early-quirks.c 16.1 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14
/* Various workarounds for chipset bugs.
   This code runs very early and can't use the regular PCI subsystem
   The entries are keyed to PCI bridges which usually identify chipsets
   uniquely.
   This is only for whole classes of chipsets with specific problems which
   need early invasive action (e.g. before the timers are initialized).
   Most PCI device specific workarounds can be done later and should be
   in standard PCI quirks
   Mainboard specific bugs should be handled by DMI entries.
   CPU specific bugs in setup.c */

#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/pci_ids.h>
15
#include <drm/i915_drm.h>
16 17
#include <asm/pci-direct.h>
#include <asm/dma.h>
18 19
#include <asm/io_apic.h>
#include <asm/apic.h>
20
#include <asm/iommu.h>
21
#include <asm/gart.h>
22
#include <asm/irq_remapping.h>
23

24 25 26 27 28 29 30 31 32 33 34
static void __init fix_hypertransport_config(int num, int slot, int func)
{
	u32 htcfg;
	/*
	 * we found a hypertransport bus
	 * make sure that we are broadcasting
	 * interrupts to all cpus on the ht bus
	 * if we're using extended apic ids
	 */
	htcfg = read_pci_config(num, slot, func, 0x68);
	if (htcfg & (1 << 18)) {
35 36
		printk(KERN_INFO "Detected use of extended apic ids "
				 "on hypertransport bus\n");
37
		if ((htcfg & (1 << 17)) == 0) {
38 39 40 41
			printk(KERN_INFO "Enabling hypertransport extended "
					 "apic interrupt broadcast\n");
			printk(KERN_INFO "Note this is a bios bug, "
					 "please contact your hw vendor\n");
42 43 44 45 46 47 48 49 50
			htcfg |= (1 << 17);
			write_pci_config(num, slot, func, 0x68, htcfg);
		}
	}


}

static void __init via_bugs(int  num, int slot, int func)
51
{
52
#ifdef CONFIG_GART_IOMMU
Y
Yinghai Lu 已提交
53
	if ((max_pfn > MAX_DMA32_PFN ||  force_iommu) &&
54
	    !gart_iommu_aperture_allowed) {
55
		printk(KERN_INFO
56 57
		       "Looks like a VIA chipset. Disabling IOMMU."
		       " Override with iommu=allowed\n");
58
		gart_iommu_aperture_disabled = 1;
59 60 61 62 63
	}
#endif
}

#ifdef CONFIG_ACPI
64
#ifdef CONFIG_X86_IO_APIC
65

66
static int __init nvidia_hpet_check(struct acpi_table_header *header)
67 68 69
{
	return 0;
}
70 71
#endif /* CONFIG_X86_IO_APIC */
#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 79
	/*
	 * All timer overrides on Nvidia are
	 * wrong unless HPET is enabled.
80 81 82
	 * Unfortunately that's not true on many Asus boards.
	 * We don't know yet how to detect this automatically, but
	 * at least allow a command line override.
83
	 */
84 85 86
	if (acpi_use_timer_override)
		return;

87
	if (acpi_table_parse(ACPI_SIG_HPET, nvidia_hpet_check)) {
88 89 90 91
		acpi_skip_timer_override = 1;
		printk(KERN_INFO "Nvidia board "
		       "detected. Ignoring ACPI "
		       "timer override.\n");
92 93
		printk(KERN_INFO "If you got timer trouble "
			"try acpi_use_timer_override\n");
94
	}
95
#endif
96 97 98 99 100
#endif
	/* RED-PEN skip them on mptables too? */

}

101 102
#if defined(CONFIG_ACPI) && defined(CONFIG_X86_IO_APIC)
static u32 __init ati_ixp4x0_rev(int num, int slot, int func)
103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145
{
	u32 d;
	u8  b;

	b = read_pci_config_byte(num, slot, func, 0xac);
	b &= ~(1<<5);
	write_pci_config_byte(num, slot, func, 0xac, b);

	d = read_pci_config(num, slot, func, 0x70);
	d |= 1<<8;
	write_pci_config(num, slot, func, 0x70, d);

	d = read_pci_config(num, slot, func, 0x8);
	d &= 0xff;
	return d;
}

static void __init ati_bugs(int num, int slot, int func)
{
	u32 d;
	u8  b;

	if (acpi_use_timer_override)
		return;

	d = ati_ixp4x0_rev(num, slot, func);
	if (d  < 0x82)
		acpi_skip_timer_override = 1;
	else {
		/* check for IRQ0 interrupt swap */
		outb(0x72, 0xcd6); b = inb(0xcd7);
		if (!(b & 0x2))
			acpi_skip_timer_override = 1;
	}

	if (acpi_skip_timer_override) {
		printk(KERN_INFO "SB4X0 revision 0x%x\n", d);
		printk(KERN_INFO "Ignoring ACPI timer override.\n");
		printk(KERN_INFO "If you got timer trouble "
		       "try acpi_use_timer_override\n");
	}
}

