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  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 */
 23static int ioc3_cfg_rd(void *addr, int where, int size, u32 *value)
 24{
 25	u32 cf, shift, mask;
 26
 27	switch (where & ~3) {
 28	case 0x00 ... 0x10:
 29	case 0x40 ... 0x44:
 30		if (get_dbe(cf, (u32 *)addr))
 31			return PCIBIOS_DEVICE_NOT_FOUND;
 32		break;
 33	case 0x3c:
 34		/* emulate sane interrupt pin value */
 35		cf = 0x00000100;
 36		break;
 37	default:
 38		cf = 0;
 39		break;
 40	}
 41	shift = (where & 3) << 3;
 42	mask = 0xffffffffU >> ((4 - size) << 3);
 43	*value = (cf >> shift) & mask;
 44
 45	return PCIBIOS_SUCCESSFUL;
 46}
 47
 48static int ioc3_cfg_wr(void *addr, int where, int size, u32 value)
 49{
 50	u32 cf, shift, mask, smask;
 51
 52	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
 53		return PCIBIOS_SUCCESSFUL;
 54
 55	if (get_dbe(cf, (u32 *)addr))
 56		return PCIBIOS_DEVICE_NOT_FOUND;
 57
 58	shift = ((where & 3) << 3);
 59	mask = (0xffffffffU >> ((4 - size) << 3));
 60	smask = mask << shift;
 61
 62	cf = (cf & ~smask) | ((value & mask) << shift);
 63	if (put_dbe(cf, (u32 *)addr))
 64		return PCIBIOS_DEVICE_NOT_FOUND;
 65
 66	return PCIBIOS_SUCCESSFUL;
 67}
 68
 69static void bridge_disable_swapping(struct pci_dev *dev)
 70{
 71	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
 72	int slot = PCI_SLOT(dev->devfn);
 73
 74	/* Turn off byte swapping */
 75	bridge_clr(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
 76	bridge_read(bc, b_widget.w_tflush);	/* Flush */
 77}
 78
 79DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
 80	bridge_disable_swapping);
 81
 82
 83/*
 84 * The Bridge ASIC supports both type 0 and type 1 access.  Type 1 is
 85 * not really documented, so right now I can't write code which uses it.
 86 * Therefore we use type 0 accesses for now even though they won't work
 87 * correctly for PCI-to-PCI bridges.
 88 *
 89 * The function is complicated by the ultimate brokenness of the IOC3 chip
 90 * which is used in SGI systems.  The IOC3 can only handle 32-bit PCI
 91 * accesses and does only decode parts of it's address space.
 92 */
 93static int pci_conf0_read_config(struct pci_bus *bus, unsigned int devfn,
 94				 int where, int size, u32 *value)
 95{
 96	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
 97	struct bridge_regs *bridge = bc->base;
 98	int slot = PCI_SLOT(devfn);
 99	int fn = PCI_FUNC(devfn);
100	void *addr;
101	u32 cf;
102	int res;
103
104	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
105	if (get_dbe(cf, (u32 *)addr))
106		return PCIBIOS_DEVICE_NOT_FOUND;
107
108	/*
109	 * IOC3 is broken beyond belief ...  Don't even give the
110	 * generic PCI code a chance to look at it for real ...
111	 */
112	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16))) {
113		addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
114		return ioc3_cfg_rd(addr, where, size, value);
115	}
116
117	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
118
119	if (size == 1)
120		res = get_dbe(*value, (u8 *)addr);
121	else if (size == 2)
122		res = get_dbe(*value, (u16 *)addr);
123	else
124		res = get_dbe(*value, (u32 *)addr);
125
126	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
127}
128
129static int pci_conf1_read_config(struct pci_bus *bus, unsigned int devfn,
130				 int where, int size, u32 *value)
131{
132	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
133	struct bridge_regs *bridge = bc->base;
134	int busno = bus->number;
135	int slot = PCI_SLOT(devfn);
136	int fn = PCI_FUNC(devfn);
137	void *addr;
138	u32 cf;
139	int res;
140
141	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
142	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
143	if (get_dbe(cf, (u32 *)addr))
144		return PCIBIOS_DEVICE_NOT_FOUND;
145
146	/*
147	 * IOC3 is broken beyond belief ...  Don't even give the
148	 * generic PCI code a chance to look at it for real ...
