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 __cpuinitdata = 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;
89 unsigned int machine_submodel_id;
90 unsigned int BIOS_revision;
91 unsigned int mca_pentium_flag;
93 /* Boot loader ID as an integer, for the benefit of proc_dointvec */
96 /* user-defined highmem size */
97 static unsigned int highmem_pages = -1;
102 struct screen_info screen_info;
103 EXPORT_SYMBOL(screen_info);
104 struct apm_info apm_info;
105 EXPORT_SYMBOL(apm_info);
106 struct edid_info edid_info;
107 EXPORT_SYMBOL_GPL(edid_info);
108 struct ist_info ist_info;
109 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
110 defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
111 EXPORT_SYMBOL(ist_info);
114 extern void early_cpu_init(void);
115 extern int root_mountflags;
117 unsigned long saved_videomode;
119 #define RAMDISK_IMAGE_START_MASK 0x07FF
120 #define RAMDISK_PROMPT_FLAG 0x8000
121 #define RAMDISK_LOAD_FLAG 0x4000
123 static char __initdata command_line[COMMAND_LINE_SIZE];
125 struct boot_params __initdata boot_params;
127 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
129 #ifdef CONFIG_EDD_MODULE
133 * copy_edd() - Copy the BIOS EDD information
134 * from boot_params into a safe place.
137 static inline void copy_edd(void)
139 memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
140 sizeof(edd.mbr_signature));
141 memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
142 edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
143 edd.edd_info_nr = boot_params.eddbuf_entries;
146 static inline void copy_edd(void)
151 int __initdata user_defined_memmap = 0;
154 * "mem=nopentium" disables the 4MB page tables.
155 * "mem=XXX[kKmM]" defines a memory region from HIGH_MEM
156 * to <mem>, overriding the bios size.
157 * "memmap=XXX[KkmM]@XXX[KkmM]" defines a memory region from
158 * <start> to <start>+<mem>, overriding the bios size.
160 * HPA tells me bootloaders need to parse mem=, so no new
161 * option should be mem= [also see Documentation/i386/boot.txt]
163 static int __init parse_mem(char *arg)
168 if (strcmp(arg, "nopentium") == 0) {
169 clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
172 /* If the user specifies memory size, we
173 * limit the BIOS-provided memory map to
174 * that size. exactmap can be used to specify
175 * the exact map. mem=number can be used to
176 * trim the existing memory map.
178 unsigned long long mem_size;
180 mem_size = memparse(arg, &arg);
181 limit_regions(mem_size);
182 user_defined_memmap = 1;
186 early_param("mem", parse_mem);
188 #ifdef CONFIG_PROC_VMCORE
189 /* elfcorehdr= specifies the location of elf core header
190 * stored by the crashed kernel.
192 static int __init parse_elfcorehdr(char *arg)
197 elfcorehdr_addr = memparse(arg, &arg);
200 early_param("elfcorehdr", parse_elfcorehdr);
201 #endif /* CONFIG_PROC_VMCORE */
204 * highmem=size forces highmem to be exactly 'size' bytes.
205 * This works even on boxes that have no highmem otherwise.
206 * This also works to reduce highmem size on bigger boxes.
208 static int __init parse_highmem(char *arg)
213 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
216 early_param("highmem", parse_highmem);
219 * vmalloc=size forces the vmalloc area to be exactly 'size'
220 * bytes. This can be used to increase (or decrease) the
221 * vmalloc area - the default is 128m.
223 static int __init parse_vmalloc(char *arg)
228 __VMALLOC_RESERVE = memparse(arg, &arg);
231 early_param("vmalloc", parse_vmalloc);
234 * reservetop=size reserves a hole at the top of the kernel address space which
235 * a hypervisor can load into later. Needed for dynamically loaded hypervisors,
236 * so relocating the fixmap can be done before paging initialization.
