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 
55 	return dn;
56 }
57 
58 /* Find dlpar-capable pci node that contains the specified name and type */
59 static struct device_node *find_php_slot_pci_node(char *drc_name,
60 						  char *drc_type)
61 {
62 	struct device_node *np = NULL;
63 	int rc;
64 
65 	while ((np = of_find_node_by_name(np, "pci"))) {
66 		rc = rpaphp_check_drc_props(np, drc_name, drc_type);
67 		if (rc == 0)
68 			break;
69 	}
70 
71 	return np;
72 }
73 
74 static struct device_node *find_dlpar_node(char *drc_name, int *node_type)
75 {
76 	struct device_node *dn;
77 
78 	dn = find_php_slot_pci_node(drc_name, "SLOT");
79 	if (dn) {
80 		*node_type = NODE_TYPE_SLOT;
81 		return dn;
82 	}
83 
84 	dn = find_php_slot_pci_node(drc_name, "PHB");
85 	if (dn) {
86 		*node_type = NODE_TYPE_PHB;
87 		return dn;
88 	}
89 
90 	dn = find_vio_slot_node(drc_name);
91 	if (dn) {
92 		*node_type = NODE_TYPE_VIO;
93 		return dn;
94 	}
95 
96 	return NULL;
97 }
98 
99 /**
100  * find_php_slot - return hotplug slot structure for device node
101  * @dn: target &device_node
102  *
103  * This routine will return the hotplug slot structure
104  * for a given device node. Note that built-in PCI slots
105  * may be dlpar-able, but not hot-pluggable, so this routine
106  * will return NULL for built-in PCI slots.
107  */
108 static struct slot *find_php_slot(struct device_node *dn)
109 {
110 	struct slot *slot, *next;
111 
112 	list_for_each_entry_safe(slot, next, &rpaphp_slot_head,
113 				 rpaphp_slot_list) {
114 		if (slot->dn == dn)
115 			return slot;
116 	}
117 
118 	return NULL;
119 }
120 
121 static struct pci_dev *dlpar_find_new_dev(struct pci_bus *parent,
122 					struct device_node *dev_dn)
123 {
124 	struct pci_dev *tmp = NULL;
125 	struct device_node *child_dn;
126 
127 	list_for_each_entry(tmp, &parent->devices, bus_list) {
128 		child_dn = pci_device_to_OF_node(tmp);
129 		if (child_dn == dev_dn)
130 			return tmp;
131 	}
132 	return NULL;
133 }
134 
135 static void dlpar_pci_add_bus(struct device_node *dn)
136 {
137 	struct pci_dn *pdn = PCI_DN(dn);
138 	struct pci_controller *phb = pdn->phb;
139 	struct pci_dev *dev = NULL;
140 
141 	eeh_add_device_tree_early(pdn);
142 
143 	/* Add EADS device to PHB bus, adding new entry to bus->devices */
144 	dev = of_create_pci_dev(dn, phb->bus, pdn->devfn);
145 	if (!dev) {
146 		printk(KERN_ERR "%s: failed to create pci dev for %pOF\n",
147 				__func__, dn);
148 		return;
149 	}
150 
151 	/* Scan below the new bridge */
152 	if (pci_is_bridge(dev))
153 		of_scan_pci_bridge(dev);
154 
155 	/* Map IO space for child bus, which may or may not succeed */
156 	pcibios_map_io_space(dev->subordinate);
157 
158 	/* Finish adding it : resource allocation, adding devices, etc...
159 	 * Note that we need to perform the finish pass on the -parent-
160 	 * bus of the EADS bridge so the bridge device itself gets
161 	 * properly added
162 	 */
163 	pcibios_finish_adding_to_bus(phb->bus);
164 }
165 
166 static int dlpar_add_pci_slot(char *drc_name, struct device_node *dn)
167 {
168 	struct pci_dev *dev;
169 	struct pci_controller *phb;
170 
171 	if (pci_find_bus_by_node(dn))
172 		return -EINVAL;
173 
174 	/* Add pci bus */
175 	dlpar_pci_add_bus(dn);
176 
177 	/* Confirm new bridge dev was created */
178 	phb = PCI_DN(dn)->phb;
179 	dev = dlpar_find_new_dev(phb->bus, dn);
180 
181 	if (!dev) {
182 		printk(KERN_ERR "%s: unable to add bus %s\n", __func__,
183 			drc_name);
184 		return -EIO;
185 	}
186 
187 	if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
188 		printk(KERN_ERR "%s: unexpected header type %d, unable to add bus %s\n",
189 			__func__, dev->hdr_type, drc_name);
190 		return -EIO;
191 	}
192 
193 	/* Add hotplug slot */
194 	if (rpaphp_add_slot(dn)) {
195 		printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
196 			__func__, drc_name);
197 		return -EIO;
198 	}
199 	return 0;
