xref: /openbmc/linux/arch/mips/pci/pci-xtalk-bridge.c (revision c4f7ac64)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2003 Christoph Hellwig (hch@lst.de)
4  * Copyright (C) 1999, 2000, 04 Ralf Baechle (ralf@linux-mips.org)
5  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
6  */
7 #include <linux/kernel.h>
8 #include <linux/export.h>
9 #include <linux/pci.h>
10 #include <linux/smp.h>
11 #include <linux/dma-direct.h>
12 #include <linux/platform_device.h>
13 #include <linux/platform_data/xtalk-bridge.h>
14 #include <linux/nvmem-consumer.h>
15 #include <linux/crc16.h>
16 
17 #include <asm/pci/bridge.h>
18 #include <asm/paccess.h>
19 #include <asm/sn/irq_alloc.h>
20 #include <asm/sn/ioc3.h>
21 
22 #define CRC16_INIT	0
23 #define CRC16_VALID	0xb001
24 
25 /*
26  * Common phys<->dma mapping for platforms using pci xtalk bridge
27  */
28 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
29 {
30 	struct pci_dev *pdev = to_pci_dev(dev);
31 	struct bridge_controller *bc = BRIDGE_CONTROLLER(pdev->bus);
32 
33 	return bc->baddr + paddr;
34 }
35 
36 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
37 {
38 	return dma_addr & ~(0xffUL << 56);
39 }
40 
41 /*
42  * Most of the IOC3 PCI config register aren't present
43  * we emulate what is needed for a normal PCI enumeration
44  */
45 static int ioc3_cfg_rd(void *addr, int where, int size, u32 *value, u32 sid)
46 {
47 	u32 cf, shift, mask;
48 
49 	switch (where & ~3) {
50 	case 0x00 ... 0x10:
51 	case 0x40 ... 0x44:
52 		if (get_dbe(cf, (u32 *)addr))
53 			return PCIBIOS_DEVICE_NOT_FOUND;
54 		break;
55 	case 0x2c:
56 		cf = sid;
57 		break;
58 	case 0x3c:
59 		/* emulate sane interrupt pin value */
60 		cf = 0x00000100;
61 		break;
62 	default:
63 		cf = 0;
64 		break;
65 	}
66 	shift = (where & 3) << 3;
67 	mask = 0xffffffffU >> ((4 - size) << 3);
68 	*value = (cf >> shift) & mask;
69 
70 	return PCIBIOS_SUCCESSFUL;
71 }
72 
73 static int ioc3_cfg_wr(void *addr, int where, int size, u32 value)
74 {
75 	u32 cf, shift, mask, smask;
76 
77 	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
78 		return PCIBIOS_SUCCESSFUL;
79 
80 	if (get_dbe(cf, (u32 *)addr))
81 		return PCIBIOS_DEVICE_NOT_FOUND;
82 
83 	shift = ((where & 3) << 3);
84 	mask = (0xffffffffU >> ((4 - size) << 3));
85 	smask = mask << shift;
86 
87 	cf = (cf & ~smask) | ((value & mask) << shift);
88 	if (put_dbe(cf, (u32 *)addr))
89 		return PCIBIOS_DEVICE_NOT_FOUND;
90 
91 	return PCIBIOS_SUCCESSFUL;
92 }
93 
94 static void bridge_disable_swapping(struct pci_dev *dev)
95 {
96 	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
97 	int slot = PCI_SLOT(dev->devfn);
98 
99 	/* Turn off byte swapping */
100 	bridge_clr(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
101 	bridge_read(bc, b_widget.w_tflush);	/* Flush */
102 }
103 
104 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
105 	bridge_disable_swapping);
106 
107 
108 /*
109  * The Bridge ASIC supports both type 0 and type 1 access.  Type 1 is
110  * not really documented, so right now I can't write code which uses it.
111  * Therefore we use type 0 accesses for now even though they won't work
112  * correctly for PCI-to-PCI bridges.
113  *
114  * The function is complicated by the ultimate brokenness of the IOC3 chip
115  * which is used in SGI systems.  The IOC3 can only handle 32-bit PCI
116  * accesses and does only decode parts of it's address space.
