diff options
Diffstat (limited to 'arch/x86/kernel/machine_kexec_32.c')
| -rw-r--r-- | arch/x86/kernel/machine_kexec_32.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c new file mode 100644 index 000000000..5409c2800 --- /dev/null +++ b/arch/x86/kernel/machine_kexec_32.c @@ -0,0 +1,266 @@ +/* + * handle transition of Linux booting another kernel + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#include <linux/mm.h> +#include <linux/kexec.h> +#include <linux/delay.h> +#include <linux/numa.h> +#include <linux/ftrace.h> +#include <linux/suspend.h> +#include <linux/gfp.h> +#include <linux/io.h> + +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/tlbflush.h> +#include <asm/mmu_context.h> +#include <asm/apic.h> +#include <asm/io_apic.h> +#include <asm/cpufeature.h> +#include <asm/desc.h> +#include <asm/set_memory.h> +#include <asm/debugreg.h> + +static void set_gdt(void *newgdt, __u16 limit) +{ + struct desc_ptr curgdt; + + /* ia32 supports unaligned loads & stores */ + curgdt.size = limit; + curgdt.address = (unsigned long)newgdt; + + load_gdt(&curgdt); +} + +static void load_segments(void) +{ +#define __STR(X) #X +#define STR(X) __STR(X) + + __asm__ __volatile__ ( + "\tljmp $"STR(__KERNEL_CS)",$1f\n" + "\t1:\n" + "\tmovl $"STR(__KERNEL_DS)",%%eax\n" + "\tmovl %%eax,%%ds\n" + "\tmovl %%eax,%%es\n" + "\tmovl %%eax,%%ss\n" + : : : "eax", "memory"); +#undef STR +#undef __STR +} + +static void machine_kexec_free_page_tables(struct kimage *image) +{ + free_pages((unsigned long)image->arch.pgd, PGD_ALLOCATION_ORDER); + image->arch.pgd = NULL; +#ifdef CONFIG_X86_PAE + free_page((unsigned long)image->arch.pmd0); + image->arch.pmd0 = NULL; + free_page((unsigned long)image->arch.pmd1); + image->arch.pmd1 = NULL; +#endif + free_page((unsigned long)image->arch.pte0); + image->arch.pte0 = NULL; + free_page((unsigned long)image->arch.pte1); + image->arch.pte1 = NULL; +} + +static int machine_kexec_alloc_page_tables(struct kimage *image) +{ + image->arch.pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, + PGD_ALLOCATION_ORDER); +#ifdef CONFIG_X86_PAE + image->arch.pmd0 = (pmd_t *)get_zeroed_page(GFP_KERNEL); + image->arch.pmd1 = (pmd_t *)get_zeroed_page(GFP_KERNEL); +#endif + image->arch.pte0 = (pte_t *)get_zeroed_page(GFP_KERNEL); + image->arch.pte1 = (pte_t *)get_zeroed_page(GFP_KERNEL); + if (!image->arch.pgd || +#ifdef CONFIG_X86_PAE + !image->arch.pmd0 || !image->arch.pmd1 || +#endif + !image->arch.pte0 || !image->arch.pte1) { + return -ENOMEM; + } + return 0; +} + +static void machine_kexec_page_table_set_one( + pgd_t *pgd, pmd_t *pmd, pte_t *pte, + unsigned long vaddr, unsigned long paddr) +{ + p4d_t *p4d; + pud_t *pud; + + pgd += pgd_index(vaddr); +#ifdef CONFIG_X86_PAE + if (!(pgd_val(*pgd) & _PAGE_PRESENT)) + set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT)); +#endif + p4d = p4d_offset(pgd, vaddr); + pud = pud_offset(p4d, vaddr); + pmd = pmd_offset(pud, vaddr); + if (!(pmd_val(*pmd) & _PAGE_PRESENT)) + set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE)); + pte = pte_offset_kernel(pmd, vaddr); + set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC)); +} + +static void machine_kexec_prepare_page_tables(struct kimage *image) +{ + void *control_page; + pmd_t *pmd = NULL; + + control_page = page_address(image->control_code_page); +#ifdef CONFIG_X86_PAE + pmd = image->arch.pmd0; +#endif + machine_kexec_page_table_set_one( + image->arch.pgd, pmd, image->arch.pte0, + (unsigned long)control_page, __pa(control_page)); +#ifdef CONFIG_X86_PAE + pmd = image->arch.pmd1; +#endif + machine_kexec_page_table_set_one( + image->arch.pgd, pmd, image->arch.pte1, + __pa(control_page), __pa(control_page)); +} + +/* + * A