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Diffstat (limited to 'arch/x86/kernel/machine_kexec_64.c')
-rw-r--r--arch/x86/kernel/machine_kexec_64.c259
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);
+