xref: /openbmc/linux/arch/mips/pci/pci-xtalk-bridge.c (revision b830f94f)
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 
15 #include <asm/pci/bridge.h>
16 #include <asm/paccess.h>
17 #include <asm/sn/irq_alloc.h>
18 
19 /*
20  * Most of the IOC3 PCI config register aren't present
21  * we emulate what is needed for a normal PCI enumeration
22  */
23 static u32 emulate_ioc3_cfg(int where, int size)
24 {
25 	if (size == 1 && where == 0x3d)
26 		return 0x01;
27 	else if (size == 2 && where == 0x3c)
28 		return 0x0100;
29 	else if (size == 4 && where == 0x3c)
30 		return 0x00000100;
31 
32 	return 0;
33 }
34 
35 static void bridge_disable_swapping(struct pci_dev *dev)
36 {
37 	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
38 	int slot = PCI_SLOT(dev->devfn);
39 
40 	/* Turn off byte swapping */
41 	bridge_clr(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
42 	bridge_read(bc, b_widget.w_tflush);	/* Flush */
43 }
44 
45 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
46 	bridge_disable_swapping);
47 
48 
49 /*
50  * The Bridge ASIC supports both type 0 and type 1 access.  Type 1 is
51  * not really documented, so right now I can't write code which uses it.
52  * Therefore we use type 0 accesses for now even though they won't work
53  * correctly for PCI-to-PCI bridges.
54  *
55  * The function is complicated by the ultimate brokenness of the IOC3 chip
56  * which is used in SGI systems.  The IOC3 can only handle 32-bit PCI
57  * accesses and does only decode parts of it's address space.
58  */
59 static int pci_conf0_read_config(struct pci_bus *bus, unsigned int devfn,
60 				 int where, int size, u32 *value)
61 {
62 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
63 	struct bridge_regs *bridge = bc->base;
64 	int slot = PCI_SLOT(devfn);
65 	int fn = PCI_FUNC(devfn);
66 	void *addr;
67 	u32 cf, shift, mask;
68 	int res;
69 
70 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
71 	if (get_dbe(cf, (u32 *)addr))
72 		return PCIBIOS_DEVICE_NOT_FOUND;
73 
74 	/*
75 	 * IOC3 is broken beyond belief ...  Don't even give the
76 	 * generic PCI code a chance to look at it for real ...
77 	 */
78 	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
79 		goto is_ioc3;
80 
81 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
82 
83 	if (size == 1)
84 		res = get_dbe(*value, (u8 *)addr);
85 	else if (size == 2)
86 		res = get_dbe(*value, (u16 *)addr);
87 	else
88 		res = get_dbe(*value, (u32 *)addr);
89 
90 	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
91 
92 is_ioc3:
93 
94 	/*
95 	 * IOC3 special handling
96 	 */
97 	if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
98 		*value = emulate_ioc3_cfg(where, size);
99 		return PCIBIOS_SUCCESSFUL;
100 	}
101 
102 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
103 	if (get_dbe(cf, (u32 *)addr))
104 		return PCIBIOS_DEVICE_NOT_FOUND;
105 
106 	shift = ((where & 3) << 3);
107 	mask = (0xffffffffU >> ((4 - size) << 3));
108 	*value = (cf >> shift) & mask;
109 
110 	return PCIBIOS_SUCCESSFUL;
111 }
112 
113 static int pci_conf1_read_config(struct pci_bus *bus, unsigned int devfn,
114 				 int where, int size, u32 *value)
115 {
116 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
117 	struct bridge_regs *bridge = bc->base;
118 	int busno = bus->number;
119 	int slot = PCI_SLOT(devfn);
120 	int fn = PCI_FUNC(devfn);
121 	void *addr;
122 	u32 cf, shift, mask;
123 	int res;
124 
125 	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
126 	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
127 	if (get_dbe(cf, (u32 *)addr))
128 		return PCIBIOS_DEVICE_NOT_FOUND;
129 
130 	/*
131 	 * IOC3 is broken beyond belief ...  Don't even give the
132 	 * generic PCI code a chance to look at it for real ...