117  */
118 static int pci_conf0_read_config(struct pci_bus *bus, unsigned int devfn,
119 				 int where, int size, u32 *value)
120 {
121 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
122 	struct bridge_regs *bridge = bc->base;
123 	int slot = PCI_SLOT(devfn);
124 	int fn = PCI_FUNC(devfn);
125 	void *addr;
126 	u32 cf;
127 	int res;
128 
129 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
130 	if (get_dbe(cf, (u32 *)addr))
131 		return PCIBIOS_DEVICE_NOT_FOUND;
132 
133 	/*
134 	 * IOC3 is broken beyond belief ...  Don't even give the
135 	 * generic PCI code a chance to look at it for real ...
136 	 */
137 	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16))) {
138 		addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
139 		return ioc3_cfg_rd(addr, where, size, value,
140 				   bc->ioc3_sid[slot]);
141 	}
142 
143 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
144 
145 	if (size == 1)
146 		res = get_dbe(*value, (u8 *)addr);
147 	else if (size == 2)
148 		res = get_dbe(*value, (u16 *)addr);
149 	else
150 		res = get_dbe(*value, (u32 *)addr);
151 
152 	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
153 }
154 
155 static int pci_conf1_read_config(struct pci_bus *bus, unsigned int devfn,
156 				 int where, int size, u32 *value)
157 {
158 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
159 	struct bridge_regs *bridge = bc->base;
160 	int busno = bus->number;
161 	int slot = PCI_SLOT(devfn);
162 	int fn = PCI_FUNC(devfn);
163 	void *addr;
164 	u32 cf;
165 	int res;
166 
167 	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
168 	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
169 	if (get_dbe(cf, (u32 *)addr))
170 		return PCIBIOS_DEVICE_NOT_FOUND;
171 
172 	/*
173 	 * IOC3 is broken beyond belief ...  Don't even give the
174 	 * generic PCI code a chance to look at it for real ...
175 	 */
176 	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16))) {
177 		addr = &bridge->b_type1_cfg.c[(fn << 8) | (where & ~3)];
178 		return ioc3_cfg_rd(addr, where, size, value,
179 				   bc->ioc3_sid[slot]);
180 	}
181 
182 	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
183 
184 	if (size == 1)
185 		res = get_dbe(*value, (u8 *)addr);
186 	else if (size == 2)
187 		res = get_dbe(*value, (u16 *)addr);
188 	else
189 		res = get_dbe(*value, (u32 *)addr);
190 
191 	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
192 }
193 
194 static int pci_read_config(struct pci_bus *bus, unsigned int devfn,
195 			   int where, int size, u32 *value)
196 {
197 	if (!pci_is_root_bus(bus))
198 		return pci_conf1_read_config(bus, devfn, where, size, value);
199 
200 	return pci_conf0_read_config(bus, devfn, where, size, value);
201 }
202 
203 static int pci_conf0_write_config(struct pci_bus *bus, unsigned int devfn,
204 				  int where, int size, u32 value)
205 {
206 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
207 	struct bridge_regs *bridge = bc->base;
208 	int slot = PCI_SLOT(devfn);
209 	int fn = PCI_FUNC(devfn);
210 	void *addr;
211 	u32 cf;
212 	int res;
213 
214 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
215 	if (get_dbe(cf, (u32 *)addr))
216 		return PCIBIOS_DEVICE_NOT_FOUND;
217 
218 	/*
219 	 * IOC3 is broken beyond belief ...  Don't even give the
220 	 * generic PCI code a chance to look at it for real ...
