1/*
2 * Shared support code for AMD K8 northbridges and derivates.
3 * Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
4 */
5#include <linux/gfp.h>
6#include <linux/types.h>
7#include <linux/init.h>
8#include <linux/errno.h>
9#include <linux/module.h>
10#include <linux/spinlock.h>
11#include <asm/k8.h>
12
13int num_k8_northbridges;
14EXPORT_SYMBOL(num_k8_northbridges);
15
16static u32 *flush_words;
17
18struct pci_device_id k8_nb_ids[] = {
19	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x1103) },
20	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x1203) },
21	{}
22};
23EXPORT_SYMBOL(k8_nb_ids);
24
25struct pci_dev **k8_northbridges;
26EXPORT_SYMBOL(k8_northbridges);
27
28static struct pci_dev *next_k8_northbridge(struct pci_dev *dev)
29{
30	do {
31		dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
32		if (!dev)
33			break;
34	} while (!pci_match_id(&k8_nb_ids[0], dev));
35	return dev;
36}
37
38int cache_k8_northbridges(void)
39{
40	int i;
41	struct pci_dev *dev;
42
43	if (num_k8_northbridges)
44		return 0;
45
46	dev = NULL;
47	while ((dev = next_k8_northbridge(dev)) != NULL)
48		num_k8_northbridges++;
49
50	k8_northbridges = kmalloc((num_k8_northbridges + 1) * sizeof(void *),
51				  GFP_KERNEL);
52	if (!k8_northbridges)
53		return -ENOMEM;
54
55	if (!num_k8_northbridges) {
56		k8_northbridges[0] = NULL;
57		return 0;
58	}
59
60	flush_words = kmalloc(num_k8_northbridges * sizeof(u32), GFP_KERNEL);
61	if (!flush_words) {
62		kfree(k8_northbridges);
63		return -ENOMEM;
64	}
65
66	dev = NULL;
67	i = 0;
68	while ((dev = next_k8_northbridge(dev)) != NULL) {
69		k8_northbridges[i] = dev;
70		pci_read_config_dword(dev, 0x9c, &flush_words[i++]);
71	}
72	k8_northbridges[i] = NULL;
73	return 0;
74}
75EXPORT_SYMBOL_GPL(cache_k8_northbridges);
76
77/* Ignores subdevice/subvendor but as far as I can figure out
78   they're useless anyways */
79int __init early_is_k8_nb(u32 device)
80{
81	struct pci_device_id *id;
82	u32 vendor = device & 0xffff;
83	device >>= 16;
84	for (id = k8_nb_ids; id->vendor; id++)
85		if (vendor == id->vendor && device == id->device)
86			return 1;
87	return 0;
88}
89
90void k8_flush_garts(void)
91{
92	int flushed, i;
93	unsigned long flags;
94	static DEFINE_SPINLOCK(gart_lock);
95
96	/* Avoid races between AGP and IOMMU. In theory it's not needed
97	   but I'm not sure if the hardware won't lose flush requests
98	   when another is pending. This whole thing is so expensive anyways
99	   that it doesn't matter to serialize more. -AK */
100	spin_lock_irqsave(&gart_lock, flags);
101	flushed = 0;
102	for (i = 0; i < num_k8_northbridges; i++) {
103		pci_write_config_dword(k8_northbridges[i], 0x9c,
104				       flush_words[i]|1);
105		flushed++;
106	}
107	for (i = 0; i < num_k8_northbridges; i++) {
108		u32 w;
109		/* Make sure the hardware actually executed the flush*/
110		for (;;) {
111			pci_read_config_dword(k8_northbridges[i],
112					      0x9c, &w);
113			if (!(w & 1))
114				break;
115			cpu_relax();
116		}
117	}
118	spin_unlock_irqrestore(&gart_lock, flags);
119	if (!flushed)
120		printk("nothing to flush?\n");
121}
122EXPORT_SYMBOL_GPL(k8_flush_garts);
123