xref: /linux/drivers/pci/hotplug/rpaphp_pci.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
1 /*
2  * PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
3  * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
4  *
5  * All rights reserved.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or (at
10  * your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
15  * NON INFRINGEMENT.  See the GNU General Public License for more
16  * details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  *
22  * Send feedback to <lxie@us.ibm.com>
23  *
24  */
25 #include <linux/pci.h>
26 #include <linux/string.h>
27 
28 #include <asm/pci-bridge.h>
29 #include <asm/rtas.h>
30 #include <asm/machdep.h>
31 
32 #include "../pci.h"		/* for pci_add_new_bus */
33 #include "rpaphp.h"
34 
35 static struct pci_bus *find_bus_among_children(struct pci_bus *bus,
36 					struct device_node *dn)
37 {
38 	struct pci_bus *child = NULL;
39 	struct list_head *tmp;
40 	struct device_node *busdn;
41 
42 	busdn = pci_bus_to_OF_node(bus);
43 	if (busdn == dn)
44 		return bus;
45 
46 	list_for_each(tmp, &bus->children) {
47 		child = find_bus_among_children(pci_bus_b(tmp), dn);
48 		if (child)
49 			break;
50 	}
51 	return child;
52 }
53 
54 struct pci_bus *rpaphp_find_pci_bus(struct device_node *dn)
55 {
56 	struct pci_dn *pdn = dn->data;
57 
58 	if (!pdn  || !pdn->phb || !pdn->phb->bus)
59 		return NULL;
60 
61 	return find_bus_among_children(pdn->phb->bus, dn);
62 }
63 EXPORT_SYMBOL_GPL(rpaphp_find_pci_bus);
64 
65 int rpaphp_claim_resource(struct pci_dev *dev, int resource)
66 {
67 	struct resource *res = &dev->resource[resource];
68 	struct resource *root = pci_find_parent_resource(dev, res);
69 	char *dtype = resource < PCI_BRIDGE_RESOURCES ? "device" : "bridge";
70 	int err = -EINVAL;
71 
72 	if (root != NULL) {
73 		err = request_resource(root, res);
74 	}
75 
76 	if (err) {
77 		err("PCI: %s region %d of %s %s [%lx:%lx]\n",
78 		    root ? "Address space collision on" :
79 		    "No parent found for",
80 		    resource, dtype, pci_name(dev), res->start, res->end);
81 	}
82 	return err;
83 }
84 
85 EXPORT_SYMBOL_GPL(rpaphp_claim_resource);
86 
87 static int rpaphp_get_sensor_state(struct slot *slot, int *state)
88 {
89 	int rc;
90 	int setlevel;
91 
92 	rc = rtas_get_sensor(DR_ENTITY_SENSE, slot->index, state);
93 
94 	if (rc < 0) {
95 		if (rc == -EFAULT || rc == -EEXIST) {
96 			dbg("%s: slot must be power up to get sensor-state\n",
97 			    __FUNCTION__);
98 
99 			/* some slots have to be powered up
100 			 * before get-sensor will succeed.
