xref: /openbmc/linux/arch/powerpc/kernel/pci_dn.c (revision 711aab1d)
1 /*
2  * pci_dn.c
3  *
4  * Copyright (C) 2001 Todd Inglett, IBM Corporation
5  *
6  * PCI manipulation via device_nodes.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
21  */
22 #include <linux/kernel.h>
23 #include <linux/pci.h>
24 #include <linux/string.h>
25 #include <linux/export.h>
26 #include <linux/init.h>
27 #include <linux/gfp.h>
28 
29 #include <asm/io.h>
30 #include <asm/prom.h>
31 #include <asm/pci-bridge.h>
32 #include <asm/ppc-pci.h>
33 #include <asm/firmware.h>
34 #include <asm/eeh.h>
35 
36 /*
37  * The function is used to find the firmware data of one
38  * specific PCI device, which is attached to the indicated
39  * PCI bus. For VFs, their firmware data is linked to that
40  * one of PF's bridge. For other devices, their firmware
41  * data is linked to that of their bridge.
42  */
43 static struct pci_dn *pci_bus_to_pdn(struct pci_bus *bus)
44 {
45 	struct pci_bus *pbus;
46 	struct device_node *dn;
47 	struct pci_dn *pdn;
48 
49 	/*
50 	 * We probably have virtual bus which doesn't
51 	 * have associated bridge.
52 	 */
53 	pbus = bus;
54 	while (pbus) {
55 		if (pci_is_root_bus(pbus) || pbus->self)
56 			break;
57 
58 		pbus = pbus->parent;
59 	}
60 
61 	/*
62 	 * Except virtual bus, all PCI buses should
63 	 * have device nodes.
64 	 */
65 	dn = pci_bus_to_OF_node(pbus);
66 	pdn = dn ? PCI_DN(dn) : NULL;
67 
68 	return pdn;
69 }
70 
71 struct pci_dn *pci_get_pdn_by_devfn(struct pci_bus *bus,
72 				    int devfn)
73 {
74 	struct device_node *dn = NULL;
75 	struct pci_dn *parent, *pdn;
76 	struct pci_dev *pdev = NULL;
77 
78 	/* Fast path: fetch from PCI device */
79 	list_for_each_entry(pdev, &bus->devices, bus_list) {
80 		if (pdev->devfn == devfn) {
81 			if (pdev->dev.archdata.pci_data)
82 				return pdev->dev.archdata.pci_data;
83 
84 			dn = pci_device_to_OF_node(pdev);
85 			break;
86 		}
87 	}
88 
89 	/* Fast path: fetch from device node */
90 	pdn = dn ? PCI_DN(dn) : NULL;
91 	if (pdn)
92 		return pdn;
93 
94 	/* Slow path: fetch from firmware data hierarchy */
95 	parent = pci_bus_to_pdn(bus);
96 	if (!parent)
97 		return NULL;
98 
99 	list_for_each_entry(pdn, &parent->child_list, list) {
100 		if (pdn->busno == bus->number &&
101                     pdn->devfn == devfn)
102                         return pdn;
103         }
104 
105 	return NULL;
106 }
107 
108 struct pci_dn *pci_get_pdn(struct pci_dev *pdev)
109 {
110 	struct device_node *dn;
111 	struct pci_dn *parent, *pdn;
112 
113 	/* Search device directly */
114 	if (pdev->dev.archdata.pci_data)
115 		return pdev->dev.archdata.pci_data;
116 
117 	/* Check device node */
118 	dn = pci_device_to_OF_node(pdev);
119 	pdn = dn ? PCI_DN(dn) : NULL;
120 	if (pdn)
121 		return pdn;
122 
123 	/*
124 	 * VFs don't have device nodes. We hook their
125 	 * firmware data to PF's bridge.
