xref: /dragonfly/sys/platform/pc64/x86_64/nexus.c (revision 75a74ed8)
1 /*
2  * Copyright 1998 Massachusetts Institute of Technology
3  * Copyright (c) 2008 The DragonFly Project.
4  *
5  * Permission to use, copy, modify, and distribute this software and
6  * its documentation for any purpose and without fee is hereby
7  * granted, provided that both the above copyright notice and this
8  * permission notice appear in all copies, that both the above
9  * copyright notice and this permission notice appear in all
10  * supporting documentation, and that the name of M.I.T. not be used
11  * in advertising or publicity pertaining to distribution of the
12  * software without specific, written prior permission.  M.I.T. makes
13  * no representations about the suitability of this software for any
14  * purpose.  It is provided "as is" without express or implied
15  * warranty.
16  *
17  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
18  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
20  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
21  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
24  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
27  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD: src/sys/i386/i386/nexus.c,v 1.26.2.10 2003/02/22 13:16:45 imp Exp $
31  */
32 
33 /*
34  * This code implements a `root nexus' for Intel Architecture
35  * machines.  The function of the root nexus is to serve as an
36  * attachment point for both processors and buses, and to manage
37  * resources which are common to all of them.  In particular,
38  * this code implements the core resource managers for interrupt
39  * requests, DMA requests (which rightfully should be a part of the
40  * ISA code but it's easier to do it here for now), I/O port addresses,
41  * and I/O memory address space.
42  */
43 
44 #include "use_pci.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/bus.h>
49 #include <sys/kernel.h>
50 #include <sys/malloc.h>
51 #include <sys/module.h>
52 #include <sys/rman.h>
53 #include <sys/interrupt.h>
54 #include <sys/machintr.h>
55 #include <sys/linker.h>
56 
57 #include <machine/vmparam.h>
58 #include <vm/vm.h>
59 #include <vm/pmap.h>
60 #include <machine/pmap.h>
61 
62 #include <machine/nexusvar.h>
63 #include <machine/smp.h>
64 #include <machine/intr_machdep.h>
65 #include <machine_base/apic/lapic.h>
66 #include <machine_base/apic/ioapic.h>
67 #include <machine/pc/bios.h>
68 #include <machine/metadata.h>
69 
70 #if NPCI > 0
71 #include "pcib_if.h"
72 #endif
73 
74 #define ELF_KERN_STR    ("elf"__XSTRING(__ELF_WORD_SIZE)" kernel")
75 
76 static MALLOC_DEFINE(M_NEXUSDEV, "nexusdev", "Nexus device");
77 struct nexus_device {
78 	struct resource_list	nx_resources;
79 	int			nx_pcibus;
80 };
81 
82 #define DEVTONX(dev)	((struct nexus_device *)device_get_ivars(dev))
83 
84 static struct rman irq_rman[MAXCPU], drq_rman, port_rman, mem_rman;
85 
86 static	int nexus_probe(device_t);
87 static	int nexus_attach(device_t);
88 static	int nexus_print_all_resources(device_t dev);
89 static	int nexus_print_child(device_t, device_t);
90 static device_t nexus_add_child(device_t bus, device_t parent, int order,
91 				const char *name, int unit);
92 static	struct resource *nexus_alloc_resource(device_t, device_t, int, int *,
93     u_long, u_long, u_long, u_int, int);
94 static	int nexus_read_ivar(device_t, device_t, int, uintptr_t *);
95 static	int nexus_write_ivar(device_t, device_t, int, uintptr_t);
96 static	int nexus_activate_resource(device_t, device_t, int, int,
97 				    struct resource *);
98 static	int nexus_deactivate_resource(device_t, device_t, int, int,
99 				      struct resource *);
100 static	int nexus_release_resource(device_t, device_t, int, int,
101 				   struct resource *);
102 static	int nexus_config_intr(device_t, device_t, int, enum intr_trigger,
103 			      enum intr_polarity);
104 static	int nexus_setup_intr(device_t, device_t, struct resource *, int flags,
105 		void (*)(void *), void *, void **, lwkt_serialize_t,
106 		const char *);
107 static	int nexus_teardown_intr(device_t, device_t, struct resource *,
108 				void *);
109 static	int nexus_set_resource(device_t, device_t, int, int, u_long, u_long,
110 			       int);
111 static	int nexus_get_resource(device_t, device_t, int, int, u_long *, u_long *);
112 static void nexus_delete_resource(device_t, device_t, int, int);
113 
114 #if NPCI > 0
115 static	int nexus_alloc_msi(device_t, device_t, int, int, int *, int);
116 static	int nexus_release_msi(device_t, device_t, int, int *, int);
117 static	int nexus_map_msi(device_t, device_t, int, uint64_t *, uint32_t *, int);
118 static	int nexus_alloc_msix(device_t, device_t, int *, int);
119 static	int nexus_release_msix(device_t, device_t, int, int);
120 #endif
121 
122 /*
123  * The device_identify method will cause nexus to automatically associate
124  * and attach to the root bus.
