xref: /openbmc/linux/arch/x86/kernel/setup.c (revision 29a36d4d)
1 /*
2  *  Copyright (C) 1995  Linus Torvalds
3  *
4  *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
5  *
6  *  Memory region support
7  *	David Parsons <orc@pell.chi.il.us>, July-August 1999
8  *
9  *  Added E820 sanitization routine (removes overlapping memory regions);
10  *  Brian Moyle <bmoyle@mvista.com>, February 2001
11  *
12  * Moved CPU detection code to cpu/${cpu}.c
13  *    Patrick Mochel <mochel@osdl.org>, March 2002
14  *
15  *  Provisions for empty E820 memory regions (reported by certain BIOSes).
16  *  Alex Achenbach <xela@slit.de>, December 2002.
17  *
18  */
19 
20 /*
21  * This file handles the architecture-dependent parts of initialization
22  */
23 
24 #include <linux/sched.h>
25 #include <linux/mm.h>
26 #include <linux/mmzone.h>
27 #include <linux/screen_info.h>
28 #include <linux/ioport.h>
29 #include <linux/acpi.h>
30 #include <linux/sfi.h>
31 #include <linux/apm_bios.h>
32 #include <linux/initrd.h>
33 #include <linux/bootmem.h>
34 #include <linux/memblock.h>
35 #include <linux/seq_file.h>
36 #include <linux/console.h>
37 #include <linux/mca.h>
38 #include <linux/root_dev.h>
39 #include <linux/highmem.h>
40 #include <linux/module.h>
41 #include <linux/efi.h>
42 #include <linux/init.h>
43 #include <linux/edd.h>
44 #include <linux/iscsi_ibft.h>
45 #include <linux/nodemask.h>
46 #include <linux/kexec.h>
47 #include <linux/dmi.h>
48 #include <linux/pfn.h>
49 #include <linux/pci.h>
50 #include <asm/pci-direct.h>
51 #include <linux/init_ohci1394_dma.h>
52 #include <linux/kvm_para.h>
53 
54 #include <linux/errno.h>
55 #include <linux/kernel.h>
56 #include <linux/stddef.h>
57 #include <linux/unistd.h>
58 #include <linux/ptrace.h>
59 #include <linux/user.h>
60 #include <linux/delay.h>
61 
62 #include <linux/kallsyms.h>
63 #include <linux/cpufreq.h>
64 #include <linux/dma-mapping.h>
65 #include <linux/ctype.h>
66 #include <linux/uaccess.h>
67 
68 #include <linux/percpu.h>
69 #include <linux/crash_dump.h>
70 #include <linux/tboot.h>
71 
72 #include <video/edid.h>
73 
74 #include <asm/mtrr.h>
75 #include <asm/apic.h>
76 #include <asm/trampoline.h>
77 #include <asm/e820.h>
78 #include <asm/mpspec.h>
79 #include <asm/setup.h>
80 #include <asm/efi.h>
81 #include <asm/timer.h>
82 #include <asm/i8259.h>
83 #include <asm/sections.h>
84 #include <asm/dmi.h>
85 #include <asm/io_apic.h>
86 #include <asm/ist.h>
87 #include <asm/setup_arch.h>
88 #include <asm/bios_ebda.h>
89 #include <asm/cacheflush.h>
90 #include <asm/processor.h>
91 #include <asm/bugs.h>
92 
93 #include <asm/system.h>
94 #include <asm/vsyscall.h>
95 #include <asm/cpu.h>
96 #include <asm/desc.h>
97 #include <asm/dma.h>
98 #include <asm/iommu.h>
99 #include <asm/gart.h>
100 #include <asm/mmu_context.h>
101 #include <asm/proto.h>
102 
103 #include <asm/paravirt.h>
104 #include <asm/hypervisor.h>
105 #include <asm/olpc_ofw.h>
106 
107 #include <asm/percpu.h>
108 #include <asm/topology.h>
109 #include <asm/apicdef.h>
110 #include <asm/amd_nb.h>
111 #ifdef CONFIG_X86_64
112 #include <asm/numa_64.h>
113 #endif
114 #include <asm/mce.h>
115 #include <asm/alternative.h>
116 #include <asm/prom.h>
117 
118 /*
119  * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
120  * The direct mapping extends to max_pfn_mapped, so that we can directly access
121  * apertures, ACPI and other tables without having to play with fixmaps.
