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  1/*
  2 *	Low-Level PCI Support for PC
  3 *
  4 *	(c) 1999--2000 Martin Mares <mj@ucw.cz>
  5 */
  6
  7#include <linux/sched.h>
  8#include <linux/pci.h>
  9#include <linux/ioport.h>
 10#include <linux/init.h>
 11#include <linux/dmi.h>
 12#include <linux/slab.h>
 13
 14#include <asm-generic/pci-bridge.h>
 15#include <asm/acpi.h>
 16#include <asm/segment.h>
 17#include <asm/io.h>
 18#include <asm/smp.h>
 19#include <asm/pci_x86.h>
 20
 21unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
 22				PCI_PROBE_MMCONF;
 23
 24unsigned int pci_early_dump_regs;
 25static int pci_bf_sort;
 26static int smbios_type_b1_flag;
 27int pci_routeirq;
 28int noioapicquirk;
 29#ifdef CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 30int noioapicreroute = 0;
 31#else
 32int noioapicreroute = 1;
 33#endif
 34int pcibios_last_bus = -1;
 35unsigned long pirq_table_addr;
 36struct pci_bus *pci_root_bus;
 37const struct pci_raw_ops *__read_mostly raw_pci_ops;
 38const struct pci_raw_ops *__read_mostly raw_pci_ext_ops;
 39
 40int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
 41						int reg, int len, u32 *val)
 42{
 43	if (domain == 0 && reg < 256 && raw_pci_ops)
 44		return raw_pci_ops->read(domain, bus, devfn, reg, len, val);
 45	if (raw_pci_ext_ops)
 46		return raw_pci_ext_ops->read(domain, bus, devfn, reg, len, val);
 47	return -EINVAL;
 48}
 49
 50int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
 51						int reg, int len, u32 val)
 52{
 53	if (domain == 0 && reg < 256 && raw_pci_ops)
 54		return raw_pci_ops->write(domain, bus, devfn, reg, len, val);
 55	if (raw_pci_ext_ops)
 56		return raw_pci_ext_ops->write(domain, bus, devfn, reg, len, val);
 57	return -EINVAL;
 58}
 59
 60static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
 61{
 62	return raw_pci_read(pci_domain_nr(bus), bus->number,
 63				 devfn, where, size, value);
 64}
 65
 66static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
 67{
 68	return raw_pci_write(pci_domain_nr(bus), bus->number,
 69				  devfn, where, size, value);
 70}
 71
 72struct pci_ops pci_root_ops = {
 73	.read = pci_read,
 74	.write = pci_write,
 75};
 76
 77/*
 78 * This interrupt-safe spinlock protects all accesses to PCI
 79 * configuration space.
 80 */
 81DEFINE_RAW_SPINLOCK(pci_config_lock);
 82
 83static int __devinit can_skip_ioresource_align(const struct dmi_system_id *d)
 84{
 85	pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
 86	printk(KERN_INFO "PCI: %s detected, can skip ISA alignment\n", d->ident);
 87	return 0;
 88}
 89
 90static const struct dmi_system_id can_skip_pciprobe_dmi_table[] __devinitconst = {
 91/*
 92 * Systems where PCI IO resource ISA alignment can be skipped
 93 * when the ISA enable bit in the bridge control is not set
 94 */
 95	{
 96		.callback = can_skip_ioresource_align,
 97		.ident = "IBM System x3800",
 98		.matches = {
 99			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
100			DMI_MATCH(DMI_PRODUCT_NAME, "x3800"),
101		},
102	},
103	{
104		.callback = can_skip_ioresource_align,
105		.ident = "IBM System x3850",
106		.matches = {
107			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
108			DMI_MATCH(DMI_PRODUCT_NAME, "x3850"),
109		},
110	},
111	{
112		.callback = can_skip_ioresource_align,
113		.ident = "IBM System x3950",
114		.matches = {
115			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
116			DMI_MATCH(DMI_PRODUCT_NAME, "x3950"),
117		},
118	},
119	{}
120};
121
122void __init dmi_check_skip_isa_align(void)
123{
124	dmi_check_system(can_skip_pciprobe_dmi_table);
125}
126
127static void __devinit pcibios_fixup_device_resources(struct pci_dev *dev)
128{
129	struct resource *rom_r = &dev->resource[PCI_ROM_RESOURCE];
130	struct resource *bar_r;
131	int bar;
132
133	if (pci_probe & PCI_NOASSIGN_BARS) {
134		/*
135		* If the BIOS did not assign the BAR, zero out the
136		* resource so the kernel doesn't attmept to assign
137		* it later on in pci_assign_unassigned_resources
138		*/
139		for (bar = 0; bar <= PCI_STD_RESOURCE_END; bar++) {
140			bar_r = &dev->resource[bar];
141			if (bar_r->start == 0 && bar_r->end != 0) {
142				bar_r->flags = 0;
143				bar_r->end = 0;
144			}
145		}
146	}
147
148	if (pci_probe & PCI_NOASSIGN_ROMS) {
149		if (rom_r->parent)
150			return;
151		if (rom_r->start) {
152			/* we deal with BIOS assigned ROM later */
153			return;
154		}
155		rom_r->start = rom_r->end = rom_r->flags = 0;
156	}
157}
158
159/*
160 *  Called after each bus is probed, but before its children
161 *  are examined.
