linux/arch/sh/include/asm/processor_64.h
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   1#ifndef __ASM_SH_PROCESSOR_64_H
   2#define __ASM_SH_PROCESSOR_64_H
   3
   4/*
   5 * include/asm-sh/processor_64.h
   6 *
   7 * Copyright (C) 2000, 2001  Paolo Alberelli
   8 * Copyright (C) 2003  Paul Mundt
   9 * Copyright (C) 2004  Richard Curnow
  10 *
  11 * This file is subject to the terms and conditions of the GNU General Public
  12 * License.  See the file "COPYING" in the main directory of this archive
  13 * for more details.
  14 */
  15#ifndef __ASSEMBLY__
  16
  17#include <linux/compiler.h>
  18#include <asm/page.h>
  19#include <asm/types.h>
  20#include <cpu/registers.h>
  21
  22/*
  23 * Default implementation of macro that returns current
  24 * instruction pointer ("program counter").
  25 */
  26#define current_text_addr() ({ \
  27void *pc; \
  28unsigned long long __dummy = 0; \
  29__asm__("gettr  tr0, %1\n\t" \
  30        "pta    4, tr0\n\t" \
  31        "gettr  tr0, %0\n\t" \
  32        "ptabs  %1, tr0\n\t"    \
  33        :"=r" (pc), "=r" (__dummy) \
  34        : "1" (__dummy)); \
  35pc; })
  36
  37#endif
  38
  39/*
  40 * User space process size: 2GB - 4k.
  41 */
  42#define TASK_SIZE       0x7ffff000UL
  43
  44#define STACK_TOP       TASK_SIZE
  45#define STACK_TOP_MAX   STACK_TOP
  46
  47/* This decides where the kernel will search for a free chunk of vm
  48 * space during mmap's.
  49 */
  50#define TASK_UNMAPPED_BASE      PAGE_ALIGN(TASK_SIZE / 3)
  51
  52/*
  53 * Bit of SR register
  54 *
  55 * FD-bit:
  56 *     When it's set, it means the processor doesn't have right to use FPU,
  57 *     and it results exception when the floating operation is executed.
  58 *
  59 * IMASK-bit:
  60 *     Interrupt level mask
  61 *
  62 * STEP-bit:
  63 *     Single step bit
  64 *
  65 */
  66#if defined(CONFIG_SH64_SR_WATCH)
  67#define SR_MMU   0x84000000
  68#else
  69#define SR_MMU   0x80000000
  70#endif
  71
  72#define SR_IMASK 0x000000f0
  73#define SR_FD    0x00008000
  74#define SR_SSTEP 0x08000000
  75
  76#ifndef __ASSEMBLY__
  77
  78/*
  79 * FPU structure and data : require 8-byte alignment as we need to access it
  80   with fld.p, fst.p
  81 */
  82
  83struct sh_fpu_hard_struct {
  84        unsigned long fp_regs[64];
  85        unsigned int fpscr;
  86        /* long status; * software status information */
  87};
  88
  89/* Dummy fpu emulator  */
  90struct sh_fpu_soft_struct {
  91        unsigned long fp_regs[64];
  92        unsigned int fpscr;
  93        unsigned char lookahead;
  94        unsigned long entry_pc;
  95};
  96
  97union thread_xstate {
  98        struct sh_fpu_hard_struct hardfpu;
  99        struct sh_fpu_soft_struct softfpu;
 100        /*
 101         * The structure definitions only produce 32 bit alignment, yet we need
 102         * to access them using 64 bit load/store as well.
