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 = (struct slot *)hotplug_slot->private;
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 		hotplug_slot->info->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 = (struct slot *)hotplug_slot->private;
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 = (struct slot *)hotplug_slot->private;
98 	*value = slot->hotplug_slot->info->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 = (struct slot *)hotplug_slot->private;
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 int **drc_indexes,
158 		const int **drc_names, const int **drc_types,
159 		const int **drc_power_domains)
160 {
161 	const int *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 int *indexes, *names;
198 	const int *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 ((unsigned int) 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, fndit;
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 
243 	for (j = 0; j < entries; j++) {
244 		of_read_drc_info_cell(&info, &value, &drc);
245 
246 		/* Should now know end of current entry */
247 
248 		if (my_index > drc.last_drc_index)
249 			continue;
250 
251 		fndit = 1;
252 		break;
253 	}
254 	/* Found it */
255 
256 	if (fndit)
257 		sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix,
258 			my_index);
259 
260 	if (((drc_name == NULL) ||
261 	     (drc_name && !strcmp(drc_name, cell_drc_name))) &&
262 	    ((drc_type == NULL) ||
263 	     (drc_type && !strcmp(drc_type, drc.drc_type))))
264 		return 0;
265 
266 	return -EINVAL;
267 }
268 
269 int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
270 			char *drc_type)
271 {
272 	const unsigned int *my_index;
273 
274 	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
275 	if (!my_index) {
276 		/* Node isn't DLPAR/hotplug capable */
277 		return -EINVAL;
278 	}
279 
280 	if (firmware_has_feature(FW_FEATURE_DRC_INFO))
281 		return rpaphp_check_drc_props_v2(dn, drc_name, drc_type,
282 						*my_index);
283 	else
284 		return rpaphp_check_drc_props_v1(dn, drc_name, drc_type,
285 						*my_index);
286 }
287 EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);
288 
289 
290 static int is_php_type(char *drc_type)
291 {
292 	unsigned long value;
293 	char *endptr;
294 
295 	/* PCI Hotplug nodes have an integer for drc_type */
296 	value = 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 int **indexes,
317 		const int **names, const int **types, const int **power_domains)
318 {
319 	const int *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 /**
334  * rpaphp_add_slot -- declare a hotplug slot to the hotplug subsystem.
335  * @dn: device node of slot
336  *
337  * This subroutine will register a hotpluggable slot with the
338  * PCI hotplug infrastructure. This routine is typically called
339  * during boot time, if the hotplug slots are present at boot time,
340  * or is called later, by the dlpar add code, if the slot is
341  * being dynamically added during runtime.
342  *
343  * If the device node points at an embedded (built-in) slot, this
344  * routine will just return without doing anything, since embedded
345  * slots cannot be hotplugged.
346  *
347  * To remove a slot, it suffices to call rpaphp_deregister_slot().
348  */
349 int rpaphp_add_slot(struct device_node *dn)
350 {
351 	struct slot *slot;
352 	int retval = 0;
353 	int i;
354 	const int *indexes, *names, *types, *power_domains;
355 	char *name, *type;
356 
357 	if (!dn->name || strcmp(dn->name, "pci"))
358 		return 0;
359 
360 	/* If this is not a hotplug slot, return without doing anything. */
361 	if (!is_php_dn(dn, &indexes, &names, &types, &power_domains))
362 		return 0;
363 
364 	dbg("Entry %s: dn=%pOF\n", __func__, dn);
365 
366 	/* register PCI devices */
367 	name = (char *) &names[1];
368 	type = (char *) &types[1];
369 	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
370 		int index;
371 
372 		index = be32_to_cpu(indexes[i + 1]);
373 		slot = alloc_slot_struct(dn, index, name,
374 					 be32_to_cpu(power_domains[i + 1]));
375 		if (!slot)
376 			return -ENOMEM;
377 
378 		slot->type = simple_strtoul(type, NULL, 10);
379 
380 		dbg("Found drc-index:0x%x drc-name:%s drc-type:%s\n",
381 				index, name, type);
382 
383 		retval = rpaphp_enable_slot(slot);
384 		if (!retval)
385 			retval = rpaphp_register_slot(slot);
386 
387 		if (retval)
388 			dealloc_slot_struct(slot);
389 
390 		name += strlen(name) + 1;
391 		type += strlen(type) + 1;
392 	}
393 	dbg("%s - Exit: rc[%d]\n", __func__, retval);
394 
395 	/* XXX FIXME: reports a failure only if last entry in loop failed */
396 	return retval;
397 }
398 EXPORT_SYMBOL_GPL(rpaphp_add_slot);
399 
400 static void __exit cleanup_slots(void)
401 {
402 	struct slot *slot, *next;
403 
404 	/*
405 	 * Unregister all of our slots with the pci_hotplug subsystem,
406 	 * and free up all memory that we had allocated.
407 	 * memory will be freed in release_slot callback.
408 	 */
409 
410 	list_for_each_entry_safe(slot, next, &rpaphp_slot_head,
411 				 rpaphp_slot_list) {
412 		list_del(&slot->rpaphp_slot_list);
413 		pci_hp_deregister(slot->hotplug_slot);
414 	}
415 	return;
416 }
417 
418 static int __init rpaphp_init(void)
419 {
420 	struct device_node *dn;
421 
422 	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
423 
424 	for_each_node_by_name(dn, "pci")
425 		rpaphp_add_slot(dn);
426 
427 	return 0;
428 }
429 
430 static void __exit rpaphp_exit(void)
431 {
432 	cleanup_slots();
433 }
434 
435 static int enable_slot(struct hotplug_slot *hotplug_slot)
436 {
437 	struct slot *slot = (struct slot *)hotplug_slot->private;
438 	int state;
439 	int retval;
440 
441 	if (slot->state == CONFIGURED)
442 		return 0;
443 
444 	retval = rpaphp_get_sensor_state(slot, &state);
445 	if (retval)
446 		return retval;
447 
448 	if (state == PRESENT) {
449 		pci_lock_rescan_remove();
450 		pci_hp_add_devices(slot->bus);
451 		pci_unlock_rescan_remove();
452 		slot->state = CONFIGURED;
453 	} else if (state == EMPTY) {
454 		slot->state = EMPTY;
455 	} else {
456 		err("%s: slot[%s] is in invalid state\n", __func__, slot->name);
457 		slot->state = NOT_VALID;
458 		return -EINVAL;
459 	}
460 
461 	slot->bus->max_bus_speed = get_max_bus_speed(slot);
462 	return 0;
463 }
464 
465 static int disable_slot(struct hotplug_slot *hotplug_slot)
466 {
467 	struct slot *slot = (struct slot *)hotplug_slot->private;
468 	if (slot->state == NOT_CONFIGURED)
469 		return -EINVAL;
470 
471 	pci_lock_rescan_remove();
472 	pci_hp_remove_devices(slot->bus);
473 	pci_unlock_rescan_remove();
474 	vm_unmap_aliases();
475 
476 	slot->state = NOT_CONFIGURED;
477 	return 0;
478 }
479 
480 struct hotplug_slot_ops rpaphp_hotplug_slot_ops = {
481 	.enable_slot = enable_slot,
482 	.disable_slot = disable_slot,
483 	.set_attention_status = set_attention_status,
484 	.get_power_status = get_power_status,
485 	.get_attention_status = get_attention_status,
486 	.get_adapter_status = get_adapter_status,
487 };
488 
489 module_init(rpaphp_init);
490 module_exit(rpaphp_exit);
491