include/asm-i386/kexec.h

   1 #ifndef _I386_KEXEC_H
   2 #define _I386_KEXEC_H
   3
   4 #include <asm/fixmap.h>
   5 #include <asm/ptrace.h>
   6 #include <asm/string.h>
   7
   8 /*
   9  * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
  10  * I.e. Maximum page that is mapped directly into kernel memory,
  11  * and kmap is not required.
  12  *
  13  * Someone correct me if FIXADDR_START - PAGEOFFSET is not the correct
  14  * calculation for the amount of memory directly mappable into the
  15  * kernel memory space.
  16  */
  17
  18 /* Maximum physical address we can use pages from */
  19 #define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
  20 /* Maximum address we can reach in physical address mode */
  21 #define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
  22 /* Maximum address we can use for the control code buffer */
  23 #define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
  24
  25 #define KEXEC_CONTROL_CODE_SIZE 4096
  26
  27 /* The native architecture */
  28 #define KEXEC_ARCH KEXEC_ARCH_386
  29
  30 #define MAX_NOTE_BYTES 1024
  31
  32 /* CPU does not save ss and esp on stack if execution is already
  33  * running in kernel mode at the time of NMI occurrence. This code
  34  * fixes it.
  35  */
  36 static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
  37                                         struct pt_regs *oldregs)
  38 {
  39         memcpy(newregs, oldregs, sizeof(*newregs));
  40         newregs->esp = (unsigned long)&(oldregs->esp);
  41         __asm__ __volatile__(
  42                         "xorl %%eax, %%eax\n\t"
  43                         "movw %%ss, %%ax\n\t"
  44                         :"=a"(newregs->xss));
  45 }
  46
  47 /*
  48  * This function is responsible for capturing register states if coming
  49  * via panic otherwise just fix up the ss and esp if coming via kernel
  50  * mode exception.
  51  */
  52 static inline void crash_setup_regs(struct pt_regs *newregs,
  53                                        struct pt_regs *oldregs)
  54 {
  55        if (oldregs)
  56                crash_fixup_ss_esp(newregs, oldregs);
  57        else {
  58                __asm__ __volatile__("movl %%ebx,%0" : "=m"(newregs->ebx));
  59                __asm__ __volatile__("movl %%ecx,%0" : "=m"(newregs->ecx));
  60                __asm__ __volatile__("movl %%edx,%0" : "=m"(newregs->edx));
  61                __asm__ __volatile__("movl %%esi,%0" : "=m"(newregs->esi));
  62                __asm__ __volatile__("movl %%edi,%0" : "=m"(newregs->edi));
  63                __asm__ __volatile__("movl %%ebp,%0" : "=m"(newregs->ebp));
  64                __asm__ __volatile__("movl %%eax,%0" : "=m"(newregs->eax));
  65                __asm__ __volatile__("movl %%esp,%0" : "=m"(newregs->esp));
  66                __asm__ __volatile__("movw %%ss, %%ax;" :"=a"(newregs->xss));
  67                __asm__ __volatile__("movw %%cs, %%ax;" :"=a"(newregs->xcs));
  68                __asm__ __volatile__("movw %%ds, %%ax;" :"=a"(newregs->xds));
  69                __asm__ __volatile__("movw %%es, %%ax;" :"=a"(newregs->xes));
  70                __asm__ __volatile__("pushfl; popl %0" :"=m"(newregs->eflags));
  71
  72                newregs->eip = (unsigned long)current_text_addr();
  73        }
  74 }
  75
  76 #endif /* _I386_KEXEC_H */