xref: /openbmc/linux/arch/parisc/kernel/drivers.c (revision 25b892b5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * drivers.c
4  *
5  * Copyright (c) 1999 The Puffin Group
6  * Copyright (c) 2001 Matthew Wilcox for Hewlett Packard
7  * Copyright (c) 2001 Helge Deller <deller@gmx.de>
8  * Copyright (c) 2001,2002 Ryan Bradetich
9  * Copyright (c) 2004-2005 Thibaut VARENE <varenet@parisc-linux.org>
10  *
11  * The file handles registering devices and drivers, then matching them.
12  * It's the closest we get to a dating agency.
13  *
14  * If you're thinking about modifying this file, here are some gotchas to
15  * bear in mind:
16  *  - 715/Mirage device paths have a dummy device between Lasi and its children
17  *  - The EISA adapter may show up as a sibling or child of Wax
18  *  - Dino has an optionally functional serial port.  If firmware enables it,
19  *    it shows up as a child of Dino.  If firmware disables it, the buswalk
20  *    finds it and it shows up as a child of Cujo
21  *  - Dino has both parisc and pci devices as children
22  *  - parisc devices are discovered in a random order, including children
23  *    before parents in some cases.
24  */
25 
26 #include <linux/slab.h>
27 #include <linux/types.h>
28 #include <linux/kernel.h>
29 #include <linux/pci.h>
30 #include <linux/spinlock.h>
31 #include <linux/string.h>
32 #include <linux/export.h>
33 #include <linux/dma-map-ops.h>
34 #include <asm/hardware.h>
35 #include <asm/io.h>
36 #include <asm/pdc.h>
37 #include <asm/parisc-device.h>
38 #include <asm/ropes.h>
39 
40 /* See comments in include/asm-parisc/pci.h */
41 const struct dma_map_ops *hppa_dma_ops __ro_after_init;
42 EXPORT_SYMBOL(hppa_dma_ops);
43 
44 static struct device root = {
45 	.init_name = "parisc",
46 };
47 
48 static inline int check_dev(struct device *dev)
49 {
50 	if (dev->bus == &parisc_bus_type) {
51 		struct parisc_device *pdev;
52 		pdev = to_parisc_device(dev);
53 		return pdev->id.hw_type != HPHW_FAULTY;
54 	}
55 	return 1;
56 }
57 
58 static struct device *
59 parse_tree_node(struct device *parent, int index, struct hardware_path *modpath);
60 
61 struct recurse_struct {
62 	void * obj;
63 	int (*fn)(struct device *, void *);
64 };
65 
66 static int descend_children(struct device * dev, void * data)
67 {
68 	struct recurse_struct * recurse_data = (struct recurse_struct *)data;
69 
70 	if (recurse_data->fn(dev, recurse_data->obj))
71 		return 1;
72 	else
73 		return device_for_each_child(dev, recurse_data, descend_children);
74 }
75 
76 /**
77  *	for_each_padev - Iterate over all devices in the tree
78  *	@fn:	Function to call for each device.
79  *	@data:	Data to pass to the called function.
80  *
81  *	This performs a depth-first traversal of the tree, calling the
82  *	function passed for each node.  It calls the function for parents
83  *	before children.
84  */
85 
86 static int for_each_padev(int (*fn)(struct device *, void *), void * data)
87 {
88 	struct recurse_struct recurse_data = {
89 		.obj	= data,
90 		.fn	= fn,
91 	};
92 	return device_for_each_child(&root, &recurse_data, descend_children);
93 }
94 
95 /**
96  * match_device - Report whether this driver can handle this device
97  * @driver: the PA-RISC driver to try
98  * @dev: the PA-RISC device to try
99  */
100 static int match_device(struct parisc_driver *driver, struct parisc_device *dev)
101 {
102 	const struct parisc_device_id *ids;
103 
104 	for (ids = driver->id_table; ids->sversion; ids++) {
105 		if ((ids->sversion != SVERSION_ANY_ID) &&
106 		    (ids->sversion != dev->id.sversion))
107 			continue;
108 
109 		if ((ids->hw_type != HWTYPE_ANY_ID) &&
110 		    (ids->hw_type != dev->id.hw_type))
111 			continue;
112 
113 		if ((ids->hversion != HVERSION_ANY_ID) &&
114 		    (ids->hversion != dev->id.hversion))
115 			continue;
116 
117 		return 1;
118 	}
119 	return 0;
120 }
121 
122 static int parisc_driver_probe(struct device *dev)
123 {
124 	int rc;
125 	struct parisc_device *pa_dev = to_parisc_device(dev);
126 	struct parisc_driver *pa_drv = to_parisc_driver(dev->driver);
127 
128 	rc = pa_drv->probe(pa_dev);
129 
130 	if (!rc)
131 		pa_dev->driver = pa_drv;
132 
133 	return rc;
134 }
135 
136 static void __exit parisc_driver_remove(struct device *dev)
137 {
138 	struct parisc_device *pa_dev = to_parisc_device(dev);
139 	struct parisc_driver *pa_drv = to_parisc_driver(dev->driver);
140 
141 	if (pa_drv->remove)