146 147
static u32 __init ati_sbx00_rev(int num, int slot, int func)
{
148
	u32 d;
149 150 151 152 153 154 155 156 157 158 159 160

	d = read_pci_config(num, slot, func, 0x8);
	d &= 0xff;

	return d;
}

static void __init ati_bugs_contd(int num, int slot, int func)
{
	u32 d, rev;

	rev = ati_sbx00_rev(num, slot, func);
161 162 163
	if (rev >= 0x40)
		acpi_fix_pin2_polarity = 1;

164 165 166 167 168 169
	/*
	 * SB600: revisions 0x11, 0x12, 0x13, 0x14, ...
	 * SB700: revisions 0x39, 0x3a, ...
	 * SB800: revisions 0x40, 0x41, ...
	 */
	if (rev >= 0x39)
170 171
		return;

172 173 174
	if (acpi_use_timer_override)
		return;

175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196
	/* check for IRQ0 interrupt swap */
	d = read_pci_config(num, slot, func, 0x64);
	if (!(d & (1<<14)))
		acpi_skip_timer_override = 1;

	if (acpi_skip_timer_override) {
		printk(KERN_INFO "SB600 revision 0x%x\n", rev);
		printk(KERN_INFO "Ignoring ACPI timer override.\n");
		printk(KERN_INFO "If you got timer trouble "
		       "try acpi_use_timer_override\n");
	}
}
#else
static void __init ati_bugs(int num, int slot, int func)
{
}

static void __init ati_bugs_contd(int num, int slot, int func)
{
}
#endif

197 198 199
static void __init intel_remapping_check(int num, int slot, int func)
{
	u8 revision;
200
	u16 device;
201

202
	device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);
203 204 205
	revision = read_pci_config_byte(num, slot, func, PCI_REVISION_ID);

	/*
206 207 208 209
	 * Revision <= 13 of all triggering devices id in this quirk
	 * have a problem draining interrupts when irq remapping is
	 * enabled, and should be flagged as broken. Additionally
	 * revision 0x22 of device id 0x3405 has this problem.
210
	 */
211
	if (revision <= 0x13)
212
		set_irq_remapping_broken();
213
	else if (device == 0x3405 && revision == 0x22)
214
		set_irq_remapping_broken();
215 216
}

217 218 219 220 221 222 223 224 225 226 227
/*
 * Systems with Intel graphics controllers set aside memory exclusively
 * for gfx driver use.  This memory is not marked in the E820 as reserved
 * or as RAM, and so is subject to overlap from E820 manipulation later
 * in the boot process.  On some systems, MMIO space is allocated on top,
 * despite the efforts of the "RAM buffer" approach, which simply rounds
 * memory boundaries up to 64M to try to catch space that may decode
 * as RAM and so is not suitable for MMIO.
 *
 * And yes, so far on current devices the base addr is always under 4G.
 */
228
static u32 __init intel_stolen_base(int num, int slot, int func, size_t stolen_size)
229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246
{
	u32 base;

	/*
	 * For the PCI IDs in this quirk, the stolen base is always
	 * in 0x5c, aka the BDSM register (yes that's really what
	 * it's called).
	 */
	base = read_pci_config(num, slot, func, 0x5c);
	base &= ~((1<<20) - 1);

	return base;
}

#define KB(x)	((x) * 1024)
#define MB(x)	(KB (KB (x)))
#define GB(x)	(MB (KB (x)))

247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354
static size_t __init i830_tseg_size(void)
{
	u8 tmp = read_pci_config_byte(0, 0, 0, I830_ESMRAMC);

	if (!(tmp & TSEG_ENABLE))
		return 0;

	if (tmp & I830_TSEG_SIZE_1M)
		return MB(1);
	else
		return KB(512);
}

static size_t __init i845_tseg_size(void)
{
	u8 tmp = read_pci_config_byte(0, 0, 0, I845_ESMRAMC);

	if (!(tmp & TSEG_ENABLE))
		return 0;

	switch (tmp & I845_TSEG_SIZE_MASK) {
	case I845_TSEG_SIZE_512K:
		return KB(512);
	case I845_TSEG_SIZE_1M:
		return MB(1);
	default:
		WARN_ON(1);
		return 0;
	}
}

static size_t __init i85x_tseg_size(void)
{
	u8 tmp = read_pci_config_byte(0, 0, 0, I85X_ESMRAMC);

	if (!(tmp & TSEG_ENABLE))
		return 0;

	return MB(1);
}

static size_t __init i830_mem_size(void)
{
	return read_pci_config_byte(0, 0, 0, I830_DRB3) * MB(32);
}

static size_t __init i85x_mem_size(void)
{
	return read_pci_config_byte(0, 0, 1, I85X_DRB3) * MB(32);
}