101 			 */
102 			rc = rtas_set_power_level(slot->power_domain, POWER_ON,
103 						  &setlevel);
104 			if (rc < 0) {
105 				dbg("%s: power on slot[%s] failed rc=%d.\n",
106 				    __FUNCTION__, slot->name, rc);
107 			} else {
108 				rc = rtas_get_sensor(DR_ENTITY_SENSE,
109 						     slot->index, state);
110 			}
111 		} else if (rc == -ENODEV)
112 			info("%s: slot is unusable\n", __FUNCTION__);
113 		else
114 			err("%s failed to get sensor state\n", __FUNCTION__);
115 	}
116 	return rc;
117 }
118 
119 /**
120  * get_pci_adapter_status - get the status of a slot
121  *
122  * 0-- slot is empty
123  * 1-- adapter is configured
124  * 2-- adapter is not configured
125  * 3-- not valid
126  */
127 int rpaphp_get_pci_adapter_status(struct slot *slot, int is_init, u8 * value)
128 {
129 	struct pci_bus *bus;
130 	int state, rc;
131 
132 	*value = NOT_VALID;
133 	rc = rpaphp_get_sensor_state(slot, &state);
134 	if (rc)
135 		goto exit;
136 
137  	if (state == EMPTY)
138  		*value = EMPTY;
139  	else if (state == PRESENT) {
140 		if (!is_init) {
141 			/* at run-time slot->state can be changed by */
142 			/* config/unconfig adapter */
143 			*value = slot->state;
144 		} else {
145 			bus = rpaphp_find_pci_bus(slot->dn);
146 			if (bus && !list_empty(&bus->devices))
147 				*value = CONFIGURED;
148 			else
149 				*value = NOT_CONFIGURED;
150 		}
151 	}
152 exit:
153 	return rc;
154 }
155 
156 /* Must be called before pci_bus_add_devices */
157 static void
158 rpaphp_fixup_new_pci_devices(struct pci_bus *bus, int fix_bus)
159 {
160 	struct pci_dev *dev;
161 
162 	list_for_each_entry(dev, &bus->devices, bus_list) {
163 		/*
164 		 * Skip already-present devices (which are on the
165 		 * global device list.)
166 		 */
167 		if (list_empty(&dev->global_list)) {
168 			int i;
169 
170 			/* Need to setup IOMMU tables */
171 			ppc_md.iommu_dev_setup(dev);
172 
173 			if(fix_bus)
174 				pcibios_fixup_device_resources(dev, bus);
175 			pci_read_irq_line(dev);
176 			for (i = 0; i < PCI_NUM_RESOURCES; i++) {
177 				struct resource *r = &dev->resource[i];
178 
179 				if (r->parent || !r->start || !r->flags)
180 					continue;
181 				rpaphp_claim_resource(dev, i);
182 			}
183 		}
184 	}
185 }
186 
187 static int rpaphp_pci_config_bridge(struct pci_dev *dev)
188 {
189 	u8 sec_busno;
190 	struct pci_bus *child_bus;
191 	struct pci_dev *child_dev;
192 
193 	dbg("Enter %s:  BRIDGE dev=%s\n", __FUNCTION__, pci_name(dev));
194 
195 	/* get busno of downstream bus */
196 	pci_read_config_byte(dev, PCI_SECONDARY_BUS, &sec_busno);
197 
198 	/* add to children of PCI bridge dev->bus */
199 	child_bus = pci_add_new_bus(dev->bus, dev, sec_busno);
200 	if (!child_bus) {
201 		err("%s: could not add second bus\n", __FUNCTION__);
202 		return -EIO;
203 	}
204 	sprintf(child_bus->name, "PCI Bus #%02x", child_bus->number);
205 	/* do pci_scan_child_bus */
206 	pci_scan_child_bus(child_bus);
207 
208 	list_for_each_entry(child_dev, &child_bus->devices, bus_list) {
209 		eeh_add_device_late(child_dev);
210 	}
211 
212 	 /* fixup new pci devices without touching bus struct */
213 	rpaphp_fixup_new_pci_devices(child_bus, 0);
214 
215 	/* Make the discovered devices available */
216 	pci_bus_add_devices(child_bus);
217 	return 0;
218 }
219 
220 /*****************************************************************************
221  rpaphp_pci_config_slot() will  configure all devices under the
222  given slot->dn and return the the first pci_dev.