142 		pa_drv->remove(pa_dev);
143 }
144 
145 
146 /**
147  * register_parisc_driver - Register this driver if it can handle a device
148  * @driver: the PA-RISC driver to try
149  */
150 int register_parisc_driver(struct parisc_driver *driver)
151 {
152 	/* FIXME: we need this because apparently the sti
153 	 * driver can be registered twice */
154 	if (driver->drv.name) {
155 		pr_warn("BUG: skipping previously registered driver %s\n",
156 			driver->name);
157 		return 1;
158 	}
159 
160 	if (!driver->probe) {
161 		pr_warn("BUG: driver %s has no probe routine\n", driver->name);
162 		return 1;
163 	}
164 
165 	driver->drv.bus = &parisc_bus_type;
166 
167 	/* We install our own probe and remove routines */
168 	WARN_ON(driver->drv.probe != NULL);
169 	WARN_ON(driver->drv.remove != NULL);
170 
171 	driver->drv.name = driver->name;
172 
173 	return driver_register(&driver->drv);
174 }
175 EXPORT_SYMBOL(register_parisc_driver);
176 
177 
178 struct match_count {
179 	struct parisc_driver * driver;
180 	int count;
181 };
182 
183 static int match_and_count(struct device * dev, void * data)
184 {
185 	struct match_count * m = data;
186 	struct parisc_device * pdev = to_parisc_device(dev);
187 
188 	if (check_dev(dev)) {
189 		if (match_device(m->driver, pdev))
190 			m->count++;
191 	}
192 	return 0;
193 }
194 
195 /**
196  * count_parisc_driver - count # of devices this driver would match
197  * @driver: the PA-RISC driver to try
198  *
199  * Use by IOMMU support to "guess" the right size IOPdir.
200  * Formula is something like memsize/(num_iommu * entry_size).
201  */
202 int __init count_parisc_driver(struct parisc_driver *driver)
203 {
204 	struct match_count m = {
205 		.driver	= driver,
206 		.count	= 0,
207 	};
208 
209 	for_each_padev(match_and_count, &m);
210 
211 	return m.count;
212 }
213 
214 
215 
216 /**
217  * unregister_parisc_driver - Unregister this driver from the list of drivers
218  * @driver: the PA-RISC driver to unregister
219  */
220 int unregister_parisc_driver(struct parisc_driver *driver)
221 {
222 	driver_unregister(&driver->drv);
223 	return 0;
224 }
225 EXPORT_SYMBOL(unregister_parisc_driver);
226 
227 struct find_data {
228 	unsigned long hpa;
229 	struct parisc_device * dev;
230 };
231 
232 static int find_device(struct device * dev, void * data)
233 {
234 	struct parisc_device * pdev = to_parisc_device(dev);
235 	struct find_data * d = (struct find_data*)data;
236 
237 	if (check_dev(dev)) {
238 		if (pdev->hpa.start == d->hpa) {
239 			d->dev = pdev;
240 			return 1;
241 		}
242 	}
243 	return 0;
244 }
245 
246 static struct parisc_device *find_device_by_addr(unsigned long hpa)
247 {
248 	struct find_data d = {
249 		.hpa	= hpa,
250 	};
251 	int ret;
252 
253 	ret = for_each_padev(find_device, &d);
254 	return ret ? d.dev : NULL;
255 }
256 
257 static int __init is_IKE_device(struct device *dev, void *data)
258 {
259 	struct parisc_device *pdev = to_parisc_device(dev);
260 
261 	if (!check_dev(dev))
262 		return 0;
263 	if (pdev->id.hw_type != HPHW_BCPORT)
264 		return 0;
265 	if (IS_IKE(pdev) ||
266 		(pdev->id.hversion == REO_MERCED_PORT) ||
267 		(pdev->id.hversion == REOG_MERCED_PORT)) {
268 			return 1;
269 	}
270 	return 0;
271 }
272 
273 int __init machine_has_merced_bus(void)
274 {
275 	int ret;
276 
277 	ret = for_each_padev(is_IKE_device, NULL);
278 	return ret ? 1 : 0;
279 }
280 
281 /**
282  * find_pa_parent_type - Find a parent of a specific type
283  * @dev: The device to start searching from
284  * @type: The device type to search for.
285  *
286  * Walks up the device tree looking for a device of the specified type.
287  * If it finds it, it returns it.  If not, it returns NULL.
288  */
289 const struct parisc_device *
290 find_pa_parent_type(const struct parisc_device *padev, int type)
291 {
292 	const struct device *dev = &padev->dev;
293 	while (dev != &root) {
294 		struct parisc_device *candidate = to_parisc_device(dev);
295 		if (candidate->id.hw_type == type)
296 			return candidate;
297 		dev = dev->parent;
298 	}
299 
300 	return NULL;
301 }
302 
303 /*
304  * get_node_path fills in @path with the firmware path to the device.
305  * Note that if @node is a parisc device, we don't fill in the 'mod' field.
306  * This is because both callers pass the parent and fill in the mod
307  * themselves.  If @node is a PCI device, we do fill it in, even though this
308  * is inconsistent.
