1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Interface for Dynamic Logical Partitioning of I/O Slots on
4 * RPA-compliant PPC64 platform.
5 *
6 * John Rose <johnrose@austin.ibm.com>
7 * Linda Xie <lxie@us.ibm.com>
8 *
9 * October 2003
10 *
11 * Copyright (C) 2003 IBM.
12 */
13
14#undef DEBUG
15
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/pci.h>
20#include <linux/string.h>
21#include <linux/vmalloc.h>
22
23#include <asm/pci-bridge.h>
24#include <linux/mutex.h>
25#include <asm/rtas.h>
26#include <asm/vio.h>
27#include <linux/firmware.h>
28
29#include "../pci.h"
30#include "rpaphp.h"
31#include "rpadlpar.h"
32
33static DEFINE_MUTEX(rpadlpar_mutex);
34
35#define DLPAR_MODULE_NAME "rpadlpar_io"
36
37#define NODE_TYPE_VIO  1
38#define NODE_TYPE_SLOT 2
39#define NODE_TYPE_PHB  3
40
41static struct device_node *find_vio_slot_node(char *drc_name)
42{
43	struct device_node *parent = of_find_node_by_name(NULL, "vdevice");
44	struct device_node *dn;
45	int rc;
46
47	if (!parent)
48		return NULL;
49
50	for_each_child_of_node(parent, dn) {
51		rc = rpaphp_check_drc_props(dn, drc_name, NULL);
52		if (rc == 0)
53			break;
54	}
55	of_node_put(parent);
56
57	return dn;
58}
59
60/* Find dlpar-capable pci node that contains the specified name and type */
61static struct device_node *find_php_slot_pci_node(char *drc_name,
62						  char *drc_type)
63{
64	struct device_node *np;
65	int rc;
66
67	for_each_node_by_name(np, "pci") {
68		rc = rpaphp_check_drc_props(np, drc_name, drc_type);
69		if (rc == 0)
70			break;
71	}
72
73	return np;
74}
75
76/* Returns a device_node with its reference count incremented */
77static struct device_node *find_dlpar_node(char *drc_name, int *node_type)
78{
79	struct device_node *dn;
80
81	dn = find_php_slot_pci_node(drc_name, "SLOT");
82	if (dn) {
83		*node_type = NODE_TYPE_SLOT;
84		return dn;
85	}
86
87	dn = find_php_slot_pci_node(drc_name, "PHB");
88	if (dn) {
89		*node_type = NODE_TYPE_PHB;
90		return dn;
91	}
92
93	dn = find_vio_slot_node(drc_name);
94	if (dn) {
95		*node_type = NODE_TYPE_VIO;
96		return dn;
97	}
98
99	return NULL;
100}
101
102/**
103 * find_php_slot - return hotplug slot structure for device node
104 * @dn: target &device_node
105 *
106 * This routine will return the hotplug slot structure
107 * for a given device node. Note that built-in PCI slots
108 * may be dlpar-able, but not hot-pluggable, so this routine
109 * will return NULL for built-in PCI slots.
110 */
111static struct slot *find_php_slot(struct device_node *dn)
112{
113	struct slot *slot, *next;
114
115	list_for_each_entry_safe(slot, next, &rpaphp_slot_head,
116				 rpaphp_slot_list) {
117		if (slot->dn == dn)
118			return slot;
119	}
120
121	return NULL;
122}
123
124static struct pci_dev *dlpar_find_new_dev(struct pci_bus *parent,
125					struct device_node *dev_dn)
126{
127	struct pci_dev *tmp = NULL;
128	struct device_node *child_dn;
129
130	list_for_each_entry(tmp, &parent->devices, bus_list) {
131		child_dn = pci_device_to_OF_node(tmp);
132		if (child_dn == dev_dn)
133			return tmp;
134	}
135	return NULL;
136}
137
138static void dlpar_pci_add_bus(struct device_node *dn)
139{
140	struct pci_dn *pdn = PCI_DN(dn);
141	struct pci_controller *phb = pdn->phb;
142	struct pci_dev *dev = NULL;
143
144	pseries_eeh_init_edev_recursive(pdn);
145
146	/* Add EADS device to PHB bus, adding new entry to bus->devices */
147	dev = of_create_pci_dev(dn, phb->bus, pdn->devfn);
148	if (!dev) {
149		printk(KERN_ERR "%s: failed to create pci dev for %pOF\n",
150				__func__, dn);
151		return;
152	}
153
154	/* Scan below the new bridge */
155	if (pci_is_bridge(dev))
156		of_scan_pci_bridge(dev);
157
158	/* Map IO space for child bus, which may or may not succeed */
159	pcibios_map_io_space(dev->subordinate);
160
161	/* Finish adding it : resource allocation, adding devices, etc...
