if (amr_device_ids[i].flag & PROBE_SIGNATURE) {
144 		sig = pci_read_config(dev, AMR_CFG_SIG, 2);
145 		if ((sig != AMR_SIGNATURE_1) && (sig != AMR_SIGNATURE_2))
146 		    continue;
147 	    }
148 	    device_set_desc(dev, "LSILogic MegaRAID");
149 	    return(-10);	/* allow room to be overridden */
150 	}
151     }
152     return(ENXIO);
153 }
154 
155 static int
156 amr_pci_attach(device_t dev)
157 {
158     struct amr_softc	*sc;
159     int			rid, rtype, error;
160     u_int32_t		command;
161 
162     debug_called(1);
163 
164     /*
165      * Initialise softc.
166      */
167     sc = device_get_softc(dev);
168     bzero(sc, sizeof(*sc));
169     sc->amr_dev = dev;
170 
171     /* assume failure is 'not configured' */
172     error = ENXIO;
173 
174     /*
175      * Determine board type.
176      */
177     command = pci_read_config(dev, PCIR_COMMAND, 1);
178     if ((pci_get_device(dev) == 0x1960) || (pci_get_device(dev) == 0x0407) ||
179 	(pci_get_device(dev) == 0x000e) || (pci_get_device(dev) == 0x000f)) {
180 	/*
181 	 * Make sure we are going to be able to talk to this board.
182 	 */
183 	if ((command & PCIM_CMD_MEMEN) == 0) {
184 	    device_printf(dev, "memory window not available\n");
185 	    goto out;
186 	}
187 	sc->amr_type |= AMR_TYPE_QUARTZ;
188 
189     } else {
190 	/*
191 	 * Make sure we are going to be able to talk to this board.
192 	 */
193 	if ((command & PCIM_CMD_PORTEN) == 0) {
194 	    device_printf(dev, "I/O window not available\n");
195 	    goto out;
196 	}
197     }
198 
199     /* force the busmaster enable bit on */
200     if (!(command & PCIM_CMD_BUSMASTEREN)) {
201 	device_printf(dev, "busmaster bit not set, enabling\n");
202 	command |= PCIM_CMD_BUSMASTEREN;
203 	pci_write_config(dev, PCIR_COMMAND, command, 2);
204     }
205 
206     /*
207      * Allocate the PCI register window.
208      */
209     rid = PCIR_MAPS;
210     rtype = AMR_IS_QUARTZ(sc) ? SYS_RES_MEMORY : SYS_RES_IOPORT;
211     sc->amr_reg = bus_alloc_resource(dev, rtype, &rid, 0, ~0, 1, RF_ACTIVE);
212     if (sc->amr_reg == NULL) {
213 	device_printf(sc->amr_dev, "can't allocate register window\n");
214 	goto out;
215     }
216     sc->amr_btag = rman_get_bustag(sc->amr_reg);
217     sc->amr_bhandle = rman_get_bushandle(sc->amr_reg);
218 
219     /*
220      * Allocate and connect our interrupt.
221      */
222     rid = 0;
223     sc->amr_irq = bus_alloc_resource(sc->amr_dev, SYS_RES_IRQ, &rid, 0, ~0, 1, RF_SHAREABLE | RF_ACTIVE);
224     if (sc->amr_irq == NULL) {
225         device_printf(sc->amr_dev, "can't allocate interrupt\n");
226 	goto out;
227     }
228     error = bus_setup_intr(sc->amr_dev, sc->amr_irq,
229 			   0, amr_pci_intr, sc,
230 			   &sc->amr_intr, NULL);
231     if (error) {
232         device_printf(sc->amr_dev, "can't set up interrupt\n");
233 	goto out;
234     }
235 
236     debug(2, "interrupt attached");
237 
238     /* assume failure is 'out of memory' */
239     error = ENOMEM;
240 
241     /*
242      * Allocate the parent bus DMA tag appropriate for PCI.
243      */
244     if (bus_dma_tag_create(NULL, 			/* parent */
245 			   1, 0, 			/* alignment, boundary */
246 			   BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
247 			   BUS_SPACE_MAXADDR, 		/* highaddr */
248 			   NULL, NULL, 			/* filter, filterarg */
249 			   MAXBSIZE, AMR_NSEG,		/* maxsize, nsegments */
250 			   BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
251 			   BUS_DMA_ALLOCNOW,		/* flags */
252 			   &sc->amr_parent_dmat)) {
253 	device_printf(dev, "can't allocate parent DMA tag\n");
254 	goto out;
255     }
256 
257     /*
258      * Create DMA tag for mapping buffers into controller-addressable space.