architecture hook called to validate the + * proposed image and prepare the control pages + * as needed. The pages for KEXEC_CONTROL_PAGE_SIZE + * have been allocated, but the segments have yet + * been copied into the kernel. + * + * Do what every setup is needed on image and the + * reboot code buffer to allow us to avoid allocations + * later. + * + * - Make control page executable. + * - Allocate page tables + * - Setup page tables + */ +int machine_kexec_prepare(struct kimage *image) +{ + int error; + + set_pages_x(image->control_code_page, 1); + error = machine_kexec_alloc_page_tables(image); + if (error) + return error; + machine_kexec_prepare_page_tables(image); + return 0; +} + +/* + * Undo anything leftover by machine_kexec_prepare + * when an image is freed. + */ +void machine_kexec_cleanup(struct kimage *image) +{ + set_pages_nx(image->control_code_page, 1); + machine_kexec_free_page_tables(image); +} + +/* + * Do not allocate memory (or fail in any way) in machine_kexec(). + * We are past the point of no return, committed to rebooting now. + */ +void machine_kexec(struct kimage *image) +{ + unsigned long page_list[PAGES_NR]; + void *control_page; + int save_ftrace_enabled; + asmlinkage unsigned long + (*relocate_kernel_ptr)(unsigned long indirection_page, + unsigned long control_page, + unsigned long start_address, + unsigned int has_pae, + unsigned int preserve_context); + +#ifdef CONFIG_KEXEC_JUMP + if (image->preserve_context) + save_processor_state(); +#endif + + save_ftrace_enabled = __ftrace_enabled_save(); + + /* Interrupts aren't acceptable while we reboot */ + local_irq_disable(); + hw_breakpoint_disable(); + + if (image->preserve_context) { +#ifdef CONFIG_X86_IO_APIC + /* + * We need to put APICs in legacy mode so that we can + * get timer interrupts in second kernel. kexec/kdump + * paths already have calls to restore_boot_irq_mode() + * in one form or other. kexec jump path also need one. + */ + clear_IO_APIC(); + restore_boot_irq_mode(); +#endif + } + + control_page = page_address(image->control_code_page); + memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE); + + relocate_kernel_ptr = control_page; + page_list[PA_CONTROL_PAGE] = __pa(control_page); + page_list[VA_CONTROL_PAGE] = (unsigned long)control_page; + page_list[PA_PGD] = __pa(image->arch.pgd); + + if (image->type == KEXEC_TYPE_DEFAULT) + page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page) + << PAGE_SHIFT); + + /* + * The segment registers are funny things, they have both a + * visible and an invisible part. Whenever the visible part is + * set to a specific selector, the invisible part is loaded + * with from a table in memory. At no other time is the + * descriptor table in memory accessed. + * + * I take advantage of this here by force loading the + * segments, before I zap the gdt with an invalid value. + */ + load_segments(); + /* + * The gdt & idt are now invalid. + * If you want to load them you must set up your own idt & gdt. + */ + idt_invalidate(phys_to_virt(0)); + set_gdt(phys_to_virt(0), 0); + + /* now call it */ + image->start = relocate_kernel_ptr((unsigned long)image->head, + (unsigned long)page_list, + image->start, + boot_cpu_has(X86_FEATURE_PAE), + image->preserve_context); + +#ifdef CONFIG_KEXEC_JUMP + if (image->preserve_context) + restore_processor_state(); +#endif + + __ftrace_enabled_restore(save_ftrace_enabled); +} + +void arch_crash_save_vmcoreinfo(void) +{ +#ifdef CONFIG_NUMA + VMCOREINFO_SYMBOL(node_data); + VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); +#endif +#ifdef CONFIG_X86_PAE + VMCOREINFO_CONFIG(X86_PAE); +#endif +} + |