221 	 */
222 	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16))) {
223 		addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
224 		return ioc3_cfg_wr(addr, where, size, value);
225 	}
226 
227 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
228 
229 	if (size == 1)
230 		res = put_dbe(value, (u8 *)addr);
231 	else if (size == 2)
232 		res = put_dbe(value, (u16 *)addr);
233 	else
234 		res = put_dbe(value, (u32 *)addr);
235 
236 	if (res)
237 		return PCIBIOS_DEVICE_NOT_FOUND;
238 
239 	return PCIBIOS_SUCCESSFUL;
240 }
241 
242 static int pci_conf1_write_config(struct pci_bus *bus, unsigned int devfn,
243 				  int where, int size, u32 value)
244 {
245 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
246 	struct bridge_regs *bridge = bc->base;
247 	int slot = PCI_SLOT(devfn);
248 	int fn = PCI_FUNC(devfn);
249 	int busno = bus->number;
250 	void *addr;
251 	u32 cf;
252 	int res;
253 
254 	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
255 	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
256 	if (get_dbe(cf, (u32 *)addr))
257 		return PCIBIOS_DEVICE_NOT_FOUND;
258 
259 	/*
260 	 * IOC3 is broken beyond belief ...  Don't even give the
261 	 * generic PCI code a chance to look at it for real ...
262 	 */
263 	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16))) {
264 		addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
265 		return ioc3_cfg_wr(addr, where, size, value);
266 	}
267 
268 	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
269 
270 	if (size == 1)
271 		res = put_dbe(value, (u8 *)addr);
272 	else if (size == 2)
273 		res = put_dbe(value, (u16 *)addr);
274 	else
275 		res = put_dbe(value, (u32 *)addr);
276 
277 	if (res)
278 		return PCIBIOS_DEVICE_NOT_FOUND;
279 
280 	return PCIBIOS_SUCCESSFUL;
281 }
282 
283 static int pci_write_config(struct pci_bus *bus, unsigned int devfn,
284 	int where, int size, u32 value)
285 {
286 	if (!pci_is_root_bus(bus))
287 		return pci_conf1_write_config(bus, devfn, where, size, value);
288 
289 	return pci_conf0_write_config(bus, devfn, where, size, value);
290 }
291 
292 static struct pci_ops bridge_pci_ops = {
293 	.read	 = pci_read_config,
294 	.write	 = pci_write_config,
295 };
296 
297 struct bridge_irq_chip_data {
298 	struct bridge_controller *bc;
299 	nasid_t nasid;
300 };
301 
302 static int bridge_set_affinity(struct irq_data *d, const struct cpumask *mask,
303 			       bool force)
304 {
305 #ifdef CONFIG_NUMA
306 	struct bridge_irq_chip_data *data = d->chip_data;
307 	int bit = d->parent_data->hwirq;
308 	int pin = d->hwirq;
309 	int ret, cpu;
310 
311 	ret = irq_chip_set_affinity_parent(d, mask, force);
312 	if (ret >= 0) {
313 		cpu = cpumask_first_and(mask, cpu_online_mask);
314 		data->nasid = cpu_to_node(cpu);
315 		bridge_write(data->bc, b_int_addr[pin].addr,
316 			     (((data->bc->intr_addr >> 30) & 0x30000) |
317 			      bit | (data->nasid << 8)));
318 		bridge_read(data->bc, b_wid_tflush);
319 	}
320 	return ret;
321 #else
322 	return irq_chip_set_affinity_parent(d, mask, force);
323 #endif
324 }
325 
326 struct irq_chip bridge_irq_chip = {
327 	.name             = "BRIDGE",
328 	.irq_mask         = irq_chip_mask_parent,
329 	.irq_unmask       = irq_chip_unmask_parent,
330 	.irq_set_affinity = bridge_set_affinity
331 };
332 
333 static int bridge_domain_alloc(struct irq_domain *domain, unsigned int virq,
334 			       unsigned int nr_irqs, void *arg)
335 {
336 	struct bridge_irq_chip_data *data;
337 	struct irq_alloc_info *info = arg;
338 	int ret;
339 
340 	if (nr_irqs > 1 || !info)
341 		return -EINVAL;
342 
343 	data = kzalloc(sizeof(*data), GFP_KERNEL);
344 	if (!data)
345 		return -ENOMEM;
346 
347 	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
348 	if (ret >= 0) {
349 		data->bc = info->ctrl;
350 		data->nasid = info->nasid;
351 		irq_domain_set_info(domain, virq, info->pin, &bridge_irq_chip,
352 				    data, handle_level_irq, NULL, NULL);
353 	} else {
354 		kfree(data);
355 	}
356 
357 	return ret;
358 }
359 
360 static void bridge_domain_free(struct irq_domain *domain, unsigned int virq,
361 			       unsigned int nr_irqs)
362 {
363 	struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
364 
365 	if (nr_irqs)
366 		return;
367 
368 	kfree(irqd->chip_data);
369 	irq_domain_free_irqs_top(domain, virq, nr_irqs);
370 }
371 
372 static int bridge_domain_activate(struct irq_domain *domain,
373 				  struct irq_data *irqd, bool reserve)
374 {
375 	struct bridge_irq_chip_data *data = irqd->chip_data;
376 	struct bridge_controller *bc = data->bc;
377 	int bit = irqd->parent_data->hwirq;
378 	int pin = irqd->hwirq;
379 	u32 device;
380 
381 	bridge_write(bc, b_int_addr[pin].addr,
382 		     (((bc->intr_addr >> 30) & 0x30000) |
383 		      bit | (data->nasid << 8)));
384 	bridge_set(bc, b_int_enable, (1 << pin));
385 	bridge_set(bc, b_int_enable, 0x7ffffe00); /* more stuff in int_enable */
386 
387 	/*
388 	 * Enable sending of an interrupt clear packet to the hub on a high to
389 	 * low transition of the interrupt pin.
