1 files changed, 171 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 000000000000..91966bafb3dc
--- /dev/null
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -0,0 +1,171 @@
+/*
+ * 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/delay.h>
+#include <linux/init.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/io.h>
+#include <asm/apic.h>
+#include <asm/cpufeature.h>
+#include <asm/desc.h>
+#include <asm/system.h>
+
+#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
+static u32 kexec_pgd[1024] PAGE_ALIGNED;
+#ifdef CONFIG_X86_PAE
+static u32 kexec_pmd0[1024] PAGE_ALIGNED;
+static u32 kexec_pmd1[1024] PAGE_ALIGNED;
+#endif
+static u32 kexec_pte0[1024] PAGE_ALIGNED;
+static u32 kexec_pte1[1024] PAGE_ALIGNED;
+
+static void set_idt(void *newidt, __u16 limit)
+{
+        struct Xgt_desc_struct curidt;
+
+        /* ia32 supports unaliged loads & stores */
+        curidt.size    = limit;
+        curidt.address = (unsigned long)newidt;
+
+        load_idt(&curidt);
+};
+
+
+static void set_gdt(void *newgdt, __u16 limit)
+{
+        struct Xgt_desc_struct 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,%%fs\n"
+                "\tmovl %%eax,%%gs\n"
+                "\tmovl %%eax,%%ss\n"
+                ::: "eax", "memory");
+#undef STR
+#undef __STR
+}
+
+/*
+ * A architecture hook called to validate the
+ * proposed image and prepare the control pages
+ * as needed.  The pages for KEXEC_CONTROL_CODE_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.
+ *
+ * Currently nothing.
+ */
+int machine_kexec_prepare(struct kimage *image)
+{
+        return 0;
+}
+
+/*
+ * Undo anything leftover by machine_kexec_prepare
+ * when an image is freed.
+ */
+void machine_kexec_cleanup(struct kimage *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.
+ */
+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);
+        memcpy(control_page, relocate_kernel, PAGE_SIZE);
+
+        page_list[PA_CONTROL_PAGE] = __pa(control_page);
+        page_list[VA_CONTROL_PAGE] = (unsigned long)relocate_kernel;
+        page_list[PA_PGD] = __pa(kexec_pgd);
+        page_list[VA_PGD] = (unsigned long)kexec_pgd;
+#ifdef CONFIG_X86_PAE
+        page_list[PA_PMD_0] = __pa(kexec_pmd0);
+        page_list[VA_PMD_0] = (unsigned long)kexec_pmd0;
+        page_list[PA_PMD_1] = __pa(kexec_pmd1);
+        page_list[VA_PMD_1] = (unsigned long)kexec_pmd1;
+#endif
+        page_list[PA_PTE_0] = __pa(kexec_pte0);
+        page_list[VA_PTE_0] = (unsigned long)kexec_pte0;
+        page_list[PA_PTE_1] = __pa(kexec_pte1);
+        page_list[VA_PTE_1] = (unsigned long)kexec_pte1;
+
+        /* 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, cpu_has_pae);
+}
+
+/* crashkernel=size@addr specifies the location to reserve for
+ * a crash kernel.  By reserving this memory we guarantee
+ * that linux never sets it up as a DMA target.
+ * Useful for holding code to do something appropriate
+ * after a kernel panic.
+ */
+static int __init parse_crashkernel(char *arg)
+{
+        unsigned long size, base;
+        size = memparse(arg, &arg);
+        if (*arg == '@') {
+                base = memparse(arg+1, &arg);
+                /* FIXME: Do I want a sanity check
+                 * to validate the memory range?
+                 */
+                crashk_res.start = base;
+                crashk_res.end   = base + size - 1;
+        }
+        return 0;
+}
+early_param("crashkernel", parse_crashkernel);