149	 */
150	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16))) {
151		addr = &bridge->b_type1_cfg.c[(fn << 8) | (where & ~3)];
152		return ioc3_cfg_rd(addr, where, size, value);
153	}
154
155	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
156
157	if (size == 1)
158		res = get_dbe(*value, (u8 *)addr);
159	else if (size == 2)
160		res = get_dbe(*value, (u16 *)addr);
161	else
162		res = get_dbe(*value, (u32 *)addr);
163
164	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
165}
166
167static int pci_read_config(struct pci_bus *bus, unsigned int devfn,
168			   int where, int size, u32 *value)
169{
170	if (!pci_is_root_bus(bus))
171		return pci_conf1_read_config(bus, devfn, where, size, value);
172
173	return pci_conf0_read_config(bus, devfn, where, size, value);
174}
175
176static int pci_conf0_write_config(struct pci_bus *bus, unsigned int devfn,
177				  int where, int size, u32 value)
178{
179	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
180	struct bridge_regs *bridge = bc->base;
181	int slot = PCI_SLOT(devfn);
182	int fn = PCI_FUNC(devfn);
183	void *addr;
184	u32 cf;
185	int res;
186
187	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
188	if (get_dbe(cf, (u32 *)addr))
189		return PCIBIOS_DEVICE_NOT_FOUND;
190
191	/*
192	 * IOC3 is broken beyond belief ...  Don't even give the
193	 * generic PCI code a chance to look at it for real ...
194	 */
195	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16))) {
196		addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
197		return ioc3_cfg_wr(addr, where, size, value);
198	}
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
215static int pci_conf1_write_config(struct pci_bus *bus, unsigned int devfn,
216				  int where, int size, u32 value)
217{
218	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
219	struct bridge_regs *bridge = bc->base;
220	int slot = PCI_SLOT(devfn);
221	int fn = PCI_FUNC(devfn);
222	int busno = bus->number;
223	void *addr;
224	u32 cf;
225	int res;
226
227	bridge_write(bc, b_pci_cfg, (busno << 16) | (slot << 11));
228	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
229	if (get_dbe(cf, (u32 *)addr))
230		return PCIBIOS_DEVICE_NOT_FOUND;
231
232	/*
233	 * IOC3 is broken beyond belief ...  Don't even give the
234	 * generic PCI code a chance to look at it for real ...
235	 */
236	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16))) {
237		addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
238		return ioc3_cfg_wr(addr, where, size, value);
239	}
240
241	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
242
243	if (size == 1)
244		res = put_dbe(value, (u8 *)addr);
245	else if (size == 2)
246		res = put_dbe(value, (u16 *)addr);
247	else
248		res = put_dbe(value, (u32 *)addr);
249
250	if (res)
251		return PCIBIOS_DEVICE_NOT_FOUND;
252
253	return PCIBIOS_SUCCESSFUL;
254}
255
256static int pci_write_config(struct pci_bus *bus, unsigned int devfn,
257	int where, int size, u32 value)
258{
259	if (!pci_is_root_bus(bus))
260		return pci_conf1_write_config(bus, devfn, where, size, value);
261
262	return pci_conf0_write_config(bus, devfn, where, size, value);
263}
264
265static struct pci_ops bridge_pci_ops = {
266	.read	 = pci_read_config,
267	.write	 = pci_write_config,
268};
269
270struct bridge_irq_chip_data {
271	struct bridge_controller *bc;
272	nasid_t nasid;
273};
274
275static int bridge_set_affinity(struct irq_data *d, const struct cpumask *mask,
276			       bool force)
277{
278#ifdef CONFIG_NUMA
279	struct bridge_irq_chip_data *data = d->chip_data;
280	int bit = d->parent_data->hwirq;
281	int pin = d->hwirq;
282	nasid_t nasid;
283	int ret, cpu;
284
285	ret = irq_chip_set_affinity_parent(d, mask, force);
286	if (ret >= 0) {
