1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
4  * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
5  *
6  * All rights reserved.
7  *
8  * Send feedback to <lxie@us.ibm.com>
9  *
10  */
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/of.h>
15 #include <linux/pci.h>
16 #include <linux/pci_hotplug.h>
17 #include <linux/smp.h>
18 #include <linux/init.h>
19 #include <linux/vmalloc.h>
20 #include <asm/firmware.h>
21 #include <asm/eeh.h>       /* for eeh_add_device() */
22 #include <asm/rtas.h>		/* rtas_call */
23 #include <asm/pci-bridge.h>	/* for pci_controller */
24 #include <asm/prom.h>
25 #include "../pci.h"		/* for pci_add_new_bus */
26 				/* and pci_do_scan_bus */
27 #include "rpaphp.h"
28 
29 bool rpaphp_debug;
30 LIST_HEAD(rpaphp_slot_head);
31 EXPORT_SYMBOL_GPL(rpaphp_slot_head);
32 
33 #define DRIVER_VERSION	"0.1"
34 #define DRIVER_AUTHOR	"Linda Xie <lxie@us.ibm.com>"
35 #define DRIVER_DESC	"RPA HOT Plug PCI Controller Driver"
36 
37 #define MAX_LOC_CODE 128
38 
39 MODULE_AUTHOR(DRIVER_AUTHOR);
40 MODULE_DESCRIPTION(DRIVER_DESC);
41 MODULE_LICENSE("GPL");
42 
43 module_param_named(debug, rpaphp_debug, bool, 0644);
44 
45 /**
46  * set_attention_status - set attention LED
47  * @hotplug_slot: target &hotplug_slot
48  * @value: LED control value
49  *
50  * echo 0 > attention -- set LED OFF
51  * echo 1 > attention -- set LED ON
52  * echo 2 > attention -- set LED ID(identify, light is blinking)
53  */
54 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 value)
55 {
56 	int rc;
57 	struct slot *slot = to_slot(hotplug_slot);
58 
59 	switch (value) {
60 	case 0:
61 	case 1:
62 	case 2:
63 		break;
64 	default:
65 		value = 1;
66 		break;
67 	}
68 
69 	rc = rtas_set_indicator(DR_INDICATOR, slot->index, value);
70 	if (!rc)
71 		slot->attention_status = value;
72 
73 	return rc;
74 }
75 
76 /**
77  * get_power_status - get power status of a slot
78  * @hotplug_slot: slot to get status
79  * @value: pointer to store status
80  */
81 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
82 {
83 	int retval, level;
84 	struct slot *slot = to_slot(hotplug_slot);
85 
86 	retval = rtas_get_power_level(slot->power_domain, &level);
87 	if (!retval)
88 		*value = level;
89 	return retval;
90 }
91 
92 /**
93  * get_attention_status - get attention LED status
94  * @hotplug_slot: slot to get status
95  * @value: pointer to store status
96  */
97 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
98 {
99 	struct slot *slot = to_slot(hotplug_slot);
100 	*value = slot->attention_status;
101 	return 0;
102 }
103 
104 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
105 {
106 	struct slot *slot = to_slot(hotplug_slot);
107 	int rc, state;
108 
109 	rc = rpaphp_get_sensor_state(slot, &state);
110 
111 	*value = NOT_VALID;
112 	if (rc)
113 		return rc;
114 
115 	if (state == EMPTY)
116 		*value = EMPTY;
117 	else if (state == PRESENT)
118 		*value = slot->state;
119 
120 	return 0;
121 }
122 
123 static enum pci_bus_speed get_max_bus_speed(struct slot *slot)
124 {
125 	enum pci_bus_speed speed;
126 	switch (slot->type) {
127 	case 1:
128 	case 2:
129 	case 3:
130 	case 4:
131 	case 5:
132 	case 6:
133 		speed = PCI_SPEED_33MHz;	/* speed for case 1-6 */
134 		break;
135 	case 7:
136 	case 8:
137 		speed = PCI_SPEED_66MHz;
138 		break;
139 	case 11:
140 	case 14:
141 		speed = PCI_SPEED_66MHz_PCIX;
142 		break;
143 	case 12:
144 	case 15:
145 		speed = PCI_SPEED_100MHz_PCIX;
146 		break;
147 	case 13:
148 	case 16:
149 		speed = PCI_SPEED_133MHz_PCIX;
150 		break;
151 	default:
152 		speed = PCI_SPEED_UNKNOWN;
153 		break;
154 	}
155 
156 	return speed;
157 }
158 
159 static int get_children_props(struct device_node *dn, const __be32 **drc_indexes,
160 			      const __be32 **drc_names, const __be32 **drc_types,
161 			      const __be32 **drc_power_domains)
162 {
163 	const __be32 *indexes, *names, *types, *domains;
164 
165 	indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
166 	names = of_get_property(dn, "ibm,drc-names", NULL);
167 	types = of_get_property(dn, "ibm,drc-types", NULL);
168 	domains = of_get_property(dn, "ibm,drc-power-domains", NULL);
169 
170 	if (!indexes || !names || !types || !domains) {
171 		/* Slot does not have dynamically-removable children */