125  */
126 static device_method_t nexus_methods[] = {
127 	/* Device interface */
128 	DEVMETHOD(device_identify,	bus_generic_identify),
129 	DEVMETHOD(device_probe,		nexus_probe),
130 	DEVMETHOD(device_attach,	nexus_attach),
131 	DEVMETHOD(device_detach,	bus_generic_detach),
132 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
133 	DEVMETHOD(device_suspend,	bus_generic_suspend),
134 	DEVMETHOD(device_resume,	bus_generic_resume),
135 
136 	/* Bus interface */
137 	DEVMETHOD(bus_print_child,	nexus_print_child),
138 	DEVMETHOD(bus_add_child,	nexus_add_child),
139 	DEVMETHOD(bus_read_ivar,	nexus_read_ivar),
140 	DEVMETHOD(bus_write_ivar,	nexus_write_ivar),
141 	DEVMETHOD(bus_alloc_resource,	nexus_alloc_resource),
142 	DEVMETHOD(bus_release_resource,	nexus_release_resource),
143 	DEVMETHOD(bus_activate_resource, nexus_activate_resource),
144 	DEVMETHOD(bus_deactivate_resource, nexus_deactivate_resource),
145 	DEVMETHOD(bus_config_intr,	nexus_config_intr),
146 	DEVMETHOD(bus_setup_intr,	nexus_setup_intr),
147 	DEVMETHOD(bus_teardown_intr,	nexus_teardown_intr),
148 	DEVMETHOD(bus_set_resource,	nexus_set_resource),
149 	DEVMETHOD(bus_get_resource,	nexus_get_resource),
150 	DEVMETHOD(bus_delete_resource,	nexus_delete_resource),
151 
152 #if NPCI > 0
153 	DEVMETHOD(pcib_alloc_msi,	nexus_alloc_msi),
154 	DEVMETHOD(pcib_release_msi,	nexus_release_msi),
155 	DEVMETHOD(pcib_map_msi,		nexus_map_msi),
156 	DEVMETHOD(pcib_alloc_msix,	nexus_alloc_msix),
157 	DEVMETHOD(pcib_release_msix,	nexus_release_msix),
158 #endif
159 
160 	DEVMETHOD_END
161 };
162 
163 static driver_t nexus_driver = {
164 	"nexus",
165 	nexus_methods,
166 	1,			/* no softc */
167 };
168 static devclass_t nexus_devclass;
169 
170 DRIVER_MODULE(nexus, root, nexus_driver, nexus_devclass, NULL, NULL);
171 
172 static int
173 nexus_probe(device_t dev)
174 {
175 	int cpuid;
176 
177 	device_quiet(dev);	/* suppress attach message for neatness */
178 
179 	for (cpuid = 0; cpuid < ncpus; ++cpuid) {
180 		struct rman *rm = &irq_rman[cpuid];
181 
182 		rm->rm_start = 0;
183 		rm->rm_end = IDT_HWI_VECTORS - 1;
184 		rm->rm_type = RMAN_ARRAY;
185 		rm->rm_descr = "Interrupt request lines";
186 
187 		if (rman_init(rm, cpuid))
188 			panic("%s rman_init", __func__);
189 		MachIntrABI.rman_setup(rm);
190 	}
191 
192 	/*
193 	 * ISA DMA on PCI systems is implemented in the ISA part of each
194 	 * PCI->ISA bridge and the channels can be duplicated if there are
195 	 * multiple bridges.  (eg: laptops with docking stations)
196 	 */
197 	drq_rman.rm_start = 0;
198 	drq_rman.rm_end = 7;
199 	drq_rman.rm_type = RMAN_ARRAY;
200 	drq_rman.rm_descr = "DMA request lines";
201 	/* XXX drq 0 not available on some machines */
202 	if (rman_init(&drq_rman, -1)
203 	    || rman_manage_region(&drq_rman,
204 				  drq_rman.rm_start, drq_rman.rm_end))
205 		panic("%s drq_rman", __func__);
206 
207 	/*
208 	 * However, IO ports and Memory truely are global at this level,
