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  * Default implementation of macro that returns current
  12  * instruction pointer ("program counter").
  13  */
  14 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
  15
  16 /*
  17  * We have a 42-bit user address space: 4TB user VM...
  18  */
  19 #define TASK_SIZE (0x40000000000UL)
  20
  21 /* This decides where the kernel will search for a free chunk of vm
  22  * space during mmap's.
  23  */
  24 #define TASK_UNMAPPED_BASE \
  25   ((current->personality & ADDR_LIMIT_32BIT) ? 0x40000000 : TASK_SIZE / 2)
  26
  27 /*
  28  * Bus types
  29  */
  30 #define EISA_bus 1
  31 #define EISA_bus__is_a_macro /* for versions in ksyms.c */
  32 #define MCA_bus 0
  33 #define MCA_bus__is_a_macro /* for versions in ksyms.c */
  34
  35 typedef struct {
  36         unsigned long seg;
  37 } mm_segment_t;
  38
  39 struct thread_struct {
  40         /* the fields below are used by PALcode and must match struct pcb: */
  41         unsigned long ksp;
  42         unsigned long usp;
  43         unsigned long ptbr;
  44         unsigned int pcc;
  45         unsigned int asn;
  46         unsigned long unique;
  47         /*
  48          * bit  0: floating point enable
  49          * bit 62: performance monitor enable
  50          */
  51         unsigned long pal_flags;
  52         unsigned long res1, res2;
  53
  54         /*
  55          * The fields below are Linux-specific:
  56          *
  57          * bit 1..5: IEEE_TRAP_ENABLE bits (see fpu.h)
  58          * bit 6..8: UAC bits (see sysinfo.h)
  59          * bit 17..21: IEEE_STATUS_MASK bits (see fpu.h)
  60          * bit 63: die_if_kernel recursion lock
  61          */
  62         unsigned long flags;
  63
  64         /* Perform syscall argument validation (get/set_fs). */
  65         mm_segment_t fs;
  66
  67         /* Breakpoint handling for ptrace.  */
  68         unsigned long bpt_addr[2];
  69         unsigned int bpt_insn[2];
  70         int bpt_nsaved;
  71 };
  72
  73 #define INIT_MMAP { &init_mm, PAGE_OFFSET,  PAGE_OFFSET+0x10000000, \
  74         NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
  75
  76 #define INIT_TSS  { \
  77         0, 0, 0, \
  78         0, 0, 0, \
  79         0, 0, 0, \
  80         0, \
  81         KERNEL_DS \
  82 }
  83
  84 #include <asm/ptrace.h>
  85
  86 /*
  87  * Return saved PC of a blocked thread.  This assumes the frame
  88  * pointer is the 6th saved long on the kernel stack and that the
  89  * saved return address is the first long in the frame.  This all
  90  * holds provided the thread blocked through a call to schedule() ($15
  91  * is the frame pointer in schedule() and $15 is saved at offset 48 by
  92  * entry.S:do_switch_stack).
  93  *
  94  * Under heavy swap load I've seen this lose in an ugly way.  So do
  95  * some extra sanity checking on the ranges we expect these pointers
  96  * to be in so that we can fail gracefully.  This is just for ps after
  97  * all.  -- r~
  98  */
  99 extern inline unsigned long thread_saved_pc(struct thread_struct *t)
 100 {
 101         unsigned long fp, sp = t->ksp, base = (unsigned long)t;
 102
 103         if (sp > base && sp+6*8 < base + 16*1024) {
 104                 fp = ((unsigned long*)sp)[6];
 105                 if (fp > sp && fp < base + 16*1024)
 106                         return *(unsigned long *)fp;
 107         }
 108
 109         return 0;
 110 }
 111
 112 /*
 113  * Do necessary setup to start up a newly executed thread.
 114  */
 115 extern void start_thread(struct pt_regs *, unsigned long, unsigned long);
 116
 117 /* Free all resources held by a thread. */
 118 extern void release_thread(struct task_struct *);
 119
 120 #define copy_segments(nr, tsk, mm)      do { } while (0)
 121 #define release_segments(mm)            do { } while (0)
 122 #define forget_segments()               do { } while (0)
 123
 124 /* NOTE: The task struct and the stack go together!  */
 125 #define alloc_task_struct() \
 126         ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
 127 #define free_task_struct(p)     free_pages((unsigned long)(p),1)
 128
 129 #define init_task       (init_task_union.task)
 130 #define init_stack      (init_task_union.stack)
 131
 132 #endif /* __ASM_ALPHA_PROCESSOR_H */