/*
* machine_kexec.c - handle transition of Linux booting another kernel
- * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
+ * 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/io.h>
#include <asm/apic.h>
#include <asm/cpufeature.h>
-
-static inline unsigned long read_cr3(void)
-{
- unsigned long cr3;
- asm volatile("movl %%cr3,%0": "=r"(cr3));
- return cr3;
-}
+#include <asm/desc.h>
+#include <asm/system.h>
#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
-
-#define L0_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
-#define L1_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
-#define L2_ATTR (_PAGE_PRESENT)
-
-#define LEVEL0_SIZE (1UL << 12UL)
-
-#ifndef CONFIG_X86_PAE
-#define LEVEL1_SIZE (1UL << 22UL)
-static u32 pgtable_level1[1024] PAGE_ALIGNED;
-
-static void identity_map_page(unsigned long address)
-{
- unsigned long level1_index, level2_index;
- u32 *pgtable_level2;
-
- /* Find the current page table */
- pgtable_level2 = __va(read_cr3());
-
- /* Find the indexes of the physical address to identity map */
- level1_index = (address % LEVEL1_SIZE)/LEVEL0_SIZE;
- level2_index = address / LEVEL1_SIZE;
-
- /* Identity map the page table entry */
- pgtable_level1[level1_index] = address | L0_ATTR;
- pgtable_level2[level2_index] = __pa(pgtable_level1) | L1_ATTR;
-
- /* Flush the tlb so the new mapping takes effect.
- * Global tlb entries are not flushed but that is not an issue.
- */
- load_cr3(pgtable_level2);
-}
-
-#else
-#define LEVEL1_SIZE (1UL << 21UL)
-#define LEVEL2_SIZE (1UL << 30UL)
-static u64 pgtable_level1[512] PAGE_ALIGNED;
-static u64 pgtable_level2[512] PAGE_ALIGNED;
-
-static void identity_map_page(unsigned long address)
-{
- unsigned long level1_index, level2_index, level3_index;
- u64 *pgtable_level3;
-
- /* Find the current page table */
- pgtable_level3 = __va(read_cr3());
-
- /* Find the indexes of the physical address to identity map */
- level1_index = (address % LEVEL1_SIZE)/LEVEL0_SIZE;
- level2_index = (address % LEVEL2_SIZE)/LEVEL1_SIZE;
- level3_index = address / LEVEL2_SIZE;
-
- /* Identity map the page table entry */
- pgtable_level1[level1_index] = address | L0_ATTR;
- pgtable_level2[level2_index] = __pa(pgtable_level1) | L1_ATTR;
- set_64bit(&pgtable_level3[level3_index], __pa(pgtable_level2) | L2_ATTR);
-
- /* Flush the tlb so the new mapping takes effect.
- * Global tlb entries are not flushed but that is not an issue.
- */
- load_cr3(pgtable_level3);
-}
+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)
{
- unsigned char curidt[6];
+ struct Xgt_desc_struct curidt;
/* ia32 supports unaliged loads & stores */
- (*(__u16 *)(curidt)) = limit;
- (*(__u32 *)(curidt +2)) = (unsigned long)(newidt);
+ curidt.size = limit;
+ curidt.address = (unsigned long)newidt;
- __asm__ __volatile__ (
- "lidt %0\n"
- : "=m" (curidt)
- );
+ load_idt(&curidt);
};
static void set_gdt(void *newgdt, __u16 limit)
{
- unsigned char curgdt[6];
+ struct Xgt_desc_struct curgdt;
/* ia32 supports unaligned loads & stores */
- (*(__u16 *)(curgdt)) = limit;
- (*(__u32 *)(curgdt +2)) = (unsigned long)(newgdt);
+ curgdt.size = limit;
+ curgdt.address = (unsigned long)newgdt;
- __asm__ __volatile__ (
- "lgdt %0\n"
- : "=m" (curgdt)
- );
+ load_gdt(&curgdt);
};
static void load_segments(void)
__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"
- );
+ "\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
}
-typedef asmlinkage void (*relocate_new_kernel_t)(
- unsigned long indirection_page, unsigned long reboot_code_buffer,
- unsigned long start_address, unsigned int has_pae);
-
-const extern unsigned char relocate_new_kernel[];
-extern void relocate_new_kernel_end(void);
-const extern unsigned int relocate_new_kernel_size;
-
/*
+ * 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.
+ * 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.
*/
-void machine_kexec(struct kimage *image)
+NORET_TYPE void machine_kexec(struct kimage *image)
{
- unsigned long indirection_page;
- unsigned long reboot_code_buffer;
- relocate_new_kernel_t rnk;
+ unsigned long page_list[PAGES_NR];
+ void *control_page;
/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
- /* Compute some offsets */
- reboot_code_buffer = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
- indirection_page = image->head & PAGE_MASK;
-
- /* Set up an identity mapping for the reboot_code_buffer */
- identity_map_page(reboot_code_buffer);
-
- /* copy it out */
- memcpy((void *)reboot_code_buffer, relocate_new_kernel, relocate_new_kernel_size);
-
- /* The segment registers are funny things, they are
- * automatically loaded from a table, in memory wherever you
- * set them to a specific selector, but this table is never
- * accessed again you set the segment to a different selector.
- *
- * The more common model is are caches where the behide
- * the scenes work is done, but is also dropped at arbitrary
- * times.
+ 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.
set_idt(phys_to_virt(0),0);
/* now call it */
- rnk = (relocate_new_kernel_t) reboot_code_buffer;
- (*rnk)(indirection_page, reboot_code_buffer, image->start, cpu_has_pae);
+ 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);
git://git.onelab.eu / linux-2.6.git / blobdiff