259      */
260     if (bus_dma_tag_create(sc->amr_parent_dmat,		/* parent */
261 			   1, 0,			/* alignment, boundary */
262 			   BUS_SPACE_MAXADDR,		/* lowaddr */
263 			   BUS_SPACE_MAXADDR,		/* highaddr */
264 			   NULL, NULL,			/* filter, filterarg */
265 			   MAXBSIZE, AMR_NSEG,		/* maxsize, nsegments */
266 			   BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
267 			   0,				/* flags */
268 			   &sc->amr_buffer_dmat)) {
269         device_printf(sc->amr_dev, "can't allocate buffer DMA tag\n");
270 	goto out;
271     }
272 
273     debug(2, "dma tag done");
274 
275     /*
276      * Allocate and set up mailbox in a bus-visible fashion.
277      */
278     if ((error = amr_setup_mbox(sc)) != 0)
279 	goto out;
280 
281     debug(2, "mailbox setup");
282 
283     /*
284      * Build the scatter/gather buffers.
285      */
286     if (amr_sglist_map(sc))
287 	goto out;
288 
289     debug(2, "s/g list mapped");
290 
291     /*
292      * Do bus-independant initialisation, bring controller online.
293      */
294     error = amr_attach(sc);
295 
296 out:
297     if (error)
298 	amr_pci_free(sc);
299     return(error);
300 }
301 
302 /********************************************************************************
303  * Disconnect from the controller completely, in preparation for unload.
304  */
305 static int
306 amr_pci_detach(device_t dev)
307 {
308     struct amr_softc	*sc = device_get_softc(dev);
309     int			error;
310 
311     debug_called(1);
312 
313     if (sc->amr_state & AMR_STATE_OPEN)
314 	return(EBUSY);
315 
316     if ((error = amr_pci_shutdown(dev)))
317 	return(error);
318 
319     amr_pci_free(sc);
320 
321     return(0);
322 }
323 
324 /********************************************************************************
325  * Bring the controller down to a dormant state and detach all child devices.
326  *
327  * This function is called before detach, system shutdown, or before performing
328  * an operation which may add or delete system disks.  (Call amr_startup to
329  * resume normal operation.)
330  *
331  * Note that we can assume that the bioq on the controller is empty, as we won't
332  * allow shutdown if any device is open.
333  */
334 static int
335 amr_pci_shutdown(device_t dev)
336 {
337     struct amr_softc	*sc = device_get_softc(dev);
338     int			i,error;
339 
340     debug_called(1);
341 
342     /* mark ourselves as in-shutdown */
343     sc->amr_state |= AMR_STATE_SHUTDOWN;
344 
345 
346     /* flush controller */
347     device_printf(sc->amr_dev, "flushing cache...");
348     kprintf("%s\n", amr_flush(sc) ? "failed" : "done");
349 
350     crit_enter();
351     error = 0;
352 
353     /* delete all our child devices */
354     for(i = 0 ; i < AMR_MAXLD; i++) {
355 	if( sc->amr_drive[i].al_disk != 0) {
356 	    if((error = device_delete_child(sc->amr_dev,sc->amr_drive[i].al_disk)) != 0)
357 		goto shutdown_out;
358 	    sc->amr_drive[i].al_disk = 0;
359 	}
360     }
361 
362     /* XXX disable interrupts? */
363 
364 shutdown_out:
365     crit_exit();
366     return(error);
367 }
368 
369 /********************************************************************************
370  * Bring the controller to a quiescent state, ready for system suspend.
371  */
372 static int
373 amr_pci_suspend(device_t dev)
374 {
375     struct amr_softc	*sc = device_get_softc(dev);
376 
377     debug_called(1);
378 
379     sc->amr_state |= AMR_STATE_SUSPEND;
380 
381     /* flush controller */
382     device_printf(sc->amr_dev, "flushing cache...");
383     kprintf("%s\n", amr_flush(sc) ? "failed" : "done");
384 
385     /* XXX disable interrupts? */
386 
387     return(0);
388 }
389 
390 /********************************************************************************
391  * Bring the controller back to a state ready for operation.
