1 /*
2  * Interface for Dynamic Logical Partitioning of I/O Slots on
3  * RPA-compliant PPC64 platform.
4  *
5  * John Rose <johnrose@austin.ibm.com>
6  * Linda Xie <lxie@us.ibm.com>
7  *
8  * October 2003
9  *
10  * Copyright (C) 2003 IBM.
11  *
12  *      This program is free software; you can redistribute it and/or
13  *      modify it under the terms of the GNU General Public License
14  *      as published by the Free Software Foundation; either version
15  *      2 of the License, or (at your option) any later version.
16  */
17 
18 #undef DEBUG
19 
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <linux/string.h>
24 #include <linux/vmalloc.h>
25 
26 #include <asm/pci-bridge.h>
27 #include <linux/mutex.h>
28 #include <asm/rtas.h>
29 #include <asm/vio.h>
30 
31 #include "../pci.h"
32 #include "rpaphp.h"
33 #include "rpadlpar.h"
34 
35 static DEFINE_MUTEX(rpadlpar_mutex);
36 
37 #define DLPAR_MODULE_NAME "rpadlpar_io"
38 
39 #define NODE_TYPE_VIO  1
40 #define NODE_TYPE_SLOT 2
41 #define NODE_TYPE_PHB  3
42 
43 static struct device_node *find_vio_slot_node(char *drc_name)
44 {
45 	struct device_node *parent = of_find_node_by_name(NULL, "vdevice");
46 	struct device_node *dn = NULL;
47 	char *name;
48 	int rc;
49 
50 	if (!parent)
51 		return NULL;
52 
53 	while ((dn = of_get_next_child(parent, dn))) {
54 		rc = rpaphp_get_drc_props(dn, NULL, &name, NULL, NULL);
55 		if ((rc == 0) && (!strcmp(drc_name, name)))
56 			break;
57 	}
58 
59 	return dn;
60 }
61 
62 /* Find dlpar-capable pci node that contains the specified name and type */
63 static struct device_node *find_php_slot_pci_node(char *drc_name,
64 						  char *drc_type)
65 {
66 	struct device_node *np = NULL;
67 	char *name;
68 	char *type;
69 	int rc;
70 
71 	while ((np = of_find_node_by_name(np, "pci"))) {
72 		rc = rpaphp_get_drc_props(np, NULL, &name, &type, NULL);
73 		if (rc == 0)
74 			if (!strcmp(drc_name, name) && !strcmp(drc_type, type))
75 				break;
76 	}
77 
78 	return np;
79 }
80 
81 static struct device_node *find_dlpar_node(char *drc_name, int *node_type)
82 {
83 	struct device_node *dn;
84 
85 	dn = find_php_slot_pci_node(drc_name, "SLOT");
86 	if (dn) {
87 		*node_type = NODE_TYPE_SLOT;
88 		return dn;
89 	}
90 
91 	dn = find_php_slot_pci_node(drc_name, "PHB");
92 	if (dn) {
93 		*node_type = NODE_TYPE_PHB;
94 		return dn;
95 	}
96 
97 	dn = find_vio_slot_node(drc_name);
98 	if (dn) {
99 		*node_type = NODE_TYPE_VIO;
100 		return dn;
101 	}
102 
103 	return NULL;
104 }
105 
106 /**
107  * find_php_slot - return hotplug slot structure for device node
108  * @dn: target &device_node
109  *
110  * This routine will return the hotplug slot structure
111  * for a given device node. Note that built-in PCI slots
112  * may be dlpar-able, but not hot-pluggable, so this routine
113  * will return NULL for built-in PCI slots.