287		cpu = cpumask_first_and(mask, cpu_online_mask);
288		nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
289		bridge_write(data->bc, b_int_addr[pin].addr,
290			     (((data->bc->intr_addr >> 30) & 0x30000) |
291			      bit | (nasid << 8)));
292		bridge_read(data->bc, b_wid_tflush);
293	}
294	return ret;
295#else
296	return irq_chip_set_affinity_parent(d, mask, force);
297#endif
298}
299
300struct irq_chip bridge_irq_chip = {
301	.name             = "BRIDGE",
302	.irq_mask         = irq_chip_mask_parent,
303	.irq_unmask       = irq_chip_unmask_parent,
304	.irq_set_affinity = bridge_set_affinity
305};
306
307static int bridge_domain_alloc(struct irq_domain *domain, unsigned int virq,
308			       unsigned int nr_irqs, void *arg)
309{
310	struct bridge_irq_chip_data *data;
311	struct irq_alloc_info *info = arg;
312	int ret;
313
314	if (nr_irqs > 1 || !info)
315		return -EINVAL;
316
317	data = kzalloc(sizeof(*data), GFP_KERNEL);
318	if (!data)
319		return -ENOMEM;
320
321	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
322	if (ret >= 0) {
323		data->bc = info->ctrl;
324		data->nasid = info->nasid;
325		irq_domain_set_info(domain, virq, info->pin, &bridge_irq_chip,
326				    data, handle_level_irq, NULL, NULL);
327	} else {
328		kfree(data);
329	}
330
331	return ret;
332}
333
334static void bridge_domain_free(struct irq_domain *domain, unsigned int virq,
335			       unsigned int nr_irqs)
336{
337	struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
338
339	if (nr_irqs)
340		return;
341
342	kfree(irqd->chip_data);
343	irq_domain_free_irqs_top(domain, virq, nr_irqs);
344}
345
346static int bridge_domain_activate(struct irq_domain *domain,
347				  struct irq_data *irqd, bool reserve)
348{
349	struct bridge_irq_chip_data *data = irqd->chip_data;
350	struct bridge_controller *bc = data->bc;
351	int bit = irqd->parent_data->hwirq;
352	int pin = irqd->hwirq;
353	u32 device;
354
355	bridge_write(bc, b_int_addr[pin].addr,
356		     (((bc->intr_addr >> 30) & 0x30000) |
357		      bit | (data->nasid << 8)));
358	bridge_set(bc, b_int_enable, (1 << pin));
359	bridge_set(bc, b_int_enable, 0x7ffffe00); /* more stuff in int_enable */
360
361	/*
362	 * Enable sending of an interrupt clear packt to the hub on a high to
363	 * low transition of the interrupt pin.
364	 *
365	 * IRIX sets additional bits in the address which are documented as
366	 * reserved in the bridge docs.
367	 */
368	bridge_set(bc, b_int_mode, (1UL << pin));
369
370	/*
371	 * We assume the bridge to have a 1:1 mapping between devices
372	 * (slots) and intr pins.
373	 */
374	device = bridge_read(bc, b_int_device);
375	device &= ~(7 << (pin*3));
376	device |= (pin << (pin*3));
377	bridge_write(bc, b_int_device, device);
378
379	bridge_read(bc, b_wid_tflush);
380	return 0;
381}
382
383static void bridge_domain_deactivate(struct irq_domain *domain,
384				     struct irq_data *irqd)
385{
386	struct bridge_irq_chip_data *data = irqd->chip_data;
387
388	bridge_clr(data->bc, b_int_enable, (1 << irqd->hwirq));
389	bridge_read(data->bc, b_wid_tflush);
390}
391
392static const struct irq_domain_ops bridge_domain_ops = {
393	.alloc      = bridge_domain_alloc,
394	.free       = bridge_domain_free,
395	.activate   = bridge_domain_activate,
396	.deactivate = bridge_domain_deactivate
397};
398
399/*
400 * All observed requests have pin == 1. We could have a global here, that
401 * gets incremented and returned every time - unfortunately, pci_map_irq
402 * may be called on the same device over and over, and need to return the
403 * same value. On O2000, pin can be 0 or 1, and PCI slots can be [0..7].
404 *
405 * A given PCI device, in general, should be able to intr any of the cpus
406 * on any one of the hubs connected to its xbow.
