xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2838_pci.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
1 /*-
2  * SPDX-License-Identifier: ISC
3  *
4  * Copyright (c) 2020 Dr Robert Harvey Crowston <crowston@protonmail.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  *
18  *
19  * $FreeBSD$
20  *
21  */
22 
23 /*
24  * BCM2838-compatible PCI-express controller.
25  *
26  * Broadcom likes to give the same chip lots of different names. The name of
27  * this driver is taken from the Raspberry Pi 4 Broadcom 2838 chip.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/endian.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/bus.h>
39 #include <sys/proc.h>
40 #include <sys/rman.h>
41 #include <sys/intr.h>
42 #include <sys/mutex.h>
43 
44 #include <dev/ofw/openfirm.h>
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
47 
48 #include <dev/pci/pci_host_generic.h>
49 #include <dev/pci/pci_host_generic_fdt.h>
50 #include <dev/pci/pcivar.h>
51 #include <dev/pci/pcireg.h>
52 #include <dev/pci/pcib_private.h>
53 
54 #include <machine/bus.h>
55 #include <machine/intr.h>
56 
57 #include "pcib_if.h"
58 #include "msi_if.h"
59 
60 #define PCI_ID_VAL3		0x43c
61 #define CLASS_SHIFT		0x10
62 #define SUBCLASS_SHIFT		0x8
63 
64 #define REG_CONTROLLER_HW_REV			0x406c
65 #define REG_BRIDGE_CTRL				0x9210
66 #define BRIDGE_DISABLE_FLAG	0x1
67 #define BRIDGE_RESET_FLAG	0x2
68 #define REG_BRIDGE_SERDES_MODE			0x4204
69 #define REG_DMA_CONFIG				0x4008
70 #define REG_DMA_WINDOW_LOW			0x4034
71 #define REG_DMA_WINDOW_HIGH			0x4038
72 #define REG_DMA_WINDOW_1			0x403c
73 #define REG_BRIDGE_GISB_WINDOW			0x402c
74 #define REG_BRIDGE_STATE			0x4068
75 #define REG_BRIDGE_LINK_STATE			0x00bc
76 #define REG_BUS_WINDOW_LOW			0x400c
77 #define REG_BUS_WINDOW_HIGH			0x4010
78 #define REG_CPU_WINDOW_LOW			0x4070
79 #define REG_CPU_WINDOW_START_HIGH		0x4080
80 #define REG_CPU_WINDOW_END_HIGH			0x4084
81 
82 #define REG_MSI_ADDR_LOW			0x4044
83 #define REG_MSI_ADDR_HIGH			0x4048
84 #define REG_MSI_CONFIG				0x404c
85 #define REG_MSI_CLR				0x4508
86 #define REG_MSI_MASK_CLR			0x4514
87 #define REG_MSI_RAISED				0x4500
88 #define REG_MSI_EOI				0x4060
89 #define NUM_MSI			32
90 
91 #define REG_EP_CONFIG_CHOICE			0x9000
92 #define REG_EP_CONFIG_DATA			0x8000
93 
94 /*
95  * The system memory controller can address up to 16 GiB of physical memory
96  * (although at time of writing the largest memory size available for purchase
97  * is 8 GiB). However, the system DMA controller is capable of accessing only a
98  * limited portion of the address space. Worse, the PCI-e controller has further
99  * constraints for DMA, and those limitations are not wholly clear to the
100  * author. NetBSD and Linux allow DMA on the lower 3 GiB of the physical memory,
101  * but experimentation shows DMA performed above 960 MiB results in data
102  * corruption with this driver. The limit of 960 MiB is taken from OpenBSD, but
103  * apparently that value was chosen for satisfying a constraint of an unrelated
104  * peripheral.
105  *
106  * Whatever the true maximum address, 960 MiB works.