390 	 *
391 	 * IRIX sets additional bits in the address which are documented as
392 	 * reserved in the bridge docs.
393 	 */
394 	bridge_set(bc, b_int_mode, (1UL << pin));
395 
396 	/*
397 	 * We assume the bridge to have a 1:1 mapping between devices
398 	 * (slots) and intr pins.
399 	 */
400 	device = bridge_read(bc, b_int_device);
401 	device &= ~(7 << (pin*3));
402 	device |= (pin << (pin*3));
403 	bridge_write(bc, b_int_device, device);
404 
405 	bridge_read(bc, b_wid_tflush);
406 	return 0;
407 }
408 
409 static void bridge_domain_deactivate(struct irq_domain *domain,
410 				     struct irq_data *irqd)
411 {
412 	struct bridge_irq_chip_data *data = irqd->chip_data;
413 
414 	bridge_clr(data->bc, b_int_enable, (1 << irqd->hwirq));
415 	bridge_read(data->bc, b_wid_tflush);
416 }
417 
418 static const struct irq_domain_ops bridge_domain_ops = {
419 	.alloc      = bridge_domain_alloc,
420 	.free       = bridge_domain_free,
421 	.activate   = bridge_domain_activate,
422 	.deactivate = bridge_domain_deactivate
423 };
424 
425 /*
426  * All observed requests have pin == 1. We could have a global here, that
427  * gets incremented and returned every time - unfortunately, pci_map_irq
428  * may be called on the same device over and over, and need to return the
429  * same value. On O2000, pin can be 0 or 1, and PCI slots can be [0..7].
430  *
431  * A given PCI device, in general, should be able to intr any of the cpus
432  * on any one of the hubs connected to its xbow.
433  */
434 static int bridge_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
435 {
436 	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
437 	struct irq_alloc_info info;
438 	int irq;
439 
440 	switch (pin) {
441 	case PCI_INTERRUPT_UNKNOWN:
442 	case PCI_INTERRUPT_INTA:
443 	case PCI_INTERRUPT_INTC:
444 		pin = 0;
445 		break;
446 	case PCI_INTERRUPT_INTB:
447 	case PCI_INTERRUPT_INTD:
448 		pin = 1;
449 	}
450 
451 	irq = bc->pci_int[slot][pin];
452 	if (irq == -1) {
453 		info.ctrl = bc;
454 		info.nasid = bc->nasid;
455 		info.pin = bc->int_mapping[slot][pin];
456 
457 		irq = irq_domain_alloc_irqs(bc->domain, 1, bc->nasid, &info);
458 		if (irq < 0)
459 			return irq;
460 
461 		bc->pci_int[slot][pin] = irq;
462 	}
463 	return irq;
464 }
465 
466 #define IOC3_SID(sid)	(PCI_VENDOR_ID_SGI | ((sid) << 16))
467 
468 static void bridge_setup_ip27_baseio6g(struct bridge_controller *bc)
469 {
470 	bc->ioc3_sid[2] = IOC3_SID(IOC3_SUBSYS_IP27_BASEIO6G);
471 	bc->ioc3_sid[6] = IOC3_SID(IOC3_SUBSYS_IP27_MIO);
472 	bc->int_mapping[2][1] = 4;
473 	bc->int_mapping[6][1] = 6;
474 }
475 
476 static void bridge_setup_ip27_baseio(struct bridge_controller *bc)
477 {
478 	bc->ioc3_sid[2] = IOC3_SID(IOC3_SUBSYS_IP27_BASEIO);
479 	bc->int_mapping[2][1] = 4;
480 }
481 
482 static void bridge_setup_ip29_baseio(struct bridge_controller *bc)