172 		return -EINVAL;
173 	}
174 	if (drc_indexes)
175 		*drc_indexes = indexes;
176 	if (drc_names)
177 		/* &drc_names[1] contains NULL terminated slot names */
178 		*drc_names = names;
179 	if (drc_types)
180 		/* &drc_types[1] contains NULL terminated slot types */
181 		*drc_types = types;
182 	if (drc_power_domains)
183 		*drc_power_domains = domains;
184 
185 	return 0;
186 }
187 
188 
189 /* Verify the existence of 'drc_name' and/or 'drc_type' within the
190  * current node.  First obtain its my-drc-index property.  Next,
191  * obtain the DRC info from its parent.  Use the my-drc-index for
192  * correlation, and obtain/validate the requested properties.
193  */
194 
195 static int rpaphp_check_drc_props_v1(struct device_node *dn, char *drc_name,
196 				char *drc_type, unsigned int my_index)
197 {
198 	char *name_tmp, *type_tmp;
199 	const __be32 *indexes, *names;
200 	const __be32 *types, *domains;
201 	int i, rc;
202 
203 	rc = get_children_props(dn->parent, &indexes, &names, &types, &domains);
204 	if (rc < 0) {
205 		return -EINVAL;
206 	}
207 
208 	name_tmp = (char *) &names[1];
209 	type_tmp = (char *) &types[1];
210 
211 	/* Iterate through parent properties, looking for my-drc-index */
212 	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
213 		if (be32_to_cpu(indexes[i + 1]) == my_index)
214 			break;
215 
216 		name_tmp += (strlen(name_tmp) + 1);
217 		type_tmp += (strlen(type_tmp) + 1);
218 	}
219 
220 	if (((drc_name == NULL) || (drc_name && !strcmp(drc_name, name_tmp))) &&
221 	    ((drc_type == NULL) || (drc_type && !strcmp(drc_type, type_tmp))))
222 		return 0;
223 
224 	return -EINVAL;
225 }
226 
227 static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
228 				char *drc_type, unsigned int my_index)
229 {
230 	struct property *info;
231 	unsigned int entries;
232 	struct of_drc_info drc;
233 	const __be32 *value;
234 	char cell_drc_name[MAX_DRC_NAME_LEN];
235 	int j;
236 
237 	info = of_find_property(dn->parent, "ibm,drc-info", NULL);
238 	if (info == NULL)
239 		return -EINVAL;
240 
241 	value = of_prop_next_u32(info, NULL, &entries);
242 	if (!value)
243 		return -EINVAL;
244 	else
245 		value++;
246 
247 	for (j = 0; j < entries; j++) {
248 		of_read_drc_info_cell(&info, &value, &drc);
249 
250 		/* Should now know end of current entry */
251 
252 		/* Found it */
253 		if (my_index >= drc.drc_index_start && my_index <= drc.last_drc_index) {
254 			int index = my_index - drc.drc_index_start;
255 			sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix,
256 				drc.drc_name_suffix_start + index);
257 			break;
258 		}
259 	}
260 
261 	if (((drc_name == NULL) ||
262 	     (drc_name && !strcmp(drc_name, cell_drc_name))) &&
263 	    ((drc_type == NULL) ||
264 	     (drc_type && !strcmp(drc_type, drc.drc_type))))
265 		return 0;
266 
267 	return -EINVAL;
268 }
269 
270 int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
271 			char *drc_type)
272 {
273 	const __be32 *my_index;
274 
275 	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
276 	if (!my_index) {
277 		/* Node isn't DLPAR/hotplug capable */
278 		return -EINVAL;
279 	}
280 
281 	if (of_property_present(dn->parent, "ibm,drc-info"))
282 		return rpaphp_check_drc_props_v2(dn, drc_name, drc_type,
283 						be32_to_cpu(*my_index));
284 	else
285 		return rpaphp_check_drc_props_v1(dn, drc_name, drc_type,
286 						be32_to_cpu(*my_index));
287 }
288 EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);
289 
290 
291 static int is_php_type(char *drc_type)
292 {
293 	char *endptr;
294 
295 	/* PCI Hotplug nodes have an integer for drc_type */
296 	simple_strtoul(drc_type, &endptr, 10);
297 	if (endptr == drc_type)
298 		return 0;
299 
300 	return 1;
301 }
302 
303 /**
304  * is_php_dn() - return 1 if this is a hotpluggable pci slot, else 0
305  * @dn: target &device_node
306  * @indexes: passed to get_children_props()
307  * @names: passed to get_children_props()
308  * @types: returned from get_children_props()
309  * @power_domains:
310  *
311  * This routine will return true only if the device node is
312  * a hotpluggable slot. This routine will return false
313  * for built-in pci slots (even when the built-in slots are
314  * dlparable.)