392  */
393 static int
394 amr_pci_resume(device_t dev)
395 {
396     struct amr_softc	*sc = device_get_softc(dev);
397 
398     debug_called(1);
399 
400     sc->amr_state &= ~AMR_STATE_SUSPEND;
401 
402     /* XXX enable interrupts? */
403 
404     return(0);
405 }
406 
407 /*******************************************************************************
408  * Take an interrupt, or be poked by other code to look for interrupt-worthy
409  * status.
410  */
411 static void
412 amr_pci_intr(void *arg)
413 {
414     struct amr_softc	*sc = (struct amr_softc *)arg;
415 
416     debug_called(2);
417 
418     /* collect finished commands, queue anything waiting */
419     amr_done(sc);
420 }
421 
422 /********************************************************************************
423  * Free all of the resources associated with (sc)
424  *
425  * Should not be called if the controller is active.
426  */
427 static void
428 amr_pci_free(struct amr_softc *sc)
429 {
430     u_int8_t			*p;
431 
432     debug_called(1);
433 
434     amr_free(sc);
435 
436     /* destroy data-transfer DMA tag */
437     if (sc->amr_buffer_dmat)
438 	bus_dma_tag_destroy(sc->amr_buffer_dmat);
439 
440     /* free and destroy DMA memory and tag for s/g lists */
441     if (sc->amr_sgtable)
442 	bus_dmamem_free(sc->amr_sg_dmat, sc->amr_sgtable, sc->amr_sg_dmamap);
443     if (sc->amr_sg_dmat)
444 	bus_dma_tag_destroy(sc->amr_sg_dmat);
445 
446     /* free and destroy DMA memory and tag for mailbox */
447     if (sc->amr_mailbox) {
448 	p = (u_int8_t *)(uintptr_t)(volatile void *)sc->amr_mailbox;
449 	bus_dmamem_free(sc->amr_mailbox_dmat, p - 16, sc->amr_mailbox_dmamap);
450     }
451     if (sc->amr_mailbox_dmat)
452 	bus_dma_tag_destroy(sc->amr_mailbox_dmat);
453 
454     /* disconnect the interrupt handler */
455     if (sc->amr_intr)
456 	bus_teardown_intr(sc->amr_dev, sc->amr_irq, sc->amr_intr);
457     if (sc->amr_irq != NULL)
458 	bus_release_resource(sc->amr_dev, SYS_RES_IRQ, 0, sc->amr_irq);
459 
460     /* destroy the parent DMA tag */
461     if (sc->amr_parent_dmat)
462 	bus_dma_tag_destroy(sc->amr_parent_dmat);
463 
464     /* release the register window mapping */
465     if (sc->amr_reg != NULL)
466 	bus_release_resource(sc->amr_dev,
467 			     AMR_IS_QUARTZ(sc) ? SYS_RES_MEMORY : SYS_RES_IOPORT,
468 			     PCIR_MAPS, sc->amr_reg);
469 }
470 
471 /********************************************************************************
472  * Allocate and map the scatter/gather table in bus space.
473  */
474 static void
475 amr_sglist_map_helper(void *arg, bus_dma_segment_t *segs, int nseg, int error)
476 {
477     struct amr_softc	*sc = (struct amr_softc *)arg;
478 
479     debug_called(1);
480 
481     /* save base of s/g table's address in bus space */
482     sc->amr_sgbusaddr = segs->ds_addr;
483 }
484 
485 static int
486 amr_sglist_map(struct amr_softc *sc)
487 {
488     size_t	segsize;
489     int		error;
490 
491     debug_called(1);
492 
493     /*
494      * Create a single tag describing a region large enough to hold all of
495      * the s/g lists we will need.
496      *
497      * Note that we could probably use AMR_LIMITCMD here, but that may become tunable.
498      */
499     segsize = sizeof(struct amr_sgentry) * AMR_NSEG * AMR_MAXCMD;
500     error = bus_dma_tag_create(sc->amr_parent_dmat, 	/* parent */
501 			       1, 0, 			/* alignment, boundary */
502 			       BUS_SPACE_MAXADDR,	/* lowaddr */
503 			       BUS_SPACE_MAXADDR, 	/* highaddr */
504 			       NULL, NULL, 		/* filter, filterarg */
505 			       segsize, 1,		/* maxsize, nsegments */
506 			       BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
507 			       0,			/* flags */
508 			       &sc->amr_sg_dmat);
509     if (error != 0) {
510 	device_printf(sc->amr_dev, "can't allocate scatter/gather DMA tag\n");
511 	return(ENOMEM);
512     }
513 
514     /*
515      * Allocate enough s/g maps for all commands and permanently map them into
516      * controller-visible space.