209 	 * as are APIC interrupts (however many IO APICS there turn out
210 	 * to be on large systems..)
211 	 */
212 	port_rman.rm_start = 0;
213 	port_rman.rm_end = 0xffff;
214 	port_rman.rm_type = RMAN_ARRAY;
215 	port_rman.rm_descr = "I/O ports";
216 	if (rman_init(&port_rman, -1)
217 	    || rman_manage_region(&port_rman, 0, 0xffff))
218 		panic("%s port_rman", __func__);
219 
220 	mem_rman.rm_start = 0;
221 	mem_rman.rm_end = ~0u;
222 	mem_rman.rm_type = RMAN_ARRAY;
223 	mem_rman.rm_descr = "I/O memory addresses";
224 	if (rman_init(&mem_rman, -1)
225 	    || rman_manage_region(&mem_rman, 0, ~0))
226 		panic("%s mem_rman", __func__);
227 
228 	return bus_generic_probe(dev);
229 }
230 
231 static int
232 nexus_attach(device_t dev)
233 {
234 	device_t	child;
235 
236 	/*
237 	 * First, let our child driver's identify any child devices that
238 	 * they can find.  Once that is done attach any devices that we
239 	 * found.
240 	 */
241 #if 0 /* FUTURE */
242 	bus_generic_probe(dev);
243 #endif
244 	bus_generic_attach(dev);
245 
246 	/*
247 	 * And if we didn't see ISA on a pci bridge, create a
248 	 * connection point now so it shows up "on motherboard".
249 	 */
250 	if (!devclass_get_device(devclass_find("isa"), 0)) {
251 		child = BUS_ADD_CHILD(dev, dev, 0, "isa", 0);
252 		if (child == NULL)
253 			panic("%s isa", __func__);
254 		device_probe_and_attach(child);
255 	}
256 
257 	return 0;
258 }
259 
260 static int
261 nexus_print_all_resources(device_t dev)
262 {
263 	struct	nexus_device *ndev = DEVTONX(dev);
264 	struct resource_list *rl = &ndev->nx_resources;
265 	int retval = 0;
266 
267 	if (SLIST_FIRST(rl) || ndev->nx_pcibus != -1)
268 		retval += kprintf(" at");
269 
270 	retval += resource_list_print_type(rl, "port", SYS_RES_IOPORT, "%#lx");
271 	retval += resource_list_print_type(rl, "iomem", SYS_RES_MEMORY, "%#lx");
272 	retval += resource_list_print_type(rl, "irq", SYS_RES_IRQ, "%ld");
273 
274 	return retval;
275 }
276 
277 static int
278 nexus_print_child(device_t bus, device_t child)
279 {
280 	struct	nexus_device *ndev = DEVTONX(child);
281 	int retval = 0;
282 
283 	retval += bus_print_child_header(bus, child);
284 	retval += nexus_print_all_resources(child);
285 	if (ndev->nx_pcibus != -1)
286 		retval += kprintf(" pcibus %d", ndev->nx_pcibus);
287 	retval += kprintf(" on motherboard\n");
288 
289 	return (retval);
290 }
291 
292 static device_t
293 nexus_add_child(device_t bus, device_t parent, int order,
294 		const char *name, int unit)
295 {
296 	device_t		child;
297 	struct nexus_device	*ndev;
298 
299 	ndev = kmalloc(sizeof(struct nexus_device), M_NEXUSDEV, M_INTWAIT|M_ZERO);
300 	resource_list_init(&ndev->nx_resources);
301 	ndev->nx_pcibus = -1;
302 
303 	child = device_add_child_ordered(parent, order, name, unit);
304 
305 	/* should we free this in nexus_child_detached? */
306 	device_set_ivars(child, ndev);
307 
308 	return(child);
309 }
