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											2008-02-23 09:58:20 +01:00
										 |  |  | /*
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							|  |  |  |  *  linux/arch/i386/kernel/head32.c -- prepare to run common code | 
					
						
							|  |  |  |  * | 
					
						
							|  |  |  |  *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE | 
					
						
							|  |  |  |  *  Copyright (C) 2007 Eric Biederman <ebiederm@xmission.com> | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | 
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							|  |  |  | #include <linux/init.h>
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							|  |  |  | #include <linux/start_kernel.h>
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												x86: Make sure free_init_pages() frees pages on page boundary
When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or
in a more compact fashion.
Example:
 Allocated new RAMDISK: 00ec2000 - 0248ce57
 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56
The new RAMDISK's end is not page aligned.
Last page could be shared with other users.
When free_init_pages are called for initrd or .init, the page
could be freed and we could corrupt other data.
code segment in free_init_pages():
 |        for (; addr < end; addr += PAGE_SIZE) {
 |                ClearPageReserved(virt_to_page(addr));
 |                init_page_count(virt_to_page(addr));
 |                memset((void *)(addr & ~(PAGE_SIZE-1)),
 |                        POISON_FREE_INITMEM, PAGE_SIZE);
 |                free_page(addr);
 |                totalram_pages++;
 |        }
last half page could be used as one whole free page.
So page align the boundaries.
-v2: make the original initramdisk to be aligned, according to
     Johannes, otherwise we have the chance to lose one page.
     we still need to keep initrd_end not aligned, otherwise it could
     confuse decompressor.
-v3: change to WARN_ON instead, suggested by Johannes.
-v4: use PAGE_ALIGN, suggested by Johannes.
     We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN
     Add comments about assuming ramdisk start is aligned
     in relocate_initrd(), change to re get ramdisk_image instead of save it
     to make diff smaller. Add warning for wrong range, suggested by Johannes.
-v6: remove one WARN()
     We need to align beginning in free_init_pages()
     do not copy more than ramdisk_size, noticed by Johannes
Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Tested-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2010-03-28 19:42:55 -07:00
										 |  |  | #include <linux/mm.h>
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										 |  |  | #include <linux/memblock.h>
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											2008-05-18 01:18:57 -07:00
										 |  |  | #include <asm/setup.h>
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							|  |  |  | #include <asm/sections.h>
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							|  |  |  | #include <asm/e820.h>
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											2009-08-19 14:36:27 +02:00
										 |  |  | #include <asm/page.h>
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											2009-08-20 09:27:29 +02:00
										 |  |  | #include <asm/apic.h>
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							|  |  |  | #include <asm/io_apic.h>
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										 |  |  | #include <asm/bios_ebda.h>
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										 |  |  | #include <asm/tlbflush.h>
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										 |  |  | #include <asm/bootparam_utils.h>
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											2009-08-29 15:03:59 +02:00
										 |  |  | 
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							|  |  |  | static void __init i386_default_early_setup(void) | 
					
						
							|  |  |  | { | 
					
						
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											2010-06-11 12:17:00 +02:00
										 |  |  | 	/* Initialize 32bit specific setup functions */ | 
					
						
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										 |  |  | 	x86_init.resources.reserve_resources = i386_reserve_resources; | 
					
						
							|  |  |  | 	x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc; | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | 	reserve_ebda_region(); | 
					
						
							|  |  |  | } | 
					
						
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										 |  |  | 
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											2014-05-02 00:44:37 +02:00
										 |  |  | asmlinkage __visible void __init i386_start_kernel(void) | 
					
						
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										 |  |  | { | 
					
						
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										 |  |  | 	sanitize_boot_params(&boot_params); | 
					
						
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											2009-08-29 15:03:59 +02:00
										 |  |  | 	/* Call the subarch specific early setup function */ | 
					
						
							|  |  |  | 	switch (boot_params.hdr.hardware_subarch) { | 
					
						
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											2013-10-17 15:35:29 -07:00
										 |  |  | 	case X86_SUBARCH_INTEL_MID: | 
					
						
							|  |  |  | 		x86_intel_mid_early_setup(); | 
					
						
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											2009-08-29 14:54:20 +02:00
										 |  |  | 		break; | 
					
						
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											2010-11-09 12:08:04 -08:00
										 |  |  | 	case X86_SUBARCH_CE4100: | 
					
						
							|  |  |  | 		x86_ce4100_early_setup(); | 
					
						
							|  |  |  | 		break; | 
					
						
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											2009-08-29 15:03:59 +02:00
										 |  |  | 	default: | 
					
						
							|  |  |  | 		i386_default_early_setup(); | 
					
						
							|  |  |  | 		break; | 
					
						
							|  |  |  | 	} | 
					
						
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											2008-05-18 01:18:57 -07:00
										 |  |  | 
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											2008-02-23 09:58:20 +01:00
										 |  |  | 	start_kernel(); | 
					
						
							|  |  |  | } |