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 list_head *tmp, *n;
118 	struct slot *slot;
119 
120 	list_for_each_safe(tmp, n, &rpaphp_slot_head) {
121 		slot = list_entry(tmp, struct slot, rpaphp_slot_list);
122 		if (slot->dn == dn)
123 			return slot;
124 	}
125 
126 	return NULL;
127 }
128 
129 static struct pci_dev *dlpar_find_new_dev(struct pci_bus *parent,
130 					struct device_node *dev_dn)
131 {
132 	struct pci_dev *tmp = NULL;
133 	struct device_node *child_dn;
134 
135 	list_for_each_entry(tmp, &parent->devices, bus_list) {
136 		child_dn = pci_device_to_OF_node(tmp);
137 		if (child_dn == dev_dn)
138 			return tmp;
139 	}
140 	return NULL;
141 }
142 
143 static void dlpar_pci_add_bus(struct device_node *dn)
144 {
145 	struct pci_dn *pdn = PCI_DN(dn);
146 	struct pci_controller *phb = pdn->phb;
147 	struct pci_dev *dev = NULL;
148 
149 	eeh_add_device_tree_early(pdn);
150 
151 	/* Add EADS device to PHB bus, adding new entry to bus->devices */
152 	dev = of_create_pci_dev(dn, phb->bus, pdn->devfn);
153 	if (!dev) {
154 		printk(KERN_ERR "%s: failed to create pci dev for %s\n",
155 				__func__, dn->full_name);
156 		return;
157 	}
158 
159 	/* Scan below the new bridge */
160 	if (pci_is_bridge(dev))
161 		of_scan_pci_bridge(dev);
162 
163 	/* Map IO space for child bus, which may or may not succeed */
164 	pcibios_map_io_space(dev->subordinate);
165 
166 	/* Finish adding it : resource allocation, adding devices, etc...
167 	 * Note that we need to perform the finish pass on the -parent-
168 	 * bus of the EADS bridge so the bridge device itself gets
169 	 * properly added
170 	 */
171 	pcibios_finish_adding_to_bus(phb->bus);
172 }
173 
174 static int dlpar_add_pci_slot(char *drc_name, struct device_node *dn)
175 {
176 	struct pci_dev *dev;
177 	struct pci_controller *phb;
178 
179 	if (pcibios_find_pci_bus(dn))
180 		return -EINVAL;
181 
182 	/* Add pci bus */
183 	dlpar_pci_add_bus(dn);
184 
185 	/* Confirm new bridge dev was created */
186 	phb = PCI_DN(dn)->phb;
187 	dev = dlpar_find_new_dev(phb->bus, dn);
188 
189 	if (!dev) {
190 		printk(KERN_ERR "%s: unable to add bus %s\n", __func__,
191 			drc_name);
192 		return -EIO;
193 	}
194 
195 	if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
196 		printk(KERN_ERR "%s: unexpected header type %d, unable to add bus %s\n",
197 			__func__, dev->hdr_type, drc_name);
198 		return -EIO;
199 	}
200 
201 	/* Add hotplug slot */
202 	if (rpaphp_add_slot(dn)) {
203 		printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
204 			__func__, drc_name);
205 		return -EIO;
206 	}
207 	return 0;
208 }
209 
210 static int dlpar_remove_phb(char *drc_name, struct device_node *dn)
211 {
212 	struct slot *slot;
213 	struct pci_dn *pdn;
214 	int rc = 0;
215 
216 	if (!pcibios_find_pci_bus(dn))
217 		return -EINVAL;
218 
219 	/* If pci slot is hotpluggable, use hotplug to remove it */
220 	slot = find_php_slot(dn);
221 	if (slot && rpaphp_deregister_slot(slot)) {
222 		printk(KERN_ERR "%s: unable to remove hotplug slot %s\n",