315  */
316 static int is_php_dn(struct device_node *dn, const __be32 **indexes,
317 		     const __be32 **names, const __be32 **types,
318 		     const __be32 **power_domains)
319 {
320 	const __be32 *drc_types;
321 	int rc;
322 
323 	rc = get_children_props(dn, indexes, names, &drc_types, power_domains);
324 	if (rc < 0)
325 		return 0;
326 
327 	if (!is_php_type((char *) &drc_types[1]))
328 		return 0;
329 
330 	*types = drc_types;
331 	return 1;
332 }
333 
334 static int rpaphp_drc_info_add_slot(struct device_node *dn)
335 {
336 	struct slot *slot;
337 	struct property *info;
338 	struct of_drc_info drc;
339 	char drc_name[MAX_DRC_NAME_LEN];
340 	const __be32 *cur;
341 	u32 count;
342 	int retval = 0;
343 
344 	info = of_find_property(dn, "ibm,drc-info", NULL);
345 	if (!info)
346 		return 0;
347 
348 	cur = of_prop_next_u32(info, NULL, &count);
349 	if (cur)
350 		cur++;
351 	else
352 		return 0;
353 
354 	of_read_drc_info_cell(&info, &cur, &drc);
355 	if (!is_php_type(drc.drc_type))
356 		return 0;
357 
358 	sprintf(drc_name, "%s%d", drc.drc_name_prefix, drc.drc_name_suffix_start);
359 
360 	slot = alloc_slot_struct(dn, drc.drc_index_start, drc_name, drc.drc_power_domain);
361 	if (!slot)
362 		return -ENOMEM;
363 
364 	slot->type = simple_strtoul(drc.drc_type, NULL, 10);
365 	retval = rpaphp_enable_slot(slot);
366 	if (!retval)
367 		retval = rpaphp_register_slot(slot);
368 
369 	if (retval)
370 		dealloc_slot_struct(slot);
371 
372 	return retval;
373 }
374 
375 static int rpaphp_drc_add_slot(struct device_node *dn)
376 {
377 	struct slot *slot;
378 	int retval = 0;
379 	int i;
380 	const __be32 *indexes, *names, *types, *power_domains;
381 	char *name, *type;
382 
383 	/* If this is not a hotplug slot, return without doing anything. */
384 	if (!is_php_dn(dn, &indexes, &names, &types, &power_domains))
385 		return 0;
386 
387 	dbg("Entry %s: dn=%pOF\n", __func__, dn);
388 
389 	/* register PCI devices */
390 	name = (char *) &names[1];
391 	type = (char *) &types[1];
392 	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
393 		int index;
394 
395 		index = be32_to_cpu(indexes[i + 1]);
396 		slot = alloc_slot_struct(dn, index, name,
397 					 be32_to_cpu(power_domains[i + 1]));
398 		if (!slot)
399 			return -ENOMEM;
400 
401 		slot->type = simple_strtoul(type, NULL, 10);
402 
403 		dbg("Found drc-index:0x%x drc-name:%s drc-type:%s\n",
404 				index, name, type);
405 
406 		retval = rpaphp_enable_slot(slot);
407 		if (!retval)
408 			retval = rpaphp_register_slot(slot);
409 
410 		if (retval)
411 			dealloc_slot_struct(slot);
412 
413 		name += strlen(name) + 1;
414 		type += strlen(type) + 1;
415 	}
416 	dbg("%s - Exit: rc[%d]\n", __func__, retval);
417 
418 	/* XXX FIXME: reports a failure only if last entry in loop failed */
419 	return retval;
420 }
421 
422 /**
423  * rpaphp_add_slot -- declare a hotplug slot to the hotplug subsystem.