122  */
123 unsigned long max_low_pfn_mapped;
124 unsigned long max_pfn_mapped;
125 
126 #ifdef CONFIG_DMI
127 RESERVE_BRK(dmi_alloc, 65536);
128 #endif
129 
130 
131 static __initdata unsigned long _brk_start = (unsigned long)__brk_base;
132 unsigned long _brk_end = (unsigned long)__brk_base;
133 
134 #ifdef CONFIG_X86_64
135 int default_cpu_present_to_apicid(int mps_cpu)
136 {
137 	return __default_cpu_present_to_apicid(mps_cpu);
138 }
139 
140 int default_check_phys_apicid_present(int phys_apicid)
141 {
142 	return __default_check_phys_apicid_present(phys_apicid);
143 }
144 #endif
145 
146 #ifndef CONFIG_DEBUG_BOOT_PARAMS
147 struct boot_params __initdata boot_params;
148 #else
149 struct boot_params boot_params;
150 #endif
151 
152 /*
153  * Machine setup..
154  */
155 static struct resource data_resource = {
156 	.name	= "Kernel data",
157 	.start	= 0,
158 	.end	= 0,
159 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
160 };
161 
162 static struct resource code_resource = {
163 	.name	= "Kernel code",
164 	.start	= 0,
165 	.end	= 0,
166 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
167 };
168 
169 static struct resource bss_resource = {
170 	.name	= "Kernel bss",
171 	.start	= 0,
172 	.end	= 0,
173 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
174 };
175 
176 
177 #ifdef CONFIG_X86_32
178 /* cpu data as detected by the assembly code in head.S */
179 struct cpuinfo_x86 new_cpu_data __cpuinitdata = {0, 0, 0, 0, -1, 1, 0, 0, -1};
180 /* common cpu data for all cpus */
181 struct cpuinfo_x86 boot_cpu_data __read_mostly = {0, 0, 0, 0, -1, 1, 0, 0, -1};
182 EXPORT_SYMBOL(boot_cpu_data);
183 static void set_mca_bus(int x)
184 {
185 #ifdef CONFIG_MCA
186 	MCA_bus = x;
187 #endif
188 }
189 
190 unsigned int def_to_bigsmp;
191 
192 /* for MCA, but anyone else can use it if they want */
193 unsigned int machine_id;
194 unsigned int machine_submodel_id;
195 unsigned int BIOS_revision;
196 
197 struct apm_info apm_info;
198 EXPORT_SYMBOL(apm_info);
199 
200 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
201 	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
202 struct ist_info ist_info;
203 EXPORT_SYMBOL(ist_info);
204 #else
205 struct ist_info ist_info;
206 #endif
207 
208 #else
209 struct cpuinfo_x86 boot_cpu_data __read_mostly = {
210 	.x86_phys_bits = MAX_PHYSMEM_BITS,
211 };
212 EXPORT_SYMBOL(boot_cpu_data);
213 #endif
214 
215 
216 #if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
217 unsigned long mmu_cr4_features;
218 #else
219 unsigned long mmu_cr4_features = X86_CR4_PAE;
220 #endif
221 
222 /* Boot loader ID and version as integers, for the benefit of proc_dointvec */
223 int bootloader_type, bootloader_version;
224 
225 /*
226  * Setup options
227  */
228 struct screen_info screen_info;
229 EXPORT_SYMBOL(screen_info);
230 struct edid_info edid_info;
231 EXPORT_SYMBOL_GPL(edid_info);
232 
233 extern int root_mountflags;
234 
235 unsigned long saved_video_mode;
236 
237 #define RAMDISK_IMAGE_START_MASK	0x07FF
238 #define RAMDISK_PROMPT_FLAG		0x8000
239 #define RAMDISK_LOAD_FLAG		0x4000
240 
241 static char __initdata command_line[COMMAND_LINE_SIZE];
242 #ifdef CONFIG_CMDLINE_BOOL
243 static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
244 #endif
245 
246 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
247 struct edd edd;
248 #ifdef CONFIG_EDD_MODULE
249 EXPORT_SYMBOL(edd);
250 #endif
251 /**
252  * copy_edd() - Copy the BIOS EDD information
253  *              from boot_params into a safe place.