133 	 */
134 	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
135 		goto is_ioc3;
136 
137 	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
138 
139 	if (size == 1)
140 		res = get_dbe(*value, (u8 *)addr);
141 	else if (size == 2)
142 		res = get_dbe(*value, (u16 *)addr);
143 	else
144 		res = get_dbe(*value, (u32 *)addr);
145 
146 	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
147 
148 is_ioc3:
149 
150 	/*
151 	 * IOC3 special handling
152 	 */
153 	if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
154 		*value = emulate_ioc3_cfg(where, size);
155 		return PCIBIOS_SUCCESSFUL;
156 	}
157 
158 	addr = &bridge->b_type1_cfg.c[(fn << 8) | where];
159 	if (get_dbe(cf, (u32 *)addr))
160 		return PCIBIOS_DEVICE_NOT_FOUND;
161 
162 	shift = ((where & 3) << 3);
163 	mask = (0xffffffffU >> ((4 - size) << 3));
164 	*value = (cf >> shift) & mask;
165 
166 	return PCIBIOS_SUCCESSFUL;
167 }
168 
169 static int pci_read_config(struct pci_bus *bus, unsigned int devfn,
170 			   int where, int size, u32 *value)
171 {
172 	if (!pci_is_root_bus(bus))
173 		return pci_conf1_read_config(bus, devfn, where, size, value);
174 
175 	return pci_conf0_read_config(bus, devfn, where, size, value);
176 }
177 
178 static int pci_conf0_write_config(struct pci_bus *bus, unsigned int devfn,
179 				  int where, int size, u32 value)
180 {
181 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
182 	struct bridge_regs *bridge = bc->base;
183 	int slot = PCI_SLOT(devfn);
184 	int fn = PCI_FUNC(devfn);
185 	void *addr;
186 	u32 cf, shift, mask, smask;
187 	int res;
188 
189 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
190 	if (get_dbe(cf, (u32 *)addr))
191 		return PCIBIOS_DEVICE_NOT_FOUND;
192 
193 	/*
194 	 * IOC3 is broken beyond belief ...  Don't even give the
195 	 * generic PCI code a chance to look at it for real ...
196 	 */
197 	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
198 		goto is_ioc3;
199 
200 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
201 
202 	if (size == 1)
203 		res = put_dbe(value, (u8 *)addr);
204 	else if (size == 2)
205 		res = put_dbe(value, (u16 *)addr);
206 	else
207 		res = put_dbe(value, (u32 *)addr);
208 
209 	if (res)
210 		return PCIBIOS_DEVICE_NOT_FOUND;
211 
212 	return PCIBIOS_SUCCESSFUL;
213 
214 is_ioc3:
215 
216 	/*
217 	 * IOC3 special handling
218 	 */
219 	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
220 		return PCIBIOS_SUCCESSFUL;
221 
222 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
223 
224 	if (get_dbe(cf, (u32 *)addr))
225 		return PCIBIOS_DEVICE_NOT_FOUND;
226 
227 	shift = ((where & 3) << 3);
228 	mask = (0xffffffffU >> ((4 - size) << 3));
229 	smask = mask << shift;
230 
231 	cf = (cf & ~smask) | ((value & mask) << shift);
232 	if (put_dbe(cf, (u32 *)addr))
233 		return PCIBIOS_DEVICE_NOT_FOUND;
234 
235 	return PCIBIOS_SUCCESSFUL;
236 }
237 
238 static int pci_conf1_write_config(struct pci_bus *bus, unsigned int devfn,
239 				  int where, int size, u32 value)
240 {
241 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
242 	struct bridge_regs *bridge = bc->base;
243 	int slot = PCI_SLOT(devfn);
244 	int fn = PCI_FUNC(devfn);
245 	int busno = bus->number;
246 	void *addr;
247 	u32 cf, shift, mask, smask;
248 	int res;
249 
250 	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
251 	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
252 	if (get_dbe(cf, (u32 *)addr))
253 		return PCIBIOS_DEVICE_NOT_FOUND;
254 
255 	/*
256 	 * IOC3 is broken beyond belief ...  Don't even give the
257 	 * generic PCI code a chance to look at it for real ...