483 {
484 	bc->ioc3_sid[2] = IOC3_SID(IOC3_SUBSYS_IP29_SYSBOARD);
485 	bc->int_mapping[2][1] = 3;
486 }
487 
488 static void bridge_setup_ip30_sysboard(struct bridge_controller *bc)
489 {
490 	bc->ioc3_sid[2] = IOC3_SID(IOC3_SUBSYS_IP30_SYSBOARD);
491 	bc->int_mapping[2][1] = 4;
492 }
493 
494 static void bridge_setup_menet(struct bridge_controller *bc)
495 {
496 	bc->ioc3_sid[0] = IOC3_SID(IOC3_SUBSYS_MENET);
497 	bc->ioc3_sid[1] = IOC3_SID(IOC3_SUBSYS_MENET);
498 	bc->ioc3_sid[2] = IOC3_SID(IOC3_SUBSYS_MENET);
499 	bc->ioc3_sid[3] = IOC3_SID(IOC3_SUBSYS_MENET4);
500 }
501 
502 static void bridge_setup_io7(struct bridge_controller *bc)
503 {
504 	bc->ioc3_sid[4] = IOC3_SID(IOC3_SUBSYS_IO7);
505 }
506 
507 static void bridge_setup_io8(struct bridge_controller *bc)
508 {
509 	bc->ioc3_sid[4] = IOC3_SID(IOC3_SUBSYS_IO8);
510 }
511 
512 static void bridge_setup_io9(struct bridge_controller *bc)
513 {
514 	bc->ioc3_sid[1] = IOC3_SID(IOC3_SUBSYS_IO9);
515 }
516 
517 static void bridge_setup_ip34_fuel_sysboard(struct bridge_controller *bc)
518 {
519 	bc->ioc3_sid[4] = IOC3_SID(IOC3_SUBSYS_IP34_SYSBOARD);
520 }
521 
522 #define BRIDGE_BOARD_SETUP(_partno, _setup)	\
523 	{ .match = _partno, .setup = _setup }
524 
525 static const struct {
526 	char *match;
527 	void (*setup)(struct bridge_controller *bc);
528 } bridge_ioc3_devid[] = {
529 	BRIDGE_BOARD_SETUP("030-0734-", bridge_setup_ip27_baseio6g),
530 	BRIDGE_BOARD_SETUP("030-0880-", bridge_setup_ip27_baseio6g),
531 	BRIDGE_BOARD_SETUP("030-1023-", bridge_setup_ip27_baseio),
532 	BRIDGE_BOARD_SETUP("030-1124-", bridge_setup_ip27_baseio),
533 	BRIDGE_BOARD_SETUP("030-1025-", bridge_setup_ip29_baseio),
534 	BRIDGE_BOARD_SETUP("030-1244-", bridge_setup_ip29_baseio),
535 	BRIDGE_BOARD_SETUP("030-1389-", bridge_setup_ip29_baseio),
536 	BRIDGE_BOARD_SETUP("030-0887-", bridge_setup_ip30_sysboard),
537 	BRIDGE_BOARD_SETUP("030-1467-", bridge_setup_ip30_sysboard),
538 	BRIDGE_BOARD_SETUP("030-0873-", bridge_setup_menet),
539 	BRIDGE_BOARD_SETUP("030-1557-", bridge_setup_io7),
540 	BRIDGE_BOARD_SETUP("030-1673-", bridge_setup_io8),
541 	BRIDGE_BOARD_SETUP("030-1771-", bridge_setup_io9),
542 	BRIDGE_BOARD_SETUP("030-1707-", bridge_setup_ip34_fuel_sysboard),
543 };
544 
545 static void bridge_setup_board(struct bridge_controller *bc, char *partnum)
546 {
547 	int i;
548 
549 	for (i = 0; i < ARRAY_SIZE(bridge_ioc3_devid); i++)
550 		if (!strncmp(partnum, bridge_ioc3_devid[i].match,
551 			     strlen(bridge_ioc3_devid[i].match))) {
552 			bridge_ioc3_devid[i].setup(bc);
553 		}
554 }
555 
556 static int bridge_nvmem_match(struct device *dev, const void *data)
557 {
558 	const char *name = dev_name(dev);
559 	const char *prefix = data;
560 
561 	if (strlen(name) < strlen(prefix))
562 		return 0;
563 