200 }
201 
202 static int dlpar_remove_phb(char *drc_name, struct device_node *dn)
203 {
204 	struct slot *slot;
205 	struct pci_dn *pdn;
206 	int rc = 0;
207 
208 	if (!pci_find_bus_by_node(dn))
209 		return -EINVAL;
210 
211 	/* If pci slot is hotpluggable, use hotplug to remove it */
212 	slot = find_php_slot(dn);
213 	if (slot && rpaphp_deregister_slot(slot)) {
214 		printk(KERN_ERR "%s: unable to remove hotplug slot %s\n",
215 		       __func__, drc_name);
216 		return -EIO;
217 	}
218 
219 	pdn = dn->data;
220 	BUG_ON(!pdn || !pdn->phb);
221 	rc = remove_phb_dynamic(pdn->phb);
222 	if (rc < 0)
223 		return rc;
224 
225 	pdn->phb = NULL;
226 
227 	return 0;
228 }
229 
230 static int dlpar_add_phb(char *drc_name, struct device_node *dn)
231 {
232 	struct pci_controller *phb;
233 
234 	if (PCI_DN(dn) && PCI_DN(dn)->phb) {
235 		/* PHB already exists */
236 		return -EINVAL;
237 	}
238 
239 	phb = init_phb_dynamic(dn);
240 	if (!phb)
241 		return -EIO;
242 
243 	if (rpaphp_add_slot(dn)) {
244 		printk(KERN_ERR "%s: unable to add hotplug slot %s\n",
245 			__func__, drc_name);
246 		return -EIO;
247 	}
248 	return 0;
249 }
250 
251 static int dlpar_add_vio_slot(char *drc_name, struct device_node *dn)
252 {
253 	struct vio_dev *vio_dev;
254 
255 	vio_dev = vio_find_node(dn);
256 	if (vio_dev) {
257 		put_device(&vio_dev->dev);
258 		return -EINVAL;
259 	}
260 
261 	if (!vio_register_device_node(dn)) {
262 		printk(KERN_ERR
263 			"%s: failed to register vio node %s\n",
264 			__func__, drc_name);
265 		return -EIO;
266 	}
267 	return 0;
268 }
269 
270 /**
271  * dlpar_add_slot - DLPAR add an I/O Slot
272  * @drc_name: drc-name of newly added slot
273  *
274  * Make the hotplug module and the kernel aware of a newly added I/O Slot.
275  * Return Codes:
276  * 0			Success
277  * -ENODEV		Not a valid drc_name
278  * -EINVAL		Slot already added
279  * -ERESTARTSYS		Signalled before obtaining lock
280  * -EIO			Internal PCI Error
281  */
282 int dlpar_add_slot(char *drc_name)
283 {
284 	struct device_node *dn = NULL;
285 	int node_type;
286 	int rc = -EIO;
287 
288 	if (mutex_lock_interruptible(&rpadlpar_mutex))
289 		return -ERESTARTSYS;
290 
291 	/* Find newly added node */
292 	dn = find_dlpar_node(drc_name, &node_type);
293 	if (!dn) {
294 		rc = -ENODEV;
295 		goto exit;
296 	}
297 
298 	switch (node_type) {
299 		case NODE_TYPE_VIO:
300 			rc = dlpar_add_vio_slot(drc_name, dn);
301 			break;
302 		case NODE_TYPE_SLOT:
303 			rc = dlpar_add_pci_slot(drc_name, dn);
304 			break;
305 		case NODE_TYPE_PHB:
306 			rc = dlpar_add_phb(drc_name, dn);
307 			break;
308 	}
309 
310 	printk(KERN_INFO "%s: slot %s added\n", DLPAR_MODULE_NAME, drc_name);
311 exit:
312 	mutex_unlock(&rpadlpar_mutex);
313 	return rc;
314 }
315 
316 /**
317  * dlpar_remove_vio_slot - DLPAR remove a virtual I/O Slot
318  * @drc_name: drc-name of newly added slot
319  * @dn: &device_node
320  *
321  * Remove the kernel and hotplug representations of an I/O Slot.
322  * Return Codes:
323  * 0			Success
324  * -EINVAL		Vio dev doesn't exist
325  */
326 static int dlpar_remove_vio_slot(char *drc_name, struct device_node *dn)
327 {
328 	struct vio_dev *vio_dev;
329 
330 	vio_dev = vio_find_node(dn);
331 	if (!vio_dev)
332 		return -EINVAL;
333 
334 	vio_unregister_device(vio_dev);
335 
336 	put_device(&vio_dev->dev);
337 
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 = pci_find_bus_by_node(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 	pci_hp_remove_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 
460 	if (!is_dlpar_capable()) {
461 		printk(KERN_WARNING "%s: partition not DLPAR capable\n",
462 			__func__);
463 		return -EPERM;
464 	}
465 
466 	return dlpar_sysfs_init();
467 }
468 
469 void rpadlpar_io_exit(void)
470 {
471 	dlpar_sysfs_exit();
472 	return;
473 }
474 
475 module_init(rpadlpar_io_init);
476 module_exit(rpadlpar_io_exit);
477 MODULE_LICENSE("GPL");
478