126 	 */
127 	parent = pci_bus_to_pdn(pdev->bus);
128 	if (!parent)
129 		return NULL;
130 
131 	list_for_each_entry(pdn, &parent->child_list, list) {
132 		if (pdn->busno == pdev->bus->number &&
133 		    pdn->devfn == pdev->devfn)
134 			return pdn;
135 	}
136 
137 	return NULL;
138 }
139 
140 #ifdef CONFIG_PCI_IOV
141 static struct pci_dn *add_one_dev_pci_data(struct pci_dn *parent,
142 					   int vf_index,
143 					   int busno, int devfn)
144 {
145 	struct pci_dn *pdn;
146 
147 	/* Except PHB, we always have the parent */
148 	if (!parent)
149 		return NULL;
150 
151 	pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
152 	if (!pdn)
153 		return NULL;
154 
155 	pdn->phb = parent->phb;
156 	pdn->parent = parent;
157 	pdn->busno = busno;
158 	pdn->devfn = devfn;
159 #ifdef CONFIG_PPC_POWERNV
160 	pdn->vf_index = vf_index;
161 	pdn->pe_number = IODA_INVALID_PE;
162 #endif
163 	INIT_LIST_HEAD(&pdn->child_list);
164 	INIT_LIST_HEAD(&pdn->list);
165 	list_add_tail(&pdn->list, &parent->child_list);
166 
167 	return pdn;
168 }
169 #endif
170 
171 struct pci_dn *add_dev_pci_data(struct pci_dev *pdev)
172 {
173 #ifdef CONFIG_PCI_IOV
174 	struct pci_dn *parent, *pdn;
175 	int i;
176 
177 	/* Only support IOV for now */
178 	if (!pdev->is_physfn)
179 		return pci_get_pdn(pdev);
180 
181 	/* Check if VFs have been populated */
182 	pdn = pci_get_pdn(pdev);
183 	if (!pdn || (pdn->flags & PCI_DN_FLAG_IOV_VF))
184 		return NULL;
185 
186 	pdn->flags |= PCI_DN_FLAG_IOV_VF;
187 	parent = pci_bus_to_pdn(pdev->bus);
188 	if (!parent)
189 		return NULL;
190 
191 	for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
192 		struct eeh_dev *edev __maybe_unused;
193 
194 		pdn = add_one_dev_pci_data(parent, i,
195 					   pci_iov_virtfn_bus(pdev, i),
196 					   pci_iov_virtfn_devfn(pdev, i));
197 		if (!pdn) {
198 			dev_warn(&pdev->dev, "%s: Cannot create firmware data for VF#%d\n",
199 				 __func__, i);
200 			return NULL;
201 		}
202 
203 #ifdef CONFIG_EEH
204 		/* Create the EEH device for the VF */
205 		edev = eeh_dev_init(pdn);
206 		BUG_ON(!edev);
207 		edev->physfn = pdev;
208 #endif /* CONFIG_EEH */
209 	}
210 #endif /* CONFIG_PCI_IOV */
211 
212 	return pci_get_pdn(pdev);
213 }
214 
215 void remove_dev_pci_data(struct pci_dev *pdev)
216 {
217 #ifdef CONFIG_PCI_IOV
218 	struct pci_dn *parent;
219 	struct pci_dn *pdn, *tmp;
220 	int i;
221 
222 	/*
223 	 * VF and VF PE are created/released dynamically, so we need to
224 	 * bind/unbind them.  Otherwise the VF and VF PE would be mismatched
225 	 * when re-enabling SR-IOV.
226 	 */
227 	if (pdev->is_virtfn) {
228 		pdn = pci_get_pdn(pdev);
229 #ifdef CONFIG_PPC_POWERNV
230 		pdn->pe_number = IODA_INVALID_PE;
231 #endif
232 		return;
233 	}
234 
235 	/* Only support IOV PF for now */
236 	if (!pdev->is_physfn)
237 		return;
238 
239 	/* Check if VFs have been populated */
240 	pdn = pci_get_pdn(pdev);
241 	if (!pdn || !(pdn->flags & PCI_DN_FLAG_IOV_VF))
242 		return;
243 
244 	pdn->flags &= ~PCI_DN_FLAG_IOV_VF;
245 	parent = pci_bus_to_pdn(pdev->bus);
246 	if (!parent)
247 		return;
248 
249 	/*
250 	 * We might introduce flag to pci_dn in future
251 	 * so that we can release VF's firmware data in
252 	 * a batch mode.