254  *
255  */
256 static inline void __init copy_edd(void)
257 {
258      memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
259 	    sizeof(edd.mbr_signature));
260      memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
261      edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
262      edd.edd_info_nr = boot_params.eddbuf_entries;
263 }
264 #else
265 static inline void __init copy_edd(void)
266 {
267 }
268 #endif
269 
270 void * __init extend_brk(size_t size, size_t align)
271 {
272 	size_t mask = align - 1;
273 	void *ret;
274 
275 	BUG_ON(_brk_start == 0);
276 	BUG_ON(align & mask);
277 
278 	_brk_end = (_brk_end + mask) & ~mask;
279 	BUG_ON((char *)(_brk_end + size) > __brk_limit);
280 
281 	ret = (void *)_brk_end;
282 	_brk_end += size;
283 
284 	memset(ret, 0, size);
285 
286 	return ret;
287 }
288 
289 #ifdef CONFIG_X86_64
290 static void __init init_gbpages(void)
291 {
292 	if (direct_gbpages && cpu_has_gbpages)
293 		printk(KERN_INFO "Using GB pages for direct mapping\n");
294 	else
295 		direct_gbpages = 0;
296 }
297 #else
298 static inline void init_gbpages(void)
299 {
300 }
301 static void __init cleanup_highmap(void)
302 {
303 }
304 #endif
305 
306 static void __init reserve_brk(void)
307 {
308 	if (_brk_end > _brk_start)
309 		memblock_x86_reserve_range(__pa(_brk_start), __pa(_brk_end), "BRK");
310 
311 	/* Mark brk area as locked down and no longer taking any
312 	   new allocations */
313 	_brk_start = 0;
314 }
315 
316 #ifdef CONFIG_BLK_DEV_INITRD
317 
318 #define MAX_MAP_CHUNK	(NR_FIX_BTMAPS << PAGE_SHIFT)
319 static void __init relocate_initrd(void)
320 {
321 	/* Assume only end is not page aligned */
322 	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
323 	u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
324 	u64 area_size     = PAGE_ALIGN(ramdisk_size);
325 	u64 end_of_lowmem = max_low_pfn_mapped << PAGE_SHIFT;
326 	u64 ramdisk_here;
327 	unsigned long slop, clen, mapaddr;
328 	char *p, *q;
329 
330 	/* We need to move the initrd down into lowmem */
331 	ramdisk_here = memblock_find_in_range(0, end_of_lowmem, area_size,
332 					 PAGE_SIZE);
333 
334 	if (ramdisk_here == MEMBLOCK_ERROR)
335 		panic("Cannot find place for new RAMDISK of size %lld\n",
336 			 ramdisk_size);
337 
338 	/* Note: this includes all the lowmem currently occupied by
339 	   the initrd, we rely on that fact to keep the data intact. */
340 	memblock_x86_reserve_range(ramdisk_here, ramdisk_here + area_size, "NEW RAMDISK");
341 	initrd_start = ramdisk_here + PAGE_OFFSET;
342 	initrd_end   = initrd_start + ramdisk_size;
343 	printk(KERN_INFO "Allocated new RAMDISK: %08llx - %08llx\n",
344 			 ramdisk_here, ramdisk_here + ramdisk_size);
345 
346 	q = (char *)initrd_start;
347 
348 	/* Copy any lowmem portion of the initrd */
349 	if (ramdisk_image < end_of_lowmem) {
350 		clen = end_of_lowmem - ramdisk_image;
351 		p = (char *)__va(ramdisk_image);
352 		memcpy(q, p, clen);
353 		q += clen;
354 		ramdisk_image += clen;
355 		ramdisk_size  -= clen;
356 	}
357 
358 	/* Copy the highmem portion of the initrd */
359 	while (ramdisk_size) {
360 		slop = ramdisk_image & ~PAGE_MASK;
361 		clen = ramdisk_size;
362 		if (clen > MAX_MAP_CHUNK-slop)
363 			clen = MAX_MAP_CHUNK-slop;
364 		mapaddr = ramdisk_image & PAGE_MASK;
365 		p = early_memremap(mapaddr, clen+slop);
366 		memcpy(q, p+slop, clen);
367 		early_iounmap(p, clen+slop);
368 		q += clen;
369 		ramdisk_image += clen;
370 		ramdisk_size  -= clen;
371 	}
372 	/* high pages is not converted by early_res_to_bootmem */
373 	ramdisk_image = boot_params.hdr.ramdisk_image;
374 	ramdisk_size  = boot_params.hdr.ramdisk_size;
375 	printk(KERN_INFO "Move RAMDISK from %016llx - %016llx to"
376 		" %08llx - %08llx\n",
377 		ramdisk_image, ramdisk_image + ramdisk_size - 1,
378 		ramdisk_here, ramdisk_here + ramdisk_size - 1);
379 }
380 
381 static void __init reserve_initrd(void)
382 {
