LXR linux/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 */
  23struct 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 */
  34struct 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 */
  48struct 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#define cpu_relax()     __asm__ __volatile__ ("" : : : "memory")
  61
  62#define cpu_relax_lowlatency() cpu_relax()
  63
  64#define copy_segments(tsk, mm)      do { } while (0)
  65#define release_segments(mm)        do { } while (0)
  66
  67#define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
  68#define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
  69
  70/*
  71 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
  72 * Look in process.c for details of kernel stack layout
  73 */
  74#define TSK_K_ESP(tsk)          (tsk->thread.ksp)
  75
  76#define TSK_K_REG(tsk, off)     (*((unsigned long *)(TSK_K_ESP(tsk) + \
  77                                        sizeof(struct callee_regs) + off)))
  78
  79#define TSK_K_BLINK(tsk)        TSK_K_REG(tsk, 4)
  80#define TSK_K_FP(tsk)           TSK_K_REG(tsk, 0)
  81
  82#define thread_saved_pc(tsk)    TSK_K_BLINK(tsk)
  83
  84extern void start_thread(struct pt_regs * regs, unsigned long pc,
  85                         unsigned long usp);
  86
  87extern unsigned int get_wchan(struct task_struct *p);
  88
  89/*
  90 * Default implementation of macro that returns current
  91 * instruction pointer ("program counter").
  92 * Should the PC register be read instead ? This macro does not seem to
  93 * be used in many places so this wont be all that bad.
  94 */
  95#define current_text_addr() ({ __label__ _l; _l: &&_l; })
  96
  97#endif /* !__ASSEMBLY__ */
  98
  99/*
 100 * System Memory Map on ARC
 101 *
 102 * ---------------------------- (lower 2G, Translated) -------------------------
 103 * 0x0000_0000          0x5FFF_FFFF     (user vaddr: TASK_SIZE)
 104 * 0x6000_0000          0x6FFF_FFFF     (reserved gutter between U/K)
 105 * 0x7000_0000          0x7FFF_FFFF     (kvaddr: vmalloc/modules/pkmap..)
 106 *
 107 * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
 108 * 0x8000_0000          0xBFFF_FFFF     (kernel direct mapped)
 109 * 0xC000_0000          0xFFFF_FFFF     (peripheral uncached space)
 110 * -----------------------------------------------------------------------------
 111 */
 112#define VMALLOC_START   0x70000000
 113
 114/*
 115 * 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter
 116 * See asm/highmem.h for details
 117 */
 118#define VMALLOC_SIZE    (PAGE_OFFSET - VMALLOC_START - PGDIR_SIZE * 4)
 119#define VMALLOC_END     (VMALLOC_START + VMALLOC_SIZE)
 120
 121#define USER_KERNEL_GUTTER    0x10000000
 122
 123#define TASK_SIZE       (VMALLOC_START - USER_KERNEL_GUTTER)
 124
 125#define STACK_TOP       TASK_SIZE
 126#define STACK_TOP_MAX   STACK_TOP
 127
 128/* This decides where the kernel will search for a free chunk of vm
 129 * space during mmap's.
 130 */
 131#define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
 132
 133#endif /* __ASM_ARC_PROCESSOR_H */
 134