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
35/*
36 * The function is used to find the firmware data of one
37 * specific PCI device, which is attached to the indicated
38 * PCI bus. For VFs, their firmware data is linked to that
39 * one of PF's bridge. For other devices, their firmware
40 * data is linked to that of their bridge.
41 */
42static struct pci_dn *pci_bus_to_pdn(struct pci_bus *bus)
43{
44	struct pci_bus *pbus;
45	struct device_node *dn;
46	struct pci_dn *pdn;
47
48	/*
49	 * We probably have virtual bus which doesn't
50	 * have associated bridge.
51	 */
52	pbus = bus;
53	while (pbus) {
54		if (pci_is_root_bus(pbus) || pbus->self)
55			break;
56
57		pbus = pbus->parent;
58	}
59
60	/*
61	 * Except virtual bus, all PCI buses should
62	 * have device nodes.
63	 */
64	dn = pci_bus_to_OF_node(pbus);
65	pdn = dn ? PCI_DN(dn) : NULL;
66
67	return pdn;
68}
69
70struct pci_dn *pci_get_pdn_by_devfn(struct pci_bus *bus,
71				    int devfn)
72{
73	struct device_node *dn = NULL;
74	struct pci_dn *parent, *pdn;
75	struct pci_dev *pdev = NULL;
76
77	/* Fast path: fetch from PCI device */
78	list_for_each_entry(pdev, &bus->devices, bus_list) {
79		if (pdev->devfn == devfn) {
80			if (pdev->dev.archdata.pci_data)
81				return pdev->dev.archdata.pci_data;
82
83			dn = pci_device_to_OF_node(pdev);
84			break;
85		}
86	}
87
88	/* Fast path: fetch from device node */
89	pdn = dn ? PCI_DN(dn) : NULL;
90	if (pdn)
91		return pdn;
92
93	/* Slow path: fetch from firmware data hierarchy */
94	parent = pci_bus_to_pdn(bus);
95	if (!parent)
96		return NULL;
97
98	list_for_each_entry(pdn, &parent->child_list, list) {
99		if (pdn->busno == bus->number &&
100                    pdn->devfn == devfn)
101                        return pdn;
102        }
103
104	return NULL;
105}
106
107struct pci_dn *pci_get_pdn(struct pci_dev *pdev)
108{
109	struct device_node *dn;
110	struct pci_dn *parent, *pdn;
111
112	/* Search device directly */
113	if (pdev->dev.archdata.pci_data)
114		return pdev->dev.archdata.pci_data;
115
116	/* Check device node */
117	dn = pci_device_to_OF_node(pdev);
118	pdn = dn ? PCI_DN(dn) : NULL;
119	if (pdn)
120		return pdn;
121
122	/*
123	 * VFs don't have device nodes. We hook their
124	 * firmware data to PF's bridge.
125	 */
126	parent = pci_bus_to_pdn(pdev->bus);
127	if (!parent)
128		return NULL;
129
130	list_for_each_entry(pdn, &parent->child_list, list) {
131		if (pdn->busno == pdev->bus->number &&
132		    pdn->devfn == pdev->devfn)
133			return pdn;
134	}
135
136	return NULL;
137}
138
139#ifdef CONFIG_PCI_IOV
140static struct pci_dn *add_one_dev_pci_data(struct pci_dn *parent,
141					   struct pci_dev *pdev,
142					   int busno, int devfn)
143{
144	struct pci_dn *pdn;
145
146	/* Except PHB, we always have the parent */
147	if (!parent)
148		return NULL;
149
150	pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
151	if (!pdn) {
152		dev_warn(&pdev->dev, "%s: Out of memory!\n", __func__);
153		return NULL;
154	}
155
156	pdn->phb = parent->phb;
157	pdn->parent = parent;
158	pdn->busno = busno;
159	pdn->devfn = devfn;
160#ifdef CONFIG_PPC_POWERNV
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	/*
168	 * If we already have PCI device instance, lets
169	 * bind them.
