arch/sh/include/asm/processor_64.h

   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() ({ \
  27 void *pc; \
  28 unsigned 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)); \
  35 pc; })
  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
  83 struct 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  */
  90 struct 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
  97 union 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
 107 struct 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 */
 167 struct task_struct;
 168 struct mm_struct;
 169
 170 /* Free all resources held by a thread. */
 171 extern 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
 181 static 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
 193 static 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 */
 216 void fpinit(struct sh_fpu_hard_struct *fpregs);
 217 #else
 218 #define fpinit(fpregs)  do { } while (0)
 219 #endif
 220
 221 extern 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
 228 extern 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 */