383 	/* Assume only end is not page aligned */
384 	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
385 	u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
386 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
387 	u64 end_of_lowmem = max_low_pfn_mapped << PAGE_SHIFT;
388 
389 	if (!boot_params.hdr.type_of_loader ||
390 	    !ramdisk_image || !ramdisk_size)
391 		return;		/* No initrd provided by bootloader */
392 
393 	initrd_start = 0;
394 
395 	if (ramdisk_size >= (end_of_lowmem>>1)) {
396 		memblock_x86_free_range(ramdisk_image, ramdisk_end);
397 		printk(KERN_ERR "initrd too large to handle, "
398 		       "disabling initrd\n");
399 		return;
400 	}
401 
402 	printk(KERN_INFO "RAMDISK: %08llx - %08llx\n", ramdisk_image,
403 			ramdisk_end);
404 
405 
406 	if (ramdisk_end <= end_of_lowmem) {
407 		/* All in lowmem, easy case */
408 		/*
409 		 * don't need to reserve again, already reserved early
410 		 * in i386_start_kernel
411 		 */
412 		initrd_start = ramdisk_image + PAGE_OFFSET;
413 		initrd_end = initrd_start + ramdisk_size;
414 		return;
415 	}
416 
417 	relocate_initrd();
418 
419 	memblock_x86_free_range(ramdisk_image, ramdisk_end);
420 }
421 #else
422 static void __init reserve_initrd(void)
423 {
424 }
425 #endif /* CONFIG_BLK_DEV_INITRD */
426 
427 static void __init parse_setup_data(void)
428 {
429 	struct setup_data *data;
430 	u64 pa_data;
431 
432 	if (boot_params.hdr.version < 0x0209)
433 		return;
434 	pa_data = boot_params.hdr.setup_data;
435 	while (pa_data) {
436 		u32 data_len, map_len;
437 
438 		map_len = max(PAGE_SIZE - (pa_data & ~PAGE_MASK),
439 			      (u64)sizeof(struct setup_data));
440 		data = early_memremap(pa_data, map_len);
441 		data_len = data->len + sizeof(struct setup_data);
442 		if (data_len > map_len) {
443 			early_iounmap(data, map_len);
444 			data = early_memremap(pa_data, data_len);
445 			map_len = data_len;
446 		}
447 
448 		switch (data->type) {
449 		case SETUP_E820_EXT:
450 			parse_e820_ext(data);
451 			break;
452 		case SETUP_DTB:
453 			add_dtb(pa_data);
454 			break;
455 		default:
456 			break;
457 		}
458 		pa_data = data->next;
459 		early_iounmap(data, map_len);
460 	}
461 }
462 
463 static void __init e820_reserve_setup_data(void)
464 {
465 	struct setup_data *data;
466 	u64 pa_data;
467 	int found = 0;
468 
469 	if (boot_params.hdr.version < 0x0209)
470 		return;
471 	pa_data = boot_params.hdr.setup_data;
472 	while (pa_data) {
473 		data = early_memremap(pa_data, sizeof(*data));
474 		e820_update_range(pa_data, sizeof(*data)+data->len,
475 			 E820_RAM, E820_RESERVED_KERN);
476 		found = 1;
477 		pa_data = data->next;
478 		early_iounmap(data, sizeof(*data));
479 	}
480 	if (!found)
481 		return;
482 
483 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
484 	memcpy(&e820_saved, &e820, sizeof(struct e820map));
485 	printk(KERN_INFO "extended physical RAM map:\n");
486 	e820_print_map("reserve setup_data");
487 }
488 
489 static void __init memblock_x86_reserve_range_setup_data(void)
490 {
491 	struct setup_data *data;
492 	u64 pa_data;
493 	char buf[32];
494 
495 	if (boot_params.hdr.version < 0x0209)
496 		return;
497 	pa_data = boot_params.hdr.setup_data;
498 	while (pa_data) {
499 		data = early_memremap(pa_data, sizeof(*data));
500 		sprintf(buf, "setup data %x", data->type);
501 		memblock_x86_reserve_range(pa_data, pa_data+sizeof(*data)+data->len, buf);
502 		pa_data = data->next;
503 		early_iounmap(data, sizeof(*data));
504 	}
505 }
506 
507 /*
508  * --------- Crashkernel reservation ------------------------------
509  */
510 
511 #ifdef CONFIG_KEXEC
512 
513 static inline unsigned long long get_total_mem(void)
514 {
515 	unsigned long long total;
516 
517 	total = max_pfn - min_low_pfn;
518 
519 	return total << PAGE_SHIFT;
520 }
521 
522 /*
523  * Keep the crash kernel below this limit.  On 32 bits earlier kernels
524  * would limit the kernel to the low 512 MiB due to mapping restrictions.