564 	return memcmp(prefix, dev_name(dev), strlen(prefix)) == 0;
565 }
566 
567 static int bridge_get_partnum(u64 baddr, char *partnum)
568 {
569 	struct nvmem_device *nvmem;
570 	char prefix[24];
571 	u8 prom[64];
572 	int i, j;
573 	int ret;
574 
575 	snprintf(prefix, sizeof(prefix), "bridge-%012llx-0b-", baddr);
576 
577 	nvmem = nvmem_device_find(prefix, bridge_nvmem_match);
578 	if (IS_ERR(nvmem))
579 		return PTR_ERR(nvmem);
580 
581 	ret = nvmem_device_read(nvmem, 0, 64, prom);
582 	nvmem_device_put(nvmem);
583 
584 	if (ret != 64)
585 		return ret;
586 
587 	if (crc16(CRC16_INIT, prom, 32) != CRC16_VALID ||
588 	    crc16(CRC16_INIT, prom + 32, 32) != CRC16_VALID)
589 		return -EINVAL;
590 
591 	/* Assemble part number */
592 	j = 0;
593 	for (i = 0; i < 19; i++)
594 		if (prom[i + 11] != ' ')
595 			partnum[j++] = prom[i + 11];
596 
597 	for (i = 0; i < 6; i++)
598 		if (prom[i + 32] != ' ')
599 			partnum[j++] = prom[i + 32];
600 
601 	partnum[j] = 0;
602 
603 	return 0;
604 }
605 
606 static int bridge_probe(struct platform_device *pdev)
607 {
608 	struct xtalk_bridge_platform_data *bd = dev_get_platdata(&pdev->dev);
609 	struct device *dev = &pdev->dev;
610 	struct bridge_controller *bc;
611 	struct pci_host_bridge *host;
612 	struct irq_domain *domain, *parent;
613 	struct fwnode_handle *fn;
614 	char partnum[26];
615 	int slot;
616 	int err;
617 
618 	/* get part number from one wire prom */
619 	if (bridge_get_partnum(virt_to_phys((void *)bd->bridge_addr), partnum))
620 		return -EPROBE_DEFER; /* not available yet */
621 
622 	parent = irq_get_default_host();
623 	if (!parent)
624 		return -ENODEV;
625 	fn = irq_domain_alloc_named_fwnode("BRIDGE");
626 	if (!fn)
627 		return -ENOMEM;
628 	domain = irq_domain_create_hierarchy(parent, 0, 8, fn,
629 					     &bridge_domain_ops, NULL);
630 	if (!domain) {
631 		irq_domain_free_fwnode(fn);
632 		return -ENOMEM;
633 	}
634 
635 	pci_set_flags(PCI_PROBE_ONLY);
636 
637 	host = devm_pci_alloc_host_bridge(dev, sizeof(*bc));
638 	if (!host) {
639 		err = -ENOMEM;
640 		goto err_remove_domain;
641 	}
642 
643 	bc = pci_host_bridge_priv(host);
644 
645 	bc->busn.name		= "Bridge PCI busn";
646 	bc->busn.start		= 0;
647 	bc->busn.end		= 0xff;
648 	bc->busn.flags		= IORESOURCE_BUS;
649 
650 	bc->domain		= domain;
651 
652 	pci_add_resource_offset(&host->windows, &bd->mem, bd->mem_offset);
653 	pci_add_resource_offset(&host->windows, &bd->io, bd->io_offset);
654 	pci_add_resource(&host->windows, &bc->busn);
655 
656 	err = devm_request_pci_bus_resources(dev, &host->windows);
657 	if (err < 0)
658 		goto err_free_resource;
659 
660 	bc->nasid = bd->nasid;
661 
662 	bc->baddr = (u64)bd->masterwid << 60 | PCI64_ATTR_BAR;
663 	bc->base = (struct bridge_regs *)bd->bridge_addr;
664 	bc->intr_addr = bd->intr_addr;
665 
666 	/*
667 	 * Clear all pending interrupts.
