2 * Copyright (C) 1995 Linus Torvalds
4 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
6 * Memory region support
7 * David Parsons <orc@pell.chi.il.us>, July-August 1999
9 * Added E820 sanitization routine (removes overlapping memory regions);
10 * Brian Moyle <bmoyle@mvista.com>, February 2001
12 * Moved CPU detection code to cpu/${cpu}.c
13 * Patrick Mochel <mochel@osdl.org>, March 2002
15 * Provisions for empty E820 memory regions (reported by certain BIOSes).
16 * Alex Achenbach <xela@slit.de>, December 2002.
21 * This file handles the architecture-dependent parts of initialization
24 #include <linux/sched.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/apm_bios.h>
31 #include <linux/initrd.h>
32 #include <linux/bootmem.h>
33 #include <linux/seq_file.h>
34 #include <linux/console.h>
35 #include <linux/mca.h>
36 #include <linux/root_dev.h>
37 #include <linux/highmem.h>
38 #include <linux/module.h>
39 #include <linux/efi.h>
40 #include <linux/init.h>
41 #include <linux/edd.h>
42 #include <linux/nodemask.h>
43 #include <linux/kexec.h>
44 #include <linux/crash_dump.h>
45 #include <linux/dmi.h>
46 #include <linux/pfn.h>
48 #include <video/edid.h>
52 #include <asm/mpspec.h>
53 #include <asm/mmzone.h>
54 #include <asm/setup.h>
55 #include <asm/arch_hooks.h>
56 #include <asm/sections.h>
57 #include <asm/io_apic.h>
61 #include <setup_arch.h>
62 #include <bios_ebda.h>
63 #include <asm/cacheflush.h>
65 /* This value is set up by the early boot code to point to the value
66 immediately after the boot time page tables. It contains a *physical*
67 address, and must not be in the .bss segment! */
68 unsigned long init_pg_tables_end __initdata = ~0UL;
70 int disable_pse __devinitdata = 0;
75 extern struct resource code_resource;
76 extern struct resource data_resource;
77 extern struct resource bss_resource;
79 /* cpu data as detected by the assembly code in head.S */
80 struct cpuinfo_x86 new_cpu_data __cpuinitdata = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
81 /* common cpu data for all cpus */
82 struct cpuinfo_x86 boot_cpu_data __read_mostly = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };
83 EXPORT_SYMBOL(boot_cpu_data);
85 unsigned long mmu_cr4_features;
87 /* for MCA, but anyone else can use it if they want */
88 unsigned int machine_id;
90 EXPORT_SYMBOL(machine_id);
92 unsigned int machine_submodel_id;
93 unsigned int BIOS_revision;
94 unsigned int mca_pentium_flag;
96 /* Boot loader ID as an integer, for the benefit of proc_dointvec */
99 /* user-defined highmem size */
100 static unsigned int highmem_pages = -1;
105 struct screen_info screen_info;
106 EXPORT_SYMBOL(screen_info);
107 struct apm_info apm_info;
108 EXPORT_SYMBOL(apm_info);
109 struct edid_info edid_info;
110 EXPORT_SYMBOL_GPL(edid_info);
111 struct ist_info ist_info;
112 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
113 defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
114 EXPORT_SYMBOL(ist_info);
117 extern void early_cpu_init(void);
118 extern int root_mountflags;
120 unsigned long saved_videomode;
122 #define RAMDISK_IMAGE_START_MASK 0x07FF
123 #define RAMDISK_PROMPT_FLAG 0x8000
124 #define RAMDISK_LOAD_FLAG 0x4000
126 static char __initdata command_line[COMMAND_LINE_SIZE];
128 struct boot_params __initdata boot_params;
130 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
132 #ifdef CONFIG_EDD_MODULE
136 * copy_edd() - Copy the BIOS EDD information
137 * from boot_params into a safe place.
140 static inline void copy_edd(void)
142 memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
143 sizeof(edd.mbr_signature));
144 memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
145 edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
146 edd.edd_info_nr = boot_params.eddbuf_entries;
149 static inline void copy_edd(void)
154 int __initdata user_defined_memmap = 0;
157 * "mem=nopentium" disables the 4MB page tables.
158 * "mem=XXX[kKmM]" defines a memory region from HIGH_MEM
159 * to <mem>, overriding the bios size.
160 * "memmap=XXX[KkmM]@XXX[KkmM]" defines a memory region from
161 * <start> to <start>+<mem>, overriding the bios size.
163 * HPA tells me bootloaders need to parse mem=, so no new
164 * option should be mem= [also see Documentation/i386/boot.txt]
166 static int __init parse_mem(char *arg)
171 if (strcmp(arg, "nopentium") == 0) {
172 clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
175 /* If the user specifies memory size, we
176 * limit the BIOS-provided memory map to
177 * that size. exactmap can be used to specify
178 * the exact map. mem=number can be used to
179 * trim the existing memory map.