258 	 */
259 	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
260 		goto is_ioc3;
261 
262 	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
263 
264 	if (size == 1)
265 		res = put_dbe(value, (u8 *)addr);
266 	else if (size == 2)
267 		res = put_dbe(value, (u16 *)addr);
268 	else
269 		res = put_dbe(value, (u32 *)addr);
270 
271 	if (res)
272 		return PCIBIOS_DEVICE_NOT_FOUND;
273 
274 	return PCIBIOS_SUCCESSFUL;
275 
276 is_ioc3:
277 
278 	/*
279 	 * IOC3 special handling
280 	 */
281 	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
282 		return PCIBIOS_SUCCESSFUL;
283 
284 	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
285 	if (get_dbe(cf, (u32 *)addr))
286 		return PCIBIOS_DEVICE_NOT_FOUND;
287 
288 	shift = ((where & 3) << 3);
289 	mask = (0xffffffffU >> ((4 - size) << 3));
290 	smask = mask << shift;
291 
292 	cf = (cf & ~smask) | ((value & mask) << shift);
293 	if (put_dbe(cf, (u32 *)addr))
294 		return PCIBIOS_DEVICE_NOT_FOUND;
295 
296 	return PCIBIOS_SUCCESSFUL;
297 }
298 
299 static int pci_write_config(struct pci_bus *bus, unsigned int devfn,
300 	int where, int size, u32 value)
301 {
302 	if (!pci_is_root_bus(bus))
303 		return pci_conf1_write_config(bus, devfn, where, size, value);
304 
305 	return pci_conf0_write_config(bus, devfn, where, size, value);
306 }
307 
308 static struct pci_ops bridge_pci_ops = {
309 	.read	 = pci_read_config,
310 	.write	 = pci_write_config,
311 };
312 
313 struct bridge_irq_chip_data {
314 	struct bridge_controller *bc;
315 	nasid_t nasid;
316 };
317 
318 static int bridge_set_affinity(struct irq_data *d, const struct cpumask *mask,
319 			       bool force)
320 {
321 #ifdef CONFIG_NUMA
322 	struct bridge_irq_chip_data *data = d->chip_data;
323 	int bit = d->parent_data->hwirq;
324 	int pin = d->hwirq;
325 	nasid_t nasid;
326 	int ret, cpu;
327 
328 	ret = irq_chip_set_affinity_parent(d, mask, force);
329 	if (ret >= 0) {
330 		cpu = cpumask_first_and(mask, cpu_online_mask);
331 		nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
332 		bridge_write(data->bc, b_int_addr[pin].addr,
333 			     (((data->bc->intr_addr >> 30) & 0x30000) |
334 			      bit | (nasid << 8)));
335 		bridge_read(data->bc, b_wid_tflush);
336 	}
337 	return ret;
338 #else
339 	return irq_chip_set_affinity_parent(d, mask, force);
340 #endif
341 }
342 
343 struct irq_chip bridge_irq_chip = {
344 	.name             = "BRIDGE",
345 	.irq_mask         = irq_chip_mask_parent,
346 	.irq_unmask       = irq_chip_unmask_parent,
347 	.irq_set_affinity = bridge_set_affinity
348 };
349 
350 static int bridge_domain_alloc(struct irq_domain *domain, unsigned int virq,
351 			       unsigned int nr_irqs, void *arg)
352 {
353 	struct bridge_irq_chip_data *data;
354 	struct irq_alloc_info *info = arg;
355 	int ret;
356 
357 	if (nr_irqs > 1 || !info)
358 		return -EINVAL;
359 
360 	data = kzalloc(sizeof(*data), GFP_KERNEL);
361 	if (!data)
362 		return -ENOMEM;
363 
364 	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
365 	if (ret >= 0) {
366 		data->bc = info->ctrl;
367 		data->nasid = info->nasid;
368 		irq_domain_set_info(domain, virq, info->pin, &bridge_irq_chip,
369 				    data, handle_level_irq, NULL, NULL);
370 	} else {
371 		kfree(data);
372 	}
373 
374 	return ret;
375 }
376 
377 static void bridge_domain_free(struct irq_domain *domain, unsigned int virq,
378 			       unsigned int nr_irqs)
379 {
380 	struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
381 
382 	if (nr_irqs)
383 		return;
384 
385 	kfree(irqd->chip_data);
386 	irq_domain_free_irqs_top(domain, virq, nr_irqs);
387 }
388 
389 static int bridge_domain_activate(struct irq_domain *domain,
390 				  struct irq_data *irqd, bool reserve)
391 {
392 	struct bridge_irq_chip_data *data = irqd->chip_data;
393 	struct bridge_controller *bc = data->bc;
394 	int bit = irqd->parent_data->hwirq;
395 	int pin = irqd->hwirq;
396 	u32 device;
397 
398 	bridge_write(bc, b_int_addr[pin].addr,
399 		     (((bc->intr_addr >> 30) & 0x30000) |
400 		      bit | (data->nasid << 8)));
401 	bridge_set(bc, b_int_enable, (1 << pin));
402 	bridge_set(bc, b_int_enable, 0x7ffffe00); /* more stuff in int_enable */
403 
404 	/*
405 	 * Enable sending of an interrupt clear packt to the hub on a high to
406 	 * low transition of the interrupt pin.
