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