310 
311 static int
312 nexus_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
313 {
314 	struct nexus_device *ndev = DEVTONX(child);
315 
316 	switch (which) {
317 	case NEXUS_IVAR_PCIBUS:
318 		*result = ndev->nx_pcibus;
319 		break;
320 	default:
321 		return ENOENT;
322 	}
323 	return 0;
324 }
325 
326 static int
327 nexus_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
328 {
329 	struct nexus_device *ndev = DEVTONX(child);
330 
331 	switch (which) {
332 	case NEXUS_IVAR_PCIBUS:
333 		ndev->nx_pcibus = value;
334 		break;
335 	default:
336 		return ENOENT;
337 	}
338 	return 0;
339 }
340 
341 /*
342  * Allocate a resource on behalf of child.  NB: child is usually going to be a
343  * child of one of our descendants, not a direct child of nexus0.
344  * (Exceptions include npx.)
345  */
346 static struct resource *
347 nexus_alloc_resource(device_t bus, device_t child, int type, int *rid,
348     u_long start, u_long end, u_long count, u_int flags, int cpuid)
349 {
350 	struct nexus_device *ndev = DEVTONX(child);
351 	struct	resource *rv;
352 	struct resource_list_entry *rle;
353 	struct	rman *rm;
354 	int needactivate = flags & RF_ACTIVE;
355 
356 	/*
357 	 * If this is an allocation of the "default" range for a given RID, and
358 	 * we know what the resources for this device are (ie. they aren't maintained
359 	 * by a child bus), then work out the start/end values.
360 	 */
361 	if ((start == 0UL) && (end == ~0UL) && (count == 1)) {
362 		if (ndev == NULL)
363 			return(NULL);
364 		rle = resource_list_find(&ndev->nx_resources, type, *rid);
365 		if (rle == NULL)
366 			return(NULL);
367 		start = rle->start;
368 		end = rle->end;
369 		count = rle->count;
370 		cpuid = rle->cpuid;
371 	}
372 
373 	flags &= ~RF_ACTIVE;
374 
375 	switch (type) {
376 	case SYS_RES_IRQ:
377 		KASSERT(cpuid >= 0 && cpuid < ncpus,
378 		    ("nexus invalid cpuid: %d", cpuid));
379 		rm = &irq_rman[cpuid];
380 		break;
381 
382 	case SYS_RES_DRQ:
383 		rm = &drq_rman;
384 		break;
385 
386 	case SYS_RES_IOPORT:
387 		rm = &port_rman;
388 		break;
389 
390 	case SYS_RES_MEMORY:
391 		rm = &mem_rman;
392 		break;
393 
394 	default:
395 		return 0;
396 	}
397 
398 	rv = rman_reserve_resource(rm, start, end, count, flags, child);
399 	if (rv == NULL)
400 		return 0;
401 	rman_set_rid(rv, *rid);
402 
403 	if (type == SYS_RES_MEMORY) {
404 		rman_set_bustag(rv, X86_64_BUS_SPACE_MEM);
405 	} else if (type == SYS_RES_IOPORT) {
406 		rman_set_bustag(rv, X86_64_BUS_SPACE_IO);
407 		rman_set_bushandle(rv, rv->r_start);
408 	}
409 
410 	if (needactivate) {
411 		if (bus_activate_resource(child, type, *rid, rv)) {
412 			rman_release_resource(rv);
413 			return 0;
414 		}
415 	}
416 
417 	return rv;
418 }
419 
420 static int
421 nexus_activate_resource(device_t bus, device_t child, int type, int rid,
422 			struct resource *r)
423 {
424 	/*
425 	 * If this is a memory resource, map it into the kernel.
