xref: /openbmc/linux/arch/x86/kernel/early-quirks.c (revision b595076a)
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 #include <asm/iommu.h>
20 #include <asm/gart.h>
21 
22 static void __init fix_hypertransport_config(int num, int slot, int func)
23 {
24 	u32 htcfg;
25 	/*
26 	 * we found a hypertransport bus
27 	 * make sure that we are broadcasting
28 	 * interrupts to all cpus on the ht bus
29 	 * if we're using extended apic ids
30 	 */
31 	htcfg = read_pci_config(num, slot, func, 0x68);
32 	if (htcfg & (1 << 18)) {
33 		printk(KERN_INFO "Detected use of extended apic ids "
34 				 "on hypertransport bus\n");
35 		if ((htcfg & (1 << 17)) == 0) {
36 			printk(KERN_INFO "Enabling hypertransport extended "
37 					 "apic interrupt broadcast\n");
38 			printk(KERN_INFO "Note this is a bios bug, "
39 					 "please contact your hw vendor\n");
40 			htcfg |= (1 << 17);
41 			write_pci_config(num, slot, func, 0x68, htcfg);
42 		}
43 	}
44 
45 
46 }
47 
48 static void __init via_bugs(int  num, int slot, int func)
49 {
50 #ifdef CONFIG_GART_IOMMU
51 	if ((max_pfn > MAX_DMA32_PFN ||  force_iommu) &&
52 	    !gart_iommu_aperture_allowed) {
53 		printk(KERN_INFO
54 		       "Looks like a VIA chipset. Disabling IOMMU."
55 		       " Override with iommu=allowed\n");
56 		gart_iommu_aperture_disabled = 1;
57 	}
58 #endif
59 }
60 
61 #ifdef CONFIG_ACPI
62 #ifdef CONFIG_X86_IO_APIC
63 
64 static int __init nvidia_hpet_check(struct acpi_table_header *header)
65 {
66 	return 0;
67 }
68 #endif /* CONFIG_X86_IO_APIC */
69 #endif /* CONFIG_ACPI */
70 
71 static void __init nvidia_bugs(int num, int slot, int func)
72 {
73 #ifdef CONFIG_ACPI
74 #ifdef CONFIG_X86_IO_APIC
75 	/*
76 	 * All timer overrides on Nvidia are
77 	 * wrong unless HPET is enabled.
78 	 * Unfortunately that's not true on many Asus boards.
79 	 * We don't know yet how to detect this automatically, but
80 	 * at least allow a command line override.
81 	 */
82 	if (acpi_use_timer_override)
83 		return;
84 
85 	if (acpi_table_parse(ACPI_SIG_HPET, nvidia_hpet_check)) {
86 		acpi_skip_timer_override = 1;
87 		printk(KERN_INFO "Nvidia board "
88 		       "detected. Ignoring ACPI "
89 		       "timer override.\n");
90 		printk(KERN_INFO "If you got timer trouble "
91 			"try acpi_use_timer_override\n");
92 	}
93 #endif
94 #endif
95 	/* RED-PEN skip them on mptables too? */
96 
97 }
98 
99 #if defined(CONFIG_ACPI) && defined(CONFIG_X86_IO_APIC)
100 static u32 __init ati_ixp4x0_rev(int num, int slot, int func)
101 {
102 	u32 d;
103 	u8  b;
104 
105 	b = read_pci_config_byte(num, slot, func, 0xac);
106 	b &= ~(1<<5);
107 	write_pci_config_byte(num, slot, func, 0xac, b);
108 
109 	d = read_pci_config(num, slot, func, 0x70);
110 	d |= 1<<8;
111 	write_pci_config(num, slot, func, 0x70, d);
112 
113 	d = read_pci_config(num, slot, func, 0x8);
114 	d &= 0xff;
115 	return d;
116 }
117 
118 static void __init ati_bugs(int num, int slot, int func)
119 {
120 	u32 d;
121 	u8  b;
122 
123 	if (acpi_use_timer_override)
124 		return;
125 
126 	d = ati_ixp4x0_rev(num, slot, func);
127 	if (d  < 0x82)
128 		acpi_skip_timer_override = 1;
129 	else {
130 		/* check for IRQ0 interrupt swap */
131 		outb(0x72, 0xcd6); b = inb(0xcd7);
132 		if (!(b & 0x2))
133 			acpi_skip_timer_override = 1;
134 	}
135 
136 	if (acpi_skip_timer_override) {
137 		printk(KERN_INFO "SB4X0 revision 0x%x\n", d);
138 		printk(KERN_INFO "Ignoring ACPI timer override.\n");
139 		printk(KERN_INFO "If you got timer trouble "
140 		       "try acpi_use_timer_override\n");
141 	}
142 }
143 
144 static u32 __init ati_sbx00_rev(int num, int slot, int func)
145 {
146 	u32 old, d;
147 
148 	d = read_pci_config(num, slot, func, 0x70);
149 	old = d;
150 	d &= ~(1<<8);
151 	write_pci_config(num, slot, func, 0x70, d);
152 	d = read_pci_config(num, slot, func, 0x8);
153 	d &= 0xff;
154 	write_pci_config(num, slot, func, 0x70, old);
155 
156 	return d;
157 }
158 