668 	 */
669 	bridge_write(bc, b_int_rst_stat, BRIDGE_IRR_ALL_CLR);
670 
671 	/*
672 	 * Until otherwise set up, assume all interrupts are from slot 0
673 	 */
674 	bridge_write(bc, b_int_device, 0x0);
675 
676 	/*
677 	 * disable swapping for big windows
678 	 */
679 	bridge_clr(bc, b_wid_control,
680 		   BRIDGE_CTRL_IO_SWAP | BRIDGE_CTRL_MEM_SWAP);
681 #ifdef CONFIG_PAGE_SIZE_4KB
682 	bridge_clr(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
683 #else /* 16kB or larger */
684 	bridge_set(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
685 #endif
686 
687 	/*
688 	 * Hmm...  IRIX sets additional bits in the address which
689 	 * are documented as reserved in the bridge docs.
690 	 */
691 	bridge_write(bc, b_wid_int_upper,
692 		     ((bc->intr_addr >> 32) & 0xffff) | (bd->masterwid << 16));
693 	bridge_write(bc, b_wid_int_lower, bc->intr_addr & 0xffffffff);
694 	bridge_write(bc, b_dir_map, (bd->masterwid << 20));	/* DMA */
695 	bridge_write(bc, b_int_enable, 0);
696 
697 	for (slot = 0; slot < 8; slot++) {
698 		bridge_set(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
699 		bc->pci_int[slot][0] = -1;
700 		bc->pci_int[slot][1] = -1;
701 		/* default interrupt pin mapping */
702 		bc->int_mapping[slot][0] = slot;
703 		bc->int_mapping[slot][1] = slot ^ 4;
704 	}
705 	bridge_read(bc, b_wid_tflush);	  /* wait until Bridge PIO complete */
706 
707 	bridge_setup_board(bc, partnum);
708 
709 	host->dev.parent = dev;
710 	host->sysdata = bc;
711 	host->busnr = 0;
712 	host->ops = &bridge_pci_ops;
713 	host->map_irq = bridge_map_irq;
714 	host->swizzle_irq = pci_common_swizzle;
715 
716 	err = pci_scan_root_bus_bridge(host);
717 	if (err < 0)
718 		goto err_free_resource;
719 
720 	pci_bus_claim_resources(host->bus);
721 	pci_bus_add_devices(host->bus);
722 
723 	platform_set_drvdata(pdev, host->bus);
724 
725 	return 0;
726 
727 err_free_resource:
728 	pci_free_resource_list(&host->windows);
729 err_remove_domain:
730 	irq_domain_remove(domain);
731 	irq_domain_free_fwnode(fn);
732 	return err;
733 }
734 
735 static int bridge_remove(struct platform_device *pdev)
736 {
737 	struct pci_bus *bus = platform_get_drvdata(pdev);
738 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
739 	struct fwnode_handle *fn = bc->domain->fwnode;
740 
741 	irq_domain_remove(bc->domain);
742 	irq_domain_free_fwnode(fn);
743 	pci_lock_rescan_remove();
744 	pci_stop_root_bus(bus);
745 	pci_remove_root_bus(bus);
746 	pci_unlock_rescan_remove();
747 
748 	return 0;
749 }
750 
751 static struct platform_driver bridge_driver = {
752 	.probe  = bridge_probe,
753 	.remove = bridge_remove,
754 	.driver = {
755 		.name = "xtalk-bridge",
756 	}
757 };
758 
759 builtin_platform_driver(bridge_driver);
760