/*
 * On 830/845/85x the stolen memory base isn't available in any
 * register. We need to calculate it as TOM-TSEG_SIZE-stolen_size.
 */
static u32 __init i830_stolen_base(int num, int slot, int func, size_t stolen_size)
{
	return i830_mem_size() - i830_tseg_size() - stolen_size;
}

static u32 __init i845_stolen_base(int num, int slot, int func, size_t stolen_size)
{
	return i830_mem_size() - i845_tseg_size() - stolen_size;
}

static u32 __init i85x_stolen_base(int num, int slot, int func, size_t stolen_size)
{
	return i85x_mem_size() - i85x_tseg_size() - stolen_size;
}

static u32 __init i865_stolen_base(int num, int slot, int func, size_t stolen_size)
{
	/*
	 * FIXME is the graphics stolen memory region
	 * always at TOUD? Ie. is it always the last
	 * one to be allocated by the BIOS?
	 */
	return read_pci_config_16(0, 0, 0, I865_TOUD) << 16;
}

static size_t __init i830_stolen_size(int num, int slot, int func)
{
	size_t stolen_size;
	u16 gmch_ctrl;

	gmch_ctrl = read_pci_config_16(0, 0, 0, I830_GMCH_CTRL);

	switch (gmch_ctrl & I830_GMCH_GMS_MASK) {
	case I830_GMCH_GMS_STOLEN_512:
		stolen_size = KB(512);
		break;
	case I830_GMCH_GMS_STOLEN_1024:
		stolen_size = MB(1);
		break;
	case I830_GMCH_GMS_STOLEN_8192:
		stolen_size = MB(8);
		break;
	case I830_GMCH_GMS_LOCAL:
		/* local memory isn't part of the normal address space */
		stolen_size = 0;
		break;
	default:
		return 0;
	}

	return stolen_size;
}

355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420
static size_t __init gen3_stolen_size(int num, int slot, int func)
{
	size_t stolen_size;
	u16 gmch_ctrl;

	gmch_ctrl = read_pci_config_16(0, 0, 0, I830_GMCH_CTRL);

	switch (gmch_ctrl & I855_GMCH_GMS_MASK) {
	case I855_GMCH_GMS_STOLEN_1M:
		stolen_size = MB(1);
		break;
	case I855_GMCH_GMS_STOLEN_4M:
		stolen_size = MB(4);
		break;
	case I855_GMCH_GMS_STOLEN_8M:
		stolen_size = MB(8);
		break;
	case I855_GMCH_GMS_STOLEN_16M:
		stolen_size = MB(16);
		break;
	case I855_GMCH_GMS_STOLEN_32M:
		stolen_size = MB(32);
		break;
	case I915_GMCH_GMS_STOLEN_48M:
		stolen_size = MB(48);
		break;
	case I915_GMCH_GMS_STOLEN_64M:
		stolen_size = MB(64);
		break;
	case G33_GMCH_GMS_STOLEN_128M:
		stolen_size = MB(128);
		break;
	case G33_GMCH_GMS_STOLEN_256M:
		stolen_size = MB(256);
		break;
	case INTEL_GMCH_GMS_STOLEN_96M:
		stolen_size = MB(96);
		break;
	case INTEL_GMCH_GMS_STOLEN_160M:
		stolen_size = MB(160);
		break;
	case INTEL_GMCH_GMS_STOLEN_224M:
		stolen_size = MB(224);
		break;
	case INTEL_GMCH_GMS_STOLEN_352M:
		stolen_size = MB(352);
		break;
	default:
		stolen_size = 0;
		break;
	}

	return stolen_size;
}

static size_t __init gen6_stolen_size(int num, int slot, int func)
{
	u16 gmch_ctrl;

	gmch_ctrl = read_pci_config_16(num, slot, func, SNB_GMCH_CTRL);
	gmch_ctrl >>= SNB_GMCH_GMS_SHIFT;
	gmch_ctrl &= SNB_GMCH_GMS_MASK;

	return gmch_ctrl << 25; /* 32 MB units */
}

421
static size_t gen8_stolen_size(int num, int slot, int func)
422 423 424 425 426 427 428 429 430
{
	u16 gmch_ctrl;

	gmch_ctrl = read_pci_config_16(num, slot, func, SNB_GMCH_CTRL);
	gmch_ctrl >>= BDW_GMCH_GMS_SHIFT;
	gmch_ctrl &= BDW_GMCH_GMS_MASK;
	return gmch_ctrl << 25; /* 32 MB units */
}