525  * On 64 bits, kexec-tools currently limits us to 896 MiB; increase this
526  * limit once kexec-tools are fixed.
527  */
528 #ifdef CONFIG_X86_32
529 # define CRASH_KERNEL_ADDR_MAX	(512 << 20)
530 #else
531 # define CRASH_KERNEL_ADDR_MAX	(896 << 20)
532 #endif
533 
534 static void __init reserve_crashkernel(void)
535 {
536 	unsigned long long total_mem;
537 	unsigned long long crash_size, crash_base;
538 	int ret;
539 
540 	total_mem = get_total_mem();
541 
542 	ret = parse_crashkernel(boot_command_line, total_mem,
543 			&crash_size, &crash_base);
544 	if (ret != 0 || crash_size <= 0)
545 		return;
546 
547 	/* 0 means: find the address automatically */
548 	if (crash_base <= 0) {
549 		const unsigned long long alignment = 16<<20;	/* 16M */
550 
551 		/*
552 		 *  kexec want bzImage is below CRASH_KERNEL_ADDR_MAX
553 		 */
554 		crash_base = memblock_find_in_range(alignment,
555 			       CRASH_KERNEL_ADDR_MAX, crash_size, alignment);
556 
557 		if (crash_base == MEMBLOCK_ERROR) {
558 			pr_info("crashkernel reservation failed - No suitable area found.\n");
559 			return;
560 		}
561 	} else {
562 		unsigned long long start;
563 
564 		start = memblock_find_in_range(crash_base,
565 				 crash_base + crash_size, crash_size, 1<<20);
566 		if (start != crash_base) {
567 			pr_info("crashkernel reservation failed - memory is in use.\n");
568 			return;
569 		}
570 	}
571 	memblock_x86_reserve_range(crash_base, crash_base + crash_size, "CRASH KERNEL");
572 
573 	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
574 			"for crashkernel (System RAM: %ldMB)\n",
575 			(unsigned long)(crash_size >> 20),
576 			(unsigned long)(crash_base >> 20),
577 			(unsigned long)(total_mem >> 20));
578 
579 	crashk_res.start = crash_base;
580 	crashk_res.end   = crash_base + crash_size - 1;
581 	insert_resource(&iomem_resource, &crashk_res);
582 }
583 #else
584 static void __init reserve_crashkernel(void)
585 {
586 }
587 #endif
588 
589 static struct resource standard_io_resources[] = {
590 	{ .name = "dma1", .start = 0x00, .end = 0x1f,
591 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
592 	{ .name = "pic1", .start = 0x20, .end = 0x21,
593 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
594 	{ .name = "timer0", .start = 0x40, .end = 0x43,
595 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
596 	{ .name = "timer1", .start = 0x50, .end = 0x53,
597 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
598 	{ .name = "keyboard", .start = 0x60, .end = 0x60,
599 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
600 	{ .name = "keyboard", .start = 0x64, .end = 0x64,
601 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
602 	{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
603 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
604 	{ .name = "pic2", .start = 0xa0, .end = 0xa1,
605 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
606 	{ .name = "dma2", .start = 0xc0, .end = 0xdf,
607 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
608 	{ .name = "fpu", .start = 0xf0, .end = 0xff,
609 		.flags = IORESOURCE_BUSY | IORESOURCE_IO }
610 };
611 
612 void __init reserve_standard_io_resources(void)
613 {
614 	int i;
615 
616 	/* request I/O space for devices used on all i[345]86 PCs */
617 	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
618 		request_resource(&ioport_resource, &standard_io_resources[i]);
619 
620 }
621 
622 static __init void reserve_ibft_region(void)
623 {
624 	unsigned long addr, size = 0;
625 
626 	addr = find_ibft_region(&size);
627 
628 	if (size)
629 		memblock_x86_reserve_range(addr, addr + size, "* ibft");
630 }
631 
632 static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
633 
634 static void __init trim_bios_range(void)
635 {
636 	/*
637 	 * A special case is the first 4Kb of memory;
638 	 * This is a BIOS owned area, not kernel ram, but generally
639 	 * not listed as such in the E820 table.
640 	 *
641 	 * This typically reserves additional memory (64KiB by default)
642 	 * since some BIOSes are known to corrupt low memory.  See the
643 	 * Kconfig help text for X86_RESERVE_LOW.