309  */
310 static void get_node_path(struct device *dev, struct hardware_path *path)
311 {
312 	int i = 5;
313 	memset(&path->bc, -1, 6);
314 
315 	if (dev_is_pci(dev)) {
316 		unsigned int devfn = to_pci_dev(dev)->devfn;
317 		path->mod = PCI_FUNC(devfn);
318 		path->bc[i--] = PCI_SLOT(devfn);
319 		dev = dev->parent;
320 	}
321 
322 	while (dev != &root) {
323 		if (dev_is_pci(dev)) {
324 			unsigned int devfn = to_pci_dev(dev)->devfn;
325 			path->bc[i--] = PCI_SLOT(devfn) | (PCI_FUNC(devfn)<< 5);
326 		} else if (dev->bus == &parisc_bus_type) {
327 			path->bc[i--] = to_parisc_device(dev)->hw_path;
328 		}
329 		dev = dev->parent;
330 	}
331 }
332 
333 static char *print_hwpath(struct hardware_path *path, char *output)
334 {
335 	int i;
336 	for (i = 0; i < 6; i++) {
337 		if (path->bc[i] == -1)
338 			continue;
339 		output += sprintf(output, "%u/", (unsigned char) path->bc[i]);
340 	}
341 	output += sprintf(output, "%u", (unsigned char) path->mod);
342 	return output;
343 }
344 
345 /**
346  * print_pa_hwpath - Returns hardware path for PA devices
347  * dev: The device to return the path for
348  * output: Pointer to a previously-allocated array to place the path in.
349  *
350  * This function fills in the output array with a human-readable path
351  * to a PA device.  This string is compatible with that used by PDC, and
352  * may be printed on the outside of the box.
353  */
354 char *print_pa_hwpath(struct parisc_device *dev, char *output)
355 {
356 	struct hardware_path path;
357 
358 	get_node_path(dev->dev.parent, &path);
359 	path.mod = dev->hw_path;
360 	return print_hwpath(&path, output);
361 }
362 EXPORT_SYMBOL(print_pa_hwpath);
363 
364 #if defined(CONFIG_PCI) || defined(CONFIG_ISA)
365 /**
366  * get_pci_node_path - Determines the hardware path for a PCI device
367  * @pdev: The device to return the path for
368  * @path: Pointer to a previously-allocated array to place the path in.
369  *
370  * This function fills in the hardware_path structure with the route to
371  * the specified PCI device.  This structure is suitable for passing to
372  * PDC calls.
373  */
374 void get_pci_node_path(struct pci_dev *pdev, struct hardware_path *path)
375 {
376 	get_node_path(&pdev->dev, path);
377 }
378 EXPORT_SYMBOL(get_pci_node_path);
379 
380 /**
381  * print_pci_hwpath - Returns hardware path for PCI devices
382  * dev: The device to return the path for
383  * output: Pointer to a previously-allocated array to place the path in.
384  *
385  * This function fills in the output array with a human-readable path
386  * to a PCI device.  This string is compatible with that used by PDC, and
387  * may be printed on the outside of the box.
388  */
389 char *print_pci_hwpath(struct pci_dev *dev, char *output)
390 {
391 	struct hardware_path path;
392 
393 	get_pci_node_path(dev, &path);
394 	return print_hwpath(&path, output);
395 }
396 EXPORT_SYMBOL(print_pci_hwpath);
397 
398 #endif /* defined(CONFIG_PCI) || defined(CONFIG_ISA) */
399 
400 static void setup_bus_id(struct parisc_device *padev)
401 {
402 	struct hardware_path path;
403 	char name[28];
404 	char *output = name;
405 	int i;
406 
407 	get_node_path(padev->dev.parent, &path);
408 
409 	for (i = 0; i < 6; i++) {
410 		if (path.bc[i] == -1)
411 			continue;
412 		output += sprintf(output, "%u:", (unsigned char) path.bc[i]);
413 	}
414 	sprintf(output, "%u", (unsigned char) padev->hw_path);
415 	dev_set_name(&padev->dev, name);
416 }
417 
418 struct parisc_device * __init create_tree_node(char id, struct device *parent)
419 {
420 	struct parisc_device *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
421 	if (!dev)
422 		return NULL;
423 
424 	dev->hw_path = id;
425 	dev->id.hw_type = HPHW_FAULTY;
426 
427 	dev->dev.parent = parent;
428 	setup_bus_id(dev);
429 
430 	dev->dev.bus = &parisc_bus_type;
431 	dev->dma_mask = 0xffffffffUL;	/* PARISC devices are 32-bit */
432 
433 	/* make the generic dma mask a pointer to the parisc one */
434 	dev->dev.dma_mask = &dev->dma_mask;
435 	dev->dev.coherent_dma_mask = dev->dma_mask;
436 	if (device_register(&dev->dev)) {
437 		kfree(dev);
438 		return NULL;
439 	}
440 
441 	return dev;
442 }
443 
444 struct match_id_data {
445 	char id;
446 	struct parisc_device * dev;
447 };
448 
449 static int match_by_id(struct device * dev, void * data)
450 {
451 	struct parisc_device * pdev = to_parisc_device(dev);
452 	struct match_id_data * d = data;
453 
454 	if (pdev->hw_path == d->id) {
455 		d->dev = pdev;
456 		return 1;
457 	}
458 	return 0;
459 }
460 
461 /**
462  * alloc_tree_node - returns a device entry in the iotree
463  * @parent: the parent node in the tree
464  * @id: the element of the module path for this entry
465  *
466  * Checks all the children of @parent for a matching @id.  If none
467  * found, it allocates a new device and returns it.