181 unsigned long long mem_size;
183 mem_size = memparse(arg, &arg);
184 limit_regions(mem_size);
185 user_defined_memmap = 1;
189 early_param("mem", parse_mem);
191 #ifdef CONFIG_PROC_VMCORE
192 /* elfcorehdr= specifies the location of elf core header
193 * stored by the crashed kernel.
195 static int __init parse_elfcorehdr(char *arg)
200 elfcorehdr_addr = memparse(arg, &arg);
203 early_param("elfcorehdr", parse_elfcorehdr);
204 #endif /* CONFIG_PROC_VMCORE */
207 * highmem=size forces highmem to be exactly 'size' bytes.
208 * This works even on boxes that have no highmem otherwise.
209 * This also works to reduce highmem size on bigger boxes.
211 static int __init parse_highmem(char *arg)
216 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
219 early_param("highmem", parse_highmem);
222 * vmalloc=size forces the vmalloc area to be exactly 'size'
223 * bytes. This can be used to increase (or decrease) the
224 * vmalloc area - the default is 128m.
226 static int __init parse_vmalloc(char *arg)
231 __VMALLOC_RESERVE = memparse(arg, &arg);
234 early_param("vmalloc", parse_vmalloc);
237 * reservetop=size reserves a hole at the top of the kernel address space which
238 * a hypervisor can load into later. Needed for dynamically loaded hypervisors,
239 * so relocating the fixmap can be done before paging initialization.
241 static int __init parse_reservetop(char *arg)
243 unsigned long address;
248 address = memparse(arg, &arg);
249 reserve_top_address(address);
252 early_param("reservetop", parse_reservetop);
255 * Determine low and high memory ranges:
257 unsigned long __init find_max_low_pfn(void)
259 unsigned long max_low_pfn;
261 max_low_pfn = max_pfn;
262 if (max_low_pfn > MAXMEM_PFN) {
263 if (highmem_pages == -1)
264 highmem_pages = max_pfn - MAXMEM_PFN;
265 if (highmem_pages + MAXMEM_PFN < max_pfn)
266 max_pfn = MAXMEM_PFN + highmem_pages;
267 if (highmem_pages + MAXMEM_PFN > max_pfn) {
268 printk("only %luMB highmem pages available, ignoring highmem size of %uMB.\n", pages_to_mb(max_pfn - MAXMEM_PFN), pages_to_mb(highmem_pages));
271 max_low_pfn = MAXMEM_PFN;
272 #ifndef CONFIG_HIGHMEM
273 /* Maximum memory usable is what is directly addressable */
274 printk(KERN_WARNING "Warning only %ldMB will be used.\n",
276 if (max_pfn > MAX_NONPAE_PFN)
277 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
279 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
280 max_pfn = MAXMEM_PFN;
281 #else /* !CONFIG_HIGHMEM */
282 #ifndef CONFIG_HIGHMEM64G
283 if (max_pfn > MAX_NONPAE_PFN) {
284 max_pfn = MAX_NONPAE_PFN;
285 printk(KERN_WARNING "Warning only 4GB will be used.\n");
286 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
288 #endif /* !CONFIG_HIGHMEM64G */
289 #endif /* !CONFIG_HIGHMEM */
291 if (highmem_pages == -1)
293 #ifdef CONFIG_HIGHMEM
294 if (highmem_pages >= max_pfn) {
295 printk(KERN_ERR "highmem size specified (%uMB) is bigger than pages available (%luMB)!.\n", pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
299 if (max_low_pfn-highmem_pages < 64*1024*1024/PAGE_SIZE){
300 printk(KERN_ERR "highmem size %uMB results in smaller than 64MB lowmem, ignoring it.\n", pages_to_mb(highmem_pages));
303 max_low_pfn -= highmem_pages;
307 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
314 * workaround for Dell systems that neglect to reserve EBDA
316 static void __init reserve_ebda_region(void)
319 addr = get_bios_ebda();
321 reserve_bootmem(addr, PAGE_SIZE);
324 #ifndef CONFIG_NEED_MULTIPLE_NODES
325 void __init setup_bootmem_allocator(void);
326 static unsigned long __init setup_memory(void)
329 * partially used pages are not usable - thus
330 * we are rounding upwards:
332 min_low_pfn = PFN_UP(init_pg_tables_end);
336 max_low_pfn = find_max_low_pfn();
338 #ifdef CONFIG_HIGHMEM
339 highstart_pfn = highend_pfn = max_pfn;
340 if (max_pfn > max_low_pfn) {
341 highstart_pfn = max_low_pfn;
343 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
344 pages_to_mb(highend_pfn - highstart_pfn));
345 num_physpages = highend_pfn;
346 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
348 num_physpages = max_low_pfn;
349 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
351 #ifdef CONFIG_FLATMEM
352 max_mapnr = num_physpages;
354 printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