114  */
115 static struct slot *find_php_slot(struct device_node *dn)
116 {
117 	struct slot *slot, *next;
118 
119 	list_for_each_entry_safe(slot, next, &rpaphp_slot_head,
120 				 rpaphp_slot_list) {
121 		if (slot->dn == dn)
122 			return slot;
123 	}
124 
125 	return NULL;
126 }
127 
128 static struct pci_dev *dlpar_find_new_dev(struct pci_bus *parent,
129 					struct device_node *dev_dn)
130 {
131 	struct pci_dev *tmp = NULL;
132 	struct device_node *child_dn;
133 
134 	list_for_each_entry(tmp, &parent->devices, bus_list) {
135 		child_dn = pci_device_to_OF_node(tmp);
136 		if (child_dn == dev_dn)
137 			return tmp;
138 	}
139 	return NULL;
140 }
141 
142 static void dlpar_pci_add_bus(struct device_node *dn)
143 {
144 	struct pci_dn *pdn = PCI_DN(dn);
145 	struct pci_controller *phb = pdn->phb;
146 	struct pci_dev *dev = NULL;
147 
148 	eeh_add_device_tree_early(pdn);
149 
150 	/* Add EADS device to PHB bus, adding new entry to bus->devices */
151 	dev = of_create_pci_dev(dn, phb->bus, pdn->devfn);
152 	if (!dev) {
153 		printk(KERN_ERR "%s: failed to create pci dev for %s\n",
154 				__func__, dn->full_name);
155 		return;
156 	}
157 
158 	/* Scan below the new bridge */
159 	if (pci_is_bridge(dev))
160 		of_scan_pci_bridge(dev);
161 
162 	/* Map IO space for child bus, which may or may not succeed */
163 	pcibios_map_io_space(dev->subordinate);
164 
165 	/* Finish adding it : resource allocation, adding devices, etc...
166 	 * Note that we need to perform the finish pass on the -parent-
167 	 * bus of the EADS bridge so the bridge device itself gets
168 	 * properly added
169 	 */
170 	pcibios_finish_adding_to_bus(phb->bus);
171 }
172 
173 static int dlpar_add_pci_slot(char *drc_name, struct device_node *dn)
174 {
175 	struct pci_dev *dev;
176 	struct pci_controller *phb;
177 
178 	if (pci_find_bus_by_node(dn))
179 		return -EINVAL;
180 
181 	/* Add pci bus */
182 	dlpar_pci_add_bus(dn);
183 
184 	/* Confirm new bridge dev was created */
185 	phb = PCI_DN(dn)->phb;
186 	dev = dlpar_find_new_dev(phb->bus, dn);
187 
188 	if (!dev) {
189 		printk(KERN_ERR "%s: unable to add bus %s\n", __func__,
190 			drc_name);
191 		return -EIO;
192 	}
193 
194 	if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
195 		printk(KERN_ERR "%s: unexpected header type %d, unable to add bus %s\n",
196 			__func__, dev->hdr_type, drc_name);
197 		return -EIO;
198 	}
199 
200 	/* Add hotplug slot */
201 	if (rpaphp_add_slot(dn)) {
202 		printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
203 			__func__, drc_name);
204 		return -EIO;
205 	}
206 	return 0;
207 }
208 
209 static int dlpar_remove_phb(char *drc_name, struct device_node *dn)
210 {
211 	struct slot *slot;
212 	struct pci_dn *pdn;
213 	int rc = 0;
214 
215 	if (!pci_find_bus_by_node(dn))
216 		return -EINVAL;
217 
218 	/* If pci slot is hotpluggable, use hotplug to remove it */
219 	slot = find_php_slot(dn);
220 	if (slot && rpaphp_deregister_slot(slot)) {
221 		printk(KERN_ERR "%s: unable to remove hotplug slot %s\n",
222 		       __func__, drc_name);
223 		return -EIO;
224 	}
225 
226 	pdn = dn->data;
227 	BUG_ON(!pdn || !pdn->phb);
228 	rc = remove_phb_dynamic(pdn->phb);
229 	if (rc < 0)
230 		return rc;
231 
232 	pdn->phb = NULL;
233 
234 	return 0;
235 }
236 
237 static int dlpar_add_phb(char *drc_name, struct device_node *dn)
238 {
239 	struct pci_controller *phb;
240 
241 	if (PCI_DN(dn) && PCI_DN(dn)->phb) {
242 		/* PHB already exists */
243 		return -EINVAL;
244 	}
245 
246 	phb = init_phb_dynamic(dn);
247 	if (!phb)
248 		return -EIO;
249 
250 	if (rpaphp_add_slot(dn)) {
251 		printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
252 			__func__, drc_name);
253 		return -EIO;
254 	}
255 	return 0;
256 }
257 
258 static int dlpar_add_vio_slot(char *drc_name, struct device_node *dn)
259 {
260 	struct vio_dev *vio_dev;
261 
262 	vio_dev = vio_find_node(dn);
263 	if (vio_dev) {
264 		put_device(&vio_dev->dev);
265 		return -EINVAL;
266 	}
267 
268 	if (!vio_register_device_node(dn)) {
269 		printk(KERN_ERR
270 			"%s: failed to register vio node %s\n",
271 			__func__, drc_name);
272 		return -EIO;
273 	}
274 	return 0;
275 }
276 
277 /**
278  * dlpar_add_slot - DLPAR add an I/O Slot
279  * @drc_name: drc-name of newly added slot
280  *
281  * Make the hotplug module and the kernel aware of a newly added I/O Slot.