162 */
163
164void __devinit pcibios_fixup_bus(struct pci_bus *b)
165{
166	struct pci_dev *dev;
167
168	pci_read_bridge_bases(b);
169	list_for_each_entry(dev, &b->devices, bus_list)
170		pcibios_fixup_device_resources(dev);
171}
172
173/*
174 * Only use DMI information to set this if nothing was passed
175 * on the kernel command line (which was parsed earlier).
176 */
177
178static int __devinit set_bf_sort(const struct dmi_system_id *d)
179{
180	if (pci_bf_sort == pci_bf_sort_default) {
181		pci_bf_sort = pci_dmi_bf;
182		printk(KERN_INFO "PCI: %s detected, enabling pci=bfsort.\n", d->ident);
183	}
184	return 0;
185}
186
187static void __devinit read_dmi_type_b1(const struct dmi_header *dm,
188				       void *private_data)
189{
190	u8 *d = (u8 *)dm + 4;
191
192	if (dm->type != 0xB1)
193		return;
194	switch (((*(u32 *)d) >> 9) & 0x03) {
195	case 0x00:
196		printk(KERN_INFO "dmi type 0xB1 record - unknown flag\n");
197		break;
198	case 0x01: /* set pci=bfsort */
199		smbios_type_b1_flag = 1;
200		break;
201	case 0x02: /* do not set pci=bfsort */
202		smbios_type_b1_flag = 2;
203		break;
204	default:
205		break;
206	}
207}
208
209static int __devinit find_sort_method(const struct dmi_system_id *d)
210{
211	dmi_walk(read_dmi_type_b1, NULL);
212
213	if (smbios_type_b1_flag == 1) {
214		set_bf_sort(d);
215		return 0;
216	}
217	return -1;
218}
219
220/*
221 * Enable renumbering of PCI bus# ranges to reach all PCI busses (Cardbus)
222 */
223#ifdef __i386__
224static int __devinit assign_all_busses(const struct dmi_system_id *d)
225{
226	pci_probe |= PCI_ASSIGN_ALL_BUSSES;
227	printk(KERN_INFO "%s detected: enabling PCI bus# renumbering"
228			" (pci=assign-busses)\n", d->ident);
229	return 0;
230}
231#endif
232
233static int __devinit set_scan_all(const struct dmi_system_id *d)
234{
235	printk(KERN_INFO "PCI: %s detected, enabling pci=pcie_scan_all\n",
236	       d->ident);
237	pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
238	return 0;
239}
240
241static const struct dmi_system_id __devinitconst pciprobe_dmi_table[] = {
242#ifdef __i386__
243/*
244 * Laptops which need pci=assign-busses to see Cardbus cards
245 */
246	{
247		.callback = assign_all_busses,
248		.ident = "Samsung X20 Laptop",
249		.matches = {
250			DMI_MATCH(DMI_SYS_VENDOR, "Samsung Electronics"),
251			DMI_MATCH(DMI_PRODUCT_NAME, "SX20S"),
252		},
253	},
254#endif		/* __i386__ */
255	{
256		.callback = set_bf_sort,
257		.ident = "Dell PowerEdge 1950",
258		.matches = {
259			DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
260			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1950"),
261		},
262	},
263	{
264		.callback = set_bf_sort,
265		.ident = "Dell PowerEdge 1955",
266		.matches = {
267			DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
268			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1955"),
269		},
270	},
271	{
272		.callback = set_bf_sort,
273		.ident = "Dell PowerEdge 2900",
274		.matches = {
275			DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
276			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2900"),
277		},
278	},
279	{
280		.callback = set_bf_sort,
281		.ident = "Dell PowerEdge 2950",
282		.matches = {
283			DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
284			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2950"),
285		},
286	},
287	{
288		.callback = set_bf_sort,
289		.ident = "Dell PowerEdge R900",
290		.matches = {
291			DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
292			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R900"),
293		},
294	},
295	{
296		.callback = find_sort_method,
297		.ident = "Dell System",
298		.matches = {
299			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc"),
300		},
301	},
302	{
303		.callback = set_bf_sort,
304		.ident = "HP ProLiant BL20p G3",
305		.matches = {
306			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
307			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL20p G3"),
308		},
309	},
310	{
311		.callback = set_bf_sort,
312		.ident = "HP ProLiant BL20p G4",
313		.matches = {
314			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
315			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL20p G4"),
316		},
317	},
318	{
319		.callback = set_bf_sort,
320		.ident = "HP ProLiant BL30p G1",
