arch/sh64/kernel/fpu.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * arch/sh64/kernel/fpu.c
   7  *
   8  * Copyright (C) 2001  Manuela Cirronis, Paolo Alberelli
   9  * Copyright (C) 2002  STMicroelectronics Limited
  10  *   Author : Stuart Menefy
  11  *
  12  * Started from SH4 version:
  13  *   Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
  14  *
  15  */
  16
  17 #include <linux/sched.h>
  18 #include <linux/signal.h>
  19 #include <asm/processor.h>
  20 #include <asm/user.h>
  21 #include <asm/io.h>
  22
  23 /*
  24  * Initially load the FPU with signalling NANS.  This bit pattern
  25  * has the property that no matter whether considered as single or as
  26  * double precision, it still represents a signalling NAN.
  27  */
  28 #define sNAN64          0xFFFFFFFFFFFFFFFFULL
  29 #define sNAN32          0xFFFFFFFFUL
  30
  31 static union sh_fpu_union init_fpuregs = {
  32         .hard = {
  33           .fp_regs = { [0 ... 63] = sNAN32 },
  34           .fpscr = FPSCR_INIT
  35         }
  36 };
  37
  38 inline void fpsave(struct sh_fpu_hard_struct *fpregs)
  39 {
  40         asm volatile("fst.p     %0, (0*8), fp0\n\t"
  41                      "fst.p     %0, (1*8), fp2\n\t"
  42                      "fst.p     %0, (2*8), fp4\n\t"
  43                      "fst.p     %0, (3*8), fp6\n\t"
  44                      "fst.p     %0, (4*8), fp8\n\t"
  45                      "fst.p     %0, (5*8), fp10\n\t"
  46                      "fst.p     %0, (6*8), fp12\n\t"
  47                      "fst.p     %0, (7*8), fp14\n\t"
  48                      "fst.p     %0, (8*8), fp16\n\t"
  49                      "fst.p     %0, (9*8), fp18\n\t"
  50                      "fst.p     %0, (10*8), fp20\n\t"
  51                      "fst.p     %0, (11*8), fp22\n\t"
  52                      "fst.p     %0, (12*8), fp24\n\t"
  53                      "fst.p     %0, (13*8), fp26\n\t"
  54                      "fst.p     %0, (14*8), fp28\n\t"
  55                      "fst.p     %0, (15*8), fp30\n\t"
  56                      "fst.p     %0, (16*8), fp32\n\t"
  57                      "fst.p     %0, (17*8), fp34\n\t"
  58                      "fst.p     %0, (18*8), fp36\n\t"
  59                      "fst.p     %0, (19*8), fp38\n\t"
  60                      "fst.p     %0, (20*8), fp40\n\t"
  61                      "fst.p     %0, (21*8), fp42\n\t"
  62                      "fst.p     %0, (22*8), fp44\n\t"
  63                      "fst.p     %0, (23*8), fp46\n\t"
  64                      "fst.p     %0, (24*8), fp48\n\t"
  65                      "fst.p     %0, (25*8), fp50\n\t"
  66                      "fst.p     %0, (26*8), fp52\n\t"
  67                      "fst.p     %0, (27*8), fp54\n\t"
  68                      "fst.p     %0, (28*8), fp56\n\t"
  69                      "fst.p     %0, (29*8), fp58\n\t"
  70                      "fst.p     %0, (30*8), fp60\n\t"
  71                      "fst.p     %0, (31*8), fp62\n\t"
  72
  73                      "fgetscr   fr63\n\t"
  74                      "fst.s     %0, (32*8), fr63\n\t"
  75                 : /* no output */
  76                 : "r" (fpregs)
  77                 : "memory");
  78 }
  79
  80
  81 static inline void
  82 fpload(struct sh_fpu_hard_struct *fpregs)
  83 {
  84         asm volatile("fld.p     %0, (0*8), fp0\n\t"
  85                      "fld.p     %0, (1*8), fp2\n\t"
  86                      "fld.p     %0, (2*8), fp4\n\t"
  87                      "fld.p     %0, (3*8), fp6\n\t"
  88                      "fld.p     %0, (4*8), fp8\n\t"
  89                      "fld.p     %0, (5*8), fp10\n\t"
  90                      "fld.p     %0, (6*8), fp12\n\t"
  91                      "fld.p     %0, (7*8), fp14\n\t"
  92                      "fld.p     %0, (8*8), fp16\n\t"
  93                      "fld.p     %0, (9*8), fp18\n\t"
  94                      "fld.p     %0, (10*8), fp20\n\t"
  95                      "fld.p     %0, (11*8), fp22\n\t"
  96                      "fld.p     %0, (12*8), fp24\n\t"
  97                      "fld.p     %0, (13*8), fp26\n\t"
  98                      "fld.p     %0, (14*8), fp28\n\t"
  99                      "fld.p     %0, (15*8), fp30\n\t"
 100                      "fld.p     %0, (16*8), fp32\n\t"
 101                      "fld.p     %0, (17*8), fp34\n\t"
 102                      "fld.p     %0, (18*8), fp36\n\t"
 103                      "fld.p     %0, (19*8), fp38\n\t"
 104                      "fld.p     %0, (20*8), fp40\n\t"
 105                      "fld.p     %0, (21*8), fp42\n\t"
 106                      "fld.p     %0, (22*8), fp44\n\t"
 107                      "fld.p     %0, (23*8), fp46\n\t"
 108                      "fld.p     %0, (24*8), fp48\n\t"
 109                      "fld.p     %0, (25*8), fp50\n\t"
 110                      "fld.p     %0, (26*8), fp52\n\t"
 111                      "fld.p     %0, (27*8), fp54\n\t"
 112                      "fld.p     %0, (28*8), fp56\n\t"
 113                      "fld.p     %0, (29*8), fp58\n\t"
 114                      "fld.p     %0, (30*8), fp60\n\t"
 115
 116                      "fld.s     %0, (32*8), fr63\n\t"
 117                      "fputscr   fr63\n\t"
 118
 119                      "fld.p     %0, (31*8), fp62\n\t"
 120                 : /* no output */
 121                 : "r" (fpregs) );
 122 }
 123
 124 void fpinit(struct sh_fpu_hard_struct *fpregs)
 125 {
 126         *fpregs = init_fpuregs.hard;
 127 }
 128
 129 asmlinkage void
 130 do_fpu_error(unsigned long ex, struct pt_regs *regs)
 131 {
 132         struct task_struct *tsk = current;
 133
 134         regs->pc += 4;
 135
 136         tsk->thread.trap_no = 11;
 137         tsk->thread.error_code = 0;
 138         force_sig(SIGFPE, tsk);
 139 }
 140
 141
 142 asmlinkage void
 143 do_fpu_state_restore(unsigned long ex, struct pt_regs *regs)
 144 {
 145         void die(const char *str, struct pt_regs *regs, long err);
 146
 147         if (! user_mode(regs))
 148                 die("FPU used in kernel", regs, ex);
 149
 150         regs->sr &= ~SR_FD;
 151
 152         if (last_task_used_math == current)
 153                 return;
 154
 155         grab_fpu();
 156         if (last_task_used_math != NULL) {
 157                 /* Other processes fpu state, save away */
 158                 fpsave(&last_task_used_math->thread.fpu.hard);
 159         }
 160         last_task_used_math = current;
 161         if (used_math()) {
 162                 fpload(&current->thread.fpu.hard);
 163         } else {
 164                 /* First time FPU user.  */
 165                 fpload(&init_fpuregs.hard);
 166                 set_used_math();
 167         }
 168         release_fpu();
 169 }
 170