238 static int __init parse_reservetop(char *arg)
240 unsigned long address;
245 address = memparse(arg, &arg);
246 reserve_top_address(address);
249 early_param("reservetop", parse_reservetop);
252 * Determine low and high memory ranges:
254 unsigned long __init find_max_low_pfn(void)
256 unsigned long max_low_pfn;
258 max_low_pfn = max_pfn;
259 if (max_low_pfn > MAXMEM_PFN) {
260 if (highmem_pages == -1)
261 highmem_pages = max_pfn - MAXMEM_PFN;
262 if (highmem_pages + MAXMEM_PFN < max_pfn)
263 max_pfn = MAXMEM_PFN + highmem_pages;
264 if (highmem_pages + MAXMEM_PFN > max_pfn) {
265 printk("only %luMB highmem pages available, ignoring highmem size of %uMB.\n", pages_to_mb(max_pfn - MAXMEM_PFN), pages_to_mb(highmem_pages));
268 max_low_pfn = MAXMEM_PFN;
269 #ifndef CONFIG_HIGHMEM
270 /* Maximum memory usable is what is directly addressable */
271 printk(KERN_WARNING "Warning only %ldMB will be used.\n",
273 if (max_pfn > MAX_NONPAE_PFN)
274 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
276 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
277 max_pfn = MAXMEM_PFN;
278 #else /* !CONFIG_HIGHMEM */
279 #ifndef CONFIG_HIGHMEM64G
280 if (max_pfn > MAX_NONPAE_PFN) {
281 max_pfn = MAX_NONPAE_PFN;
282 printk(KERN_WARNING "Warning only 4GB will be used.\n");
283 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
285 #endif /* !CONFIG_HIGHMEM64G */
286 #endif /* !CONFIG_HIGHMEM */
288 if (highmem_pages == -1)
290 #ifdef CONFIG_HIGHMEM
291 if (highmem_pages >= max_pfn) {
292 printk(KERN_ERR "highmem size specified (%uMB) is bigger than pages available (%luMB)!.\n", pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
296 if (max_low_pfn-highmem_pages < 64*1024*1024/PAGE_SIZE){
297 printk(KERN_ERR "highmem size %uMB results in smaller than 64MB lowmem, ignoring it.\n", pages_to_mb(highmem_pages));
300 max_low_pfn -= highmem_pages;
304 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
311 * workaround for Dell systems that neglect to reserve EBDA
313 static void __init reserve_ebda_region(void)
316 addr = get_bios_ebda();
318 reserve_bootmem(addr, PAGE_SIZE);
321 #ifndef CONFIG_NEED_MULTIPLE_NODES
322 void __init setup_bootmem_allocator(void);
323 static unsigned long __init setup_memory(void)
326 * partially used pages are not usable - thus
327 * we are rounding upwards:
329 min_low_pfn = PFN_UP(init_pg_tables_end);
333 max_low_pfn = find_max_low_pfn();
335 #ifdef CONFIG_HIGHMEM
336 highstart_pfn = highend_pfn = max_pfn;
337 if (max_pfn > max_low_pfn) {
338 highstart_pfn = max_low_pfn;
340 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
341 pages_to_mb(highend_pfn - highstart_pfn));
342 num_physpages = highend_pfn;
343 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
345 num_physpages = max_low_pfn;
346 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
348 #ifdef CONFIG_FLATMEM
349 max_mapnr = num_physpages;
351 printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
352 pages_to_mb(max_low_pfn));
354 setup_bootmem_allocator();
359 void __init zone_sizes_init(void)
361 unsigned long max_zone_pfns[MAX_NR_ZONES];
362 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
363 max_zone_pfns[ZONE_DMA] =
364 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
365 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
366 #ifdef CONFIG_HIGHMEM
367 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
368 add_active_range(0, 0, highend_pfn);
370 add_active_range(0, 0, max_low_pfn);
373 free_area_init_nodes(max_zone_pfns);
376 extern unsigned long __init setup_memory(void);
377 extern void zone_sizes_init(void);
378 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
380 static inline unsigned long long get_total_mem(void)
382 unsigned long long total;
384 total = max_low_pfn - min_low_pfn;
385 #ifdef CONFIG_HIGHMEM
386 total += highend_pfn - highstart_pfn;
389 return total << PAGE_SHIFT;
393 static void __init reserve_crashkernel(void)
395 unsigned long long total_mem;
396 unsigned long long crash_size, crash_base;
399 total_mem = get_total_mem();
