Merge branch 'upstream-jeff' of git://git.kernel.org/pub/scm/linux/kernel/git/romieu...
[linux-2.6] / arch / x86 / 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/dma.h>
17 #include <asm/io_apic.h>
18 #include <asm/apic.h>
19
20 #ifdef CONFIG_IOMMU
21 #include <asm/iommu.h>
22 #endif
23
24 static void __init via_bugs(void)
25 {
26 #ifdef CONFIG_IOMMU
27         if ((end_pfn > MAX_DMA32_PFN ||  force_iommu) &&
28             !iommu_aperture_allowed) {
29                 printk(KERN_INFO
30                        "Looks like a VIA chipset. Disabling IOMMU."
31                        " Override with iommu=allowed\n");
32                 iommu_aperture_disabled = 1;
33         }
34 #endif
35 }
36
37 #ifdef CONFIG_ACPI
38 #ifdef CONFIG_X86_IO_APIC
39
40 static int __init nvidia_hpet_check(struct acpi_table_header *header)
41 {
42         return 0;
43 }
44 #endif /* CONFIG_X86_IO_APIC */
45 #endif /* CONFIG_ACPI */
46
47 static void __init nvidia_bugs(void)
48 {
49 #ifdef CONFIG_ACPI
50 #ifdef CONFIG_X86_IO_APIC
51         /*
52          * All timer overrides on Nvidia are
53          * wrong unless HPET is enabled.
54          * Unfortunately that's not true on many Asus boards.
55          * We don't know yet how to detect this automatically, but
56          * at least allow a command line override.
57          */
58         if (acpi_use_timer_override)
59                 return;
60
61         if (acpi_table_parse(ACPI_SIG_HPET, nvidia_hpet_check)) {
62                 acpi_skip_timer_override = 1;
63                 printk(KERN_INFO "Nvidia board "
64                        "detected. Ignoring ACPI "
65                        "timer override.\n");
66                 printk(KERN_INFO "If you got timer trouble "
67                         "try acpi_use_timer_override\n");
68         }
69 #endif
70 #endif
71         /* RED-PEN skip them on mptables too? */
72
73 }
74
75 static void __init ati_bugs(void)
76 {
77 #ifdef CONFIG_X86_IO_APIC
78         if (timer_over_8254 == 1) {
79                 timer_over_8254 = 0;
80                 printk(KERN_INFO
81                 "ATI board detected. Disabling timer routing over 8254.\n");
82         }
83 #endif
84 }
85
86 struct chipset {
87         u16 vendor;
88         void (*f)(void);
89 };
90
91 static struct chipset early_qrk[] __initdata = {
92         { PCI_VENDOR_ID_NVIDIA, nvidia_bugs },
93         { PCI_VENDOR_ID_VIA, via_bugs },
94         { PCI_VENDOR_ID_ATI, ati_bugs },
95         {}
96 };
97
98 void __init early_quirks(void)
99 {
100         int num, slot, func;
101
102         if (!early_pci_allowed())
103                 return;
104
105         /* Poor man's PCI discovery */
106         for (num = 0; num < 32; num++) {
107                 for (slot = 0; slot < 32; slot++) {
108                         for (func = 0; func < 8; func++) {
109                                 u32 class;
110                                 u32 vendor;
111                                 u8 type;
112                                 int i;
113                                 class = read_pci_config(num,slot,func,
114                                                         PCI_CLASS_REVISION);
115                                 if (class == 0xffffffff)
116                                         break;
117
118                                 if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
119                                         continue;
120
121                                 vendor = read_pci_config(num, slot, func,
122                                                          PCI_VENDOR_ID);
123                                 vendor &= 0xffff;
124
125                                 for (i = 0; early_qrk[i].f; i++)
126                                         if (early_qrk[i].vendor == vendor) {
127                                                 early_qrk[i].f();
128                                                 return;
129                                         }
130
131                                 type = read_pci_config_byte(num, slot, func,
132                                                             PCI_HEADER_TYPE);
133                                 if (!(type & 0x80))
134                                         break;
135                         }
136                 }
137         }
138 }