223 		       __func__, drc_name);
224 		return -EIO;
225 	}
226 
227 	pdn = dn->data;
228 	BUG_ON(!pdn || !pdn->phb);
229 	rc = remove_phb_dynamic(pdn->phb);
230 	if (rc < 0)
231 		return rc;
232 
233 	pdn->phb = NULL;
234 
235 	return 0;
236 }
237 
238 static int dlpar_add_phb(char *drc_name, struct device_node *dn)
239 {
240 	struct pci_controller *phb;
241 
242 	if (PCI_DN(dn) && PCI_DN(dn)->phb) {
243 		/* PHB already exists */
244 		return -EINVAL;
245 	}
246 
247 	phb = init_phb_dynamic(dn);
248 	if (!phb)
249 		return -EIO;
250 
251 	if (rpaphp_add_slot(dn)) {
252 		printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
253 			__func__, drc_name);
254 		return -EIO;
255 	}
256 	return 0;
257 }
258 
259 static int dlpar_add_vio_slot(char *drc_name, struct device_node *dn)
260 {
261 	if (vio_find_node(dn))
262 		return -EINVAL;
263 
264 	if (!vio_register_device_node(dn)) {
265 		printk(KERN_ERR
266 			"%s: failed to register vio node %s\n",
267 			__func__, drc_name);
268 		return -EIO;
269 	}
270 	return 0;
271 }
272 
273 /**
274  * dlpar_add_slot - DLPAR add an I/O Slot
275  * @drc_name: drc-name of newly added slot
276  *
277  * Make the hotplug module and the kernel aware of a newly added I/O Slot.
278  * Return Codes:
279  * 0			Success
280  * -ENODEV		Not a valid drc_name
281  * -EINVAL		Slot already added
282  * -ERESTARTSYS		Signalled before obtaining lock
283  * -EIO			Internal PCI Error
284  */
285 int dlpar_add_slot(char *drc_name)
286 {
287 	struct device_node *dn = NULL;
288 	int node_type;
289 	int rc = -EIO;
290 
291 	if (mutex_lock_interruptible(&rpadlpar_mutex))
292 		return -ERESTARTSYS;
293 
294 	/* Find newly added node */
295 	dn = find_dlpar_node(drc_name, &node_type);
296 	if (!dn) {
297 		rc = -ENODEV;
298 		goto exit;
299 	}
300 
301 	switch (node_type) {
302 		case NODE_TYPE_VIO:
303 			rc = dlpar_add_vio_slot(drc_name, dn);
304 			break;
305 		case NODE_TYPE_SLOT:
306 			rc = dlpar_add_pci_slot(drc_name, dn);
307 			break;
308 		case NODE_TYPE_PHB:
309 			rc = dlpar_add_phb(drc_name, dn);
310 			break;
311 	}
312 
313 	printk(KERN_INFO "%s: slot %s added\n", DLPAR_MODULE_NAME, drc_name);
314 exit:
315 	mutex_unlock(&rpadlpar_mutex);
316 	return rc;
317 }
318 
319 /**
320  * dlpar_remove_vio_slot - DLPAR remove a virtual I/O Slot
321  * @drc_name: drc-name of newly added slot
322  * @dn: &device_node
323  *
324  * Remove the kernel and hotplug representations of an I/O Slot.
325  * Return Codes:
326  * 0			Success
327  * -EINVAL		Vio dev doesn't exist
328  */
329 static int dlpar_remove_vio_slot(char *drc_name, struct device_node *dn)
330 {
331 	struct vio_dev *vio_dev;
332 
333 	vio_dev = vio_find_node(dn);
334 	if (!vio_dev)
335 		return -EINVAL;
336 
337 	vio_unregister_device(vio_dev);
338 	return 0;
339 }
340 
341 /**
342  * dlpar_remove_pci_slot - DLPAR remove a PCI I/O Slot
343  * @drc_name: drc-name of newly added slot
344  * @dn: &device_node
345  *
346  * Remove the kernel and hotplug representations of a PCI I/O Slot.