282  * Return Codes:
283  * 0			Success
284  * -ENODEV		Not a valid drc_name
285  * -EINVAL		Slot already added
286  * -ERESTARTSYS		Signalled before obtaining lock
287  * -EIO			Internal PCI Error
288  */
289 int dlpar_add_slot(char *drc_name)
290 {
291 	struct device_node *dn = NULL;
292 	int node_type;
293 	int rc = -EIO;
294 
295 	if (mutex_lock_interruptible(&rpadlpar_mutex))
296 		return -ERESTARTSYS;
297 
298 	/* Find newly added node */
299 	dn = find_dlpar_node(drc_name, &node_type);
300 	if (!dn) {
301 		rc = -ENODEV;
302 		goto exit;
303 	}
304 
305 	switch (node_type) {
306 		case NODE_TYPE_VIO:
307 			rc = dlpar_add_vio_slot(drc_name, dn);
308 			break;
309 		case NODE_TYPE_SLOT:
310 			rc = dlpar_add_pci_slot(drc_name, dn);
311 			break;
312 		case NODE_TYPE_PHB:
313 			rc = dlpar_add_phb(drc_name, dn);
314 			break;
315 	}
316 
317 	printk(KERN_INFO "%s: slot %s added\n", DLPAR_MODULE_NAME, drc_name);
318 exit:
319 	mutex_unlock(&rpadlpar_mutex);
320 	return rc;
321 }
322 
323 /**
324  * dlpar_remove_vio_slot - DLPAR remove a virtual I/O Slot
325  * @drc_name: drc-name of newly added slot
326  * @dn: &device_node
327  *
328  * Remove the kernel and hotplug representations of an I/O Slot.
329  * Return Codes:
330  * 0			Success
331  * -EINVAL		Vio dev doesn't exist
332  */
333 static int dlpar_remove_vio_slot(char *drc_name, struct device_node *dn)
334 {
335 	struct vio_dev *vio_dev;
336 
337 	vio_dev = vio_find_node(dn);
338 	if (!vio_dev)
339 		return -EINVAL;
340 
341 	vio_unregister_device(vio_dev);
342 
343 	put_device(&vio_dev->dev);
344 
345 	return 0;
346 }
347 
348 /**
349  * dlpar_remove_pci_slot - DLPAR remove a PCI I/O Slot
350  * @drc_name: drc-name of newly added slot
351  * @dn: &device_node
352  *
353  * Remove the kernel and hotplug representations of a PCI I/O Slot.
