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 <asm/ptrace.h>
  21#include <cpu/registers.h>
  22
  23/*
  24 * Default implementation of macro that returns current
  25 * instruction pointer ("program counter").
  26 */
  27#define current_text_addr() ({ \
  28void *pc; \
  29unsigned long long __dummy = 0; \
  30__asm__("gettr  tr0, %1\n\t" \
  31        "pta    4, tr0\n\t" \
  32        "gettr  tr0, %0\n\t" \
  33        "ptabs  %1, tr0\n\t"    \
  34        :"=r" (pc), "=r" (__dummy) \
  35        : "1" (__dummy)); \
  36pc; })
  37
  38#endif
  39
  40/*
  41 * User space process size: 2GB - 4k.
  42 */
  43#define TASK_SIZE       0x7ffff000UL
  44
  45#define STACK_TOP       TASK_SIZE
  46#define STACK_TOP_MAX   STACK_TOP
  47
  48/* This decides where the kernel will search for a free chunk of vm
  49 * space during mmap's.
  50 */
  51#define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
  52
  53/*
  54 * Bit of SR register
  55 *
  56 * FD-bit:
  57 *     When it's set, it means the processor doesn't have right to use FPU,
  58 *     and it results exception when the floating operation is executed.
  59 *
  60 * IMASK-bit:
  61 *     Interrupt level mask
  62 *
  63 * STEP-bit:
  64 *     Single step bit
  65 *
  66 */
  67#if defined(CONFIG_SH64_SR_WATCH)
  68#define SR_MMU   0x84000000
  69#else
  70#define SR_MMU   0x80000000
  71#endif
  72
  73#define SR_IMASK 0x000000f0
  74#define SR_FD    0x00008000
  75#define SR_SSTEP 0x08000000
  76
  77#ifndef __ASSEMBLY__
  78
  79/*
  80 * FPU structure and data : require 8-byte alignment as we need to access it
  81   with fld.p, fst.p
  82 */
  83
  84struct sh_fpu_hard_struct {
  85        unsigned long fp_regs[64];
  86        unsigned int fpscr;
  87        /* long status; * software status information */
  88};
  89
  90#if 0
  91/* Dummy fpu emulator  */
  92struct sh_fpu_soft_struct {
  93        unsigned long long fp_regs[32];
  94        unsigned int fpscr;
  95        unsigned char lookahead;
  96        unsigned long entry_pc;
  97};
  98#endif
  99
 100union sh_fpu_union {
 101        struct sh_fpu_hard_struct hard;
 102        /* 'hard' itself only produces 32 bit alignment, yet we need
 103           to access it using 64 bit load/store as well. */
 104        unsigned long long alignment_dummy;
 105};
 106
 107struct thread_struct {
 108        unsigned long sp;
 109        unsigned long pc;
 110        /* This stores the address of the pt_regs built during a context
 111           switch, or of the register save area built for a kernel mode
 112           exception.  It is used for backtracing the stack of a sleeping task
 113           or one that traps in kernel mode. */
 114        struct pt_regs *kregs;
 115        /* This stores the address of the pt_regs constructed on entry from
 116           user mode.  It is a fixed value over the lifetime of a process, or
 117           NULL for a kernel thread. */
 118        struct pt_regs *uregs;
 119
 120        unsigned long trap_no, error_code;
 121        unsigned long address;
 122        /* Hardware debugging registers may come here */
 123
 124        /* floating point info */
 125        union sh_fpu_union fpu;
 126};
 127
 128#define INIT_MMAP \
 129{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
 130
 131#define INIT_THREAD  {                          \
 132        .sp             = sizeof(init_stack) +  \
 133                          (long) &init_stack,   \
 134        .pc             = 0,                    \
 135        .kregs          = &fake_swapper_regs,   \
 136        .uregs          = NULL,                 \
 137        .trap_no        = 0,                    \
 138        .error_code     = 0,                    \
 139        .address        = 0,                    \
 140        .fpu            = { { { 0, } }, }       \
 141}
 142
 143/*
 144 * Do necessary setup to start up a newly executed thread.
 145 */
 146#define SR_USER (SR_MMU | SR_FD)
 147
 148#define start_thread(_regs, new_pc, new_sp)                     \
 149        set_fs(USER_DS);                                        \
 150        _regs->sr = SR_USER;    /* User mode. */                \
 151        _regs->pc = new_pc - 4; /* Compensate syscall exit */   \
 152        _regs->pc |= 1;         /* Set SHmedia ! */             \
 153        _regs->regs[18] = 0;                                    \
 154        _regs->regs[15] = new_sp
 155
 156/* Forward declaration, a strange C thing */
 157struct task_struct;
 158struct mm_struct;
 159
 160/* Free all resources held by a thread. */
 161extern void release_thread(struct task_struct *);
 162/*
 163 * create a kernel thread without removing it from tasklists
 164 */
 165extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 166
 167
 168/* Copy and release all segment info associated with a VM */
 169#define copy_segments(p, mm)    do { } while (0)
 170#define release_segments(mm)    do { } while (0)
 171#define forget_segments()       do { } while (0)
 172#define prepare_to_copy(tsk)    do { } while (0)
 173/*
 174 * FPU lazy state save handling.
 175 */
 176
 177static inline void disable_fpu(void)
 178{
 179        unsigned long long __dummy;
 180
 181        /* Set FD flag in SR */
 182        __asm__ __volatile__("getcon    " __SR ", %0\n\t"
 183                             "or        %0, %1, %0\n\t"
 184                             "putcon    %0, " __SR "\n\t"
 185                             : "=&r" (__dummy)
 186                             : "r" (SR_FD));
 187}
 188
 189static inline void enable_fpu(void)
 190{
 191        unsigned long long __dummy;
 192
 193        /* Clear out FD flag in SR */
 194        __asm__ __volatile__("getcon    " __SR ", %0\n\t"
 195                             "and       %0, %1, %0\n\t"
 196                             "putcon    %0, " __SR "\n\t"
 197                             : "=&r" (__dummy)
 198                             : "r" (~SR_FD));
 199}
 200
 201/* Round to nearest, no exceptions on inexact, overflow, underflow,
 202   zero-divide, invalid.  Configure option for whether to flush denorms to
 203   zero, or except if a denorm is encountered.  */
 204#if defined(CONFIG_SH64_FPU_DENORM_FLUSH)
 205#define FPSCR_INIT  0x00040000
 206#else
 207#define FPSCR_INIT  0x00000000
 208#endif
 209
 210#ifdef CONFIG_SH_FPU
 211/* Initialise the FP state of a task */
 212void fpinit(struct sh_fpu_hard_struct *fpregs);
 213#else
 214#define fpinit(fpregs)  do { } while (0)
 215#endif
 216
 217extern struct task_struct *last_task_used_math;
 218
 219/*
 220 * Return saved PC of a blocked thread.
 221 */
 222#define thread_saved_pc(tsk)    (tsk->thread.pc)
 223
 224extern unsigned long get_wchan(struct task_struct *p);
 225
 226#define KSTK_EIP(tsk)  ((tsk)->thread.pc)
 227#define KSTK_ESP(tsk)  ((tsk)->thread.sp)
 228
 229#define user_stack_pointer(_regs)       ((_regs)->regs[15])
 230
 231#endif  /* __ASSEMBLY__ */
 232#endif /* __ASM_SH_PROCESSOR_64_H */
 233