644 	 */
645 	e820_update_range(0, ALIGN(reserve_low, PAGE_SIZE),
646 			  E820_RAM, E820_RESERVED);
647 
648 	/*
649 	 * special case: Some BIOSen report the PC BIOS
650 	 * area (640->1Mb) as ram even though it is not.
651 	 * take them out.
652 	 */
653 	e820_remove_range(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_RAM, 1);
654 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
655 }
656 
657 static int __init parse_reservelow(char *p)
658 {
659 	unsigned long long size;
660 
661 	if (!p)
662 		return -EINVAL;
663 
664 	size = memparse(p, &p);
665 
666 	if (size < 4096)
667 		size = 4096;
668 
669 	if (size > 640*1024)
670 		size = 640*1024;
671 
672 	reserve_low = size;
673 
674 	return 0;
675 }
676 
677 early_param("reservelow", parse_reservelow);
678 
679 /*
680  * Determine if we were loaded by an EFI loader.  If so, then we have also been
681  * passed the efi memmap, systab, etc., so we should use these data structures
682  * for initialization.  Note, the efi init code path is determined by the
683  * global efi_enabled. This allows the same kernel image to be used on existing
684  * systems (with a traditional BIOS) as well as on EFI systems.
685  */
686 /*
687  * setup_arch - architecture-specific boot-time initializations
688  *
689  * Note: On x86_64, fixmaps are ready for use even before this is called.
690  */
691 
692 void __init setup_arch(char **cmdline_p)
693 {
694 #ifdef CONFIG_X86_32
695 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
696 	visws_early_detect();
697 
698 	/*
699 	 * copy kernel address range established so far and switch
700 	 * to the proper swapper page table
701 	 */
702 	clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
703 			initial_page_table + KERNEL_PGD_BOUNDARY,
704 			KERNEL_PGD_PTRS);
705 
706 	load_cr3(swapper_pg_dir);
707 	__flush_tlb_all();
708 #else
709 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
710 #endif
711 
712 	/*
713 	 * If we have OLPC OFW, we might end up relocating the fixmap due to
714 	 * reserve_top(), so do this before touching the ioremap area.
715 	 */
716 	olpc_ofw_detect();
717 
718 	early_trap_init();
719 	early_cpu_init();
720 	early_ioremap_init();
721 
722 	setup_olpc_ofw_pgd();
723 
724 	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
725 	screen_info = boot_params.screen_info;
726 	edid_info = boot_params.edid_info;
727 #ifdef CONFIG_X86_32
728 	apm_info.bios = boot_params.apm_bios_info;
729 	ist_info = boot_params.ist_info;
730 	if (boot_params.sys_desc_table.length != 0) {
731 		set_mca_bus(boot_params.sys_desc_table.table[3] & 0x2);
732 		machine_id = boot_params.sys_desc_table.table[0];
733 		machine_submodel_id = boot_params.sys_desc_table.table[1];
734 		BIOS_revision = boot_params.sys_desc_table.table[2];
735 	}
736 #endif
737 	saved_video_mode = boot_params.hdr.vid_mode;
738 	bootloader_type = boot_params.hdr.type_of_loader;
739 	if ((bootloader_type >> 4) == 0xe) {
740 		bootloader_type &= 0xf;
741 		bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
742 	}
743 	bootloader_version  = bootloader_type & 0xf;
744 	bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
745 
746 #ifdef CONFIG_BLK_DEV_RAM
747 	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
748 	rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
749 	rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
750 #endif
751 #ifdef CONFIG_EFI
752 	if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
753 #ifdef CONFIG_X86_32
754 		     "EL32",
755 #else
756 		     "EL64",
757 #endif
758 	 4)) {
759 		efi_enabled = 1;
760 		efi_memblock_x86_reserve_range();
761 	}
762 #endif
763 
764 	x86_init.oem.arch_setup();
765 
766 	iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
767 	setup_memory_map();
768 	parse_setup_data();
769 	/* update the e820_saved too */
770 	e820_reserve_setup_data();
771 
772 	copy_edd();
773 
774 	if (!boot_params.hdr.root_flags)
775 		root_mountflags &= ~MS_RDONLY;
776 	init_mm.start_code = (unsigned long) _text;
777 	init_mm.end_code = (unsigned long) _etext;
778 	init_mm.end_data = (unsigned long) _edata;
779 	init_mm.brk = _brk_end;
780 
781 	code_resource.start = virt_to_phys(_text);
782 	code_resource.end = virt_to_phys(_etext)-1;
783 	data_resource.start = virt_to_phys(_etext);
784 	data_resource.end = virt_to_phys(_edata)-1;
785 	bss_resource.start = virt_to_phys(&__bss_start);
786 	bss_resource.end = virt_to_phys(&__bss_stop)-1;
787 
788 #ifdef CONFIG_CMDLINE_BOOL
789 #ifdef CONFIG_CMDLINE_OVERRIDE
790 	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
791 #else
792 	if (builtin_cmdline[0]) {
793 		/* append boot loader cmdline to builtin */
794 		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
795 		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
796 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
797 	}
798 #endif
799 #endif
800 
801 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
802 	*cmdline_p = command_line;
803 
804 	/*
805 	 * x86_configure_nx() is called before parse_early_param() to detect
806 	 * whether hardware doesn't support NX (so that the early EHCI debug
807 	 * console setup can safely call set_fixmap()). It may then be called
808 	 * again from within noexec_setup() during parsing early parameters
809 	 * to honor the respective command line option.