159 static void __init ati_bugs_contd(int num, int slot, int func)
160 {
161 	u32 d, rev;
162 
163 	if (acpi_use_timer_override)
164 		return;
165 
166 	rev = ati_sbx00_rev(num, slot, func);
167 	if (rev > 0x13)
168 		return;
169 
170 	/* check for IRQ0 interrupt swap */
171 	d = read_pci_config(num, slot, func, 0x64);
172 	if (!(d & (1<<14)))
173 		acpi_skip_timer_override = 1;
174 
175 	if (acpi_skip_timer_override) {
176 		printk(KERN_INFO "SB600 revision 0x%x\n", rev);
177 		printk(KERN_INFO "Ignoring ACPI timer override.\n");
178 		printk(KERN_INFO "If you got timer trouble "
179 		       "try acpi_use_timer_override\n");
180 	}
181 }
182 #else
183 static void __init ati_bugs(int num, int slot, int func)
184 {
185 }
186 
187 static void __init ati_bugs_contd(int num, int slot, int func)
188 {
189 }
190 #endif
191 
192 #define QFLAG_APPLY_ONCE 	0x1
193 #define QFLAG_APPLIED		0x2
194 #define QFLAG_DONE		(QFLAG_APPLY_ONCE|QFLAG_APPLIED)
195 struct chipset {
196 	u32 vendor;
197 	u32 device;
198 	u32 class;
199 	u32 class_mask;
200 	u32 flags;
201 	void (*f)(int num, int slot, int func);
202 };
203 
204 /*
205  * Only works for devices on the root bus. If you add any devices
206  * not on bus 0 readd another loop level in early_quirks(). But
207  * be careful because at least the Nvidia quirk here relies on
208  * only matching on bus 0.
209  */
210 static struct chipset early_qrk[] __initdata = {
211 	{ PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
212 	  PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, nvidia_bugs },
213 	{ PCI_VENDOR_ID_VIA, PCI_ANY_ID,
214 	  PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, via_bugs },
215 	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB,
216 	  PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, fix_hypertransport_config },
217 	{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS,
218 	  PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs },
219 	{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,
220 	  PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs_contd },
221 	{}
222 };
223 
224 /**
225  * check_dev_quirk - apply early quirks to a given PCI device
226  * @num: bus number
227  * @slot: slot number
228  * @func: PCI function
229  *
230  * Check the vendor & device ID against the early quirks table.
231  *
232  * If the device is single function, let early_quirks() know so we don't
233  * poke at this device again.
234  */
235 static int __init check_dev_quirk(int num, int slot, int func)
236 {
237 	u16 class;
238 	u16 vendor;
239 	u16 device;
240 	u8 type;
241 	int i;
242 
243 	class = read_pci_config_16(num, slot, func, PCI_CLASS_DEVICE);
244 
245 	if (class == 0xffff)
246 		return -1; /* no class, treat as single function */
247 
248 	vendor = read_pci_config_16(num, slot, func, PCI_VENDOR_ID);
249 
250 	device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);
251 
252 	for (i = 0; early_qrk[i].f != NULL; i++) {
253 		if (((early_qrk[i].vendor == PCI_ANY_ID) ||
254 			(early_qrk[i].vendor == vendor)) &&
255 			((early_qrk[i].device == PCI_ANY_ID) ||
256 			(early_qrk[i].device == device)) &&
257 			(!((early_qrk[i].class ^ class) &
258 			    early_qrk[i].class_mask))) {
259 				if ((early_qrk[i].flags &
260 				     QFLAG_DONE) != QFLAG_DONE)
261 					early_qrk[i].f(num, slot, func);
262 				early_qrk[i].flags |= QFLAG_APPLIED;
263 			}
264 	}
265 
266 	type = read_pci_config_byte(num, slot, func,
267 				    PCI_HEADER_TYPE);
268 	if (!(type & 0x80))
269 		return -1;
270 
271 	return 0;
272 }
273 
274 void __init early_quirks(void)
275 {
276 	int slot, func;
277 
278 	if (!early_pci_allowed())
279 		return;
280 
281 	/* Poor man's PCI discovery */
282 	/* Only scan the root bus */
283 	for (slot = 0; slot < 32; slot++)
284 		for (func = 0; func < 8; func++) {
285 			/* Only probe function 0 on single fn devices */
286 			if (check_dev_quirk(0, slot, func))
287 				break;
288 		}
289 }
290