Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6] / arch / x86_64 / kernel / early-quirks.c
1 /* Various workarounds for chipset bugs.
2    This code runs very early and can't use the regular PCI subsystem
3    The entries are keyed to PCI bridges which usually identify chipsets
4    uniquely.
5    This is only for whole classes of chipsets with specific problems which
6    need early invasive action (e.g. before the timers are initialized).
7    Most PCI device specific workarounds can be done later and should be
8    in standard PCI quirks
9    Mainboard specific bugs should be handled by DMI entries.
10    CPU specific bugs in setup.c */
11
12 #include <linux/pci.h>
13 #include <linux/acpi.h>
14 #include <linux/pci_ids.h>
15 #include <asm/pci-direct.h>
16 #include <asm/proto.h>
17 #include <asm/iommu.h>
18 #include <asm/dma.h>
19
20 static void __init via_bugs(void)
21 {
22 #ifdef CONFIG_IOMMU
23         if ((end_pfn > MAX_DMA32_PFN ||  force_iommu) &&
24             !iommu_aperture_allowed) {
25                 printk(KERN_INFO
26   "Looks like a VIA chipset. Disabling IOMMU. Override with iommu=allowed\n");
27                 iommu_aperture_disabled = 1;
28         }
29 #endif
30 }
31
32 #ifdef CONFIG_ACPI
33
34 static int __init nvidia_hpet_check(struct acpi_table_header *header)
35 {
36         return 0;
37 }
38 #endif
39
40 static void __init nvidia_bugs(void)
41 {
42 #ifdef CONFIG_ACPI
43         /*
44          * All timer overrides on Nvidia are
45          * wrong unless HPET is enabled.
46          * Unfortunately that's not true on many Asus boards.
47          * We don't know yet how to detect this automatically, but
48          * at least allow a command line override.
49          */
50         if (acpi_use_timer_override)
51                 return;
52
53         if (acpi_table_parse(ACPI_SIG_HPET, nvidia_hpet_check)) {
54                 acpi_skip_timer_override = 1;
55                 printk(KERN_INFO "Nvidia board "
56                        "detected. Ignoring ACPI "
57                        "timer override.\n");
58                 printk(KERN_INFO "If you got timer trouble "
59                         "try acpi_use_timer_override\n");
60         }
61 #endif
62         /* RED-PEN skip them on mptables too? */
63
64 }
65
66 static void __init ati_bugs(void)
67 {
68         if (timer_over_8254 == 1) {
69                 timer_over_8254 = 0;
70                 printk(KERN_INFO
71                 "ATI board detected. Disabling timer routing over 8254.\n");
72         }
73 }
74
75 struct chipset {
76         u16 vendor;
77         void (*f)(void);
78 };
79
80 static struct chipset early_qrk[] __initdata = {
81         { PCI_VENDOR_ID_NVIDIA, nvidia_bugs },
82         { PCI_VENDOR_ID_VIA, via_bugs },
83         { PCI_VENDOR_ID_ATI, ati_bugs },
84         {}
85 };
86
87 void __init early_quirks(void)
88 {
89         int num, slot, func;
90
91         if (!early_pci_allowed())
92                 return;
93
94         /* Poor man's PCI discovery */
95         for (num = 0; num < 32; num++) {
96                 for (slot = 0; slot < 32; slot++) {
97                         for (func = 0; func < 8; func++) {
98                                 u32 class;
99                                 u32 vendor;
100                                 u8 type;
101                                 int i;
102                                 class = read_pci_config(num,slot,func,
103                                                         PCI_CLASS_REVISION);
104                                 if (class == 0xffffffff)
105                                         break;
106
107                                 if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
108                                         continue;
109
110                                 vendor = read_pci_config(num, slot, func,
111                                                          PCI_VENDOR_ID);
112                                 vendor &= 0xffff;
113
114                                 for (i = 0; early_qrk[i].f; i++)
115                                         if (early_qrk[i].vendor == vendor) {
116                                                 early_qrk[i].f();
117                                                 return;
118                                         }
119
120                                 type = read_pci_config_byte(num, slot, func,
121                                                             PCI_HEADER_TYPE);
122                                 if (!(type & 0x80))
123                                         break;
124                         }
125                 }
126         }
127 }