468  */
469 static struct parisc_device * __init alloc_tree_node(
470 			struct device *parent, char id)
471 {
472 	struct match_id_data d = {
473 		.id = id,
474 	};
475 	if (device_for_each_child(parent, &d, match_by_id))
476 		return d.dev;
477 	else
478 		return create_tree_node(id, parent);
479 }
480 
481 static struct parisc_device *create_parisc_device(struct hardware_path *modpath)
482 {
483 	int i;
484 	struct device *parent = &root;
485 	for (i = 0; i < 6; i++) {
486 		if (modpath->bc[i] == -1)
487 			continue;
488 		parent = &alloc_tree_node(parent, modpath->bc[i])->dev;
489 	}
490 	return alloc_tree_node(parent, modpath->mod);
491 }
492 
493 struct parisc_device * __init
494 alloc_pa_dev(unsigned long hpa, struct hardware_path *mod_path)
495 {
496 	int status;
497 	unsigned long bytecnt;
498 	u8 iodc_data[32];
499 	struct parisc_device *dev;
500 	const char *name;
501 
502 	/* Check to make sure this device has not already been added - Ryan */
503 	if (find_device_by_addr(hpa) != NULL)
504 		return NULL;
505 
506 	status = pdc_iodc_read(&bytecnt, hpa, 0, &iodc_data, 32);
507 	if (status != PDC_OK)
508 		return NULL;
509 
510 	dev = create_parisc_device(mod_path);
511 	if (dev->id.hw_type != HPHW_FAULTY) {
512 		pr_err("Two devices have hardware path [%s].  IODC data for second device: %7phN\n"
513 		       "Rearranging GSC cards sometimes helps\n",
514 			parisc_pathname(dev), iodc_data);
515 		return NULL;
516 	}
517 
518 	dev->id.hw_type = iodc_data[3] & 0x1f;
519 	dev->id.hversion = (iodc_data[0] << 4) | ((iodc_data[1] & 0xf0) >> 4);
520 	dev->id.hversion_rev = iodc_data[1] & 0x0f;
521 	dev->id.sversion = ((iodc_data[4] & 0x0f) << 16) |
522 			(iodc_data[5] << 8) | iodc_data[6];
523 	dev->hpa.name = parisc_pathname(dev);
524 	dev->hpa.start = hpa;
525 	/* This is awkward.  The STI spec says that gfx devices may occupy
526 	 * 32MB or 64MB.  Unfortunately, we don't know how to tell whether
527 	 * it's the former or the latter.  Assumptions either way can hurt us.
528 	 */
529 	if (hpa == 0xf4000000 || hpa == 0xf8000000) {
530 		dev->hpa.end = hpa + 0x03ffffff;
531 	} else if (hpa == 0xf6000000 || hpa == 0xfa000000) {
532 		dev->hpa.end = hpa + 0x01ffffff;
533 	} else {
534 		dev->hpa.end = hpa + 0xfff;
535 	}
536 	dev->hpa.flags = IORESOURCE_MEM;
537 	name = parisc_hardware_description(&dev->id);
538 	if (name) {
539 		strlcpy(dev->name, name, sizeof(dev->name));
540 	}
541 
542 	/* Silently fail things like mouse ports which are subsumed within
543 	 * the keyboard controller
544 	 */
545 	if ((hpa & 0xfff) == 0 && insert_resource(&iomem_resource, &dev->hpa))
546 		pr_warn("Unable to claim HPA %lx for device %s\n", hpa, name);
547 
548 	return dev;
549 }
550 
551 static int parisc_generic_match(struct device *dev, struct device_driver *drv)
552 {
553 	return match_device(to_parisc_driver(drv), to_parisc_device(dev));
554 }
555 
556 static ssize_t make_modalias(struct device *dev, char *buf)
557 {
558 	const struct parisc_device *padev = to_parisc_device(dev);
559 	const struct parisc_device_id *id = &padev->id;
560 
561 	return sprintf(buf, "parisc:t%02Xhv%04Xrev%02Xsv%08X\n",
562 		(u8)id->hw_type, (u16)id->hversion, (u8)id->hversion_rev,
563 		(u32)id->sversion);
564 }
565 
566 static int parisc_uevent(struct device *dev, struct kobj_uevent_env *env)
567 {
568 	const struct parisc_device *padev;
569 	char modalias[40];
570 
571 	if (!dev)
572 		return -ENODEV;
573 
574 	padev = to_parisc_device(dev);
575 	if (!padev)
576 		return -ENODEV;
577 
578 	if (add_uevent_var(env, "PARISC_NAME=%s", padev->name))
579 		return -ENOMEM;
580 
581 	make_modalias(dev, modalias);
582 	if (add_uevent_var(env, "MODALIAS=%s", modalias))
583 		return -ENOMEM;
584 
585 	return 0;
586 }
587 
588 #define pa_dev_attr(name, field, format_string)				\
589 static ssize_t name##_show(struct device *dev, struct device_attribute *attr, char *buf)		\
590 {									\
591 	struct parisc_device *padev = to_parisc_device(dev);		\
592 	return sprintf(buf, format_string, padev->field);		\
593 }									\
594 static DEVICE_ATTR_RO(name);
595 
596 #define pa_dev_attr_id(field, format) pa_dev_attr(field, id.field, format)
597 
598 pa_dev_attr(irq, irq, "%u\n");
599 pa_dev_attr_id(hw_type, "0x%02x\n");
600 pa_dev_attr(rev, id.hversion_rev, "0x%x\n");
601 pa_dev_attr_id(hversion, "0x%03x\n");
602 pa_dev_attr_id(sversion, "0x%05x\n");
603 
604 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
605 {
606 	return make_modalias(dev, buf);
607 }
608 static DEVICE_ATTR_RO(modalias);
609 
610 static struct attribute *parisc_device_attrs[] = {
611 	&dev_attr_irq.attr,
612 	&dev_attr_hw_type.attr,
613 	&dev_attr_rev.attr,
614 	&dev_attr_hversion.attr,
615 	&dev_attr_sversion.attr,
616 	&dev_attr_modalias.attr,
617 	NULL,
618 };
619 ATTRIBUTE_GROUPS(parisc_device);
620 
621 struct bus_type parisc_bus_type = {
622 	.name = "parisc",
623 	.match = parisc_generic_match,
624 	.uevent = parisc_uevent,
625 	.dev_groups = parisc_device_groups,
626 	.probe = parisc_driver_probe,
627 	.remove = __exit_p(parisc_driver_remove),
628 };
629 
630 /**
631  * register_parisc_device - Locate a driver to manage this device.