401 ret = parse_crashkernel(boot_command_line, total_mem,
402 &crash_size, &crash_base);
403 if (ret == 0 && crash_size > 0) {
404 if (crash_base > 0) {
405 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
406 "for crashkernel (System RAM: %ldMB)\n",
407 (unsigned long)(crash_size >> 20),
408 (unsigned long)(crash_base >> 20),
409 (unsigned long)(total_mem >> 20));
410 crashk_res.start = crash_base;
411 crashk_res.end = crash_base + crash_size - 1;
412 reserve_bootmem(crash_base, crash_size);
414 printk(KERN_INFO "crashkernel reservation failed - "
415 "you have to specify a base address\n");
419 static inline void __init reserve_crashkernel(void)
423 void __init setup_bootmem_allocator(void)
425 unsigned long bootmap_size;
427 * Initialize the boot-time allocator (with low memory only):
429 bootmap_size = init_bootmem(min_low_pfn, max_low_pfn);
431 register_bootmem_low_pages(max_low_pfn);
434 * Reserve the bootmem bitmap itself as well. We do this in two
435 * steps (first step was init_bootmem()) because this catches
436 * the (very unlikely) case of us accidentally initializing the
437 * bootmem allocator with an invalid RAM area.
439 reserve_bootmem(__pa_symbol(_text), (PFN_PHYS(min_low_pfn) +
440 bootmap_size + PAGE_SIZE-1) - __pa_symbol(_text));
443 * reserve physical page 0 - it's a special BIOS page on many boxes,
444 * enabling clean reboots, SMP operation, laptop functions.
446 reserve_bootmem(0, PAGE_SIZE);
448 /* reserve EBDA region, it's a 4K region */
449 reserve_ebda_region();
451 /* could be an AMD 768MPX chipset. Reserve a page before VGA to prevent
452 PCI prefetch into it (errata #56). Usually the page is reserved anyways,
453 unless you have no PS/2 mouse plugged in. */
454 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
455 boot_cpu_data.x86 == 6)
456 reserve_bootmem(0xa0000 - 4096, 4096);
460 * But first pinch a few for the stack/trampoline stuff
461 * FIXME: Don't need the extra page at 4K, but need to fix
462 * trampoline before removing it. (see the GDT stuff)
464 reserve_bootmem(PAGE_SIZE, PAGE_SIZE);
466 #ifdef CONFIG_ACPI_SLEEP
468 * Reserve low memory region for sleep support.
470 acpi_reserve_bootmem();
472 #ifdef CONFIG_X86_FIND_SMP_CONFIG
474 * Find and reserve possible boot-time SMP configuration:
479 #ifdef CONFIG_BLK_DEV_INITRD
480 if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
481 unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
482 unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
483 unsigned long ramdisk_end = ramdisk_image + ramdisk_size;
484 unsigned long end_of_lowmem = max_low_pfn << PAGE_SHIFT;
486 if (ramdisk_end <= end_of_lowmem) {
487 reserve_bootmem(ramdisk_image, ramdisk_size);
488 initrd_start = ramdisk_image + PAGE_OFFSET;
489 initrd_end = initrd_start+ramdisk_size;
491 printk(KERN_ERR "initrd extends beyond end of memory "
492 "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
493 ramdisk_end, end_of_lowmem);
498 reserve_crashkernel();
502 * The node 0 pgdat is initialized before all of these because
503 * it's needed for bootmem. node>0 pgdats have their virtual
504 * space allocated before the pagetables are in place to access
505 * them, so they can't be cleared then.
507 * This should all compile down to nothing when NUMA is off.
509 static void __init remapped_pgdat_init(void)
513 for_each_online_node(nid) {
515 memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
520 static void set_mca_bus(int x)
525 static void set_mca_bus(int x) { }
528 /* Overridden in paravirt.c if CONFIG_PARAVIRT */
529 char * __init __attribute__((weak)) memory_setup(void)
531 return machine_specific_memory_setup();
535 * Determine if we were loaded by an EFI loader. If so, then we have also been
536 * passed the efi memmap, systab, etc., so we should use these data structures
537 * for initialization. Note, the efi init code path is determined by the
538 * global efi_enabled. This allows the same kernel image to be used on existing
539 * systems (with a traditional BIOS) as well as on EFI systems.