426 	 */
427 	if (rman_get_bustag(r) == X86_64_BUS_SPACE_MEM) {
428 		caddr_t vaddr = 0;
429 
430 		if (rman_get_end(r) < 1024 * 1024) {
431 			/*
432 			 * The first 1Mb is mapped at KERNBASE.
433 			 */
434 			vaddr = (caddr_t)(uintptr_t)(KERNBASE + rman_get_start(r));
435 		} else {
436 			u_int64_t paddr;
437 			u_int64_t psize;
438 			u_int32_t poffs;
439 
440 			paddr = rman_get_start(r);
441 			psize = rman_get_size(r);
442 
443 			poffs = paddr - trunc_page(paddr);
444 			vaddr = (caddr_t) pmap_mapdev(paddr-poffs, psize+poffs) + poffs;
445 		}
446 		rman_set_virtual(r, vaddr);
447 		/* IBM-PC: the type of bus_space_handle_t is u_int */
448 		rman_set_bushandle(r, (bus_space_handle_t) vaddr);
449 	}
450 	return (rman_activate_resource(r));
451 }
452 
453 static int
454 nexus_deactivate_resource(device_t bus, device_t child, int type, int rid,
455 			  struct resource *r)
456 {
457 	/*
458 	 * If this is a memory resource, unmap it.
459 	 */
460 	if ((rman_get_bustag(r) == X86_64_BUS_SPACE_MEM) &&
461 	    (rman_get_end(r) >= 1024 * 1024)) {
462 		u_int32_t psize;
463 
464 		psize = rman_get_size(r);
465 		pmap_unmapdev((vm_offset_t)rman_get_virtual(r), psize);
466 	}
467 
468 	return (rman_deactivate_resource(r));
469 }
470 
471 static int
472 nexus_release_resource(device_t bus, device_t child, int type, int rid,
473 		       struct resource *r)
474 {
475 	if (rman_get_flags(r) & RF_ACTIVE) {
476 		int error = bus_deactivate_resource(child, type, rid, r);
477 		if (error)
478 			return error;
479 	}
480 	return (rman_release_resource(r));
481 }
482 
483 static int
484 nexus_config_intr(device_t bus, device_t chile, int irq,
485     enum intr_trigger trig, enum intr_polarity pola)
486 {
487 	machintr_legacy_intr_config(irq, trig, pola);
488 	return 0;
489 }
490 
491 /*
492  * Currently this uses the really grody interface from kern/kern_intr.c
493  * (which really doesn't belong in kern/anything.c).  Eventually, all of
494  * the code in kern_intr.c and machdep_intr.c should get moved here, since
495  * this is going to be the official interface.
496  */
497 static int
498 nexus_setup_intr(device_t bus, device_t child, struct resource *irq,
499     int flags, void (*ihand)(void *), void *arg, void **cookiep,
500     lwkt_serialize_t serializer, const char *desc)
501 {
502 	int	error, icflags;
503 
504 	/* somebody tried to setup an irq that failed to allocate! */
505 	if (irq == NULL)
506 		panic("%s: NULL irq resource!", __func__);
507 
508 	*cookiep = NULL;
509 	icflags = flags;
510 	if ((irq->r_flags & RF_SHAREABLE) == 0)
511 		icflags |= INTR_EXCL;
512 
513 	/*
514 	 * We depend here on rman_activate_resource() being idempotent.
