xref: /openbmc/linux/arch/x86/kernel/early-quirks.c (revision 643d1f7f)
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_GART_IOMMU
21 #include <asm/gart.h>
22 #endif
23 
24 static void __init fix_hypertransport_config(int num, int slot, int func)
25 {
26 	u32 htcfg;
27 	/*
28 	 * we found a hypertransport bus
29 	 * make sure that we are broadcasting
30 	 * interrupts to all cpus on the ht bus
31 	 * if we're using extended apic ids
32 	 */
33 	htcfg = read_pci_config(num, slot, func, 0x68);
34 	if (htcfg & (1 << 18)) {
35 		printk(KERN_INFO "Detected use of extended apic ids "
36 				 "on hypertransport bus\n");
37 		if ((htcfg & (1 << 17)) == 0) {
38 			printk(KERN_INFO "Enabling hypertransport extended "
39 					 "apic interrupt broadcast\n");
40 			printk(KERN_INFO "Note this is a bios bug, "
41 					 "please contact your hw vendor\n");
42 			htcfg |= (1 << 17);
43 			write_pci_config(num, slot, func, 0x68, htcfg);
44 		}
45 	}
46 
47 
48 }
49 
50 static void __init via_bugs(int  num, int slot, int func)
51 {
52 #ifdef CONFIG_GART_IOMMU
53 	if ((end_pfn > MAX_DMA32_PFN ||  force_iommu) &&
54 	    !gart_iommu_aperture_allowed) {
55 		printk(KERN_INFO
56 		       "Looks like a VIA chipset. Disabling IOMMU."
57 		       " Override with iommu=allowed\n");
58 		gart_iommu_aperture_disabled = 1;
59 	}
60 #endif
61 }
62 
63 #ifdef CONFIG_ACPI
64 #ifdef CONFIG_X86_IO_APIC
65 
66 static int __init nvidia_hpet_check(struct acpi_table_header *header)
67 {
68 	return 0;
69 }
70 #endif /* CONFIG_X86_IO_APIC */
71 #endif /* CONFIG_ACPI */
72 
73 static void __init nvidia_bugs(int num, int slot, int func)
74 {
75 #ifdef CONFIG_ACPI
76 #ifdef CONFIG_X86_IO_APIC
77 	/*
78 	 * All timer overrides on Nvidia are
79 	 * wrong unless HPET is enabled.
80 	 * Unfortunately that's not true on many Asus boards.
81 	 * We don't know yet how to detect this automatically, but
82 	 * at least allow a command line override.
83 	 */
84 	if (acpi_use_timer_override)
85 		return;
86 
87 	if (acpi_table_parse(ACPI_SIG_HPET, nvidia_hpet_check)) {
88 		acpi_skip_timer_override = 1;
89 		printk(KERN_INFO "Nvidia board "
90 		       "detected. Ignoring ACPI "
91 		       "timer override.\n");
92 		printk(KERN_INFO "If you got timer trouble "
93 			"try acpi_use_timer_override\n");
94 	}
95 #endif
96 #endif
97 	/* RED-PEN skip them on mptables too? */
98 
99 }
100 
101 static void __init ati_bugs(int num, int slot, int func)
102 {
103 #ifdef CONFIG_X86_IO_APIC
104 	if (timer_over_8254 == 1) {
105 		timer_over_8254 = 0;
106 		printk(KERN_INFO
107 		"ATI board detected. Disabling timer routing over 8254.\n");
108 	}
109 #endif
110 }
111 
112 #define QFLAG_APPLY_ONCE 	0x1
113 #define QFLAG_APPLIED		0x2
114 #define QFLAG_DONE		(QFLAG_APPLY_ONCE|QFLAG_APPLIED)
115 struct chipset {
116 	u32 vendor;
117 	u32 device;
118 	u32 class;
119 	u32 class_mask;
120 	u32 flags;
121 	void (*f)(int num, int slot, int func);
122 };
123 
124 static struct chipset early_qrk[] __initdata = {
125 	{ PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
126 	  PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, nvidia_bugs },
127 	{ PCI_VENDOR_ID_VIA, PCI_ANY_ID,
128 	  PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, via_bugs },
129 	{ PCI_VENDOR_ID_ATI, PCI_ANY_ID,
130 	  PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, ati_bugs },
131 	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB,
132 	  PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, fix_hypertransport_config },
133 	{}
134 };
135 
136 static void __init check_dev_quirk(int num, int slot, int func)
137 {
138 	u16 class;
139 	u16 vendor;
140 	u16 device;
141 	u8 type;
142 	int i;
143 
144 	class = read_pci_config_16(num, slot, func, PCI_CLASS_DEVICE);
145 
146 	if (class == 0xffff)
147 		return;
148 
149 	vendor = read_pci_config_16(num, slot, func, PCI_VENDOR_ID);
150 
151 	device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);
152 
153 	for (i = 0; early_qrk[i].f != NULL; i++) {
154 		if (((early_qrk[i].vendor == PCI_ANY_ID) ||
155 			(early_qrk[i].vendor == vendor)) &&
156 			((early_qrk[i].device == PCI_ANY_ID) ||
157 			(early_qrk[i].device == device)) &&
158 			(!((early_qrk[i].class ^ class) &
159 			    early_qrk[i].class_mask))) {
160 				if ((early_qrk[i].flags &
161 				     QFLAG_DONE) != QFLAG_DONE)
162 					early_qrk[i].f(num, slot, func);
163 				early_qrk[i].flags |= QFLAG_APPLIED;
164 			}
165 	}
166 
167 	type = read_pci_config_byte(num, slot, func,
168 				    PCI_HEADER_TYPE);
169 	if (!(type & 0x80))
170 		return;
171 }
172 
173 void __init early_quirks(void)
174 {
175 	int num, slot, func;
176 
177 	if (!early_pci_allowed())
178 		return;
179 
180 	/* Poor man's PCI discovery */
181 	for (num = 0; num < 32; num++)
182 		for (slot = 0; slot < 32; slot++)
183 			for (func = 0; func < 8; func++)
184 				check_dev_quirk(num, slot, func);
185 }
186