arch/arc/include/asm/processor.h

   1 /*
   2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * vineetg: March 2009
   9  *  -Implemented task_pt_regs( )
  10  *
  11  * Amit Bhor, Sameer Dhavale, Ashwin Chaugule: Codito Technologies 2004
  12  */
  13
  14 #ifndef __ASM_ARC_PROCESSOR_H
  15 #define __ASM_ARC_PROCESSOR_H
  16
  17 #ifndef __ASSEMBLY__
  18
  19 #include <asm/ptrace.h>
  20
  21 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
  22 /* These DPFP regs need to be saved/restored across ctx-sw */
  23 struct arc_fpu {
  24         struct {
  25                 unsigned int l, h;
  26         } aux_dpfp[2];
  27 };
  28 #endif
  29
  30 /* Arch specific stuff which needs to be saved per task.
  31  * However these items are not so important so as to earn a place in
  32  * struct thread_info
  33  */
  34 struct thread_struct {
  35         unsigned long ksp;      /* kernel mode stack pointer */
  36         unsigned long callee_reg;       /* pointer to callee regs */
  37         unsigned long fault_address;    /* dbls as brkpt holder as well */
  38 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
  39         struct arc_fpu fpu;
  40 #endif
  41 };
  42
  43 #define INIT_THREAD  {                          \
  44         .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
  45 }
  46
  47 /* Forward declaration, a strange C thing */
  48 struct task_struct;
  49
  50 #define task_pt_regs(p) \
  51         ((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
  52
  53 /* Free all resources held by a thread */
  54 #define release_thread(thread) do { } while (0)
  55
  56 /*
  57  * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
  58  * get optimised away by gcc
  59  */
  60 #ifdef CONFIG_SMP
  61 #define cpu_relax()     __asm__ __volatile__ ("" : : : "memory")
  62 #else
  63 #define cpu_relax()     do { } while (0)
  64 #endif
  65
  66 #define cpu_relax_lowlatency() cpu_relax()
  67
  68 #define copy_segments(tsk, mm)      do { } while (0)
  69 #define release_segments(mm)        do { } while (0)
  70
  71 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
  72 #define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
  73
  74 /*
  75  * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
  76  * Look in process.c for details of kernel stack layout
  77  */
  78 #define TSK_K_ESP(tsk)          (tsk->thread.ksp)
  79
  80 #define TSK_K_REG(tsk, off)     (*((unsigned long *)(TSK_K_ESP(tsk) + \
  81                                         sizeof(struct callee_regs) + off)))
  82
  83 #define TSK_K_BLINK(tsk)        TSK_K_REG(tsk, 4)
  84 #define TSK_K_FP(tsk)           TSK_K_REG(tsk, 0)
  85
  86 #define thread_saved_pc(tsk)    TSK_K_BLINK(tsk)
  87
  88 extern void start_thread(struct pt_regs * regs, unsigned long pc,
  89                          unsigned long usp);
  90
  91 extern unsigned int get_wchan(struct task_struct *p);
  92
  93 /*
  94  * Default implementation of macro that returns current
  95  * instruction pointer ("program counter").
  96  * Should the PC register be read instead ? This macro does not seem to
  97  * be used in many places so this wont be all that bad.
  98  */
  99 #define current_text_addr() ({ __label__ _l; _l: &&_l; })
 100
 101 #endif /* !__ASSEMBLY__ */
 102
 103 /*
 104  * System Memory Map on ARC
 105  *
 106  * ---------------------------- (lower 2G, Translated) -------------------------
 107  * 0x0000_0000          0x5FFF_FFFF     (user vaddr: TASK_SIZE)
 108  * 0x6000_0000          0x6FFF_FFFF     (reserved gutter between U/K)
 109  * 0x7000_0000          0x7FFF_FFFF     (kvaddr: vmalloc/modules/pkmap..)
 110  *
 111  * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
 112  * 0x8000_0000          0xBFFF_FFFF     (kernel direct mapped)
 113  * 0xC000_0000          0xFFFF_FFFF     (peripheral uncached space)
 114  * -----------------------------------------------------------------------------
 115  */
 116 #define VMALLOC_START   0x70000000
 117 #define VMALLOC_SIZE    (PAGE_OFFSET - VMALLOC_START)
 118 #define VMALLOC_END     (VMALLOC_START + VMALLOC_SIZE)
 119
 120 #define USER_KERNEL_GUTTER    0x10000000
 121
 122 #define TASK_SIZE       (VMALLOC_START - USER_KERNEL_GUTTER)
 123
 124 #define STACK_TOP       TASK_SIZE
 125 #define STACK_TOP_MAX   STACK_TOP
 126
 127 /* This decides where the kernel will search for a free chunk of vm
 128  * space during mmap's.
 129  */
 130 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
 131
 132 #endif /* __ASM_ARC_PROCESSOR_H */