107  */
108 #define DMA_HIGH_LIMIT			0x3c000000
109 #define MAX_MEMORY_LOG2			0x21
110 #define REG_VALUE_DMA_WINDOW_LOW	(MAX_MEMORY_LOG2 - 0xf)
111 #define REG_VALUE_DMA_WINDOW_HIGH	0x0
112 #define DMA_WINDOW_ENABLE		0x3000
113 #define REG_VALUE_DMA_WINDOW_CONFIG	\
114     (((MAX_MEMORY_LOG2 - 0xf) << 0x1b) | DMA_WINDOW_ENABLE)
115 
116 #define REG_VALUE_MSI_CONFIG	0xffe06540
117 
118 struct bcm_pcib_irqsrc {
119 	struct intr_irqsrc	isrc;
120 	u_int			irq;
121 	bool			allocated;
122 };
123 
124 struct bcm_pcib_softc {
125 	struct generic_pcie_fdt_softc	base;
126 	device_t			dev;
127 	bus_dma_tag_t			dmat;
128 	struct mtx			config_mtx;
129 	struct mtx			msi_mtx;
130 	struct resource 		*msi_irq_res;
131 	void				*msi_intr_cookie;
132 	struct bcm_pcib_irqsrc		*msi_isrcs;
133 	pci_addr_t			msi_addr;
134 };
135 
136 static struct ofw_compat_data compat_data[] = {
137 	{"brcm,bcm2711-pcie",			1},
138 	{"brcm,bcm7211-pcie",			1},
139 	{"brcm,bcm7445-pcie",			1},
140 	{NULL,					0}
141 };
142 
143 static int
144 bcm_pcib_probe(device_t dev)
145 {
146 
147 	if (!ofw_bus_status_okay(dev))
148 		return (ENXIO);
149 
150 	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
151 		return (ENXIO);
152 
153 	device_set_desc(dev,
154 	    "BCM2838-compatible PCI-express controller");
155 	return (BUS_PROBE_DEFAULT);
156 }
157 
158 static bus_dma_tag_t
159 bcm_pcib_get_dma_tag(device_t dev, device_t child)
160 {
161 	struct bcm_pcib_softc *sc;
162 
163 	sc = device_get_softc(dev);
164 	return (sc->dmat);
165 }
166 
167 static void
168 bcm_pcib_set_reg(struct bcm_pcib_softc *sc, uint32_t reg, uint32_t val)
169 {
170 
171 	bus_space_write_4(sc->base.base.bst, sc->base.base.bsh, reg,
172 	    htole32(val));
173 }
174 
175 static uint32_t
176 bcm_pcib_read_reg(struct bcm_pcib_softc *sc, uint32_t reg)
177 {
178 
179 	return (le32toh(bus_space_read_4(sc->base.base.bst, sc->base.base.bsh,
180 	    reg)));
181 }
182 
183 static void
184 bcm_pcib_reset_controller(struct bcm_pcib_softc *sc)
185 {
186 	uint32_t val;
187 
188 	val = bcm_pcib_read_reg(sc, REG_BRIDGE_CTRL);
189 	val = val | BRIDGE_RESET_FLAG | BRIDGE_DISABLE_FLAG;
190 	bcm_pcib_set_reg(sc, REG_BRIDGE_CTRL, val);
191 
192 	DELAY(100);
193 
194 	val = bcm_pcib_read_reg(sc, REG_BRIDGE_CTRL);
195 	val = val & ~BRIDGE_RESET_FLAG;
196 	bcm_pcib_set_reg(sc, REG_BRIDGE_CTRL, val);
197 
198 	DELAY(100);
199 
200 	bcm_pcib_set_reg(sc, REG_BRIDGE_SERDES_MODE, 0);
201 
202 	DELAY(100);
203 }
204 
205 static void
206 bcm_pcib_enable_controller(struct bcm_pcib_softc *sc)
207 {
208 	uint32_t val;
209 
210 	val = bcm_pcib_read_reg(sc, REG_BRIDGE_CTRL);
211 	val = val & ~BRIDGE_DISABLE_FLAG;
212 	bcm_pcib_set_reg(sc, REG_BRIDGE_CTRL, val);
213 
214 	DELAY(100);
215 }
216 
217 static int
218 bcm_pcib_check_ranges(device_t dev)
219 {
220 	struct bcm_pcib_softc *sc;
221 	struct pcie_range *ranges;
222 	int error = 0, i;
223 
224 	sc = device_get_softc(dev);
225 	ranges = &sc->base.base.ranges[0];
226 
227 	/* The first range needs to be non-zero. */
228 	if (ranges[0].size == 0) {
229 		device_printf(dev, "error: first outbound memory range "
230 		    "(pci addr: 0x%jx, cpu addr: 0x%jx) has zero size.\n",
231 		    ranges[0].pci_base, ranges[0].phys_base);
232 		error = ENXIO;
233 	}
234 
235 	/*
236 	 * The controller can actually handle three distinct ranges, but we
237 	 * only implement support for one.