253 	 */
254 	for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
255 		struct eeh_dev *edev __maybe_unused;
256 
257 		list_for_each_entry_safe(pdn, tmp,
258 			&parent->child_list, list) {
259 			if (pdn->busno != pci_iov_virtfn_bus(pdev, i) ||
260 			    pdn->devfn != pci_iov_virtfn_devfn(pdev, i))
261 				continue;
262 
263 #ifdef CONFIG_EEH
264 			/* Release EEH device for the VF */
265 			edev = pdn_to_eeh_dev(pdn);
266 			if (edev) {
267 				pdn->edev = NULL;
268 				kfree(edev);
269 			}
270 #endif /* CONFIG_EEH */
271 
272 			if (!list_empty(&pdn->list))
273 				list_del(&pdn->list);
274 
275 			kfree(pdn);
276 		}
277 	}
278 #endif /* CONFIG_PCI_IOV */
279 }
280 
281 struct pci_dn *pci_add_device_node_info(struct pci_controller *hose,
282 					struct device_node *dn)
283 {
284 	const __be32 *type = of_get_property(dn, "ibm,pci-config-space-type", NULL);
285 	const __be32 *regs;
286 	struct device_node *parent;
287 	struct pci_dn *pdn;
288 #ifdef CONFIG_EEH
289 	struct eeh_dev *edev;
290 #endif
291 
292 	pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
293 	if (pdn == NULL)
294 		return NULL;
295 	dn->data = pdn;
296 	pdn->phb = hose;
297 #ifdef CONFIG_PPC_POWERNV
298 	pdn->pe_number = IODA_INVALID_PE;
299 #endif
300 	regs = of_get_property(dn, "reg", NULL);
301 	if (regs) {
302 		u32 addr = of_read_number(regs, 1);
303 
304 		/* First register entry is addr (00BBSS00)  */
305 		pdn->busno = (addr >> 16) & 0xff;
306 		pdn->devfn = (addr >> 8) & 0xff;
307 	}
308 
309 	/* vendor/device IDs and class code */
310 	regs = of_get_property(dn, "vendor-id", NULL);
311 	pdn->vendor_id = regs ? of_read_number(regs, 1) : 0;
312 	regs = of_get_property(dn, "device-id", NULL);
313 	pdn->device_id = regs ? of_read_number(regs, 1) : 0;
314 	regs = of_get_property(dn, "class-code", NULL);
315 	pdn->class_code = regs ? of_read_number(regs, 1) : 0;
316 
317 	/* Extended config space */
318 	pdn->pci_ext_config_space = (type && of_read_number(type, 1) == 1);
319 
320 	/* Create EEH device */
321 #ifdef CONFIG_EEH
322 	edev = eeh_dev_init(pdn);
323 	if (!edev) {
324 		kfree(pdn);
325 		return NULL;
326 	}
327 #endif
328 
329 	/* Attach to parent node */
330 	INIT_LIST_HEAD(&pdn->child_list);
331 	INIT_LIST_HEAD(&pdn->list);
332 	parent = of_get_parent(dn);
333 	pdn->parent = parent ? PCI_DN(parent) : NULL;
334 	if (pdn->parent)
335 		list_add_tail(&pdn->list, &pdn->parent->child_list);
336 
337 	return pdn;
338 }
339 EXPORT_SYMBOL_GPL(pci_add_device_node_info);
340 
341 void pci_remove_device_node_info(struct device_node *dn)
342 {
343 	struct pci_dn *pdn = dn ? PCI_DN(dn) : NULL;
344 	struct device_node *parent;
345 #ifdef CONFIG_EEH
346 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
347 
348 	if (edev)
349 		edev->pdn = NULL;
350 #endif
351 
352 	if (!pdn)
353 		return;
354 
355 	WARN_ON(!list_empty(&pdn->child_list));
356 	list_del(&pdn->list);
357 
358 	parent = of_get_parent(dn);
359 	if (parent)
360 		of_node_put(parent);
361 
362 	dn->data = NULL;
363 	kfree(pdn);
364 }
365 EXPORT_SYMBOL_GPL(pci_remove_device_node_info);
366 
367 /*
368  * Traverse a device tree stopping each PCI device in the tree.
369  * This is done depth first.  As each node is processed, a "pre"
370  * function is called and the children are processed recursively.
371  *
372  * The "pre" func returns a value.  If non-zero is returned from
373  * the "pre" func, the traversal stops and this value is returned.
374  * This return value is useful when using traverse as a method of
375  * finding a device.
376  *
377  * NOTE: we do not run the func for devices that do not appear to
378  * be PCI except for the start node which we assume (this is good
379  * because the start node is often a phb which may be missing PCI
380  * properties).
381  * We use the class-code as an indicator. If we run into
382  * one of these nodes we also assume its siblings are non-pci for
383  * performance.
