172 lines
4.5 KiB
C
172 lines
4.5 KiB
C
/*
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* machine_kexec.c - 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 <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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#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 Xgt_desc_struct 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 Xgt_desc_struct 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_CODE_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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* Currently nothing.
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*/
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int machine_kexec_prepare(struct kimage *image)
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{
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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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}
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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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NORET_TYPE 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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/* Interrupts aren't acceptable while we reboot */
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local_irq_disable();
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control_page = page_address(image->control_code_page);
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memcpy(control_page, relocate_kernel, PAGE_SIZE);
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page_list[PA_CONTROL_PAGE] = __pa(control_page);
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page_list[VA_CONTROL_PAGE] = (unsigned long)relocate_kernel;
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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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/* 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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relocate_kernel((unsigned long)image->head, (unsigned long)page_list,
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image->start, cpu_has_pae);
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}
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/* crashkernel=size@addr specifies the location to reserve for
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* a crash kernel. By reserving this memory we guarantee
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* that linux never sets it up as a DMA target.
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* Useful for holding code to do something appropriate
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* after a kernel panic.
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*/
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static int __init parse_crashkernel(char *arg)
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{
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unsigned long size, base;
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size = memparse(arg, &arg);
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if (*arg == '@') {
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base = memparse(arg+1, &arg);
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/* FIXME: Do I want a sanity check
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* to validate the memory range?
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*/
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crashk_res.start = base;
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crashk_res.end = base + size - 1;
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}
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return 0;
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}
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early_param("crashkernel", parse_crashkernel);
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