238 	 */
239 	for (i = 1; (bootverbose || error) && i < MAX_RANGES_TUPLES; ++i) {
240 		if (ranges[i].size > 0)
241 			device_printf(dev,
242 			    "note: outbound memory range %d (pci addr: 0x%jx, "
243 			    "cpu addr: 0x%jx, size: 0x%jx) will be ignored.\n",
244 			    i, ranges[i].pci_base, ranges[i].phys_base,
245 			    ranges[i].size);
246 	}
247 
248 	return (error);
249 }
250 
251 static const char *
252 bcm_pcib_link_state_string(uint32_t mode)
253 {
254 
255 	switch(mode & PCIEM_LINK_STA_SPEED) {
256 	case 0:
257 		return ("not up");
258 	case 1:
259 		return ("2.5 GT/s");
260 	case 2:
261 		return ("5.0 GT/s");
262 	case 4:
263 		return ("8.0 GT/s");
264 	default:
265 		return ("unknown");
266 	}
267 }
268 
269 static bus_addr_t
270 bcm_get_offset_and_prepare_config(struct bcm_pcib_softc *sc, u_int bus,
271     u_int slot, u_int func, u_int reg)
272 {
273 	/*
274 	 * Config for an end point is only available through a narrow window for
275 	 * one end point at a time. We first tell the controller which end point
276 	 * we want, then access it through the window.
277 	 */
278 	uint32_t func_index;
279 
280 	if (bus == 0 && slot == 0 && func == 0)
281 		/*
282 		 * Special case for root device; its config is always available
283 		 * through the zero-offset.
284 		 */
285 		return (reg);
286 
287 	/* Tell the controller to show us the config in question. */
288 	func_index = PCIE_ADDR_OFFSET(bus, slot, func, 0);
289 	bcm_pcib_set_reg(sc, REG_EP_CONFIG_CHOICE, func_index);
290 
291 	return (REG_EP_CONFIG_DATA + reg);
292 }
293 
294 static bool
295 bcm_pcib_is_valid_quad(struct bcm_pcib_softc *sc, u_int bus, u_int slot,
296     u_int func, u_int reg)
297 {
298 
299 	if ((bus < sc->base.base.bus_start) || (bus > sc->base.base.bus_end))
300 		return (false);
301 	if ((slot > PCI_SLOTMAX) || (func > PCI_FUNCMAX) || (reg > PCIE_REGMAX))
302 		return (false);
303 
304 	if (bus == 0 && slot == 0 && func == 0)
305 		return (true);
306 	if (bus == 0)
307 		/*
308 		 * Probing other slots and funcs on bus 0 will lock up the
309 		 * memory controller.
310 		 */
311 		return (false);
312 
313 	return (true);
314 }
315 
316 static uint32_t
317 bcm_pcib_read_config(device_t dev, u_int bus, u_int slot, u_int func, u_int reg,
318     int bytes)
319 {
320 	struct bcm_pcib_softc *sc;
321 	bus_space_handle_t h;
322 	bus_space_tag_t	t;
323 	bus_addr_t offset;
324 	uint32_t data;
325 
326 	sc = device_get_softc(dev);
327 	if (!bcm_pcib_is_valid_quad(sc, bus, slot, func, reg))
328 		return (~0U);
329 
330 	mtx_lock(&sc->config_mtx);
331 	offset = bcm_get_offset_and_prepare_config(sc, bus, slot, func, reg);
332 
333 	t = sc->base.base.bst;
334 	h = sc->base.base.bsh;
335 
336 	switch (bytes) {
337 	case 1:
338 		data = bus_space_read_1(t, h, offset);
339 		break;
340 	case 2:
341 		data = le16toh(bus_space_read_2(t, h, offset));
342 		break;
343 	case 4:
344 		data = le32toh(bus_space_read_4(t, h, offset));
345 		break;
346 	default:
347 		data = ~0U;
348 		break;
349 	}
350 
351 	mtx_unlock(&sc->config_mtx);
352 	return (data);
353 }
354 
355 static void
356 bcm_pcib_write_config(device_t dev, u_int bus, u_int slot,