810 	 */
811 	x86_configure_nx();
812 
813 	parse_early_param();
814 
815 	x86_report_nx();
816 
817 	/* after early param, so could get panic from serial */
818 	memblock_x86_reserve_range_setup_data();
819 
820 	if (acpi_mps_check()) {
821 #ifdef CONFIG_X86_LOCAL_APIC
822 		disable_apic = 1;
823 #endif
824 		setup_clear_cpu_cap(X86_FEATURE_APIC);
825 	}
826 
827 #ifdef CONFIG_PCI
828 	if (pci_early_dump_regs)
829 		early_dump_pci_devices();
830 #endif
831 
832 	finish_e820_parsing();
833 
834 	if (efi_enabled)
835 		efi_init();
836 
837 	dmi_scan_machine();
838 
839 	/*
840 	 * VMware detection requires dmi to be available, so this
841 	 * needs to be done after dmi_scan_machine, for the BP.
842 	 */
843 	init_hypervisor_platform();
844 
845 	x86_init.resources.probe_roms();
846 
847 	/* after parse_early_param, so could debug it */
848 	insert_resource(&iomem_resource, &code_resource);
849 	insert_resource(&iomem_resource, &data_resource);
850 	insert_resource(&iomem_resource, &bss_resource);
851 
852 	trim_bios_range();
853 #ifdef CONFIG_X86_32
854 	if (ppro_with_ram_bug()) {
855 		e820_update_range(0x70000000ULL, 0x40000ULL, E820_RAM,
856 				  E820_RESERVED);
857 		sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
858 		printk(KERN_INFO "fixed physical RAM map:\n");
859 		e820_print_map("bad_ppro");
860 	}
861 #else
862 	early_gart_iommu_check();
863 #endif
864 
865 	/*
866 	 * partially used pages are not usable - thus
867 	 * we are rounding upwards:
868 	 */
869 	max_pfn = e820_end_of_ram_pfn();
870 
871 	/* update e820 for memory not covered by WB MTRRs */
872 	mtrr_bp_init();
873 	if (mtrr_trim_uncached_memory(max_pfn))
874 		max_pfn = e820_end_of_ram_pfn();
875 
876 #ifdef CONFIG_X86_32
877 	/* max_low_pfn get updated here */
878 	find_low_pfn_range();
879 #else
880 	num_physpages = max_pfn;
881 
882 	check_x2apic();
883 
884 	/* How many end-of-memory variables you have, grandma! */
885 	/* need this before calling reserve_initrd */
886 	if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
887 		max_low_pfn = e820_end_of_low_ram_pfn();
888 	else
889 		max_low_pfn = max_pfn;
890 
891 	high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
892 #endif
893 
894 	/*
895 	 * Find and reserve possible boot-time SMP configuration:
896 	 */
897 	find_smp_config();
898 
899 	reserve_ibft_region();
900 
901 	/*
902 	 * Need to conclude brk, before memblock_x86_fill()
903 	 *  it could use memblock_find_in_range, could overlap with
904 	 *  brk area.
905 	 */
906 	reserve_brk();
907 
908 	cleanup_highmap();
909 
910 	memblock.current_limit = get_max_mapped();
911 	memblock_x86_fill();
912 
913 	/*
914 	 * The EFI specification says that boot service code won't be called
915 	 * after ExitBootServices(). This is, in fact, a lie.
