diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2007-10-11 11:17:24 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2007-10-11 11:17:24 +0200 |
commit | 250c22777fe1ccd7ac588579a6c16db4c0161cc5 (patch) | |
tree | 55c317efb7d792ec6fdae1d1937c67a502c48dec /arch/x86/kernel/machine_kexec_64.c | |
parent | 2db55d344e529492545cb3b755c7e9ba8e4fa94e (diff) |
x86_64: move kernel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/machine_kexec_64.c')
-rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c new file mode 100644 index 00000000000..c3a55470367 --- /dev/null +++ b/arch/x86/kernel/machine_kexec_64.c @@ -0,0 +1,259 @@ +/* + * machine_kexec.c - 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/string.h> +#include <linux/reboot.h> +#include <asm/pgtable.h> +#include <asm/tlbflush.h> +#include <asm/mmu_context.h> +#include <asm/io.h> + +#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE))) +static u64 kexec_pgd[512] PAGE_ALIGNED; +static u64 kexec_pud0[512] PAGE_ALIGNED; +static u64 kexec_pmd0[512] PAGE_ALIGNED; +static u64 kexec_pte0[512] PAGE_ALIGNED; +static u64 kexec_pud1[512] PAGE_ALIGNED; +static u64 kexec_pmd1[512] PAGE_ALIGNED; +static u64 kexec_pte1[512] PAGE_ALIGNED; + +static void init_level2_page(pmd_t *level2p, unsigned long addr) +{ + unsigned long end_addr; + + addr &= PAGE_MASK; + end_addr = addr + PUD_SIZE; + while (addr < end_addr) { + set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC)); + addr += PMD_SIZE; + } +} + +static int init_level3_page(struct kimage *image, pud_t *level3p, + unsigned long addr, unsigned long last_addr) +{ + unsigned long end_addr; + int result; + + result = 0; + addr &= PAGE_MASK; + end_addr = addr + PGDIR_SIZE; + while ((addr < last_addr) && (addr < end_addr)) { + struct page *page; + pmd_t *level2p; + + page = kimage_alloc_control_pages(image, 0); + if (!page) { + result = -ENOMEM; + goto out; + } + level2p = (pmd_t *)page_address(page); + init_level2_page(level2p, addr); + set_pud(level3p++, __pud(__pa(level2p) | _KERNPG_TABLE)); + addr += PUD_SIZE; + } + /* clear the unused entries */ + while (addr < end_addr) { + pud_clear(level3p++); + addr += PUD_SIZE; + } +out: + return result; +} + + +static int init_level4_page(struct kimage *image, pgd_t *level4p, + unsigned long addr, unsigned long last_addr) +{ + unsigned long end_addr; + int result; + + result = 0; + addr &= PAGE_MASK; + end_addr = addr + (PTRS_PER_PGD * PGDIR_SIZE); + while ((addr < last_addr) && (addr < end_addr)) { + struct page *page; + pud_t *level3p; + + page = kimage_alloc_control_pages(image, 0); + if (!page) { + result = -ENOMEM; + goto out; + } + level3p = (pud_t *)page_address(page); + result = init_level3_page(image, level3p, addr, last_addr); + if (result) { + goto out; + } + set_pgd(level4p++, __pgd(__pa(level3p) | _KERNPG_TABLE)); + addr += PGDIR_SIZE; + } + /* clear the unused entries */ + while (addr < end_addr) { + pgd_clear(level4p++); + addr += PGDIR_SIZE; + } +out: + return result; +} + + +static int init_pgtable(struct kimage *image, unsigned long start_pgtable) +{ + pgd_t *level4p; + level4p = (pgd_t *)__va(start_pgtable); + return init_level4_page(image, level4p, 0, end_pfn << PAGE_SHIFT); +} + +static void set_idt(void *newidt, u16 limit) +{ + struct desc_ptr curidt; + + /* x86-64 supports unaliged loads & stores */ + curidt.size = limit; + curidt.address = (unsigned long)newidt; + + __asm__ __volatile__ ( + "lidtq %0\n" + : : "m" (curidt) + ); +}; + + +static void set_gdt(void *newgdt, u16 limit) +{ + struct desc_ptr curgdt; + + /* x86-64 supports unaligned loads & stores */ + curgdt.size = limit; + curgdt.address = (unsigned long)newgdt; + + __asm__ __volatile__ ( + "lgdtq %0\n" + : : "m" (curgdt) + ); +}; + +static void load_segments(void) +{ + __asm__ __volatile__ ( + "\tmovl %0,%%ds\n" + "\tmovl %0,%%es\n" + "\tmovl %0,%%ss\n" + "\tmovl %0,%%fs\n" + "\tmovl %0,%%gs\n" + : : "a" (__KERNEL_DS) : "memory" + ); +} + +int machine_kexec_prepare(struct kimage *image) +{ + unsigned long start_pgtable; + int result; + + /* Calculate the offsets */ + start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT; + + /* Setup the identity mapped 64bit page table */ + result = init_pgtable(image, start_pgtable); + if (result) + return result; + + return 0; +} + +void machine_kexec_cleanup(struct kimage *image) +{ + return; +} + +/* + * Do not allocate memory (or fail in any way) in machine_kexec(). + * We are past the point of no return, committed to rebooting now. + */ +NORET_TYPE void machine_kexec(struct kimage *image) +{ + unsigned long page_list[PAGES_NR]; + void *control_page; + + /* Interrupts aren't acceptable while we reboot */ + local_irq_disable(); + + control_page = page_address(image->control_code_page) + PAGE_SIZE; + memcpy(control_page, relocate_kernel, PAGE_SIZE); + + page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page); + page_list[VA_CONTROL_PAGE] = (unsigned long)relocate_kernel; + page_list[PA_PGD] = virt_to_phys(&kexec_pgd); + page_list[VA_PGD] = (unsigned long)kexec_pgd; + page_list[PA_PUD_0] = virt_to_phys(&kexec_pud0); + page_list[VA_PUD_0] = (unsigned long)kexec_pud0; + page_list[PA_PMD_0] = virt_to_phys(&kexec_pmd0); + page_list[VA_PMD_0] = (unsigned long)kexec_pmd0; + page_list[PA_PTE_0] = virt_to_phys(&kexec_pte0); + page_list[VA_PTE_0] = (unsigned long)kexec_pte0; + page_list[PA_PUD_1] = virt_to_phys(&kexec_pud1); + page_list[VA_PUD_1] = (unsigned long)kexec_pud1; + page_list[PA_PMD_1] = virt_to_phys(&kexec_pmd1); + page_list[VA_PMD_1] = (unsigned long)kexec_pmd1; + page_list[PA_PTE_1] = virt_to_phys(&kexec_pte1); + page_list[VA_PTE_1] = (unsigned long)kexec_pte1; + + page_list[PA_TABLE_PAGE] = + (unsigned long)__pa(page_address(image->control_code_page)); + + /* 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. + */ + set_gdt(phys_to_virt(0),0); + set_idt(phys_to_virt(0),0); + + /* now call it */ + relocate_kernel((unsigned long)image->head, (unsigned long)page_list, + image->start); +} + +/* crashkernel=size@addr specifies the location to reserve for + * a crash kernel. By reserving this memory we guarantee + * that linux never set's it up as a DMA target. + * Useful for holding code to do something appropriate + * after a kernel panic. + */ +static int __init setup_crashkernel(char *arg) +{ + unsigned long size, base; + char *p; + if (!arg) + return -EINVAL; + size = memparse(arg, &p); + if (arg == p) + return -EINVAL; + if (*p == '@') { + base = memparse(p+1, &p); + /* FIXME: Do I want a sanity check to validate the + * memory range? Yes you do, but it's too early for + * e820 -AK */ + crashk_res.start = base; + crashk_res.end = base + size - 1; + } + return 0; +} +early_param("crashkernel", setup_crashkernel); + |