357     u_int func, u_int reg, uint32_t val, int bytes)
358 {
359 	struct bcm_pcib_softc *sc;
360 	bus_space_handle_t h;
361 	bus_space_tag_t	t;
362 	uint32_t offset;
363 
364 	sc = device_get_softc(dev);
365 	if (!bcm_pcib_is_valid_quad(sc, bus, slot, func, reg))
366 		return;
367 
368 	mtx_lock(&sc->config_mtx);
369 	offset = bcm_get_offset_and_prepare_config(sc, bus, slot, func, reg);
370 
371 	t = sc->base.base.bst;
372 	h = sc->base.base.bsh;
373 
374 	switch (bytes) {
375 	case 1:
376 		bus_space_write_1(t, h, offset, val);
377 		break;
378 	case 2:
379 		bus_space_write_2(t, h, offset, htole16(val));
380 		break;
381 	case 4:
382 		bus_space_write_4(t, h, offset, htole32(val));
383 		break;
384 	default:
385 		break;
386 	}
387 
388 	mtx_unlock(&sc->config_mtx);
389 }
390 
391 static void
392 bcm_pcib_msi_intr_process(struct bcm_pcib_softc *sc, uint32_t interrupt_bitmap,
393     struct trapframe *tf)
394 {
395 	struct bcm_pcib_irqsrc *irqsrc;
396 	uint32_t bit, irq;
397 
398 	while ((bit = ffs(interrupt_bitmap))) {
399 		irq = bit - 1;
400 
401 		/* Acknowledge interrupt. */
402 		bcm_pcib_set_reg(sc, REG_MSI_CLR, 1 << irq);
403 
404 		/* Send EOI. */
405 		bcm_pcib_set_reg(sc, REG_MSI_EOI, 1);
406 
407 		/* Despatch to handler. */
408 		irqsrc = &sc->msi_isrcs[irq];
409 		if (intr_isrc_dispatch(&irqsrc->isrc, tf))
410 			device_printf(sc->dev,
411 			    "note: unexpected interrupt (%d) triggered.\n",
412 			    irq);
413 
414 		/* Done with this interrupt. */
415 		interrupt_bitmap = interrupt_bitmap & ~(1 << irq);
416 	}
417 }
418 
419 static int
420 bcm_pcib_msi_intr(void *arg)
421 {
422 	struct bcm_pcib_softc *sc;
423 	struct trapframe *tf;
424 	uint32_t interrupt_bitmap;
425 
426 	sc = (struct bcm_pcib_softc *) arg;
427 	tf = curthread->td_intr_frame;
428 
429 	while ((interrupt_bitmap = bcm_pcib_read_reg(sc, REG_MSI_RAISED)))
430 		bcm_pcib_msi_intr_process(sc, interrupt_bitmap, tf);
431 
432 	return (FILTER_HANDLED);
433 }
434 
435 static int
436 bcm_pcib_alloc_msi(device_t dev, device_t child, int count, int maxcount,
437     device_t *pic, struct intr_irqsrc **srcs)
438 {
439 	struct bcm_pcib_softc *sc;
440 	int first_int, i;
441 
442 	sc = device_get_softc(dev);
443 	mtx_lock(&sc->msi_mtx);
444 
445 	/* Find a continguous region of free message-signalled interrupts. */
446 	for (first_int = 0; first_int + count < NUM_MSI; ) {
447 		for (i = first_int; i < first_int + count; ++i) {
448 			if (sc->msi_isrcs[i].allocated)
449 				goto next;
450 		}
451 		goto found;
452 next:
453 		first_int = i + 1;
454 	}
455 
456 	/* No appropriate region available. */
457 	mtx_unlock(&sc->msi_mtx);
458 	device_printf(dev, "warning: failed to allocate %d MSI messages.\n",
459 	    count);
460 	return (ENXIO);
461 
462 found:
463 	/* Mark the messages as in use. */
464 	for (i = 0; i < count; ++i) {
465 		sc->msi_isrcs[i + first_int].allocated = true;
466 		srcs[i] = &(sc->msi_isrcs[i + first_int].isrc);
467 	}
468 
469 	mtx_unlock(&sc->msi_mtx);
470 	*pic = device_get_parent(dev);
471 
472 	return (0);
473 }
474 
475 static int
476 bcm_pcib_map_msi(device_t dev, device_t child, struct intr_irqsrc *isrc,