223  *****************************************************************************/
224 static struct pci_dev *
225 rpaphp_pci_config_slot(struct pci_bus *bus)
226 {
227 	struct device_node *dn = pci_bus_to_OF_node(bus);
228 	struct pci_dev *dev = NULL;
229 	int slotno;
230 	int num;
231 
232 	dbg("Enter %s: dn=%s bus=%s\n", __FUNCTION__, dn->full_name, bus->name);
233 	if (!dn || !dn->child)
234 		return NULL;
235 
236 	slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
237 
238 	/* pci_scan_slot should find all children */
239 	num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
240 	if (num) {
241 		rpaphp_fixup_new_pci_devices(bus, 1);
242 		pci_bus_add_devices(bus);
243 	}
244 	if (list_empty(&bus->devices)) {
245 		err("%s: No new device found\n", __FUNCTION__);
246 		return NULL;
247 	}
248 	list_for_each_entry(dev, &bus->devices, bus_list) {
249 		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
250 			rpaphp_pci_config_bridge(dev);
251 	}
252 
253 	return dev;
254 }
255 
256 static void enable_eeh(struct device_node *dn)
257 {
258 	struct device_node *sib;
259 
260 	for (sib = dn->child; sib; sib = sib->sibling)
261 		enable_eeh(sib);
262 	eeh_add_device_early(dn);
263 	return;
264 
265 }
266 
267 static void print_slot_pci_funcs(struct pci_bus *bus)
268 {
269 	struct device_node *dn;
270 	struct pci_dev *dev;
271 
272 	dn = pci_bus_to_OF_node(bus);
273 	if (!dn)
274 		return;
275 
276 	dbg("%s: pci_devs of slot[%s]\n", __FUNCTION__, dn->full_name);
277 	list_for_each_entry (dev, &bus->devices, bus_list)
278 		dbg("\t%s\n", pci_name(dev));
279 	return;
280 }
281 
282 int rpaphp_config_pci_adapter(struct pci_bus *bus)
283 {
284 	struct device_node *dn = pci_bus_to_OF_node(bus);
285 	struct pci_dev *dev;
286 	int rc = -ENODEV;
287 
288 	dbg("Entry %s: slot[%s]\n", __FUNCTION__, dn->full_name);
289 	if (!dn)
290 		goto exit;
291 
292 	enable_eeh(dn);
293 	dev = rpaphp_pci_config_slot(bus);
294 	if (!dev) {
295 		err("%s: can't find any devices.\n", __FUNCTION__);
296 		goto exit;
297 	}
298 	print_slot_pci_funcs(bus);
299 	rc = 0;
300 exit:
301 	dbg("Exit %s:  rc=%d\n", __FUNCTION__, rc);
302 	return rc;
303 }
304 EXPORT_SYMBOL_GPL(rpaphp_config_pci_adapter);
305 
306 static void rpaphp_eeh_remove_bus_device(struct pci_dev *dev)
307 {
308 	eeh_remove_device(dev);
309 	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
310 		struct pci_bus *bus = dev->subordinate;
311 		struct list_head *ln;
312 		if (!bus)
313 			return;
314 		for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
315 			struct pci_dev *pdev = pci_dev_b(ln);
316 			if (pdev)
317 				rpaphp_eeh_remove_bus_device(pdev);
318 		}
319 
320 	}
321 	return;
322 }
323 
324 int rpaphp_unconfig_pci_adapter(struct pci_bus *bus)
325 {
326 	struct pci_dev *dev, *tmp;
327 
328 	list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
329 		rpaphp_eeh_remove_bus_device(dev);
330 		pci_remove_bus_device(dev);
331 	}
332 	return 0;
333 }
334 
335 static int setup_pci_hotplug_slot_info(struct slot *slot)
336 {
337 	dbg("%s Initilize the PCI slot's hotplug->info structure ...\n",
338 	    __FUNCTION__);
339 	rpaphp_get_power_status(slot, &slot->hotplug_slot->info->power_status);
340 	rpaphp_get_pci_adapter_status(slot, 1,
341 				      &slot->hotplug_slot->info->
342 				      adapter_status);
343 	if (slot->hotplug_slot->info->adapter_status == NOT_VALID) {
344 		err("%s: NOT_VALID: skip dn->full_name=%s\n",