354  * Return Codes:
355  * 0			Success
356  * -ENODEV		Not a valid drc_name
357  * -EIO			Internal PCI Error
358  */
359 int dlpar_remove_pci_slot(char *drc_name, struct device_node *dn)
360 {
361 	struct pci_bus *bus;
362 	struct slot *slot;
363 	int ret = 0;
364 
365 	pci_lock_rescan_remove();
366 
367 	bus = pci_find_bus_by_node(dn);
368 	if (!bus) {
369 		ret = -EINVAL;
370 		goto out;
371 	}
372 
373 	pr_debug("PCI: Removing PCI slot below EADS bridge %s\n",
374 		 bus->self ? pci_name(bus->self) : "<!PHB!>");
375 
376 	slot = find_php_slot(dn);
377 	if (slot) {
378 		pr_debug("PCI: Removing hotplug slot for %04x:%02x...\n",
379 			 pci_domain_nr(bus), bus->number);
380 
381 		if (rpaphp_deregister_slot(slot)) {
382 			printk(KERN_ERR
383 				"%s: unable to remove hotplug slot %s\n",
384 				__func__, drc_name);
385 			ret = -EIO;
386 			goto out;
387 		}
388 	}
389 
390 	/* Remove all devices below slot */
391 	pci_hp_remove_devices(bus);
392 
393 	/* Unmap PCI IO space */
394 	if (pcibios_unmap_io_space(bus)) {
395 		printk(KERN_ERR "%s: failed to unmap bus range\n",
396 			__func__);
397 		ret = -ERANGE;
398 		goto out;
399 	}
400 
401 	/* Remove the EADS bridge device itself */
402 	BUG_ON(!bus->self);
403 	pr_debug("PCI: Now removing bridge device %s\n", pci_name(bus->self));
404 	pci_stop_and_remove_bus_device(bus->self);
405 
406  out:
407 	pci_unlock_rescan_remove();
408 	return ret;
409 }
410 
411 /**
412  * dlpar_remove_slot - DLPAR remove an I/O Slot
413  * @drc_name: drc-name of newly added slot
414  *
415  * Remove the kernel and hotplug representations of an I/O Slot.
416  * Return Codes:
417  * 0			Success
418  * -ENODEV		Not a valid drc_name
419  * -EINVAL		Slot already removed
420  * -ERESTARTSYS		Signalled before obtaining lock
421  * -EIO			Internal Error
422  */
423 int dlpar_remove_slot(char *drc_name)
424 {
425 	struct device_node *dn;
426 	int node_type;
427 	int rc = 0;
428 
429 	if (mutex_lock_interruptible(&rpadlpar_mutex))
430 		return -ERESTARTSYS;
431 
432 	dn = find_dlpar_node(drc_name, &node_type);
433 	if (!dn) {
434 		rc = -ENODEV;
435 		goto exit;
436 	}
437 
438 	switch (node_type) {
439 		case NODE_TYPE_VIO:
440 			rc = dlpar_remove_vio_slot(drc_name, dn);
441 			break;
442 		case NODE_TYPE_PHB:
443 			rc = dlpar_remove_phb(drc_name, dn);
444 			break;
445 		case NODE_TYPE_SLOT:
446 			rc = dlpar_remove_pci_slot(drc_name, dn);
447 			break;
448 	}
449 	vm_unmap_aliases();
450 
451 	printk(KERN_INFO "%s: slot %s removed\n", DLPAR_MODULE_NAME, drc_name);
452 exit:
453 	mutex_unlock(&rpadlpar_mutex);
454 	return rc;
455 }
456 
457 static inline int is_dlpar_capable(void)
458 {
459 	int rc = rtas_token("ibm,configure-connector");
460 
461 	return (int) (rc != RTAS_UNKNOWN_SERVICE);
462 }
463 
464 int __init rpadlpar_io_init(void)
465 {
466 
467 	if (!is_dlpar_capable()) {
468 		printk(KERN_WARNING "%s: partition not DLPAR capable\n",
469 			__func__);
470 		return -EPERM;
471 	}
472 
473 	return dlpar_sysfs_init();
474 }
475 
476 void rpadlpar_io_exit(void)
477 {
478 	dlpar_sysfs_exit();
479 	return;
480 }
481 
482 module_init(rpadlpar_io_init);
483 module_exit(rpadlpar_io_exit);
484 MODULE_LICENSE("GPL");
485