477     uint64_t *addr, uint32_t *data)
478 {
479 	struct bcm_pcib_softc *sc;
480 	struct bcm_pcib_irqsrc *msi_msg;
481 
482 	sc = device_get_softc(dev);
483 	msi_msg = (struct bcm_pcib_irqsrc *) isrc;
484 
485 	*addr = sc->msi_addr;
486 	*data = (REG_VALUE_MSI_CONFIG & 0xffff) | msi_msg->irq;
487 	return (0);
488 }
489 
490 static int
491 bcm_pcib_release_msi(device_t dev, device_t child, int count,
492     struct intr_irqsrc **isrc)
493 {
494 	struct bcm_pcib_softc *sc;
495 	struct bcm_pcib_irqsrc *msi_isrc;
496 	int i;
497 
498 	sc = device_get_softc(dev);
499 	mtx_lock(&sc->msi_mtx);
500 
501 	for (i = 0; i < count; i++) {
502 		msi_isrc = (struct bcm_pcib_irqsrc *) isrc[i];
503 		msi_isrc->allocated = false;
504 	}
505 
506 	mtx_unlock(&sc->msi_mtx);
507 	return (0);
508 }
509 
510 static int
511 bcm_pcib_msi_attach(device_t dev)
512 {
513 	struct bcm_pcib_softc *sc;
514 	phandle_t node, xref;
515 	char const *bcm_name;
516 	int i, rid;
517 
518 	sc = device_get_softc(dev);
519 	sc->msi_addr = 0xffffffffc;
520 
521 	/* Clear any pending interrupts. */
522 	bcm_pcib_set_reg(sc, REG_MSI_CLR, 0xffffffff);
523 
524 	rid = 1;
525 	sc->msi_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
526 	    RF_ACTIVE);
527 	if (sc->msi_irq_res == NULL) {
528 		device_printf(dev, "could not allocate MSI irq resource.\n");
529 		return (ENXIO);
530 	}
531 
532 	sc->msi_isrcs = malloc(sizeof(*sc->msi_isrcs) * NUM_MSI, M_DEVBUF,
533 	    M_WAITOK | M_ZERO);
534 
535 	int error = bus_setup_intr(dev, sc->msi_irq_res, INTR_TYPE_BIO |
536 	    INTR_MPSAFE, bcm_pcib_msi_intr, NULL, sc, &sc->msi_intr_cookie);
537 	if (error) {
538 		device_printf(dev, "error: failed to setup MSI handler.\n");
539 		return (ENXIO);
540 	}
541 
542 	bcm_name = device_get_nameunit(dev);
543 	for (i = 0; i < NUM_MSI; i++) {
544 		sc->msi_isrcs[i].irq = i;
545 		error = intr_isrc_register(&sc->msi_isrcs[i].isrc, dev, 0,
546 		    "%s,%u", bcm_name, i);
547 		if (error) {
548 			device_printf(dev,
549 			"error: failed to register interrupt %d.\n", i);
550 			return (ENXIO);
551 		}
552 	}
553 
554 	node = ofw_bus_get_node(dev);
555 	xref = OF_xref_from_node(node);
556 	OF_device_register_xref(xref, dev);
557 
558 	error = intr_msi_register(dev, xref);
559 	if (error)
560 		return (ENXIO);
561 
562 	mtx_init(&sc->msi_mtx, "bcm_pcib: msi_mtx", NULL, MTX_DEF);
563 
564 	bcm_pcib_set_reg(sc, REG_MSI_MASK_CLR, 0xffffffff);
565 	bcm_pcib_set_reg(sc, REG_MSI_ADDR_LOW, (sc->msi_addr & 0xffffffff) | 1);
566 	bcm_pcib_set_reg(sc, REG_MSI_ADDR_HIGH, (sc->msi_addr >> 32));
567 	bcm_pcib_set_reg(sc, REG_MSI_CONFIG, REG_VALUE_MSI_CONFIG);
568 
569 	return (0);
570 }
571 
572 static void
573 bcm_pcib_relocate_bridge_window(device_t dev)
574 {
575 	/*
576 	 * In principle an out-of-bounds bridge window could be automatically
577 	 * adjusted at resource-activation time to lie within the bus address
578 	 * space by pcib_grow_window(), but that is not possible because the
579 	 * out-of-bounds resource allocation fails at allocation time. Instead,
580 	 * we will just fix up the window on the controller here, before it is
581 	 * re-discovered by pcib_probe_windows().