632  * @dev: The parisc device.
633  *
634  * Search the driver list for a driver that is willing to manage
635  * this device.
636  */
637 int __init register_parisc_device(struct parisc_device *dev)
638 {
639 	if (!dev)
640 		return 0;
641 
642 	if (dev->driver)
643 		return 1;
644 
645 	return 0;
646 }
647 
648 /**
649  * match_pci_device - Matches a pci device against a given hardware path
650  * entry.
651  * @dev: the generic device (known to be contained by a pci_dev).
652  * @index: the current BC index
653  * @modpath: the hardware path.
654  * @return: true if the device matches the hardware path.
655  */
656 static int match_pci_device(struct device *dev, int index,
657 		struct hardware_path *modpath)
658 {
659 	struct pci_dev *pdev = to_pci_dev(dev);
660 	int id;
661 
662 	if (index == 5) {
663 		/* we are at the end of the path, and on the actual device */
664 		unsigned int devfn = pdev->devfn;
665 		return ((modpath->bc[5] == PCI_SLOT(devfn)) &&
666 					(modpath->mod == PCI_FUNC(devfn)));
667 	}
668 
669 	/* index might be out of bounds for bc[] */
670 	if (index >= 6)
671 		return 0;
672 
673 	id = PCI_SLOT(pdev->devfn) | (PCI_FUNC(pdev->devfn) << 5);
674 	return (modpath->bc[index] == id);
675 }
676 
677 /**
678  * match_parisc_device - Matches a parisc device against a given hardware
679  * path entry.
680  * @dev: the generic device (known to be contained by a parisc_device).
681  * @index: the current BC index
682  * @modpath: the hardware path.
683  * @return: true if the device matches the hardware path.
684  */
685 static int match_parisc_device(struct device *dev, int index,
686 		struct hardware_path *modpath)
687 {
688 	struct parisc_device *curr = to_parisc_device(dev);
689 	char id = (index == 6) ? modpath->mod : modpath->bc[index];
690 
691 	return (curr->hw_path == id);
692 }
693 
694 struct parse_tree_data {
695 	int index;
696 	struct hardware_path * modpath;
697 	struct device * dev;
698 };
699 
700 static int check_parent(struct device * dev, void * data)
701 {
702 	struct parse_tree_data * d = data;
703 
704 	if (check_dev(dev)) {
705 		if (dev->bus == &parisc_bus_type) {
706 			if (match_parisc_device(dev, d->index, d->modpath))
707 				d->dev = dev;
708 		} else if (dev_is_pci(dev)) {
709 			if (match_pci_device(dev, d->index, d->modpath))
710 				d->dev = dev;
711 		} else if (dev->bus == NULL) {
712 			/* we are on a bus bridge */
713 			struct device *new = parse_tree_node(dev, d->index, d->modpath);
714 			if (new)
715 				d->dev = new;
716 		}
717 	}
718 	return d->dev != NULL;
719 }
720 
721 /**
722  * parse_tree_node - returns a device entry in the iotree
723  * @parent: the parent node in the tree
724  * @index: the current BC index
725  * @modpath: the hardware_path struct to match a device against
726  * @return: The corresponding device if found, NULL otherwise.
727  *
728  * Checks all the children of @parent for a matching @id.  If none
729  * found, it returns NULL.
730  */
731 static struct device *
732 parse_tree_node(struct device *parent, int index, struct hardware_path *modpath)
733 {
734 	struct parse_tree_data d = {
735 		.index          = index,
736 		.modpath        = modpath,
737 	};
738 
739 	struct recurse_struct recurse_data = {
740 		.obj	= &d,
741 		.fn	= check_parent,
742 	};
743 
744 	if (device_for_each_child(parent, &recurse_data, descend_children))
745 		/* nothing */;
746 
747 	return d.dev;
748 }
749 
750 /**
751  * hwpath_to_device - Finds the generic device corresponding to a given hardware path.