162	 * Note that we need to perform the finish pass on the -parent-
163	 * bus of the EADS bridge so the bridge device itself gets
164	 * properly added
165	 */
166	pcibios_finish_adding_to_bus(phb->bus);
167}
168
169static int dlpar_add_pci_slot(char *drc_name, struct device_node *dn)
170{
171	struct pci_dev *dev;
172	struct pci_controller *phb;
173
174	if (pci_find_bus_by_node(dn))
175		return -EINVAL;
176
177	/* Add pci bus */
178	dlpar_pci_add_bus(dn);
179
180	/* Confirm new bridge dev was created */
181	phb = PCI_DN(dn)->phb;
182	dev = dlpar_find_new_dev(phb->bus, dn);
183
184	if (!dev) {
185		printk(KERN_ERR "%s: unable to add bus %s\n", __func__,
186			drc_name);
187		return -EIO;
188	}
189
190	if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
191		printk(KERN_ERR "%s: unexpected header type %d, unable to add bus %s\n",
192			__func__, dev->hdr_type, drc_name);
193		return -EIO;
194	}
195
196	/* Add hotplug slot */
197	if (rpaphp_add_slot(dn)) {
198		printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
199			__func__, drc_name);
200		return -EIO;
201	}
202	return 0;
203}
204
205static int dlpar_remove_phb(char *drc_name, struct device_node *dn)
206{
207	struct slot *slot;
208	struct pci_dn *pdn;
209	int rc = 0;
210
211	if (!pci_find_bus_by_node(dn))
212		return -EINVAL;
213
214	/* If pci slot is hotpluggable, use hotplug to remove it */
215	slot = find_php_slot(dn);
216	if (slot && rpaphp_deregister_slot(slot)) {
217		printk(KERN_ERR "%s: unable to remove hotplug slot %s\n",
218		       __func__, drc_name);
219		return -EIO;
220	}
221
222	pdn = dn->data;
223	BUG_ON(!pdn || !pdn->phb);
224	rc = remove_phb_dynamic(pdn->phb);
225	if (rc < 0)
226		return rc;
227
228	pdn->phb = NULL;
229
230	return 0;
231}
232
233static int dlpar_add_phb(char *drc_name, struct device_node *dn)
234{
235	struct pci_controller *phb;
236
237	if (PCI_DN(dn) && PCI_DN(dn)->phb) {
238		/* PHB already exists */
239		return -EINVAL;
240	}
241
242	phb = init_phb_dynamic(dn);
243	if (!phb)
244		return -EIO;
245
246	if (rpaphp_add_slot(dn)) {
247		printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
248			__func__, drc_name);
249		return -EIO;
250	}
251	return 0;
252}
253
254static int dlpar_add_vio_slot(char *drc_name, struct device_node *dn)
255{
256	struct vio_dev *vio_dev;
257
258	vio_dev = vio_find_node(dn);
259	if (vio_dev) {
260		put_device(&vio_dev->dev);
261		return -EINVAL;
262	}
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 */
285int 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	of_node_put(dn);
313
314	printk(KERN_INFO "%s: slot %s added\n", DLPAR_MODULE_NAME, drc_name);
315exit:
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 */
330static 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
340	put_device(&vio_dev->dev);
341
342	return 0;
343}
344
345/**
346 * dlpar_remove_pci_slot - DLPAR remove a PCI I/O Slot
347 * @drc_name: drc-name of newly added slot
348 * @dn: &device_node
349 *
350 * Remove the kernel and hotplug representations of a PCI I/O Slot.