321		.matches = {
322			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
323			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL30p G1"),
324		},
325	},
326	{
327		.callback = set_bf_sort,
328		.ident = "HP ProLiant BL25p G1",
329		.matches = {
330			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
331			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL25p G1"),
332		},
333	},
334	{
335		.callback = set_bf_sort,
336		.ident = "HP ProLiant BL35p G1",
337		.matches = {
338			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
339			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL35p G1"),
340		},
341	},
342	{
343		.callback = set_bf_sort,
344		.ident = "HP ProLiant BL45p G1",
345		.matches = {
346			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
347			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL45p G1"),
348		},
349	},
350	{
351		.callback = set_bf_sort,
352		.ident = "HP ProLiant BL45p G2",
353		.matches = {
354			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
355			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL45p G2"),
356		},
357	},
358	{
359		.callback = set_bf_sort,
360		.ident = "HP ProLiant BL460c G1",
361		.matches = {
362			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
363			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL460c G1"),
364		},
365	},
366	{
367		.callback = set_bf_sort,
368		.ident = "HP ProLiant BL465c G1",
369		.matches = {
370			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
371			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL465c G1"),
372		},
373	},
374	{
375		.callback = set_bf_sort,
376		.ident = "HP ProLiant BL480c G1",
377		.matches = {
378			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
379			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL480c G1"),
380		},
381	},
382	{
383		.callback = set_bf_sort,
384		.ident = "HP ProLiant BL685c G1",
385		.matches = {
386			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
387			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL685c G1"),
388		},
389	},
390	{
391		.callback = set_bf_sort,
392		.ident = "HP ProLiant DL360",
393		.matches = {
394			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
395			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL360"),
396		},
397	},
398	{
399		.callback = set_bf_sort,
400		.ident = "HP ProLiant DL380",
401		.matches = {
402			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
403			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL380"),
404		},
405	},
406#ifdef __i386__
407	{
408		.callback = assign_all_busses,
409		.ident = "Compaq EVO N800c",
410		.matches = {
411			DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
412			DMI_MATCH(DMI_PRODUCT_NAME, "EVO N800c"),
413		},
414	},
415#endif
416	{
417		.callback = set_bf_sort,
418		.ident = "HP ProLiant DL385 G2",
419		.matches = {
420			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
421			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL385 G2"),
422		},
423	},
424	{
425		.callback = set_bf_sort,
426		.ident = "HP ProLiant DL585 G2",
427		.matches = {
428			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
429			DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL585 G2"),
430		},
431	},
432	{
433		.callback = set_scan_all,
434		.ident = "Stratus/NEC ftServer",
435		.matches = {
436			DMI_MATCH(DMI_SYS_VENDOR, "ftServer"),
437		},
438	},
439	{}
440};
441
442void __init dmi_check_pciprobe(void)
443{
444	dmi_check_system(pciprobe_dmi_table);
445}
446
447struct pci_bus * __devinit pcibios_scan_root(int busnum)
448{
449	struct pci_bus *bus = NULL;
450
451	while ((bus = pci_find_next_bus(bus)) != NULL) {
452		if (bus->number == busnum) {
453			/* Already scanned */
454			return bus;
455		}
456	}
457
458	return pci_scan_bus_on_node(busnum, &pci_root_ops,
459					get_mp_bus_to_node(busnum));
460}
461
462void __init pcibios_set_cache_line_size(void)
463{
464	struct cpuinfo_x86 *c = &boot_cpu_data;
465
466	/*
467	 * Set PCI cacheline size to that of the CPU if the CPU has reported it.
468	 * (For older CPUs that don't support cpuid, we se it to 32 bytes
469	 * It's also good for 386/486s (which actually have 16)
470	 * as quite a few PCI devices do not support smaller values.