752  * @modpath: the hardware path.
753  * @return: The target device, NULL if not found.
754  */
755 struct device *hwpath_to_device(struct hardware_path *modpath)
756 {
757 	int i;
758 	struct device *parent = &root;
759 	for (i = 0; i < 6; i++) {
760 		if (modpath->bc[i] == -1)
761 			continue;
762 		parent = parse_tree_node(parent, i, modpath);
763 		if (!parent)
764 			return NULL;
765 	}
766 	if (dev_is_pci(parent)) /* pci devices already parse MOD */
767 		return parent;
768 	else
769 		return parse_tree_node(parent, 6, modpath);
770 }
771 EXPORT_SYMBOL(hwpath_to_device);
772 
773 /**
774  * device_to_hwpath - Populates the hwpath corresponding to the given device.
775  * @param dev the target device
776  * @param path pointer to a previously allocated hwpath struct to be filled in
777  */
778 void device_to_hwpath(struct device *dev, struct hardware_path *path)
779 {
780 	struct parisc_device *padev;
781 	if (dev->bus == &parisc_bus_type) {
782 		padev = to_parisc_device(dev);
783 		get_node_path(dev->parent, path);
784 		path->mod = padev->hw_path;
785 	} else if (dev_is_pci(dev)) {
786 		get_node_path(dev, path);
787 	}
788 }
789 EXPORT_SYMBOL(device_to_hwpath);
790 
791 #define BC_PORT_MASK 0x8
792 #define BC_LOWER_PORT 0x8
793 
794 #define BUS_CONVERTER(dev) \
795         ((dev->id.hw_type == HPHW_IOA) || (dev->id.hw_type == HPHW_BCPORT))
796 
797 #define IS_LOWER_PORT(dev) \
798         ((gsc_readl(dev->hpa.start + offsetof(struct bc_module, io_status)) \
799                 & BC_PORT_MASK) == BC_LOWER_PORT)
800 
801 #define MAX_NATIVE_DEVICES 64
802 #define NATIVE_DEVICE_OFFSET 0x1000
803 
804 #define FLEX_MASK 	F_EXTEND(0xfffc0000)
805 #define IO_IO_LOW	offsetof(struct bc_module, io_io_low)
806 #define IO_IO_HIGH	offsetof(struct bc_module, io_io_high)
807 #define READ_IO_IO_LOW(dev)  (unsigned long)(signed int)gsc_readl(dev->hpa.start + IO_IO_LOW)
808 #define READ_IO_IO_HIGH(dev) (unsigned long)(signed int)gsc_readl(dev->hpa.start + IO_IO_HIGH)
809 
810 static void walk_native_bus(unsigned long io_io_low, unsigned long io_io_high,
811                             struct device *parent);
812 
813 static void __init walk_lower_bus(struct parisc_device *dev)
814 {
815 	unsigned long io_io_low, io_io_high;
816 
817 	if (!BUS_CONVERTER(dev) || IS_LOWER_PORT(dev))
818 		return;
819 
820 	if (dev->id.hw_type == HPHW_IOA) {
821 		io_io_low = (unsigned long)(signed int)(READ_IO_IO_LOW(dev) << 16);
822 		io_io_high = io_io_low + MAX_NATIVE_DEVICES * NATIVE_DEVICE_OFFSET;
823 	} else {
824 		io_io_low = (READ_IO_IO_LOW(dev) + ~FLEX_MASK) & FLEX_MASK;
825 		io_io_high = (READ_IO_IO_HIGH(dev)+ ~FLEX_MASK) & FLEX_MASK;
826 	}
827 
828 	walk_native_bus(io_io_low, io_io_high, &dev->dev);
829 }
830 
831 /**
832  * walk_native_bus -- Probe a bus for devices
833  * @io_io_low: Base address of this bus.
834  * @io_io_high: Last address of this bus.
835  * @parent: The parent bus device.
836  *
837  * A native bus (eg Runway or GSC) may have up to 64 devices on it,
838  * spaced at intervals of 0x1000 bytes.  PDC may not inform us of these
839  * devices, so we have to probe for them.  Unfortunately, we may find
840  * devices which are not physically connected (such as extra serial &
841  * keyboard ports).  This problem is not yet solved.
842  */
843 static void __init walk_native_bus(unsigned long io_io_low,
844 	unsigned long io_io_high, struct device *parent)
845 {
846 	int i, devices_found = 0;
847 	unsigned long hpa = io_io_low;
848 	struct hardware_path path;
849 
850 	get_node_path(parent, &path);
851 	do {
852 		for(i = 0; i < MAX_NATIVE_DEVICES; i++, hpa += NATIVE_DEVICE_OFFSET) {
853 			struct parisc_device *dev;
854 
855 			/* Was the device already added by Firmware? */
856 			dev = find_device_by_addr(hpa);
857 			if (!dev) {
858 				path.mod = i;
859 				dev = alloc_pa_dev(hpa, &path);
860 				if (!dev)
861 					continue;
862 
863 				register_parisc_device(dev);
864 				devices_found++;
865 			}
866 			walk_lower_bus(dev);
867 		}
868 	} while(!devices_found && hpa < io_io_high);
869 }
870 
871 #define CENTRAL_BUS_ADDR F_EXTEND(0xfff80000)
872 
873 /**
874  * walk_central_bus - Find devices attached to the central bus
875  *
876  * PDC doesn't tell us about all devices in the system.  This routine
877  * finds devices connected to the central bus.