351 * Return Codes:
352 * 0			Success
353 * -ENODEV		Not a valid drc_name
354 * -EIO			Internal PCI Error
355 */
356static int dlpar_remove_pci_slot(char *drc_name, struct device_node *dn)
357{
358	struct pci_bus *bus;
359	struct slot *slot;
360	int ret = 0;
361
362	pci_lock_rescan_remove();
363
364	bus = pci_find_bus_by_node(dn);
365	if (!bus) {
366		ret = -EINVAL;
367		goto out;
368	}
369
370	pr_debug("PCI: Removing PCI slot below EADS bridge %s\n",
371		 bus->self ? pci_name(bus->self) : "<!PHB!>");
372
373	slot = find_php_slot(dn);
374	if (slot) {
375		pr_debug("PCI: Removing hotplug slot for %04x:%02x...\n",
376			 pci_domain_nr(bus), bus->number);
377
378		if (rpaphp_deregister_slot(slot)) {
379			printk(KERN_ERR
380				"%s: unable to remove hotplug slot %s\n",
381				__func__, drc_name);
382			ret = -EIO;
383			goto out;
384		}
385	}
386
387	/* Remove all devices below slot */
388	pci_hp_remove_devices(bus);
389
390	/* Unmap PCI IO space */
391	if (pcibios_unmap_io_space(bus)) {
392		printk(KERN_ERR "%s: failed to unmap bus range\n",
393			__func__);
394		ret = -ERANGE;
395		goto out;
396	}
397
398	/* Remove the EADS bridge device itself */
399	BUG_ON(!bus->self);
400	pr_debug("PCI: Now removing bridge device %s\n", pci_name(bus->self));
401	pci_stop_and_remove_bus_device(bus->self);
402
403 out:
404	pci_unlock_rescan_remove();
405	return ret;
406}
407
408/**
409 * dlpar_remove_slot - DLPAR remove an I/O Slot
410 * @drc_name: drc-name of newly added slot
411 *
412 * Remove the kernel and hotplug representations of an I/O Slot.
413 * Return Codes:
414 * 0			Success
415 * -ENODEV		Not a valid drc_name
416 * -EINVAL		Slot already removed
417 * -ERESTARTSYS		Signalled before obtaining lock
418 * -EIO			Internal Error
419 */
420int dlpar_remove_slot(char *drc_name)
421{
422	struct device_node *dn;
423	int node_type;
424	int rc = 0;
425
426	if (mutex_lock_interruptible(&rpadlpar_mutex))
427		return -ERESTARTSYS;
428
429	dn = find_dlpar_node(drc_name, &node_type);
430	if (!dn) {
431		rc = -ENODEV;
432		goto exit;
433	}
434
435	switch (node_type) {
436		case NODE_TYPE_VIO:
437			rc = dlpar_remove_vio_slot(drc_name, dn);
438			break;
439		case NODE_TYPE_PHB:
440			rc = dlpar_remove_phb(drc_name, dn);
441			break;
442		case NODE_TYPE_SLOT:
443			rc = dlpar_remove_pci_slot(drc_name, dn);
444			break;
445	}
446	of_node_put(dn);
447	vm_unmap_aliases();
448
449	printk(KERN_INFO "%s: slot %s removed\n", DLPAR_MODULE_NAME, drc_name);
450exit:
451	mutex_unlock(&rpadlpar_mutex);
452	return rc;
453}
454
455static inline int is_dlpar_capable(void)
456{
457	int rc = rtas_token("ibm,configure-connector");
458
459	return (int) (rc != RTAS_UNKNOWN_SERVICE);
460}
461
462static int __init rpadlpar_io_init(void)
463{
464
465	if (!is_dlpar_capable()) {
466		printk(KERN_WARNING "%s: partition not DLPAR capable\n",
467			__func__);
468		return -EPERM;
469	}
470
471	return dlpar_sysfs_init();
472}
473
474static void __exit rpadlpar_io_exit(void)
475{
476	dlpar_sysfs_exit();
477}
478
479module_init(rpadlpar_io_init);
480module_exit(rpadlpar_io_exit);
481MODULE_LICENSE("GPL");
482MODULE_DESCRIPTION("RPA Dynamic Logical Partitioning driver for I/O slots");
483