407 */
408static int bridge_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
409{
410	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
411	struct irq_alloc_info info;
412	int irq;
413
414	irq = bc->pci_int[slot];
415	if (irq == -1) {
416		info.ctrl = bc;
417		info.nasid = bc->nasid;
418		info.pin = slot;
419
420		irq = irq_domain_alloc_irqs(bc->domain, 1, bc->nasid, &info);
421		if (irq < 0)
422			return irq;
423
424		bc->pci_int[slot] = irq;
425	}
426	return irq;
427}
428
429static int bridge_probe(struct platform_device *pdev)
430{
431	struct xtalk_bridge_platform_data *bd = dev_get_platdata(&pdev->dev);
432	struct device *dev = &pdev->dev;
433	struct bridge_controller *bc;
434	struct pci_host_bridge *host;
435	struct irq_domain *domain, *parent;
436	struct fwnode_handle *fn;
437	int slot;
438	int err;
439
440	parent = irq_get_default_host();
441	if (!parent)
442		return -ENODEV;
443	fn = irq_domain_alloc_named_fwnode("BRIDGE");
444	if (!fn)
445		return -ENOMEM;
446	domain = irq_domain_create_hierarchy(parent, 0, 8, fn,
447					     &bridge_domain_ops, NULL);
448	irq_domain_free_fwnode(fn);
449	if (!domain)
450		return -ENOMEM;
451
452	pci_set_flags(PCI_PROBE_ONLY);
453
454	host = devm_pci_alloc_host_bridge(dev, sizeof(*bc));
455	if (!host) {
456		err = -ENOMEM;
457		goto err_remove_domain;
458	}
459
460	bc = pci_host_bridge_priv(host);
461
462	bc->busn.name		= "Bridge PCI busn";
463	bc->busn.start		= 0;
464	bc->busn.end		= 0xff;
465	bc->busn.flags		= IORESOURCE_BUS;
466
467	bc->domain		= domain;
468
469	pci_add_resource_offset(&host->windows, &bd->mem, bd->mem_offset);
470	pci_add_resource_offset(&host->windows, &bd->io, bd->io_offset);
471	pci_add_resource(&host->windows, &bc->busn);
472
473	err = devm_request_pci_bus_resources(dev, &host->windows);
474	if (err < 0)
475		goto err_free_resource;
476
477	bc->nasid = bd->nasid;
478
479	bc->baddr = (u64)bd->masterwid << 60 | PCI64_ATTR_BAR;
480	bc->base = (struct bridge_regs *)bd->bridge_addr;
481	bc->intr_addr = bd->intr_addr;
482
483	/*
484	 * Clear all pending interrupts.
485	 */
486	bridge_write(bc, b_int_rst_stat, BRIDGE_IRR_ALL_CLR);
487
488	/*
489	 * Until otherwise set up, assume all interrupts are from slot 0
490	 */
491	bridge_write(bc, b_int_device, 0x0);
492
493	/*
494	 * disable swapping for big windows
495	 */
496	bridge_clr(bc, b_wid_control,
497		   BRIDGE_CTRL_IO_SWAP | BRIDGE_CTRL_MEM_SWAP);
498#ifdef CONFIG_PAGE_SIZE_4KB
499	bridge_clr(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
500#else /* 16kB or larger */
501	bridge_set(bc, b_wid_control, BRIDGE_CTRL_PAGE_SIZE);
502#endif
503
504	/*
505	 * Hmm...  IRIX sets additional bits in the address which
506	 * are documented as reserved in the bridge docs.
507	 */
508	bridge_write(bc, b_wid_int_upper,
509		     ((bc->intr_addr >> 32) & 0xffff) | (bd->masterwid << 16));
510	bridge_write(bc, b_wid_int_lower, bc->intr_addr & 0xffffffff);
511	bridge_write(bc, b_dir_map, (bd->masterwid << 20));	/* DMA */
512	bridge_write(bc, b_int_enable, 0);
513
514	for (slot = 0; slot < 8; slot++) {
515		bridge_set(bc, b_device[slot].reg, BRIDGE_DEV_SWAP_DIR);
516		bc->pci_int[slot] = -1;
517	}
518	bridge_read(bc, b_wid_tflush);	  /* wait until Bridge PIO complete */
519
520	host->dev.parent = dev;
521	host->sysdata = bc;
522	host->busnr = 0;
523	host->ops = &bridge_pci_ops;
524	host->map_irq = bridge_map_irq;
525	host->swizzle_irq = pci_common_swizzle;
526
527	err = pci_scan_root_bus_bridge(host);
528	if (err < 0)
529		goto err_free_resource;
530
531	pci_bus_claim_resources(host->bus);
532	pci_bus_add_devices(host->bus);
533
534	platform_set_drvdata(pdev, host->bus);
535
536	return 0;
537
538err_free_resource:
539	pci_free_resource_list(&host->windows);
540err_remove_domain:
541	irq_domain_remove(domain);
542	return err;
543}
544
545static int bridge_remove(struct platform_device *pdev)
546{
547	struct pci_bus *bus = platform_get_drvdata(pdev);
548	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
549
550	irq_domain_remove(bc->domain);
551	pci_lock_rescan_remove();
552	pci_stop_root_bus(bus);
553	pci_remove_root_bus(bus);
554	pci_unlock_rescan_remove();
555
556	return 0;
557}
558
559static struct platform_driver bridge_driver = {
560	.probe  = bridge_probe,
561	.remove = bridge_remove,
562	.driver = {
563		.name = "xtalk-bridge",
564	}
565};
566
567builtin_platform_driver(bridge_driver);