355 pages_to_mb(max_low_pfn));
357 setup_bootmem_allocator();
362 void __init zone_sizes_init(void)
364 unsigned long max_zone_pfns[MAX_NR_ZONES];
365 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
366 max_zone_pfns[ZONE_DMA] =
367 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
368 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
369 #ifdef CONFIG_HIGHMEM
370 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
371 add_active_range(0, 0, highend_pfn);
373 add_active_range(0, 0, max_low_pfn);
376 free_area_init_nodes(max_zone_pfns);
379 extern unsigned long __init setup_memory(void);
380 extern void zone_sizes_init(void);
381 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
383 static inline unsigned long long get_total_mem(void)
385 unsigned long long total;
387 total = max_low_pfn - min_low_pfn;
388 #ifdef CONFIG_HIGHMEM
389 total += highend_pfn - highstart_pfn;
392 return total << PAGE_SHIFT;
396 static void __init reserve_crashkernel(void)
398 unsigned long long total_mem;
399 unsigned long long crash_size, crash_base;
402 total_mem = get_total_mem();
404 ret = parse_crashkernel(boot_command_line, total_mem,
405 &crash_size, &crash_base);
406 if (ret == 0 && crash_size > 0) {
407 if (crash_base > 0) {
408 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
409 "for crashkernel (System RAM: %ldMB)\n",
410 (unsigned long)(crash_size >> 20),
411 (unsigned long)(crash_base >> 20),
412 (unsigned long)(total_mem >> 20));
413 crashk_res.start = crash_base;
414 crashk_res.end = crash_base + crash_size - 1;
415 reserve_bootmem(crash_base, crash_size);
417 printk(KERN_INFO "crashkernel reservation failed - "
418 "you have to specify a base address\n");
422 static inline void __init reserve_crashkernel(void)
426 void __init setup_bootmem_allocator(void)
428 unsigned long bootmap_size;
430 * Initialize the boot-time allocator (with low memory only):
432 bootmap_size = init_bootmem(min_low_pfn, max_low_pfn);
434 register_bootmem_low_pages(max_low_pfn);
437 * Reserve the bootmem bitmap itself as well. We do this in two
438 * steps (first step was init_bootmem()) because this catches
439 * the (very unlikely) case of us accidentally initializing the
440 * bootmem allocator with an invalid RAM area.
442 reserve_bootmem(__pa_symbol(_text), (PFN_PHYS(min_low_pfn) +
443 bootmap_size + PAGE_SIZE-1) - __pa_symbol(_text));
446 * reserve physical page 0 - it's a special BIOS page on many boxes,
447 * enabling clean reboots, SMP operation, laptop functions.
449 reserve_bootmem(0, PAGE_SIZE);
451 /* reserve EBDA region, it's a 4K region */
452 reserve_ebda_region();
454 /* could be an AMD 768MPX chipset. Reserve a page before VGA to prevent
455 PCI prefetch into it (errata #56). Usually the page is reserved anyways,
456 unless you have no PS/2 mouse plugged in. */
457 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
458 boot_cpu_data.x86 == 6)
459 reserve_bootmem(0xa0000 - 4096, 4096);
463 * But first pinch a few for the stack/trampoline stuff
464 * FIXME: Don't need the extra page at 4K, but need to fix
465 * trampoline before removing it. (see the GDT stuff)
467 reserve_bootmem(PAGE_SIZE, PAGE_SIZE);
469 #ifdef CONFIG_ACPI_SLEEP
471 * Reserve low memory region for sleep support.
473 acpi_reserve_bootmem();
475 #ifdef CONFIG_X86_FIND_SMP_CONFIG
477 * Find and reserve possible boot-time SMP configuration:
482 #ifdef CONFIG_BLK_DEV_INITRD
483 if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
484 unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
485 unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
486 unsigned long ramdisk_end = ramdisk_image + ramdisk_size;
487 unsigned long end_of_lowmem = max_low_pfn << PAGE_SHIFT;
489 if (ramdisk_end <= end_of_lowmem) {
490 reserve_bootmem(ramdisk_image, ramdisk_size);
491 initrd_start = ramdisk_image + PAGE_OFFSET;
492 initrd_end = initrd_start+ramdisk_size;
494 printk(KERN_ERR "initrd extends beyond end of memory "
495 "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
496 ramdisk_end, end_of_lowmem);
501 reserve_crashkernel();
505 * The node 0 pgdat is initialized before all of these because
506 * it's needed for bootmem. node>0 pgdats have their virtual
507 * space allocated before the pagetables are in place to access
508 * them, so they can't be cleared then.
