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