170	 */
171	if (pdev)
172		pdev->dev.archdata.pci_data = pdn;
173
174	return pdn;
175}
176#endif
177
178struct pci_dn *add_dev_pci_data(struct pci_dev *pdev)
179{
180#ifdef CONFIG_PCI_IOV
181	struct pci_dn *parent, *pdn;
182	int i;
183
184	/* Only support IOV for now */
185	if (!pdev->is_physfn)
186		return pci_get_pdn(pdev);
187
188	/* Check if VFs have been populated */
189	pdn = pci_get_pdn(pdev);
190	if (!pdn || (pdn->flags & PCI_DN_FLAG_IOV_VF))
191		return NULL;
192
193	pdn->flags |= PCI_DN_FLAG_IOV_VF;
194	parent = pci_bus_to_pdn(pdev->bus);
195	if (!parent)
196		return NULL;
197
198	for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
199		pdn = add_one_dev_pci_data(parent, NULL,
200					   pci_iov_virtfn_bus(pdev, i),
201					   pci_iov_virtfn_devfn(pdev, i));
202		if (!pdn) {
203			dev_warn(&pdev->dev, "%s: Cannot create firmware data for VF#%d\n",
204				 __func__, i);
205			return NULL;
206		}
207	}
208#endif /* CONFIG_PCI_IOV */
209
210	return pci_get_pdn(pdev);
211}
212
213void remove_dev_pci_data(struct pci_dev *pdev)
214{
215#ifdef CONFIG_PCI_IOV
216	struct pci_dn *parent;
217	struct pci_dn *pdn, *tmp;
218	int i;
219
220	/*
221	 * VF and VF PE are created/released dynamically, so we need to
222	 * bind/unbind them.  Otherwise the VF and VF PE would be mismatched
223	 * when re-enabling SR-IOV.
224	 */
225	if (pdev->is_virtfn) {
226		pdn = pci_get_pdn(pdev);
227#ifdef CONFIG_PPC_POWERNV
228		pdn->pe_number = IODA_INVALID_PE;
229#endif
230		return;
231	}
232
233	/* Only support IOV PF for now */
234	if (!pdev->is_physfn)
235		return;
236
237	/* Check if VFs have been populated */
238	pdn = pci_get_pdn(pdev);
239	if (!pdn || !(pdn->flags & PCI_DN_FLAG_IOV_VF))
240		return;
241
242	pdn->flags &= ~PCI_DN_FLAG_IOV_VF;
243	parent = pci_bus_to_pdn(pdev->bus);
244	if (!parent)
245		return;
246
247	/*
248	 * We might introduce flag to pci_dn in future
249	 * so that we can release VF's firmware data in
250	 * a batch mode.
251	 */
252	for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
253		list_for_each_entry_safe(pdn, tmp,
254			&parent->child_list, list) {
255			if (pdn->busno != pci_iov_virtfn_bus(pdev, i) ||
256			    pdn->devfn != pci_iov_virtfn_devfn(pdev, i))
257				continue;
258
259			if (!list_empty(&pdn->list))
260				list_del(&pdn->list);
261
262			kfree(pdn);
263		}
264	}
265#endif /* CONFIG_PCI_IOV */
266}
267
268/*
269 * Traverse_func that inits the PCI fields of the device node.
270 * NOTE: this *must* be done before read/write config to the device.
271 */
272void *update_dn_pci_info(struct device_node *dn, void *data)
273{
274	struct pci_controller *phb = data;
275	const __be32 *type = of_get_property(dn, "ibm,pci-config-space-type", NULL);
276	const __be32 *regs;
277	struct device_node *parent;
278	struct pci_dn *pdn;
279
280	pdn = zalloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
281	if (pdn == NULL)
282		return NULL;
283	dn->data = pdn;
284	pdn->node = dn;
285	pdn->phb = phb;
286#ifdef CONFIG_PPC_POWERNV
287	pdn->pe_number = IODA_INVALID_PE;
288#endif
289	regs = of_get_property(dn, "reg", NULL);
290	if (regs) {
291		u32 addr = of_read_number(regs, 1);
292
293		/* First register entry is addr (00BBSS00)  */
294		pdn->busno = (addr >> 16) & 0xff;
295		pdn->devfn = (addr >> 8) & 0xff;
296	}
297
298	/* vendor/device IDs and class code */
299	regs = of_get_property(dn, "vendor-id", NULL);
300	pdn->vendor_id = regs ? of_read_number(regs, 1) : 0;
301	regs = of_get_property(dn, "device-id", NULL);
302	pdn->device_id = regs ? of_read_number(regs, 1) : 0;
303	regs = of_get_property(dn, "class-code", NULL);
304	pdn->class_code = regs ? of_read_number(regs, 1) : 0;
305
306	/* Extended config space */
307	pdn->pci_ext_config_space = (type && of_read_number(type, 1) == 1);
308
309	/* Attach to parent node */
310	INIT_LIST_HEAD(&pdn->child_list);
311	INIT_LIST_HEAD(&pdn->list);
312	parent = of_get_parent(dn);
313	pdn->parent = parent ? PCI_DN(parent) : NULL;
314	if (pdn->parent)
315		list_add_tail(&pdn->list, &pdn->parent->child_list);
316
317	return NULL;
318}
319
320/*
321 * Traverse a device tree stopping each PCI device in the tree.
322 * This is done depth first.  As each node is processed, a "pre"
323 * function is called and the children are processed recursively.