878  */
879 void __init walk_central_bus(void)
880 {
881 	walk_native_bus(CENTRAL_BUS_ADDR,
882 			CENTRAL_BUS_ADDR + (MAX_NATIVE_DEVICES * NATIVE_DEVICE_OFFSET),
883 			&root);
884 }
885 
886 static void print_parisc_device(struct parisc_device *dev)
887 {
888 	char hw_path[64];
889 	static int count;
890 
891 	print_pa_hwpath(dev, hw_path);
892 	pr_info("%d. %s at %pap [%s] { %d, 0x%x, 0x%.3x, 0x%.5x }",
893 		++count, dev->name, &(dev->hpa.start), hw_path, dev->id.hw_type,
894 		dev->id.hversion_rev, dev->id.hversion, dev->id.sversion);
895 
896 	if (dev->num_addrs) {
897 		int k;
898 		pr_cont(", additional addresses: ");
899 		for (k = 0; k < dev->num_addrs; k++)
900 			pr_cont("0x%lx ", dev->addr[k]);
901 	}
902 	pr_cont("\n");
903 }
904 
905 /**
906  * init_parisc_bus - Some preparation to be done before inventory
907  */
908 void __init init_parisc_bus(void)
909 {
910 	if (bus_register(&parisc_bus_type))
911 		panic("Could not register PA-RISC bus type\n");
912 	if (device_register(&root))
913 		panic("Could not register PA-RISC root device\n");
914 	get_device(&root);
915 }
916 
917 static __init void qemu_header(void)
918 {
919 	int num;
920 	unsigned long *p;
921 
922 	pr_info("--- cut here ---\n");
923 	pr_info("/* AUTO-GENERATED HEADER FILE FOR SEABIOS FIRMWARE */\n");
924 	pr_cont("/* generated with Linux kernel */\n");
925 	pr_cont("/* search for PARISC_QEMU_MACHINE_HEADER in Linux */\n\n");
926 
927 	pr_info("#define PARISC_MODEL \"%s\"\n\n",
928 			boot_cpu_data.pdc.sys_model_name);
929 
930 	pr_info("#define PARISC_PDC_MODEL 0x%lx, 0x%lx, 0x%lx, "
931 		"0x%lx, 0x%lx, 0x%lx, 0x%lx, 0x%lx, 0x%lx\n\n",
932 	#define p ((unsigned long *)&boot_cpu_data.pdc.model)
933 		p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], p[8]);
934 	#undef p
935 
936 	pr_info("#define PARISC_PDC_VERSION 0x%04lx\n\n",
937 			boot_cpu_data.pdc.versions);
938 
939 	pr_info("#define PARISC_PDC_CPUID 0x%04lx\n\n",
940 			boot_cpu_data.pdc.cpuid);
941 
942 	pr_info("#define PARISC_PDC_CAPABILITIES 0x%04lx\n\n",
943 			boot_cpu_data.pdc.capabilities);
944 
945 	pr_info("#define PARISC_PDC_ENTRY_ORG 0x%04lx\n\n",
946 #ifdef CONFIG_64BIT
947 		(unsigned long)(PAGE0->mem_pdc_hi) << 32 |
948 #endif
949 		(unsigned long)PAGE0->mem_pdc);
950 
951 	pr_info("#define PARISC_PDC_CACHE_INFO");
952 	p = (unsigned long *) &cache_info;
953 	for (num = 0; num < sizeof(cache_info); num += sizeof(unsigned long)) {
954 		if (((num % 5) == 0)) {
955 			pr_cont(" \\\n");
956 			pr_info("\t");
957 		}
958 		pr_cont("%s0x%04lx",
959 			num?", ":"", *p++);
960 	}
961 	pr_cont("\n\n");
962 }
963 
964 static __init int qemu_print_hpa(struct device *lin_dev, void *data)
965 {
966 	struct parisc_device *dev = to_parisc_device(lin_dev);
967 	unsigned long hpa = dev->hpa.start;
968 
969 	pr_cont("\t{\t.hpa = 0x%08lx,\\\n", hpa);
970 	pr_cont("\t\t.iodc = &iodc_data_hpa_%08lx,\\\n", hpa);
971 	pr_cont("\t\t.mod_info = &mod_info_hpa_%08lx,\\\n", hpa);
972 	pr_cont("\t\t.mod_path = &mod_path_hpa_%08lx,\\\n", hpa);
973 	pr_cont("\t\t.num_addr = HPA_%08lx_num_addr,\\\n", hpa);
974 	pr_cont("\t\t.add_addr = { HPA_%08lx_add_addr } },\\\n", hpa);
975 	return 0;
976 }
977 
978 
979 static __init void qemu_footer(void)
980 {
981 	pr_info("\n\n#define PARISC_DEVICE_LIST \\\n");
982 	for_each_padev(qemu_print_hpa, NULL);
983 	pr_cont("\t{ 0, }\n");
984 	pr_info("--- cut here ---\n");
985 }
986 
987 /* print iodc data of the various hpa modules for qemu inclusion */
988 static __init int qemu_print_iodc_data(struct device *lin_dev, void *data)