582 	 */
583 
584 	struct bcm_pcib_softc *sc;
585 	pci_addr_t base, size, new_base, new_limit;
586 	uint16_t val;
587 
588 	sc = device_get_softc(dev);
589 
590 	val = bcm_pcib_read_config(dev, 0, 0, 0, PCIR_MEMBASE_1, 2);
591 	base = PCI_PPBMEMBASE(0, val);
592 
593 	val = bcm_pcib_read_config(dev, 0, 0, 0, PCIR_MEMLIMIT_1, 2);
594 	size = PCI_PPBMEMLIMIT(0, val) - base;
595 
596 	new_base = sc->base.base.ranges[0].pci_base;
597 	val = (uint16_t) (new_base >> 16);
598 	bcm_pcib_write_config(dev, 0, 0, 0, PCIR_MEMBASE_1, val, 2);
599 
600 	new_limit = new_base + size;
601 	val = (uint16_t) (new_limit >> 16);
602 	bcm_pcib_write_config(dev, 0, 0, 0, PCIR_MEMLIMIT_1, val, 2);
603 }
604 
605 static uint32_t
606 encode_cpu_window_low(pci_addr_t phys_base, bus_size_t size)
607 {
608 
609 	return (((phys_base >> 0x10) & 0xfff0) |
610 	    ((phys_base + size - 1) & 0xfff00000));
611 }
612 
613 static uint32_t
614 encode_cpu_window_start_high(pci_addr_t phys_base)
615 {
616 
617 	return ((phys_base >> 0x20) & 0xff);
618 }
619 
620 static uint32_t
621 encode_cpu_window_end_high(pci_addr_t phys_base, bus_size_t size)
622 {
623 
624 	return (((phys_base + size - 1) >> 0x20) & 0xff);
625 }
626 
627 static int
628 bcm_pcib_attach(device_t dev)
629 {
630 	struct bcm_pcib_softc *sc;
631 	pci_addr_t phys_base, pci_base;
632 	bus_size_t size;
633 	uint32_t hardware_rev, bridge_state, link_state;
634 	int error, tries;
635 
636 	sc = device_get_softc(dev);
637 	sc->dev = dev;
638 
639 	/*
640 	 * This tag will be used in preference to the one created in
641 	 * pci_host_generic.c.
642 	 */
643 	error = bus_dma_tag_create(bus_get_dma_tag(dev), /* parent */
644 	    1, 0,				/* alignment, bounds */
645 	    DMA_HIGH_LIMIT,			/* lowaddr */
646 	    BUS_SPACE_MAXADDR,			/* highaddr */
647 	    NULL, NULL,				/* filter, filterarg */
648 	    DMA_HIGH_LIMIT,			/* maxsize */
649 	    BUS_SPACE_UNRESTRICTED,		/* nsegments */
650 	    DMA_HIGH_LIMIT,			/* maxsegsize */
651 	    0, 					/* flags */
652 	    NULL, NULL,				/* lockfunc, lockarg */
653 	    &sc->dmat);
654 	if (error)
655 		return (error);
656 
657 	error = pci_host_generic_setup_fdt(dev);
658 	if (error)
659 		return (error);
660 
661 	error = bcm_pcib_check_ranges(dev);
662 	if (error)
663 		return (error);
664 
665 	mtx_init(&sc->config_mtx, "bcm_pcib: config_mtx", NULL, MTX_DEF);
666 
667 	bcm_pcib_reset_controller(sc);
668 
669 	hardware_rev = bcm_pcib_read_reg(sc, REG_CONTROLLER_HW_REV) & 0xffff;
670 	device_printf(dev, "hardware identifies as revision 0x%x.\n",
671 	    hardware_rev);
672 
673 	/*
674 	 * Set PCI->CPU memory window. This encodes the inbound window showing
675 	 * the system memory to the controller.
