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linux/include/asm-i386/kexec.h
Ian Campbell 79e030114a [PATCH] i386: Allow i386 crash kernels to handle x86_64 dumps
The specific case I am encountering is kdump under Xen with a 64 bit
hypervisor and 32 bit kernel/userspace.  The dump created is 64 bit due to
the hypervisor but the dump kernel is 32 bit for maximum compatibility.

It's possibly less likely to be useful in a purely native scenario but I
see no reason to disallow it.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Ian Campbell <ian.campbell@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Horms <horms@verge.net.au>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-05-02 19:27:09 +02:00

102 lines
3.3 KiB
C

#ifndef _I386_KEXEC_H
#define _I386_KEXEC_H
#define PA_CONTROL_PAGE 0
#define VA_CONTROL_PAGE 1
#define PA_PGD 2
#define VA_PGD 3
#define PA_PTE_0 4
#define VA_PTE_0 5
#define PA_PTE_1 6
#define VA_PTE_1 7
#ifdef CONFIG_X86_PAE
#define PA_PMD_0 8
#define VA_PMD_0 9
#define PA_PMD_1 10
#define VA_PMD_1 11
#define PAGES_NR 12
#else
#define PAGES_NR 8
#endif
#ifndef __ASSEMBLY__
#include <asm/ptrace.h>
#include <asm/string.h>
/*
* KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
* I.e. Maximum page that is mapped directly into kernel memory,
* and kmap is not required.
*/
/* Maximum physical address we can use pages from */
#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
/* Maximum address we can reach in physical address mode */
#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
/* Maximum address we can use for the control code buffer */
#define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
#define KEXEC_CONTROL_CODE_SIZE 4096
/* The native architecture */
#define KEXEC_ARCH KEXEC_ARCH_386
/* We can also handle crash dumps from 64 bit kernel. */
#define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
#define MAX_NOTE_BYTES 1024
/* CPU does not save ss and esp on stack if execution is already
* running in kernel mode at the time of NMI occurrence. This code
* fixes it.
*/
static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
struct pt_regs *oldregs)
{
memcpy(newregs, oldregs, sizeof(*newregs));
newregs->esp = (unsigned long)&(oldregs->esp);
__asm__ __volatile__(
"xorl %%eax, %%eax\n\t"
"movw %%ss, %%ax\n\t"
:"=a"(newregs->xss));
}
/*
* This function is responsible for capturing register states if coming
* via panic otherwise just fix up the ss and esp if coming via kernel
* mode exception.
*/
static inline void crash_setup_regs(struct pt_regs *newregs,
struct pt_regs *oldregs)
{
if (oldregs)
crash_fixup_ss_esp(newregs, oldregs);
else {
__asm__ __volatile__("movl %%ebx,%0" : "=m"(newregs->ebx));
__asm__ __volatile__("movl %%ecx,%0" : "=m"(newregs->ecx));
__asm__ __volatile__("movl %%edx,%0" : "=m"(newregs->edx));
__asm__ __volatile__("movl %%esi,%0" : "=m"(newregs->esi));
__asm__ __volatile__("movl %%edi,%0" : "=m"(newregs->edi));
__asm__ __volatile__("movl %%ebp,%0" : "=m"(newregs->ebp));
__asm__ __volatile__("movl %%eax,%0" : "=m"(newregs->eax));
__asm__ __volatile__("movl %%esp,%0" : "=m"(newregs->esp));
__asm__ __volatile__("movw %%ss, %%ax;" :"=a"(newregs->xss));
__asm__ __volatile__("movw %%cs, %%ax;" :"=a"(newregs->xcs));
__asm__ __volatile__("movw %%ds, %%ax;" :"=a"(newregs->xds));
__asm__ __volatile__("movw %%es, %%ax;" :"=a"(newregs->xes));
__asm__ __volatile__("pushfl; popl %0" :"=m"(newregs->eflags));
newregs->eip = (unsigned long)current_text_addr();
}
}
asmlinkage NORET_TYPE void
relocate_kernel(unsigned long indirection_page,
unsigned long control_page,
unsigned long start_address,
unsigned int has_pae) ATTRIB_NORET;
#endif /* __ASSEMBLY__ */
#endif /* _I386_KEXEC_H */