517      *
518      * XXX this assumes we can get enough space for all the s/g maps in one
519      * contiguous slab.  We may need to switch to a more complex arrangement where
520      * we allocate in smaller chunks and keep a lookup table from slot to bus address.
521      *
522      * XXX HACK ALERT: at least some controllers don't like the s/g memory being
523      *                 allocated below 0x2000.  We leak some memory if we get some
524      *                 below this mark and allocate again.  We should be able to
525      *	               avoid this with the tag setup, but that does't seem to work.
526      */
527 retry:
528     error = bus_dmamem_alloc(sc->amr_sg_dmat, (void **)&sc->amr_sgtable, BUS_DMA_NOWAIT, &sc->amr_sg_dmamap);
529     if (error) {
530 	device_printf(sc->amr_dev, "can't allocate s/g table\n");
531 	return(ENOMEM);
532     }
533     bus_dmamap_load(sc->amr_sg_dmat, sc->amr_sg_dmamap, sc->amr_sgtable, segsize, amr_sglist_map_helper, sc, 0);
534     if (sc->amr_sgbusaddr < 0x2000) {
535 	debug(1, "s/g table too low (0x%x), reallocating\n", sc->amr_sgbusaddr);
536 	goto retry;
537     }
538     return(0);
539 }
540 
541 /********************************************************************************
542  * Allocate and set up mailbox areas for the controller (sc)
543  *
544  * The basic mailbox structure should be 16-byte aligned.  This means that the
545  * mailbox64 structure has 4 bytes hanging off the bottom.
546  */
547 static void
548 amr_setup_mbox_helper(void *arg, bus_dma_segment_t *segs, int nseg, int error)
549 {
550     struct amr_softc	*sc = (struct amr_softc *)arg;
551 
552     debug_called(1);
553 
554     /* save phsyical base of the basic mailbox structure */
555     sc->amr_mailboxphys = segs->ds_addr + 16;
556 }
557 
558 static int
559 amr_setup_mbox(struct amr_softc *sc)
560 {
561     int		error;
562     u_int8_t	*p;
563 
564     debug_called(1);
565 
566     /*
567      * Create a single tag describing a region large enough to hold the entire
568      * mailbox.
569      */
570     error = bus_dma_tag_create(sc->amr_parent_dmat,	/* parent */
571 			       16, 0,			/* alignment, boundary */
572 			       BUS_SPACE_MAXADDR,	/* lowaddr */
573 			       BUS_SPACE_MAXADDR,	/* highaddr */
574 			       NULL, NULL,		/* filter, filterarg */
575 			       sizeof(struct amr_mailbox) + 16, 1, /* maxsize, nsegments */
576 			       BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
577 			       0,			/* flags */
578 			       &sc->amr_mailbox_dmat);
579     if (error != 0) {
580 	device_printf(sc->amr_dev, "can't allocate mailbox tag\n");
581 	return(ENOMEM);
582     }
583 
584     /*
585      * Allocate the mailbox structure and permanently map it into
586      * controller-visible space.
587      */
588     error = bus_dmamem_alloc(sc->amr_mailbox_dmat, (void **)&p, BUS_DMA_NOWAIT,
589 			     &sc->amr_mailbox_dmamap);
590     if (error) {
591 	device_printf(sc->amr_dev, "can't allocate mailbox memory\n");
592 	return(ENOMEM);
593     }
594     bus_dmamap_load(sc->amr_mailbox_dmat, sc->amr_mailbox_dmamap, p,
595 		    sizeof(struct amr_mailbox64), amr_setup_mbox_helper, sc, 0);
596     /*
597      * Conventional mailbox is inside the mailbox64 region.
598      */
599     bzero(p, sizeof(struct amr_mailbox64));
600     sc->amr_mailbox64 = (struct amr_mailbox64 *)(p + 12);
601     sc->amr_mailbox = (struct amr_mailbox *)(p + 16);
602 
603     return(0);
604 }
605