676 	 */
677 	bcm_pcib_set_reg(sc, REG_DMA_WINDOW_LOW, REG_VALUE_DMA_WINDOW_LOW);
678 	bcm_pcib_set_reg(sc, REG_DMA_WINDOW_HIGH, REG_VALUE_DMA_WINDOW_HIGH);
679 	bcm_pcib_set_reg(sc, REG_DMA_CONFIG, REG_VALUE_DMA_WINDOW_CONFIG);
680 
681 	bcm_pcib_set_reg(sc, REG_BRIDGE_GISB_WINDOW, 0);
682 	bcm_pcib_set_reg(sc, REG_DMA_WINDOW_1, 0);
683 
684 	bcm_pcib_enable_controller(sc);
685 
686 	/* Wait for controller to start. */
687 	for(tries = 0; ; ++tries) {
688 		bridge_state = bcm_pcib_read_reg(sc, REG_BRIDGE_STATE);
689 
690 		if ((bridge_state & 0x30) == 0x30)
691 			/* Controller ready. */
692 			break;
693 
694 		if (tries > 100) {
695 			device_printf(dev,
696 			    "error: controller failed to start.\n");
697 			return (ENXIO);
698 		}
699 
700 		DELAY(1000);
701 	}
702 
703 	link_state = bcm_pcib_read_reg(sc, REG_BRIDGE_LINK_STATE) >> 0x10;
704 	if (!link_state) {
705 		device_printf(dev, "error: controller started but link is not "
706 		    "up.\n");
707 		return (ENXIO);
708 	}
709 	if (bootverbose)
710 		device_printf(dev, "note: reported link speed is %s.\n",
711 		    bcm_pcib_link_state_string(link_state));
712 
713 	/*
714 	 * Set the CPU->PCI memory window. The map in this direction is not 1:1.
715 	 * Addresses seen by the CPU need to be adjusted to make sense to the
716 	 * controller as they pass through the window.
717 	 */
718 	pci_base  = sc->base.base.ranges[0].pci_base;
719 	phys_base = sc->base.base.ranges[0].phys_base;
720 	size      = sc->base.base.ranges[0].size;
721 
722 	bcm_pcib_set_reg(sc, REG_BUS_WINDOW_LOW, pci_base & 0xffffffff);
723 	bcm_pcib_set_reg(sc, REG_BUS_WINDOW_HIGH, pci_base >> 32);
724 
725 	bcm_pcib_set_reg(sc, REG_CPU_WINDOW_LOW,
726 	    encode_cpu_window_low(phys_base, size));
727 	bcm_pcib_set_reg(sc, REG_CPU_WINDOW_START_HIGH,
728 	    encode_cpu_window_start_high(phys_base));
729 	bcm_pcib_set_reg(sc, REG_CPU_WINDOW_END_HIGH,
730 	    encode_cpu_window_end_high(phys_base, size));
731 
732 	/*
733 	 * The controller starts up declaring itself an endpoint; readvertise it
734 	 * as a bridge.
735 	 */
736 	bcm_pcib_set_reg(sc, PCI_ID_VAL3,
737 	    PCIC_BRIDGE << CLASS_SHIFT | PCIS_BRIDGE_PCI << SUBCLASS_SHIFT);
738 
739 	bcm_pcib_set_reg(sc, REG_BRIDGE_SERDES_MODE, 0x2);
740 	DELAY(100);
741 
742 	bcm_pcib_relocate_bridge_window(dev);
743 
744 	/* Configure interrupts. */
745 	error = bcm_pcib_msi_attach(dev);
746 	if (error)
747 		return (error);
748 
749 	/* Done. */
750 	device_add_child(dev, "pci", -1);
751 	return (bus_generic_attach(dev));
752 }
753 
754 /*
755  * Device method table.
756  */
757 static device_method_t bcm_pcib_methods[] = {
758 	/* Bus interface. */
759 	DEVMETHOD(bus_get_dma_tag,		bcm_pcib_get_dma_tag),
760 
761 	/* Device interface. */
762 	DEVMETHOD(device_probe,			bcm_pcib_probe),
763 	DEVMETHOD(device_attach,		bcm_pcib_attach),
764 
765 	/* PCIB interface. */
766 	DEVMETHOD(pcib_read_config,		bcm_pcib_read_config),
767 	DEVMETHOD(pcib_write_config,		bcm_pcib_write_config),
768 
769 	/* MSI interface. */
770 	DEVMETHOD(msi_alloc_msi,		bcm_pcib_alloc_msi),
771 	DEVMETHOD(msi_release_msi,		bcm_pcib_release_msi),
772 	DEVMETHOD(msi_map_msi,			bcm_pcib_map_msi),
773 
774 	DEVMETHOD_END
775 };
776 
777 DEFINE_CLASS_1(pcib, bcm_pcib_driver, bcm_pcib_methods,
778     sizeof(struct bcm_pcib_softc), generic_pcie_fdt_driver);
779 
780 static devclass_t bcm_pcib_devclass;
781 DRIVER_MODULE(bcm_pcib, simplebus, bcm_pcib_driver, bcm_pcib_devclass, 0, 0);
782 
783