510 * This should all compile down to nothing when NUMA is off.
512 static void __init remapped_pgdat_init(void)
516 for_each_online_node(nid) {
518 memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
523 static void set_mca_bus(int x)
528 static void set_mca_bus(int x) { }
531 /* Overridden in paravirt.c if CONFIG_PARAVIRT */
532 char * __init __attribute__((weak)) memory_setup(void)
534 return machine_specific_memory_setup();
538 * Determine if we were loaded by an EFI loader. If so, then we have also been
539 * passed the efi memmap, systab, etc., so we should use these data structures
540 * for initialization. Note, the efi init code path is determined by the
541 * global efi_enabled. This allows the same kernel image to be used on existing
542 * systems (with a traditional BIOS) as well as on EFI systems.
544 void __init setup_arch(char **cmdline_p)
546 unsigned long max_low_pfn;
548 memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
549 pre_setup_arch_hook();
553 * FIXME: This isn't an official loader_type right
554 * now but does currently work with elilo.
555 * If we were configured as an EFI kernel, check to make
556 * sure that we were loaded correctly from elilo and that
557 * the system table is valid. If not, then initialize normally.
560 if ((boot_params.hdr.type_of_loader == 0x50) &&
561 boot_params.efi_info.efi_systab)
565 ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
566 screen_info = boot_params.screen_info;
567 edid_info = boot_params.edid_info;
568 apm_info.bios = boot_params.apm_bios_info;
569 ist_info = boot_params.ist_info;
570 saved_videomode = boot_params.hdr.vid_mode;
571 if( boot_params.sys_desc_table.length != 0 ) {
572 set_mca_bus(boot_params.sys_desc_table.table[3] & 0x2);
573 machine_id = boot_params.sys_desc_table.table[0];
574 machine_submodel_id = boot_params.sys_desc_table.table[1];
575 BIOS_revision = boot_params.sys_desc_table.table[2];
577 bootloader_type = boot_params.hdr.type_of_loader;
579 #ifdef CONFIG_BLK_DEV_RAM
580 rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
581 rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
582 rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
588 printk(KERN_INFO "BIOS-provided physical RAM map:\n");
589 print_memory_map(memory_setup());
594 if (!boot_params.hdr.root_flags)
595 root_mountflags &= ~MS_RDONLY;
596 init_mm.start_code = (unsigned long) _text;
597 init_mm.end_code = (unsigned long) _etext;
598 init_mm.end_data = (unsigned long) _edata;
599 init_mm.brk = init_pg_tables_end + PAGE_OFFSET;
601 code_resource.start = virt_to_phys(_text);
602 code_resource.end = virt_to_phys(_etext)-1;
603 data_resource.start = virt_to_phys(_etext);
604 data_resource.end = virt_to_phys(_edata)-1;
605 bss_resource.start = virt_to_phys(&__bss_start);
606 bss_resource.end = virt_to_phys(&__bss_stop)-1;
610 if (user_defined_memmap) {
611 printk(KERN_INFO "user-defined physical RAM map:\n");
612 print_memory_map("user");
615 strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
616 *cmdline_p = command_line;
618 max_low_pfn = setup_memory();
622 * Must be after max_low_pfn is determined, and before kernel
623 * pagetables are setup.
629 * NOTE: before this point _nobody_ is allowed to allocate
630 * any memory using the bootmem allocator. Although the
631 * allocator is now initialised only the first 8Mb of the kernel
632 * virtual address space has been mapped. All allocations before
633 * paging_init() has completed must use the alloc_bootmem_low_pages()
634 * variant (which allocates DMA'able memory) and care must be taken
635 * not to exceed the 8Mb limit.
639 smp_alloc_memory(); /* AP processor realmode stacks in low memory*/
642 remapped_pgdat_init();
647 * NOTE: at this point the bootmem allocator is fully available.
650 paravirt_post_allocator_init();
654 #ifdef CONFIG_X86_GENERICARCH
655 generic_apic_probe();
662 * Parse the ACPI tables for possible boot-time SMP configuration.
664 acpi_boot_table_init();
674 #if defined(CONFIG_SMP) && defined(CONFIG_X86_PC)
676 printk(KERN_WARNING "More than 8 CPUs detected and "
677 "CONFIG_X86_PC cannot handle it.\nUse "
678 "CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n");
681 #ifdef CONFIG_X86_LOCAL_APIC
682 if (smp_found_config)
686 e820_register_memory();
687 e820_mark_nosave_regions();
690 #if defined(CONFIG_VGA_CONSOLE)
691 if (!efi_enabled || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
692 conswitchp = &vga_con;
693 #elif defined(CONFIG_DUMMY_CONSOLE)
694 conswitchp = &dummy_con;