include/asm-alpha/processor.h

   1 /*
   2  * include/asm-alpha/processor.h
   3  *
   4  * Copyright (C) 1994 Linus Torvalds
   5  */
   6
   7 #ifndef __ASM_ALPHA_PROCESSOR_H
   8 #define __ASM_ALPHA_PROCESSOR_H
   9
  10 /*
  11  * We have a 42-bit user address space: 4TB user VM...
  12  */
  13 #define TASK_SIZE (0x40000000000UL)
  14
  15 /* This decides where the kernel will search for a free chunk of vm
  16  * space during mmap's.
  17  */
  18 #define TASK_UNMAPPED_BASE \
  19   ((current->personality & ADDR_LIMIT_32BIT) ? 0x40000000 : TASK_SIZE / 2)
  20
  21 /*
  22  * Bus types
  23  */
  24 #define EISA_bus 1
  25 #define EISA_bus__is_a_macro /* for versions in ksyms.c */
  26 #define MCA_bus 0
  27 #define MCA_bus__is_a_macro /* for versions in ksyms.c */
  28
  29 typedef struct {
  30         unsigned long seg;
  31 } mm_segment_t;
  32
  33 struct thread_struct {
  34         /* the fields below are used by PALcode and must match struct pcb: */
  35         unsigned long ksp;
  36         unsigned long usp;
  37         unsigned long ptbr;
  38         unsigned int pcc;
  39         unsigned int asn;
  40         unsigned long unique;
  41         /*
  42          * bit  0: floating point enable
  43          * bit 62: performance monitor enable
  44          */
  45         unsigned long pal_flags;
  46         unsigned long res1, res2;
  47
  48         /*
  49          * The fields below are Linux-specific:
  50          *
  51          * bit 1..5: IEEE_TRAP_ENABLE bits (see fpu.h)
  52          * bit 6..8: UAC bits (see sysinfo.h)
  53          * bit 17..21: IEEE_STATUS_MASK bits (see fpu.h)
  54          * bit 63: die_if_kernel recursion lock
  55          */
  56         unsigned long flags;
  57
  58         /* Perform syscall argument validation (get/set_fs). */
  59         mm_segment_t fs;
  60
  61         /* Breakpoint handling for ptrace.  */
  62         unsigned long bpt_addr[2];
  63         unsigned int bpt_insn[2];
  64         int bpt_nsaved;
  65 };
  66
  67 #define INIT_MMAP { &init_mm, PAGE_OFFSET,  PAGE_OFFSET+0x10000000, \
  68         NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
  69
  70 #define INIT_TSS  { \
  71         0, 0, 0, \
  72         0, 0, 0, \
  73         0, 0, 0, \
  74         0, \
  75         KERNEL_DS \
  76 }
  77
  78 #include <asm/ptrace.h>
  79
  80 /*
  81  * Return saved PC of a blocked thread.  This assumes the frame
  82  * pointer is the 6th saved long on the kernel stack and that the
  83  * saved return address is the first long in the frame.  This all
  84  * holds provided the thread blocked through a call to schedule() ($15
  85  * is the frame pointer in schedule() and $15 is saved at offset 48 by
  86  * entry.S:do_switch_stack).
  87  *
  88  * Under heavy swap load I've seen this lose in an ugly way.  So do
  89  * some extra sanity checking on the ranges we expect these pointers
  90  * to be in so that we can fail gracefully.  This is just for ps after
  91  * all.  -- r~
  92  */
  93 extern inline unsigned long thread_saved_pc(struct thread_struct *t)
  94 {
  95         unsigned long fp, sp = t->ksp, base = (unsigned long)t;
  96
  97         if (sp > base && sp+6*8 < base + 16*1024) {
  98                 fp = ((unsigned long*)sp)[6];
  99                 if (fp > sp && fp < base + 16*1024)
 100                         return *(unsigned long *)fp;
 101         }
 102
 103         return 0;
 104 }
 105
 106 /*
 107  * Do necessary setup to start up a newly executed thread.
 108  */
 109 extern void start_thread(struct pt_regs *, unsigned long, unsigned long);
 110
 111 /* Free all resources held by a thread. */
 112 extern void release_thread(struct task_struct *);
 113
 114 #define copy_segments(nr, tsk, mm)      do { } while (0)
 115 #define release_segments(mm)            do { } while (0)
 116 #define forget_segments()               do { } while (0)
 117
 118 /* NOTE: The task struct and the stack go together!  */
 119 #define alloc_task_struct() \
 120         ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
 121 #define free_task_struct(p)     free_pages((unsigned long)(p),1)
 122
 123 #define init_task       (init_task_union.task)
 124 #define init_stack      (init_task_union.stack)
 125
 126 #endif /* __ASM_ALPHA_PROCESSOR_H */