 103         */
 104        unsigned long long alignment_dummy;
 105};
 106
 107struct thread_struct {
 108        unsigned long sp;
 109        unsigned long pc;
 110
 111        /* Various thread flags, see SH_THREAD_xxx */
 112        unsigned long flags;
 113
 114        /* This stores the address of the pt_regs built during a context
 115           switch, or of the register save area built for a kernel mode
 116           exception.  It is used for backtracing the stack of a sleeping task
 117           or one that traps in kernel mode. */
 118        struct pt_regs *kregs;
 119        /* This stores the address of the pt_regs constructed on entry from
 120           user mode.  It is a fixed value over the lifetime of a process, or
 121           NULL for a kernel thread. */
 122        struct pt_regs *uregs;
 123
 124        unsigned long address;
 125        /* Hardware debugging registers may come here */
 126
 127        /* floating point info */
 128        union thread_xstate *xstate;
 129
 130        /*
 131         * fpu_counter contains the number of consecutive context switches
 132         * that the FPU is used. If this is over a threshold, the lazy fpu
 133         * saving becomes unlazy to save the trap. This is an unsigned char
 134         * so that after 256 times the counter wraps and the behavior turns
 135         * lazy again; this to deal with bursty apps that only use FPU for
 136         * a short time
 137         */
 138        unsigned char fpu_counter;
 139};
 140
 141#define INIT_MMAP \
 142{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
 143
 144#define INIT_THREAD  {                          \
 145        .sp             = sizeof(init_stack) +  \
 146                          (long) &init_stack,   \
 147        .pc             = 0,                    \
 148        .kregs          = &fake_swapper_regs,   \
 149        .uregs          = NULL,                 \
 150        .address        = 0,                    \
 151        .flags          = 0,                    \
 152}
 153
 154/*
 155 * Do necessary setup to start up a newly executed thread.
 156 */
 157#define SR_USER (SR_MMU | SR_FD)
 158
 159#define start_thread(_regs, new_pc, new_sp)                     \
 160        _regs->sr = SR_USER;    /* User mode. */                \
 161        _regs->pc = new_pc - 4; /* Compensate syscall exit */   \
 162        _regs->pc |= 1;         /* Set SHmedia ! */             \
 163        _regs->regs[18] = 0;                                    \
 164        _regs->regs[15] = new_sp
 165
 166/* Forward declaration, a strange C thing */
 167struct task_struct;
 168struct mm_struct;
 169
 170/* Free all resources held by a thread. */
 171extern void release_thread(struct task_struct *);
 172
 173/* Copy and release all segment info associated with a VM */
 174#define copy_segments(p, mm)    do { } while (0)
 175#define release_segments(mm)    do { } while (0)
 176#define forget_segments()       do { } while (0)
 177/*
 178 * FPU lazy state save handling.
 179 */
 180
 181static inline void disable_fpu(void)
 182{
 183        unsigned long long __dummy;
 184
 185        /* Set FD flag in SR */
 186        __asm__ __volatile__("getcon    " __SR ", %0\n\t"
 187                             "or        %0, %1, %0\n\t"
 188                             "putcon    %0, " __SR "\n\t"
 189                             : "=&r" (__dummy)
 190                             : "r" (SR_FD));
 191}
 192
 193static inline void enable_fpu(void)
 194{
 195        unsigned long long __dummy;
 196
 197        /* Clear out FD flag in SR */
 198        __asm__ __volatile__("getcon    " __SR ", %0\n\t"
 199                             "and       %0, %1, %0\n\t"
 200                             "putcon    %0, " __SR "\n\t"
 201                             : "=&r" (__dummy)
 202                             : "r" (~SR_FD));
 203}
 204
 205/* Round to nearest, no exceptions on inexact, overflow, underflow,
 206   zero-divide, invalid.  Configure option for whether to flush denorms to
 207   zero, or except if a denorm is encountered.  */
 208#if defined(CONFIG_SH64_FPU_DENORM_FLUSH)
 209#define FPSCR_INIT  0x00040000
 210#else
 211#define FPSCR_INIT  0x00000000
 212#endif
 213
 214#ifdef CONFIG_SH_FPU
 215/* Initialise the FP state of a task */
 216void fpinit(struct sh_fpu_hard_struct *fpregs);
 217#else
 218#define fpinit(fpregs)  do { } while (0)
 219#endif
 220
 221extern struct task_struct *last_task_used_math;
 222
 223/*
 224 * Return saved PC of a blocked thread.
 225 */
 226#define thread_saved_pc(tsk)    (tsk->thread.pc)
 227
 228extern unsigned long get_wchan(struct task_struct *p);
 229
 230#define KSTK_EIP(tsk)  ((tsk)->thread.pc)
 231#define KSTK_ESP(tsk)  ((tsk)->thread.sp)
 232
 233#endif  /* __ASSEMBLY__ */
 234#endif /* __ASM_SH_PROCESSOR_64_H */
 235