324 *
325 * The "pre" func returns a value.  If non-zero is returned from
326 * the "pre" func, the traversal stops and this value is returned.
327 * This return value is useful when using traverse as a method of
328 * finding a device.
329 *
330 * NOTE: we do not run the func for devices that do not appear to
331 * be PCI except for the start node which we assume (this is good
332 * because the start node is often a phb which may be missing PCI
333 * properties).
334 * We use the class-code as an indicator. If we run into
335 * one of these nodes we also assume its siblings are non-pci for
336 * performance.
337 */
338void *traverse_pci_devices(struct device_node *start, traverse_func pre,
339		void *data)
340{
341	struct device_node *dn, *nextdn;
342	void *ret;
343
344	/* We started with a phb, iterate all childs */
345	for (dn = start->child; dn; dn = nextdn) {
346		const __be32 *classp;
347		u32 class = 0;
348
349		nextdn = NULL;
350		classp = of_get_property(dn, "class-code", NULL);
351		if (classp)
352			class = of_read_number(classp, 1);
353
354		if (pre && ((ret = pre(dn, data)) != NULL))
355			return ret;
356
357		/* If we are a PCI bridge, go down */
358		if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
359				  (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
360			/* Depth first...do children */
361			nextdn = dn->child;
362		else if (dn->sibling)
363			/* ok, try next sibling instead. */
364			nextdn = dn->sibling;
365		if (!nextdn) {
366			/* Walk up to next valid sibling. */
367			do {
368				dn = dn->parent;
369				if (dn == start)
370					return NULL;
371			} while (dn->sibling == NULL);
372			nextdn = dn->sibling;
373		}
374	}
375	return NULL;
376}
377
378static struct pci_dn *pci_dn_next_one(struct pci_dn *root,
379				      struct pci_dn *pdn)
380{
381	struct list_head *next = pdn->child_list.next;
382
383	if (next != &pdn->child_list)
384		return list_entry(next, struct pci_dn, list);
385
386	while (1) {
387		if (pdn == root)
388			return NULL;
389
390		next = pdn->list.next;
391		if (next != &pdn->parent->child_list)
392			break;
393
394		pdn = pdn->parent;
395	}
396
397	return list_entry(next, struct pci_dn, list);
398}
399
400void *traverse_pci_dn(struct pci_dn *root,
401		      void *(*fn)(struct pci_dn *, void *),
402		      void *data)
403{
404	struct pci_dn *pdn = root;
405	void *ret;
406
407	/* Only scan the child nodes */
408	for (pdn = pci_dn_next_one(root, pdn); pdn;
409	     pdn = pci_dn_next_one(root, pdn)) {
410		ret = fn(pdn, data);
411		if (ret)
412			return ret;
413	}
414
415	return NULL;
416}
417
418/**
419 * pci_devs_phb_init_dynamic - setup pci devices under this PHB
420 * phb: pci-to-host bridge (top-level bridge connecting to cpu)
421 *
422 * This routine is called both during boot, (before the memory
423 * subsystem is set up, before kmalloc is valid) and during the
424 * dynamic lpar operation of adding a PHB to a running system.
425 */
426void pci_devs_phb_init_dynamic(struct pci_controller *phb)
427{
428	struct device_node *dn = phb->dn;
429	struct pci_dn *pdn;
430
431	/* PHB nodes themselves must not match */
432	update_dn_pci_info(dn, phb);
433	pdn = dn->data;
434	if (pdn) {
435		pdn->devfn = pdn->busno = -1;
436		pdn->vendor_id = pdn->device_id = pdn->class_code = 0;
437		pdn->phb = phb;
438		phb->pci_data = pdn;
439	}
440
441	/* Update dn->phb ptrs for new phb and children devices */
442	traverse_pci_devices(dn, update_dn_pci_info, phb);
443}
444
445/**
446 * pci_devs_phb_init - Initialize phbs and pci devs under them.
447 *
448 * This routine walks over all phb's (pci-host bridges) on the
449 * system, and sets up assorted pci-related structures
450 * (including pci info in the device node structs) for each
451 * pci device found underneath.  This routine runs once,
452 * early in the boot sequence.
453 */
454void __init pci_devs_phb_init(void)
455{
456	struct pci_controller *phb, *tmp;
457
458	/* This must be done first so the device nodes have valid pci info! */
459	list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
460		pci_devs_phb_init_dynamic(phb);
461}
462
463static void pci_dev_pdn_setup(struct pci_dev *pdev)
464{
465	struct pci_dn *pdn;
466
467	if (pdev->dev.archdata.pci_data)
468		return;
469
470	/* Setup the fast path */
471	pdn = pci_get_pdn(pdev);
472	pdev->dev.archdata.pci_data = pdn;
473}
474DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, pci_dev_pdn_setup);
475