384  */
385 void *pci_traverse_device_nodes(struct device_node *start,
386 				void *(*fn)(struct device_node *, void *),
387 				void *data)
388 {
389 	struct device_node *dn, *nextdn;
390 	void *ret;
391 
392 	/* We started with a phb, iterate all childs */
393 	for (dn = start->child; dn; dn = nextdn) {
394 		const __be32 *classp;
395 		u32 class = 0;
396 
397 		nextdn = NULL;
398 		classp = of_get_property(dn, "class-code", NULL);
399 		if (classp)
400 			class = of_read_number(classp, 1);
401 
402 		if (fn) {
403 			ret = fn(dn, data);
404 			if (ret)
405 				return ret;
406 		}
407 
408 		/* If we are a PCI bridge, go down */
409 		if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
410 				  (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
411 			/* Depth first...do children */
412 			nextdn = dn->child;
413 		else if (dn->sibling)
414 			/* ok, try next sibling instead. */
415 			nextdn = dn->sibling;
416 		if (!nextdn) {
417 			/* Walk up to next valid sibling. */
418 			do {
419 				dn = dn->parent;
420 				if (dn == start)
421 					return NULL;
422 			} while (dn->sibling == NULL);
423 			nextdn = dn->sibling;
424 		}
425 	}
426 	return NULL;
427 }
428 EXPORT_SYMBOL_GPL(pci_traverse_device_nodes);
429 
430 static struct pci_dn *pci_dn_next_one(struct pci_dn *root,
431 				      struct pci_dn *pdn)
432 {
433 	struct list_head *next = pdn->child_list.next;
434 
435 	if (next != &pdn->child_list)
436 		return list_entry(next, struct pci_dn, list);
437 
438 	while (1) {
439 		if (pdn == root)
440 			return NULL;
441 
442 		next = pdn->list.next;
443 		if (next != &pdn->parent->child_list)
444 			break;
445 
446 		pdn = pdn->parent;
447 	}
448 
449 	return list_entry(next, struct pci_dn, list);
450 }
451 
452 void *traverse_pci_dn(struct pci_dn *root,
453 		      void *(*fn)(struct pci_dn *, void *),
454 		      void *data)
455 {
456 	struct pci_dn *pdn = root;
457 	void *ret;
458 
459 	/* Only scan the child nodes */
460 	for (pdn = pci_dn_next_one(root, pdn); pdn;
461 	     pdn = pci_dn_next_one(root, pdn)) {
462 		ret = fn(pdn, data);
463 		if (ret)
464 			return ret;
465 	}
466 
467 	return NULL;
468 }
469 
470 static void *add_pdn(struct device_node *dn, void *data)
471 {
472 	struct pci_controller *hose = data;
473 	struct pci_dn *pdn;
474 
475 	pdn = pci_add_device_node_info(hose, dn);
476 	if (!pdn)
477 		return ERR_PTR(-ENOMEM);
478 
479 	return NULL;
480 }
481 
482 /**
483  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
484  * phb: pci-to-host bridge (top-level bridge connecting to cpu)
485  *
486  * This routine is called both during boot, (before the memory
487  * subsystem is set up, before kmalloc is valid) and during the
488  * dynamic lpar operation of adding a PHB to a running system.
489  */
490 void pci_devs_phb_init_dynamic(struct pci_controller *phb)
491 {
492 	struct device_node *dn = phb->dn;
493 	struct pci_dn *pdn;
494 
495 	/* PHB nodes themselves must not match */
496 	pdn = pci_add_device_node_info(phb, dn);
497 	if (pdn) {
498 		pdn->devfn = pdn->busno = -1;
499 		pdn->vendor_id = pdn->device_id = pdn->class_code = 0;
500 		pdn->phb = phb;
501 		phb->pci_data = pdn;
502 	}
503 
504 	/* Update dn->phb ptrs for new phb and children devices */
505 	pci_traverse_device_nodes(dn, add_pdn, phb);
506 }
507 
508 /**
509  * pci_devs_phb_init - Initialize phbs and pci devs under them.
510  *
511  * This routine walks over all phb's (pci-host bridges) on the
512  * system, and sets up assorted pci-related structures
513  * (including pci info in the device node structs) for each
514  * pci device found underneath.  This routine runs once,
515  * early in the boot sequence.
516  */
517 static int __init pci_devs_phb_init(void)
518 {
519 	struct pci_controller *phb, *tmp;
520 
521 	/* This must be done first so the device nodes have valid pci info! */
522 	list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
523 		pci_devs_phb_init_dynamic(phb);
524 
525 	return 0;
526 }
527 
528 core_initcall(pci_devs_phb_init);
529 
530 static void pci_dev_pdn_setup(struct pci_dev *pdev)
531 {
532 	struct pci_dn *pdn;
533 
534 	if (pdev->dev.archdata.pci_data)
535 		return;
536 
537 	/* Setup the fast path */
538 	pdn = pci_get_pdn(pdev);
539 	pdev->dev.archdata.pci_data = pdn;
540 }
541 DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, pci_dev_pdn_setup);
542