431 432 433 434 435 436

struct intel_stolen_funcs {
	size_t (*size)(int num, int slot, int func);
	u32 (*base)(int num, int slot, int func, size_t size);
};

437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456
static const struct intel_stolen_funcs i830_stolen_funcs = {
	.base = i830_stolen_base,
	.size = i830_stolen_size,
};

static const struct intel_stolen_funcs i845_stolen_funcs = {
	.base = i845_stolen_base,
	.size = i830_stolen_size,
};

static const struct intel_stolen_funcs i85x_stolen_funcs = {
	.base = i85x_stolen_base,
	.size = gen3_stolen_size,
};

static const struct intel_stolen_funcs i865_stolen_funcs = {
	.base = i865_stolen_base,
	.size = gen3_stolen_size,
};

457 458 459 460 461 462 463 464 465 466 467 468 469 470
static const struct intel_stolen_funcs gen3_stolen_funcs = {
	.base = intel_stolen_base,
	.size = gen3_stolen_size,
};

static const struct intel_stolen_funcs gen6_stolen_funcs = {
	.base = intel_stolen_base,
	.size = gen6_stolen_size,
};

static const struct intel_stolen_funcs gen8_stolen_funcs = {
	.base = intel_stolen_base,
	.size = gen8_stolen_size,
};
471 472

static struct pci_device_id intel_stolen_ids[] __initdata = {
473 474 475 476
	INTEL_I830_IDS(&i830_stolen_funcs),
	INTEL_I845G_IDS(&i845_stolen_funcs),
	INTEL_I85X_IDS(&i85x_stolen_funcs),
	INTEL_I865G_IDS(&i865_stolen_funcs),
477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498
	INTEL_I915G_IDS(&gen3_stolen_funcs),
	INTEL_I915GM_IDS(&gen3_stolen_funcs),
	INTEL_I945G_IDS(&gen3_stolen_funcs),
	INTEL_I945GM_IDS(&gen3_stolen_funcs),
	INTEL_VLV_M_IDS(&gen6_stolen_funcs),
	INTEL_VLV_D_IDS(&gen6_stolen_funcs),
	INTEL_PINEVIEW_IDS(&gen3_stolen_funcs),
	INTEL_I965G_IDS(&gen3_stolen_funcs),
	INTEL_G33_IDS(&gen3_stolen_funcs),
	INTEL_I965GM_IDS(&gen3_stolen_funcs),
	INTEL_GM45_IDS(&gen3_stolen_funcs),
	INTEL_G45_IDS(&gen3_stolen_funcs),
	INTEL_IRONLAKE_D_IDS(&gen3_stolen_funcs),
	INTEL_IRONLAKE_M_IDS(&gen3_stolen_funcs),
	INTEL_SNB_D_IDS(&gen6_stolen_funcs),
	INTEL_SNB_M_IDS(&gen6_stolen_funcs),
	INTEL_IVB_M_IDS(&gen6_stolen_funcs),
	INTEL_IVB_D_IDS(&gen6_stolen_funcs),
	INTEL_HSW_D_IDS(&gen6_stolen_funcs),
	INTEL_HSW_M_IDS(&gen6_stolen_funcs),
	INTEL_BDW_M_IDS(&gen8_stolen_funcs),
	INTEL_BDW_D_IDS(&gen8_stolen_funcs)
499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514
};

static void __init intel_graphics_stolen(int num, int slot, int func)
{
	size_t size;
	int i;
	u32 start;
	u16 device, subvendor, subdevice;

	device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);
	subvendor = read_pci_config_16(num, slot, func,
				       PCI_SUBSYSTEM_VENDOR_ID);
	subdevice = read_pci_config_16(num, slot, func, PCI_SUBSYSTEM_ID);

	for (i = 0; i < ARRAY_SIZE(intel_stolen_ids); i++) {
		if (intel_stolen_ids[i].device == device) {
515 516 517 518
			const struct intel_stolen_funcs *stolen_funcs =
				(const struct intel_stolen_funcs *)intel_stolen_ids[i].driver_data;
			size = stolen_funcs->size(num, slot, func);
			start = stolen_funcs->base(num, slot, func, size);
519
			if (size && start) {
520 521
				printk(KERN_INFO "Reserving Intel graphics stolen memory at 0x%x-0x%x\n",
				       start, start + (u32)size - 1);
522 523 524 525 526 527 528 529 530 531 532
				/* Mark this space as reserved */
				e820_add_region(start, size, E820_RESERVED);
				sanitize_e820_map(e820.map,
						  ARRAY_SIZE(e820.map),
						  &e820.nr_map);
			}
			return;
		}
	}
}