407 	 *
408 	 * IRIX sets additional bits in the address which are documented as
409 	 * reserved in the bridge docs.
410 	 */
411 	bridge_set(bc, b_int_mode, (1UL << pin));
412 
413 	/*
414 	 * We assume the bridge to have a 1:1 mapping between devices
415 	 * (slots) and intr pins.
416 	 */
417 	device = bridge_read(bc, b_int_device);
418 	device &= ~(7 << (pin*3));
419 	device |= (pin << (pin*3));
420 	bridge_write(bc, b_int_device, device);
421 
422 	bridge_read(bc, b_wid_tflush);
423 	return 0;
424 }
425 
426 static void bridge_domain_deactivate(struct irq_domain *domain,
427 				     struct irq_data *irqd)
428 {
429 	struct bridge_irq_chip_data *data = irqd->chip_data;
430 
431 	bridge_clr(data->bc, b_int_enable, (1 << irqd->hwirq));
432 	bridge_read(data->bc, b_wid_tflush);
433 }
434 
435 static const struct irq_domain_ops bridge_domain_ops = {
436 	.alloc      = bridge_domain_alloc,
437 	.free       = bridge_domain_free,
438 	.activate   = bridge_domain_activate,
439 	.deactivate = bridge_domain_deactivate
440 };
441 
442 /*
443  * All observed requests have pin == 1. We could have a global here, that
444  * gets incremented and returned every time - unfortunately, pci_map_irq
445  * may be called on the same device over and over, and need to return the
446  * same value. On O2000, pin can be 0 or 1, and PCI slots can be [0..7].
447  *
448  * A given PCI device, in general, should be able to intr any of the cpus
449  * on any one of the hubs connected to its xbow.
450  */
451 static int bridge_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
452 {
453 	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
454 	struct irq_alloc_info info;
455 	int irq;
456 
457 	irq = bc->pci_int[slot];
458 	if (irq == -1) {
459 		info.ctrl = bc;
460 		info.nasid = bc->nasid;
461 		info.pin = slot;
462 
463 		irq = irq_domain_alloc_irqs(bc->domain, 1, bc->nasid, &info);
464 		if (irq < 0)
465 			return irq;
466 
467 		bc->pci_int[slot] = irq;
468 	}
469 	return irq;
470 }
471 
472 static int bridge_probe(struct platform_device *pdev)
473 {
474 	struct xtalk_bridge_platform_data *bd = dev_get_platdata(&pdev->dev);
475 	struct device *dev = &pdev->dev;
476 	struct bridge_controller *bc;
477 	struct pci_host_bridge *host;
478 	struct irq_domain *domain, *parent;
479 	struct fwnode_handle *fn;
480 	int slot;
481 	int err;
482 
483 	parent = irq_get_default_host();
484 	if (!parent)
485 		return -ENODEV;
486 	fn = irq_domain_alloc_named_fwnode("BRIDGE");
487 	if (!fn)
488 		return -ENOMEM;
489 	domain = irq_domain_create_hierarchy(parent, 0, 8, fn,
490 					     &bridge_domain_ops, NULL);
491 	irq_domain_free_fwnode(fn);
492 	if (!domain)
493 		return -ENOMEM;
494 
495 	pci_set_flags(PCI_PROBE_ONLY);
496 
497 	host = devm_pci_alloc_host_bridge(dev, sizeof(*bc));
498 	if (!host) {
499 		err = -ENOMEM;
500 		goto err_remove_domain;
501 	}
502 
503 	bc = pci_host_bridge_priv(host);
504 
505 	bc->busn.name		= "Bridge PCI busn";
506 	bc->busn.start		= 0;
507 	bc->busn.end		= 0xff;
508 	bc->busn.flags		= IORESOURCE_BUS;
509 
510 	bc->domain		= domain;
511 
512 	pci_add_resource_offset(&host->windows, &bd->mem, bd->mem_offset);
513 	pci_add_resource_offset(&host->windows, &bd->io, bd->io_offset);
514 	pci_add_resource(&host->windows, &bc->busn);
515 
516 	err = devm_request_pci_bus_resources(dev, &host->windows);
517 	if (err < 0)
518 		goto err_free_resource;
519 
520 	bc->nasid = bd->nasid;
521 
522 	bc->baddr = (u64)bd->masterwid << 60 | PCI64_ATTR_BAR;
523 	bc->base = (struct bridge_regs *)bd->bridge_addr;
524 	bc->intr_addr = bd->intr_addr;
525 
526 	/*
527 	 * Clear all pending interrupts.
