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