541 void __init setup_arch(char **cmdline_p)
543 unsigned long max_low_pfn;
545 memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
546 pre_setup_arch_hook();
550 * FIXME: This isn't an official loader_type right
551 * now but does currently work with elilo.
552 * If we were configured as an EFI kernel, check to make
553 * sure that we were loaded correctly from elilo and that
554 * the system table is valid. If not, then initialize normally.
557 if ((boot_params.hdr.type_of_loader == 0x50) &&
558 boot_params.efi_info.efi_systab)
562 ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
563 screen_info = boot_params.screen_info;
564 edid_info = boot_params.edid_info;
565 apm_info.bios = boot_params.apm_bios_info;
566 ist_info = boot_params.ist_info;
567 saved_videomode = boot_params.hdr.vid_mode;
568 if( boot_params.sys_desc_table.length != 0 ) {
569 set_mca_bus(boot_params.sys_desc_table.table[3] & 0x2);
570 machine_id = boot_params.sys_desc_table.table[0];
571 machine_submodel_id = boot_params.sys_desc_table.table[1];
572 BIOS_revision = boot_params.sys_desc_table.table[2];
574 bootloader_type = boot_params.hdr.type_of_loader;
576 #ifdef CONFIG_BLK_DEV_RAM
577 rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
578 rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
579 rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
585 printk(KERN_INFO "BIOS-provided physical RAM map:\n");
586 print_memory_map(memory_setup());
591 if (!boot_params.hdr.root_flags)
592 root_mountflags &= ~MS_RDONLY;
593 init_mm.start_code = (unsigned long) _text;
594 init_mm.end_code = (unsigned long) _etext;
595 init_mm.end_data = (unsigned long) _edata;
596 init_mm.brk = init_pg_tables_end + PAGE_OFFSET;
598 code_resource.start = virt_to_phys(_text);
599 code_resource.end = virt_to_phys(_etext)-1;
600 data_resource.start = virt_to_phys(_etext);
601 data_resource.end = virt_to_phys(_edata)-1;
602 bss_resource.start = virt_to_phys(&__bss_start);
603 bss_resource.end = virt_to_phys(&__bss_stop)-1;
607 if (user_defined_memmap) {
608 printk(KERN_INFO "user-defined physical RAM map:\n");
609 print_memory_map("user");
612 strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
613 *cmdline_p = command_line;
615 max_low_pfn = setup_memory();
619 * Must be after max_low_pfn is determined, and before kernel
620 * pagetables are setup.
626 * NOTE: before this point _nobody_ is allowed to allocate
627 * any memory using the bootmem allocator. Although the
628 * allocator is now initialised only the first 8Mb of the kernel
629 * virtual address space has been mapped. All allocations before
630 * paging_init() has completed must use the alloc_bootmem_low_pages()
631 * variant (which allocates DMA'able memory) and care must be taken
632 * not to exceed the 8Mb limit.
636 smp_alloc_memory(); /* AP processor realmode stacks in low memory*/
639 remapped_pgdat_init();
644 * NOTE: at this point the bootmem allocator is fully available.
647 paravirt_post_allocator_init();
651 #ifdef CONFIG_X86_GENERICARCH
652 generic_apic_probe();
659 * Parse the ACPI tables for possible boot-time SMP configuration.
661 acpi_boot_table_init();
671 #if defined(CONFIG_SMP) && defined(CONFIG_X86_PC)
673 printk(KERN_WARNING "More than 8 CPUs detected and "
674 "CONFIG_X86_PC cannot handle it.\nUse "
675 "CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n");
678 #ifdef CONFIG_X86_LOCAL_APIC
679 if (smp_found_config)
683 e820_register_memory();
684 e820_mark_nosave_regions();
687 #if defined(CONFIG_VGA_CONSOLE)
688 if (!efi_enabled || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
689 conswitchp = &vga_con;
690 #elif defined(CONFIG_DUMMY_CONSOLE)
691 conswitchp = &dummy_con;