345 		    __FUNCTION__, slot->dn->full_name);
346 		return -EINVAL;
347 	}
348 	return 0;
349 }
350 
351 static void set_slot_name(struct slot *slot)
352 {
353 	struct pci_bus *bus = slot->bus;
354 	struct pci_dev *bridge;
355 
356 	bridge = bus->self;
357 	if (bridge)
358 		strcpy(slot->name, pci_name(bridge));
359 	else
360 		sprintf(slot->name, "%04x:%02x:00.0", pci_domain_nr(bus),
361 			bus->number);
362 }
363 
364 static int setup_pci_slot(struct slot *slot)
365 {
366 	struct device_node *dn = slot->dn;
367 	struct pci_bus *bus;
368 
369 	BUG_ON(!dn);
370 	bus = rpaphp_find_pci_bus(dn);
371 	if (!bus) {
372 		err("%s: no pci_bus for dn %s\n", __FUNCTION__, dn->full_name);
373 		goto exit_rc;
374 	}
375 
376 	slot->bus = bus;
377 	slot->pci_devs = &bus->devices;
378 	set_slot_name(slot);
379 
380 	/* find slot's pci_dev if it's not empty */
381 	if (slot->hotplug_slot->info->adapter_status == EMPTY) {
382 		slot->state = EMPTY;	/* slot is empty */
383 	} else {
384 		/* slot is occupied */
385 		if (!dn->child) {
386 			/* non-empty slot has to have child */
387 			err("%s: slot[%s]'s device_node doesn't have child for adapter\n",
388 				__FUNCTION__, slot->name);
389 			goto exit_rc;
390 		}
391 
392 		if (slot->hotplug_slot->info->adapter_status == NOT_CONFIGURED) {
393 			dbg("%s CONFIGURING pci adapter in slot[%s]\n",
394 				__FUNCTION__, slot->name);
395 			if (rpaphp_config_pci_adapter(slot->bus)) {
396 				err("%s: CONFIG pci adapter failed\n", __FUNCTION__);
397 				goto exit_rc;
398 			}
399 
400 		} else if (slot->hotplug_slot->info->adapter_status != CONFIGURED) {
401 			err("%s: slot[%s]'s adapter_status is NOT_VALID.\n",
402 				__FUNCTION__, slot->name);
403 			goto exit_rc;
404 		}
405 		print_slot_pci_funcs(slot->bus);
406 		if (!list_empty(slot->pci_devs)) {
407 			slot->state = CONFIGURED;
408 		} else {
409 			/* DLPAR add as opposed to
410 		 	 * boot time */
411 			slot->state = NOT_CONFIGURED;
412 		}
413 	}
414 	return 0;
415 exit_rc:
416 	dealloc_slot_struct(slot);
417 	return -EINVAL;
418 }
419 
420 int register_pci_slot(struct slot *slot)
421 {
422 	int rc = -EINVAL;
423 
424 	if (setup_pci_hotplug_slot_info(slot))
425 		goto exit_rc;
426 	if (setup_pci_slot(slot))
427 		goto exit_rc;
428 	rc = register_slot(slot);
429 exit_rc:
430 	return rc;
431 }
432 
433 int rpaphp_enable_pci_slot(struct slot *slot)
434 {
435 	int retval = 0, state;
436 
437 	retval = rpaphp_get_sensor_state(slot, &state);
438 	if (retval)
439 		goto exit;
440 	dbg("%s: sensor state[%d]\n", __FUNCTION__, state);
441 	/* if slot is not empty, enable the adapter */
442 	if (state == PRESENT) {
443 		dbg("%s : slot[%s] is occupied.\n", __FUNCTION__, slot->name);
444 		retval = rpaphp_config_pci_adapter(slot->bus);
445 		if (!retval) {
446 			slot->state = CONFIGURED;
447 			dbg("%s: PCI devices in slot[%s] has been configured\n",
448 				__FUNCTION__, slot->name);
449 		} else {
450 			slot->state = NOT_CONFIGURED;
451 			dbg("%s: no pci_dev struct for adapter in slot[%s]\n",
452 			    __FUNCTION__, slot->name);
453 		}
454 	} else if (state == EMPTY) {
455 		dbg("%s : slot[%s] is empty\n", __FUNCTION__, slot->name);
456 		slot->state = EMPTY;
457 	} else {
458 		err("%s: slot[%s] is in invalid state\n", __FUNCTION__,
459 		    slot->name);
460 		slot->state = NOT_VALID;
461 		retval = -EINVAL;
462 	}
463 exit:
464 	dbg("%s - Exit: rc[%d]\n", __FUNCTION__, retval);
465 	return retval;
466 }
467