989 {
990 	struct parisc_device *dev = to_parisc_device(lin_dev);
991 	unsigned long count;
992 	unsigned long hpa = dev->hpa.start;
993 	int status;
994 	struct pdc_iodc iodc_data;
995 
996 	int mod_index;
997 	struct pdc_system_map_mod_info pdc_mod_info;
998 	struct pdc_module_path mod_path;
999 
1000 	status = pdc_iodc_read(&count, hpa, 0,
1001 		&iodc_data, sizeof(iodc_data));
1002 	if (status != PDC_OK) {
1003 		pr_info("No IODC data for hpa 0x%08lx\n", hpa);
1004 		return 0;
1005 	}
1006 
1007 	pr_info("\n");
1008 
1009 	pr_info("#define HPA_%08lx_DESCRIPTION \"%s\"\n",
1010 		hpa, parisc_hardware_description(&dev->id));
1011 
1012 	mod_index = 0;
1013 	do {
1014 		status = pdc_system_map_find_mods(&pdc_mod_info,
1015 				&mod_path, mod_index++);
1016 	} while (status == PDC_OK && pdc_mod_info.mod_addr != hpa);
1017 
1018 	pr_info("static struct pdc_system_map_mod_info"
1019 		" mod_info_hpa_%08lx = {\n", hpa);
1020 	#define DO(member) \
1021 		pr_cont("\t." #member " = 0x%x,\n", \
1022 			(unsigned int)pdc_mod_info.member)
1023 	DO(mod_addr);
1024 	DO(mod_pgs);
1025 	DO(add_addrs);
1026 	pr_cont("};\n");
1027 	#undef DO
1028 	pr_info("static struct pdc_module_path "
1029 		"mod_path_hpa_%08lx = {\n", hpa);
1030 	pr_cont("\t.path = { ");
1031 	pr_cont(".flags = 0x%x, ", mod_path.path.flags);
1032 	pr_cont(".bc = { 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x }, ",
1033 		(unsigned char)mod_path.path.bc[0],
1034 		(unsigned char)mod_path.path.bc[1],
1035 		(unsigned char)mod_path.path.bc[2],
1036 		(unsigned char)mod_path.path.bc[3],
1037 		(unsigned char)mod_path.path.bc[4],
1038 		(unsigned char)mod_path.path.bc[5]);
1039 	pr_cont(".mod = 0x%x ", mod_path.path.mod);
1040 	pr_cont(" },\n");
1041 	pr_cont("\t.layers = { 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x }\n",
1042 		mod_path.layers[0], mod_path.layers[1], mod_path.layers[2],
1043 		mod_path.layers[3], mod_path.layers[4], mod_path.layers[5]);
1044 	pr_cont("};\n");
1045 
1046 	pr_info("static struct pdc_iodc iodc_data_hpa_%08lx = {\n", hpa);
1047 	#define DO(member) \
1048 		pr_cont("\t." #member " = 0x%04lx,\n", \
1049 			(unsigned long)iodc_data.member)
1050 	DO(hversion_model);
1051 	DO(hversion);
1052 	DO(spa);
1053 	DO(type);
1054 	DO(sversion_rev);
1055 	DO(sversion_model);
1056 	DO(sversion_opt);
1057 	DO(rev);
1058 	DO(dep);
1059 	DO(features);
1060 	DO(checksum);
1061 	DO(length);
1062 	#undef DO
1063 	pr_cont("\t/* pad: 0x%04x, 0x%04x */\n",
1064 		iodc_data.pad[0], iodc_data.pad[1]);
1065 	pr_cont("};\n");
1066 
1067 	pr_info("#define HPA_%08lx_num_addr %d\n", hpa, dev->num_addrs);
1068 	pr_info("#define HPA_%08lx_add_addr ", hpa);
1069 	count = 0;
1070 	if (dev->num_addrs == 0)
1071 		pr_cont("0");
1072 	while (count < dev->num_addrs) {
1073 		pr_cont("0x%08lx, ", dev->addr[count]);
1074 		count++;
1075 	}
1076 	pr_cont("\n\n");
1077 
1078 	return 0;
1079 }
1080 
1081 
1082 
1083 static int print_one_device(struct device * dev, void * data)
1084 {
1085 	struct parisc_device * pdev = to_parisc_device(dev);
1086 
1087 	if (check_dev(dev))
1088 		print_parisc_device(pdev);
1089 	return 0;
1090 }
1091 
1092 /**
1093  * print_parisc_devices - Print out a list of devices found in this system
1094  */
1095 void __init print_parisc_devices(void)
1096 {
1097 	for_each_padev(print_one_device, NULL);
1098 	#define PARISC_QEMU_MACHINE_HEADER 0
1099 	if (PARISC_QEMU_MACHINE_HEADER) {
1100 		qemu_header();
1101 		for_each_padev(qemu_print_iodc_data, NULL);
1102 		qemu_footer();
1103 	}
1104 }
1105