424  * @dn: device node of slot
425  *
426  * This subroutine will register a hotpluggable slot with the
427  * PCI hotplug infrastructure. This routine is typically called
428  * during boot time, if the hotplug slots are present at boot time,
429  * or is called later, by the dlpar add code, if the slot is
430  * being dynamically added during runtime.
431  *
432  * If the device node points at an embedded (built-in) slot, this
433  * routine will just return without doing anything, since embedded
434  * slots cannot be hotplugged.
435  *
436  * To remove a slot, it suffices to call rpaphp_deregister_slot().
437  */
438 int rpaphp_add_slot(struct device_node *dn)
439 {
440 	if (!of_node_name_eq(dn, "pci"))
441 		return 0;
442 
443 	if (of_property_present(dn, "ibm,drc-info"))
444 		return rpaphp_drc_info_add_slot(dn);
445 	else
446 		return rpaphp_drc_add_slot(dn);
447 }
448 EXPORT_SYMBOL_GPL(rpaphp_add_slot);
449 
450 static void __exit cleanup_slots(void)
451 {
452 	struct slot *slot, *next;
453 
454 	/*
455 	 * Unregister all of our slots with the pci_hotplug subsystem,
456 	 * and free up all memory that we had allocated.
457 	 */
458 
459 	list_for_each_entry_safe(slot, next, &rpaphp_slot_head,
460 				 rpaphp_slot_list) {
461 		list_del(&slot->rpaphp_slot_list);
462 		pci_hp_deregister(&slot->hotplug_slot);
463 		dealloc_slot_struct(slot);
464 	}
465 }
466 
467 static int __init rpaphp_init(void)
468 {
469 	struct device_node *dn;
470 
471 	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
472 
473 	for_each_node_by_name(dn, "pci")
474 		rpaphp_add_slot(dn);
475 
476 	return 0;
477 }
478 
479 static void __exit rpaphp_exit(void)
480 {
481 	cleanup_slots();
482 }
483 
484 static int enable_slot(struct hotplug_slot *hotplug_slot)
485 {
486 	struct slot *slot = to_slot(hotplug_slot);
487 	int state;
488 	int retval;
489 
490 	if (slot->state == CONFIGURED)
491 		return 0;
492 
493 	retval = rpaphp_get_sensor_state(slot, &state);
494 	if (retval)
495 		return retval;
496 
497 	if (state == PRESENT) {
498 		pseries_eeh_init_edev_recursive(PCI_DN(slot->dn));
499 
500 		pci_lock_rescan_remove();
501 		pci_hp_add_devices(slot->bus);
502 		pci_unlock_rescan_remove();
503 		slot->state = CONFIGURED;
504 	} else if (state == EMPTY) {
505 		slot->state = EMPTY;
506 	} else {
507 		err("%s: slot[%s] is in invalid state\n", __func__, slot->name);
508 		slot->state = NOT_VALID;
509 		return -EINVAL;
510 	}
511 
512 	slot->bus->max_bus_speed = get_max_bus_speed(slot);
513 	return 0;
514 }
515 
516 static int disable_slot(struct hotplug_slot *hotplug_slot)
517 {
518 	struct slot *slot = to_slot(hotplug_slot);
519 	if (slot->state == NOT_CONFIGURED)
520 		return -EINVAL;
521 
522 	pci_lock_rescan_remove();
523 	pci_hp_remove_devices(slot->bus);
524 	pci_unlock_rescan_remove();
525 	vm_unmap_aliases();
526 
527 	slot->state = NOT_CONFIGURED;
528 	return 0;
529 }
530 
531 const struct hotplug_slot_ops rpaphp_hotplug_slot_ops = {
532 	.enable_slot = enable_slot,
533 	.disable_slot = disable_slot,
534 	.set_attention_status = set_attention_status,
535 	.get_power_status = get_power_status,
536 	.get_attention_status = get_attention_status,
537 	.get_adapter_status = get_adapter_status,
538 };
539 
540 module_init(rpaphp_init);
541 module_exit(rpaphp_exit);
542