916 	 */
917 	if (efi_enabled)
918 		efi_reserve_boot_services();
919 
920 	/* preallocate 4k for mptable mpc */
921 	early_reserve_e820_mpc_new();
922 
923 #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
924 	setup_bios_corruption_check();
925 #endif
926 
927 	printk(KERN_DEBUG "initial memory mapped : 0 - %08lx\n",
928 			max_pfn_mapped<<PAGE_SHIFT);
929 
930 	setup_trampolines();
931 
932 	init_gbpages();
933 
934 	/* max_pfn_mapped is updated here */
935 	max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT);
936 	max_pfn_mapped = max_low_pfn_mapped;
937 
938 #ifdef CONFIG_X86_64
939 	if (max_pfn > max_low_pfn) {
940 		max_pfn_mapped = init_memory_mapping(1UL<<32,
941 						     max_pfn<<PAGE_SHIFT);
942 		/* can we preseve max_low_pfn ?*/
943 		max_low_pfn = max_pfn;
944 	}
945 #endif
946 	memblock.current_limit = get_max_mapped();
947 
948 	/*
949 	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
950 	 */
951 
952 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
953 	if (init_ohci1394_dma_early)
954 		init_ohci1394_dma_on_all_controllers();
955 #endif
956 	/* Allocate bigger log buffer */
957 	setup_log_buf(1);
958 
959 	reserve_initrd();
960 
961 	reserve_crashkernel();
962 
963 	vsmp_init();
964 
965 	io_delay_init();
966 
967 	/*
968 	 * Parse the ACPI tables for possible boot-time SMP configuration.
969 	 */
970 	acpi_boot_table_init();
971 
972 	early_acpi_boot_init();
973 
974 	initmem_init();
975 	memblock_find_dma_reserve();
976 
977 #ifdef CONFIG_KVM_CLOCK
978 	kvmclock_init();
979 #endif
980 
981 	x86_init.paging.pagetable_setup_start(swapper_pg_dir);
982 	paging_init();
983 	x86_init.paging.pagetable_setup_done(swapper_pg_dir);
984 
985 	if (boot_cpu_data.cpuid_level >= 0) {
986 		/* A CPU has %cr4 if and only if it has CPUID */
987 		mmu_cr4_features = read_cr4();
988 	}
989 
990 #ifdef CONFIG_X86_32
991 	/* sync back kernel address range */
992 	clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
993 			swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
994 			KERNEL_PGD_PTRS);
995 #endif
996 
997 	tboot_probe();
998 
999 #ifdef CONFIG_X86_64
1000 	map_vsyscall();
1001 #endif
1002 
1003 	generic_apic_probe();
1004 
1005 	early_quirks();
1006 
1007 	/*
1008 	 * Read APIC and some other early information from ACPI tables.
1009 	 */
1010 	acpi_boot_init();
1011 	sfi_init();
1012 	x86_dtb_init();
1013 
1014 	/*
1015 	 * get boot-time SMP configuration:
1016 	 */
1017 	if (smp_found_config)
1018 		get_smp_config();
1019 
1020 	prefill_possible_map();
1021 
1022 	init_cpu_to_node();
1023 
1024 	init_apic_mappings();
1025 	ioapic_and_gsi_init();
1026 
1027 	kvm_guest_init();
1028 
1029 	e820_reserve_resources();
1030 	e820_mark_nosave_regions(max_low_pfn);
1031 
1032 	x86_init.resources.reserve_resources();
1033 
1034 	e820_setup_gap();
1035 
1036 #ifdef CONFIG_VT
1037 #if defined(CONFIG_VGA_CONSOLE)
1038 	if (!efi_enabled || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
1039 		conswitchp = &vga_con;
1040 #elif defined(CONFIG_DUMMY_CONSOLE)
1041 	conswitchp = &dummy_con;
1042 #endif
1043 #endif
1044 	x86_init.oem.banner();
1045 
1046 	x86_init.timers.wallclock_init();
1047 
1048 	mcheck_init();
1049 
1050 	arch_init_ideal_nops();
1051 }
1052 
1053 #ifdef CONFIG_X86_32
1054 
1055 static struct resource video_ram_resource = {
1056 	.name	= "Video RAM area",
1057 	.start	= 0xa0000,
1058 	.end	= 0xbffff,
1059 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
1060 };
1061 
1062 void __init i386_reserve_resources(void)
1063 {
1064 	request_resource(&iomem_resource, &video_ram_resource);
1065 	reserve_standard_io_resources();
1066 }
1067 
1068 #endif /* CONFIG_X86_32 */
1069