347  * Return Codes:
348  * 0			Success
349  * -ENODEV		Not a valid drc_name
350  * -EIO			Internal PCI Error
351  */
352 int dlpar_remove_pci_slot(char *drc_name, struct device_node *dn)
353 {
354 	struct pci_bus *bus;
355 	struct slot *slot;
356 	int ret = 0;
357 
358 	pci_lock_rescan_remove();
359 
360 	bus = pcibios_find_pci_bus(dn);
361 	if (!bus) {
362 		ret = -EINVAL;
363 		goto out;
364 	}
365 
366 	pr_debug("PCI: Removing PCI slot below EADS bridge %s\n",
367 		 bus->self ? pci_name(bus->self) : "<!PHB!>");
368 
369 	slot = find_php_slot(dn);
370 	if (slot) {
371 		pr_debug("PCI: Removing hotplug slot for %04x:%02x...\n",
372 			 pci_domain_nr(bus), bus->number);
373 
374 		if (rpaphp_deregister_slot(slot)) {
375 			printk(KERN_ERR
376 				"%s: unable to remove hotplug slot %s\n",
377 				__func__, drc_name);
378 			ret = -EIO;
379 			goto out;
380 		}
381 	}
382 
383 	/* Remove all devices below slot */
384 	pcibios_remove_pci_devices(bus);
385 
386 	/* Unmap PCI IO space */
387 	if (pcibios_unmap_io_space(bus)) {
388 		printk(KERN_ERR "%s: failed to unmap bus range\n",
389 			__func__);
390 		ret = -ERANGE;
391 		goto out;
392 	}
393 
394 	/* Remove the EADS bridge device itself */
395 	BUG_ON(!bus->self);
396 	pr_debug("PCI: Now removing bridge device %s\n", pci_name(bus->self));
397 	pci_stop_and_remove_bus_device(bus->self);
398 
399  out:
400 	pci_unlock_rescan_remove();
401 	return ret;
402 }
403 
404 /**
405  * dlpar_remove_slot - DLPAR remove an I/O Slot
406  * @drc_name: drc-name of newly added slot
407  *
408  * Remove the kernel and hotplug representations of an I/O Slot.
409  * Return Codes:
410  * 0			Success
411  * -ENODEV		Not a valid drc_name
412  * -EINVAL		Slot already removed
413  * -ERESTARTSYS		Signalled before obtaining lock
414  * -EIO			Internal Error
415  */
416 int dlpar_remove_slot(char *drc_name)
417 {
418 	struct device_node *dn;
419 	int node_type;
420 	int rc = 0;
421 
422 	if (mutex_lock_interruptible(&rpadlpar_mutex))
423 		return -ERESTARTSYS;
424 
425 	dn = find_dlpar_node(drc_name, &node_type);
426 	if (!dn) {
427 		rc = -ENODEV;
428 		goto exit;
429 	}
430 
431 	switch (node_type) {
432 		case NODE_TYPE_VIO:
433 			rc = dlpar_remove_vio_slot(drc_name, dn);
434 			break;
435 		case NODE_TYPE_PHB:
436 			rc = dlpar_remove_phb(drc_name, dn);
437 			break;
438 		case NODE_TYPE_SLOT:
439 			rc = dlpar_remove_pci_slot(drc_name, dn);
440 			break;
441 	}
442 	vm_unmap_aliases();
443 
444 	printk(KERN_INFO "%s: slot %s removed\n", DLPAR_MODULE_NAME, drc_name);
445 exit:
446 	mutex_unlock(&rpadlpar_mutex);
447 	return rc;
448 }
449 
450 static inline int is_dlpar_capable(void)
451 {
452 	int rc = rtas_token("ibm,configure-connector");
453 
454 	return (int) (rc != RTAS_UNKNOWN_SERVICE);
455 }
456 
457 int __init rpadlpar_io_init(void)
458 {
459 	int rc = 0;
460 
461 	if (!is_dlpar_capable()) {
462 		printk(KERN_WARNING "%s: partition not DLPAR capable\n",
463 			__func__);
464 		return -EPERM;
465 	}
466 
467 	rc = dlpar_sysfs_init();
468 	return rc;
469 }
470 
471 void rpadlpar_io_exit(void)
472 {
473 	dlpar_sysfs_exit();
474 	return;
475 }
476 
477 module_init(rpadlpar_io_init);
478 module_exit(rpadlpar_io_exit);
479 MODULE_LICENSE("GPL");
480