471	 */
472	if (c->x86_clflush_size > 0) {
473		pci_dfl_cache_line_size = c->x86_clflush_size >> 2;
474		printk(KERN_DEBUG "PCI: pci_cache_line_size set to %d bytes\n",
475			pci_dfl_cache_line_size << 2);
476	} else {
477 		pci_dfl_cache_line_size = 32 >> 2;
478		printk(KERN_DEBUG "PCI: Unknown cacheline size. Setting to 32 bytes\n");
479	}
480}
481
482int __init pcibios_init(void)
483{
484	if (!raw_pci_ops) {
485		printk(KERN_WARNING "PCI: System does not support PCI\n");
486		return 0;
487	}
488
489	pcibios_set_cache_line_size();
490	pcibios_resource_survey();
491
492	if (pci_bf_sort >= pci_force_bf)
493		pci_sort_breadthfirst();
494	return 0;
495}
496
497char * __devinit  pcibios_setup(char *str)
498{
499	if (!strcmp(str, "off")) {
500		pci_probe = 0;
501		return NULL;
502	} else if (!strcmp(str, "bfsort")) {
503		pci_bf_sort = pci_force_bf;
504		return NULL;
505	} else if (!strcmp(str, "nobfsort")) {
506		pci_bf_sort = pci_force_nobf;
507		return NULL;
508	}
509#ifdef CONFIG_PCI_BIOS
510	else if (!strcmp(str, "bios")) {
511		pci_probe = PCI_PROBE_BIOS;
512		return NULL;
513	} else if (!strcmp(str, "nobios")) {
514		pci_probe &= ~PCI_PROBE_BIOS;
515		return NULL;
516	} else if (!strcmp(str, "biosirq")) {
517		pci_probe |= PCI_BIOS_IRQ_SCAN;
518		return NULL;
519	} else if (!strncmp(str, "pirqaddr=", 9)) {
520		pirq_table_addr = simple_strtoul(str+9, NULL, 0);
521		return NULL;
522	}
523#endif
524#ifdef CONFIG_PCI_DIRECT
525	else if (!strcmp(str, "conf1")) {
526		pci_probe = PCI_PROBE_CONF1 | PCI_NO_CHECKS;
527		return NULL;
528	}
529	else if (!strcmp(str, "conf2")) {
530		pci_probe = PCI_PROBE_CONF2 | PCI_NO_CHECKS;
531		return NULL;
532	}
533#endif
534#ifdef CONFIG_PCI_MMCONFIG
535	else if (!strcmp(str, "nommconf")) {
536		pci_probe &= ~PCI_PROBE_MMCONF;
537		return NULL;
538	}
539	else if (!strcmp(str, "check_enable_amd_mmconf")) {
540		pci_probe |= PCI_CHECK_ENABLE_AMD_MMCONF;
541		return NULL;
542	}
543#endif
544	else if (!strcmp(str, "noacpi")) {
545		acpi_noirq_set();
546		return NULL;
547	}
548	else if (!strcmp(str, "noearly")) {
549		pci_probe |= PCI_PROBE_NOEARLY;
550		return NULL;
551	}
552#ifndef CONFIG_X86_VISWS
553	else if (!strcmp(str, "usepirqmask")) {
554		pci_probe |= PCI_USE_PIRQ_MASK;
555		return NULL;
556	} else if (!strncmp(str, "irqmask=", 8)) {
557		pcibios_irq_mask = simple_strtol(str+8, NULL, 0);
558		return NULL;
559	} else if (!strncmp(str, "lastbus=", 8)) {
560		pcibios_last_bus = simple_strtol(str+8, NULL, 0);
561		return NULL;
562	}
563#endif
564	else if (!strcmp(str, "rom")) {
565		pci_probe |= PCI_ASSIGN_ROMS;
566		return NULL;
567	} else if (!strcmp(str, "norom")) {
568		pci_probe |= PCI_NOASSIGN_ROMS;
569		return NULL;
570	} else if (!strcmp(str, "nobar")) {
571		pci_probe |= PCI_NOASSIGN_BARS;
572		return NULL;
573	} else if (!strcmp(str, "assign-busses")) {
574		pci_probe |= PCI_ASSIGN_ALL_BUSSES;
575		return NULL;
576	} else if (!strcmp(str, "use_crs")) {
577		pci_probe |= PCI_USE__CRS;
578		return NULL;
579	} else if (!strcmp(str, "nocrs")) {
580		pci_probe |= PCI_ROOT_NO_CRS;
581		return NULL;
582	} else if (!strcmp(str, "earlydump")) {
583		pci_early_dump_regs = 1;
584		return NULL;
585	} else if (!strcmp(str, "routeirq")) {
586		pci_routeirq = 1;
587		return NULL;
588	} else if (!strcmp(str, "skip_isa_align")) {
589		pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
590		return NULL;
591	} else if (!strcmp(str, "noioapicquirk")) {
592		noioapicquirk = 1;