515 	 */
516 	error = rman_activate_resource(irq);
517 	if (error)
518 		return (error);
519 
520 	/* Use device name, if description is not specified */
521 	if (desc == NULL)
522 		desc = device_get_nameunit(child);
523 
524 	/*
525 	 * XXX cast the interrupt handler function to an inthand2_t.  The
526 	 * difference is that an additional frame argument is passed which
527 	 * we do not currently want to expose the BUS subsystem to.
528 	 */
529 	*cookiep = register_int(irq->r_start, (inthand2_t *)ihand, arg,
530 				desc, serializer, icflags, rman_get_cpuid(irq));
531 	if (*cookiep == NULL)
532 		error = EINVAL;
533 	return (error);
534 }
535 
536 static int
537 nexus_teardown_intr(device_t dev, device_t child, struct resource *r, void *ih)
538 {
539 	if (ih) {
540 		unregister_int(ih, rman_get_cpuid(r));
541 		return (0);
542 	}
543 	return(-1);
544 }
545 
546 static int
547 nexus_set_resource(device_t dev, device_t child, int type, int rid,
548     u_long start, u_long count, int cpuid)
549 {
550 	struct nexus_device	*ndev = DEVTONX(child);
551 	struct resource_list	*rl = &ndev->nx_resources;
552 
553 	/* XXX this should return a success/failure indicator */
554 	resource_list_add(rl, type, rid, start, start + count - 1, count,
555 	    cpuid);
556 	return(0);
557 }
558 
559 static int
560 nexus_get_resource(device_t dev, device_t child, int type, int rid, u_long *startp, u_long *countp)
561 {
562 	struct nexus_device	*ndev = DEVTONX(child);
563 	struct resource_list	*rl = &ndev->nx_resources;
564 	struct resource_list_entry *rle;
565 
566 	rle = resource_list_find(rl, type, rid);
567 	device_printf(child, "type %d  rid %d  startp %p  countp %p - got %p\n",
568 		      type, rid, startp, countp, rle);
569 	if (!rle)
570 		return(ENOENT);
571 	if (startp)
572 		*startp = rle->start;
573 	if (countp)
574 		*countp = rle->count;
575 	return(0);
576 }
577 
578 static void
579 nexus_delete_resource(device_t dev, device_t child, int type, int rid)
580 {
581 	struct nexus_device	*ndev = DEVTONX(child);
582 	struct resource_list	*rl = &ndev->nx_resources;
583 
584 	resource_list_delete(rl, type, rid);
585 }
586 
587 #if NPCI > 0
588 static int
589 nexus_alloc_msi(device_t dev, device_t child, int count, int maxcount,
590     int *irqs, int cpuid)
591 {
592 	if (!lapic_enable)
593 		return ENODEV;
594 
595 	return MachIntrABI.msi_alloc(irqs, count, cpuid);
596 }
597 
598 static int
599 nexus_release_msi(device_t dev, device_t child, int count, int *irqs, int cpuid)
600 {
601 	KKASSERT(lapic_enable);
602 	MachIntrABI.msi_release(irqs, count, cpuid);
603 	return 0;
604 }
605 
606 static int
607 nexus_map_msi(device_t dev, device_t child, int irq, uint64_t *addr,
608     uint32_t *data, int cpuid)
609 {
610 	KKASSERT(lapic_enable);
611 	MachIntrABI.msi_map(irq, addr, data, cpuid);
612 	return 0;
613 }
614 
615 static int
616 nexus_alloc_msix(device_t dev, device_t child, int *irq, int cpuid)
617 {
618 	if (!lapic_enable)
619 		return ENODEV;
620 
621 	return MachIntrABI.msix_alloc(irq, cpuid);
622 }
623 
624 static int
625 nexus_release_msix(device_t dev, device_t child, int irq, int cpuid)
626 {
627 	KKASSERT(lapic_enable);
628 	MachIntrABI.msix_release(irq, cpuid);
629 	return 0;
630 }
631 #endif
632 