528 	 */
529 	bridge_write(bc, b_int_rst_stat, BRIDGE_IRR_ALL_CLR);
530 
531 	/*
532 	 * Until otherwise set up, assume all interrupts are from slot 0
533 	 */
534 	bridge_write(bc, b_int_device, 0x0);
535 
536 	/*
537 	 * disable swapping for big windows
538 	 */
539 	bridge_clr(bc, b_wid_control,
540 		   BRIDGE_CTRL_IO_SWAP | BRIDGE_CTRL_MEM_SWAP);
541 #ifdef CONFIG_PAGE_SIZE_4KB
542 	bridge_clr(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
543 #else /* 16kB or larger */
544 	bridge_set(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
545 #endif
546 
547 	/*
548 	 * Hmm...  IRIX sets additional bits in the address which
549 	 * are documented as reserved in the bridge docs.
550 	 */
551 	bridge_write(bc, b_wid_int_upper,
552 		     ((bc->intr_addr >> 32) & 0xffff) | (bd->masterwid << 16));
553 	bridge_write(bc, b_wid_int_lower, bc->intr_addr & 0xffffffff);
554 	bridge_write(bc, b_dir_map, (bd->masterwid << 20));	/* DMA */
555 	bridge_write(bc, b_int_enable, 0);
556 
557 	for (slot = 0; slot < 8; slot++) {
558 		bridge_set(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
559 		bc->pci_int[slot] = -1;
560 	}
561 	bridge_read(bc, b_wid_tflush);	  /* wait until Bridge PIO complete */
562 
563 	host->dev.parent = dev;
564 	host->sysdata = bc;
565 	host->busnr = 0;
566 	host->ops = &bridge_pci_ops;
567 	host->map_irq = bridge_map_irq;
568 	host->swizzle_irq = pci_common_swizzle;
569 
570 	err = pci_scan_root_bus_bridge(host);
571 	if (err < 0)
572 		goto err_free_resource;
573 
574 	pci_bus_claim_resources(host->bus);
575 	pci_bus_add_devices(host->bus);
576 
577 	platform_set_drvdata(pdev, host->bus);
578 
579 	return 0;
580 
581 err_free_resource:
582 	pci_free_resource_list(&host->windows);
583 err_remove_domain:
584 	irq_domain_remove(domain);
585 	return err;
586 }
587 
588 static int bridge_remove(struct platform_device *pdev)
589 {
590 	struct pci_bus *bus = platform_get_drvdata(pdev);
591 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
592 
593 	irq_domain_remove(bc->domain);
594 	pci_lock_rescan_remove();
595 	pci_stop_root_bus(bus);
596 	pci_remove_root_bus(bus);
597 	pci_unlock_rescan_remove();
598 
599 	return 0;
600 }
601 
602 static struct platform_driver bridge_driver = {
603 	.probe  = bridge_probe,
604 	.remove = bridge_remove,
605 	.driver = {
606 		.name = "xtalk-bridge",
607 	}
608 };
609 
610 builtin_platform_driver(bridge_driver);
611