211 lines
5.4 KiB
C
211 lines
5.4 KiB
C
/*
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* handle transition of Linux booting another kernel
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* Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com>
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*
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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*/
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#include <linux/mm.h>
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#include <linux/kexec.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/numa.h>
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#include <linux/ftrace.h>
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#include <linux/suspend.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/tlbflush.h>
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#include <asm/mmu_context.h>
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#include <asm/io.h>
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#include <asm/apic.h>
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#include <asm/cpufeature.h>
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#include <asm/desc.h>
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#include <asm/system.h>
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#include <asm/cacheflush.h>
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#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
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static u32 kexec_pgd[1024] PAGE_ALIGNED;
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#ifdef CONFIG_X86_PAE
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static u32 kexec_pmd0[1024] PAGE_ALIGNED;
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static u32 kexec_pmd1[1024] PAGE_ALIGNED;
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#endif
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static u32 kexec_pte0[1024] PAGE_ALIGNED;
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static u32 kexec_pte1[1024] PAGE_ALIGNED;
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static void set_idt(void *newidt, __u16 limit)
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{
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struct desc_ptr curidt;
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/* ia32 supports unaliged loads & stores */
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curidt.size = limit;
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curidt.address = (unsigned long)newidt;
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load_idt(&curidt);
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}
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static void set_gdt(void *newgdt, __u16 limit)
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{
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struct desc_ptr curgdt;
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/* ia32 supports unaligned loads & stores */
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curgdt.size = limit;
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curgdt.address = (unsigned long)newgdt;
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load_gdt(&curgdt);
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}
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static void load_segments(void)
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{
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#define __STR(X) #X
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#define STR(X) __STR(X)
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__asm__ __volatile__ (
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"\tljmp $"STR(__KERNEL_CS)",$1f\n"
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"\t1:\n"
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"\tmovl $"STR(__KERNEL_DS)",%%eax\n"
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"\tmovl %%eax,%%ds\n"
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"\tmovl %%eax,%%es\n"
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"\tmovl %%eax,%%fs\n"
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"\tmovl %%eax,%%gs\n"
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"\tmovl %%eax,%%ss\n"
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::: "eax", "memory");
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#undef STR
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#undef __STR
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}
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/*
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* A architecture hook called to validate the
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* proposed image and prepare the control pages
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* as needed. The pages for KEXEC_CONTROL_PAGE_SIZE
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* have been allocated, but the segments have yet
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* been copied into the kernel.
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*
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* Do what every setup is needed on image and the
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* reboot code buffer to allow us to avoid allocations
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* later.
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*
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* Make control page executable.
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*/
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int machine_kexec_prepare(struct kimage *image)
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{
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if (nx_enabled)
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set_pages_x(image->control_code_page, 1);
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return 0;
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}
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/*
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* Undo anything leftover by machine_kexec_prepare
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* when an image is freed.
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*/
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void machine_kexec_cleanup(struct kimage *image)
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{
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if (nx_enabled)
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set_pages_nx(image->control_code_page, 1);
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}
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/*
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* Do not allocate memory (or fail in any way) in machine_kexec().
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* We are past the point of no return, committed to rebooting now.
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*/
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void machine_kexec(struct kimage *image)
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{
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unsigned long page_list[PAGES_NR];
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void *control_page;
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int save_ftrace_enabled;
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asmlinkage unsigned long
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(*relocate_kernel_ptr)(unsigned long indirection_page,
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unsigned long control_page,
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unsigned long start_address,
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unsigned int has_pae,
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unsigned int preserve_context);
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#ifdef CONFIG_KEXEC_JUMP
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if (kexec_image->preserve_context)
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save_processor_state();
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#endif
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save_ftrace_enabled = __ftrace_enabled_save();
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/* Interrupts aren't acceptable while we reboot */
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local_irq_disable();
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if (image->preserve_context) {
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#ifdef CONFIG_X86_IO_APIC
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/* We need to put APICs in legacy mode so that we can
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* get timer interrupts in second kernel. kexec/kdump
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* paths already have calls to disable_IO_APIC() in
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* one form or other. kexec jump path also need
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* one.
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*/
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disable_IO_APIC();
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#endif
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}
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control_page = page_address(image->control_code_page);
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memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
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relocate_kernel_ptr = control_page;
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page_list[PA_CONTROL_PAGE] = __pa(control_page);
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page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
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page_list[PA_PGD] = __pa(kexec_pgd);
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page_list[VA_PGD] = (unsigned long)kexec_pgd;
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#ifdef CONFIG_X86_PAE
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page_list[PA_PMD_0] = __pa(kexec_pmd0);
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page_list[VA_PMD_0] = (unsigned long)kexec_pmd0;
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page_list[PA_PMD_1] = __pa(kexec_pmd1);
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page_list[VA_PMD_1] = (unsigned long)kexec_pmd1;
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#endif
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page_list[PA_PTE_0] = __pa(kexec_pte0);
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page_list[VA_PTE_0] = (unsigned long)kexec_pte0;
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page_list[PA_PTE_1] = __pa(kexec_pte1);
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page_list[VA_PTE_1] = (unsigned long)kexec_pte1;
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if (image->type == KEXEC_TYPE_DEFAULT)
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page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
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<< PAGE_SHIFT);
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/* The segment registers are funny things, they have both a
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* visible and an invisible part. Whenever the visible part is
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* set to a specific selector, the invisible part is loaded
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* with from a table in memory. At no other time is the
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* descriptor table in memory accessed.
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*
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* I take advantage of this here by force loading the
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* segments, before I zap the gdt with an invalid value.
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*/
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load_segments();
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/* The gdt & idt are now invalid.
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* If you want to load them you must set up your own idt & gdt.
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*/
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set_gdt(phys_to_virt(0),0);
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set_idt(phys_to_virt(0),0);
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/* now call it */
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image->start = relocate_kernel_ptr((unsigned long)image->head,
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(unsigned long)page_list,
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image->start, cpu_has_pae,
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image->preserve_context);
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#ifdef CONFIG_KEXEC_JUMP
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if (kexec_image->preserve_context)
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restore_processor_state();
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#endif
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__ftrace_enabled_restore(save_ftrace_enabled);
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}
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void arch_crash_save_vmcoreinfo(void)
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{
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#ifdef CONFIG_NUMA
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VMCOREINFO_SYMBOL(node_data);
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VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
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#endif
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#ifdef CONFIG_X86_PAE
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VMCOREINFO_CONFIG(X86_PAE);
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#endif
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}
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