633 /* Placeholder for system RAM. */
634 static void
635 ram_identify(driver_t *driver, device_t parent)
636 {
637 	if (resource_disabled("ram", 0))
638 		return;
639 	if (BUS_ADD_CHILD(parent, parent, 0, "ram", 0) == NULL)
640 		panic("%s", __func__);
641 }
642 
643 static int
644 ram_probe(device_t dev)
645 {
646 	device_quiet(dev);
647 	device_set_desc(dev, "System RAM");
648 	return (0);
649 }
650 
651 static int
652 ram_attach(device_t dev)
653 {
654 	struct bios_smap *smapbase, *smap, *smapend;
655 	struct resource *res;
656 	vm_phystable_t *p;
657 	caddr_t kmdp;
658 	uint32_t smapsize;
659 	int error, rid;
660 
661 	device_quiet(dev);
662 	device_set_desc(dev, "System RAM");
663 
664 	/* Retrieve the system memory map from the loader. */
665 	kmdp = preload_search_by_type("elf kernel");
666 	if (kmdp == NULL)
667 		kmdp = preload_search_by_type(ELF_KERN_STR);
668 	if (kmdp != NULL)
669 		smapbase = (struct bios_smap *)preload_search_info(kmdp,
670 		    MODINFO_METADATA | MODINFOMD_SMAP);
671 	else
672 		smapbase = NULL;
673 	if (smapbase != NULL) {
674 		smapsize = *((u_int32_t *)smapbase - 1);
675 		smapend = (struct bios_smap *)((uintptr_t)smapbase + smapsize);
676 
677 		rid = 0;
678 		for (smap = smapbase; smap < smapend; smap++) {
679 			if (smap->type != SMAP_TYPE_MEMORY ||
680 			    smap->length == 0)
681 				continue;
682 			error = bus_set_resource(dev, SYS_RES_MEMORY, rid,
683 			    smap->base, smap->length, -1);
684 			if (error)
685 				panic("%s: resource %d failed set with %d",
686 				    __func__, rid, error);
687 			res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
688 			    0);
689 			if (res == NULL) {
690 				panic("%s: resource %d failed to "
691 				      "attach 0x%016jx/%jd",
692 				    __func__, rid,
693 				    (intmax_t)smap->base,
694 				    (intmax_t)smap->length);
695 			}
696 			rid++;
697 		}
698 		return (0);
699 	}
700 
701 	/*
702 	 * If the system map is not available, fall back to using
703 	 * dump_avail[].  We use the dump_avail[] array rather than
704 	 * phys_avail[] for the memory map as phys_avail[] contains
705 	 * holes for kernel memory, page 0, the message buffer, and
706 	 * the dcons buffer.  We test the end address in the loop
707 	 * instead of the start since the start address for the first
708 	 * segment is 0.
709 	 */
710 	for (rid = 0, p = &dump_avail[0]; p->phys_end; ++rid, ++p) {
711 		error = bus_set_resource(dev, SYS_RES_MEMORY, rid,
712 					 p->phys_beg,
713 					 p->phys_end - p->phys_beg,
714 					 -1);
715 		if (error)
716 			panic("%s: resource %d failed set with %d", __func__,
717 			      rid, error);
718 		res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 0);
719 		if (res == NULL)
720 			panic("%s: resource %d failed to attach", __func__,
721 			      rid);
722 	}
723 	return (0);
724 }
725 static device_method_t ram_methods[] = {
726 	/* Device interface */
727 	DEVMETHOD(device_identify,      ram_identify),
728 	DEVMETHOD(device_probe,	 	ram_probe),
729 	DEVMETHOD(device_attach,	ram_attach),
730 	{ 0, 0 }
731 };
732 
733 static driver_t ram_driver = {
734 	"ram",
735 	ram_methods,
736 	1,		/* no softc */
737 };
738 
739 static devclass_t ram_devclass;
740 DRIVER_MODULE(ram, nexus, ram_driver, ram_devclass, NULL, NULL);
741