533 534 535
#define QFLAG_APPLY_ONCE 	0x1
#define QFLAG_APPLIED		0x2
#define QFLAG_DONE		(QFLAG_APPLY_ONCE|QFLAG_APPLIED)
536
struct chipset {
537 538 539 540 541 542
	u32 vendor;
	u32 device;
	u32 class;
	u32 class_mask;
	u32 flags;
	void (*f)(int num, int slot, int func);
543 544
};

545 546 547 548 549 550
/*
 * Only works for devices on the root bus. If you add any devices
 * not on bus 0 readd another loop level in early_quirks(). But
 * be careful because at least the Nvidia quirk here relies on
 * only matching on bus 0.
 */
551
static struct chipset early_qrk[] __initdata = {
552 553 554 555 556 557
	{ PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
	  PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, nvidia_bugs },
	{ PCI_VENDOR_ID_VIA, PCI_ANY_ID,
	  PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, via_bugs },
	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB,
	  PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, fix_hypertransport_config },
558 559
	{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS,
	  PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs },
560 561
	{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,
	  PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs_contd },
562 563
	{ PCI_VENDOR_ID_INTEL, 0x3403, PCI_CLASS_BRIDGE_HOST,
	  PCI_BASE_CLASS_BRIDGE, 0, intel_remapping_check },
564 565
	{ PCI_VENDOR_ID_INTEL, 0x3405, PCI_CLASS_BRIDGE_HOST,
	  PCI_BASE_CLASS_BRIDGE, 0, intel_remapping_check },
566 567
	{ PCI_VENDOR_ID_INTEL, 0x3406, PCI_CLASS_BRIDGE_HOST,
	  PCI_BASE_CLASS_BRIDGE, 0, intel_remapping_check },
568 569
	{ PCI_VENDOR_ID_INTEL, PCI_ANY_ID, PCI_CLASS_DISPLAY_VGA, PCI_ANY_ID,
	  QFLAG_APPLY_ONCE, intel_graphics_stolen },
570 571 572
	{}
};

573 574 575 576 577 578 579 580 581 582 583 584
/**
 * check_dev_quirk - apply early quirks to a given PCI device
 * @num: bus number
 * @slot: slot number
 * @func: PCI function
 *
 * Check the vendor & device ID against the early quirks table.
 *
 * If the device is single function, let early_quirks() know so we don't
 * poke at this device again.
 */
static int __init check_dev_quirk(int num, int slot, int func)
585 586 587 588 589 590 591 592 593 594
{
	u16 class;
	u16 vendor;
	u16 device;
	u8 type;
	int i;

	class = read_pci_config_16(num, slot, func, PCI_CLASS_DEVICE);

	if (class == 0xffff)
595
		return -1; /* no class, treat as single function */
596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617

	vendor = read_pci_config_16(num, slot, func, PCI_VENDOR_ID);

	device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);

	for (i = 0; early_qrk[i].f != NULL; i++) {
		if (((early_qrk[i].vendor == PCI_ANY_ID) ||
			(early_qrk[i].vendor == vendor)) &&
			((early_qrk[i].device == PCI_ANY_ID) ||
			(early_qrk[i].device == device)) &&
			(!((early_qrk[i].class ^ class) &
			    early_qrk[i].class_mask))) {
				if ((early_qrk[i].flags &
				     QFLAG_DONE) != QFLAG_DONE)
					early_qrk[i].f(num, slot, func);
				early_qrk[i].flags |= QFLAG_APPLIED;
			}
	}

	type = read_pci_config_byte(num, slot, func,
				    PCI_HEADER_TYPE);
	if (!(type & 0x80))
618 619 620
		return -1;

	return 0;
621 622
}

623 624
void __init early_quirks(void)
{
625
	int slot, func;
626 627 628 629

	if (!early_pci_allowed())
		return;

630
	/* Poor man's PCI discovery */
631 632 633 634 635 636 637
	/* Only scan the root bus */
	for (slot = 0; slot < 32; slot++)
		for (func = 0; func < 8; func++) {
			/* Only probe function 0 on single fn devices */
			if (check_dev_quirk(0, slot, func))
				break;
		}
638
}