593		return NULL;
594	} else if (!strcmp(str, "ioapicreroute")) {
595		if (noioapicreroute != -1)
596			noioapicreroute = 0;
597		return NULL;
598	} else if (!strcmp(str, "noioapicreroute")) {
599		if (noioapicreroute != -1)
600			noioapicreroute = 1;
601		return NULL;
602	}
603	return str;
604}
605
606unsigned int pcibios_assign_all_busses(void)
607{
608	return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
609}
610
611int pcibios_enable_device(struct pci_dev *dev, int mask)
612{
613	int err;
614
615	if ((err = pci_enable_resources(dev, mask)) < 0)
616		return err;
617
618	if (!pci_dev_msi_enabled(dev))
619		return pcibios_enable_irq(dev);
620	return 0;
621}
622
623void pcibios_disable_device (struct pci_dev *dev)
624{
625	if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq)
626		pcibios_disable_irq(dev);
627}
628
629int pci_ext_cfg_avail(struct pci_dev *dev)
630{
631	if (raw_pci_ext_ops)
632		return 1;
633	else
634		return 0;
635}
636
637struct pci_bus * __devinit pci_scan_bus_on_node(int busno, struct pci_ops *ops, int node)
638{
639	LIST_HEAD(resources);
640	struct pci_bus *bus = NULL;
641	struct pci_sysdata *sd;
642
643	/*
644	 * Allocate per-root-bus (not per bus) arch-specific data.
645	 * TODO: leak; this memory is never freed.
646	 * It's arguable whether it's worth the trouble to care.
647	 */
648	sd = kzalloc(sizeof(*sd), GFP_KERNEL);
649	if (!sd) {
650		printk(KERN_ERR "PCI: OOM, skipping PCI bus %02x\n", busno);
651		return NULL;
652	}
653	sd->node = node;
654	x86_pci_root_bus_resources(busno, &resources);
655	printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busno);
656	bus = pci_scan_root_bus(NULL, busno, ops, sd, &resources);
657	if (!bus) {
658		pci_free_resource_list(&resources);
659		kfree(sd);
660	}
661
662	return bus;
663}
664
665struct pci_bus * __devinit pci_scan_bus_with_sysdata(int busno)
666{
667	return pci_scan_bus_on_node(busno, &pci_root_ops, -1);
668}
669
670/*
671 * NUMA info for PCI busses
672 *
673 * Early arch code is responsible for filling in reasonable values here.
674 * A node id of "-1" means "use current node".  In other words, if a bus
675 * has a -1 node id, it's not tightly coupled to any particular chunk
676 * of memory (as is the case on some Nehalem systems).
677 */
678#ifdef CONFIG_NUMA
679
680#define BUS_NR 256
681
682#ifdef CONFIG_X86_64
683
684static int mp_bus_to_node[BUS_NR] = {
685	[0 ... BUS_NR - 1] = -1
686};
687
688void set_mp_bus_to_node(int busnum, int node)
689{
690	if (busnum >= 0 &&  busnum < BUS_NR)
691		mp_bus_to_node[busnum] = node;
692}
693
694int get_mp_bus_to_node(int busnum)
695{
696	int node = -1;
697
698	if (busnum < 0 || busnum > (BUS_NR - 1))
699		return node;
700
701	node = mp_bus_to_node[busnum];
702
703	/*
704	 * let numa_node_id to decide it later in dma_alloc_pages
705	 * if there is no ram on that node
706	 */
707	if (node != -1 && !node_online(node))
708		node = -1;
709
710	return node;
711}
712
713#else /* CONFIG_X86_32 */
714
715static int mp_bus_to_node[BUS_NR] = {
716	[0 ... BUS_NR - 1] = -1
717};
718
719void set_mp_bus_to_node(int busnum, int node)
720{
721	if (busnum >= 0 &&  busnum < BUS_NR)
722	mp_bus_to_node[busnum] = (unsigned char) node;
723}
724
725int get_mp_bus_to_node(int busnum)
726{
727	int node;
728
729	if (busnum < 0 || busnum > (BUS_NR - 1))
730		return 0;
731	node = mp_bus_to_node[busnum];
732	return node;
733}
734
735#endif /* CONFIG_X86_32 */
736
737#endif /* CONFIG_NUMA */