1 files changed, 739 insertions, 0 deletions

diff --git a/arch/x86/math-emu/errors.c b/arch/x86/math-emu/errors.c
new file mode 100644
index 000000000000..a1b0d22f6978
--- /dev/null
+++ b/arch/x86/math-emu/errors.c
@@ -0,0 +1,739 @@
+/*---------------------------------------------------------------------------+
+ |  errors.c                                                                 |
+ |                                                                           |
+ |  The error handling functions for wm-FPU-emu                              |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1994,1996                                         |
+ |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ |                  E-mail   billm@jacobi.maths.monash.edu.au                |
+ |                                                                           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------+
+ | Note:                                                                     |
+ |    The file contains code which accesses user memory.                     |
+ |    Emulator static data may change when user memory is accessed, due to   |
+ |    other processes using the emulator while swapping is in progress.      |
+ +---------------------------------------------------------------------------*/
+
+#include <linux/signal.h>
+
+#include <asm/uaccess.h>
+
+#include "fpu_emu.h"
+#include "fpu_system.h"
+#include "exception.h"
+#include "status_w.h"
+#include "control_w.h"
+#include "reg_constant.h"
+#include "version.h"
+
+/* */
+#undef PRINT_MESSAGES
+/* */
+
+
+#if 0
+void Un_impl(void)
+{
+  u_char byte1, FPU_modrm;
+  unsigned long address = FPU_ORIG_EIP;
+
+  RE_ENTRANT_CHECK_OFF;
+  /* No need to check access_ok(), we have previously fetched these bytes. */
+  printk("Unimplemented FPU Opcode at eip=%p : ", (void __user *) address);
+  if ( FPU_CS == __USER_CS )
+    {
+      while ( 1 )
+        {
+          FPU_get_user(byte1, (u_char __user *) address);
+          if ( (byte1 & 0xf8) == 0xd8 ) break;
+          printk("[%02x]", byte1);
+          address++;
+        }
+      printk("%02x ", byte1);
+      FPU_get_user(FPU_modrm, 1 + (u_char __user *) address);
+      
+      if (FPU_modrm >= 0300)
+        printk("%02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8, FPU_modrm & 7);
+      else
+        printk("/%d\n", (FPU_modrm >> 3) & 7);
+    }
+  else
+    {
+      printk("cs selector = %04x\n", FPU_CS);
+    }
+
+  RE_ENTRANT_CHECK_ON;
+
+  EXCEPTION(EX_Invalid);
+
+}
+#endif  /*  0  */
+
+
+/*
+   Called for opcodes which are illegal and which are known to result in a
+   SIGILL with a real 80486.
+   */
+void FPU_illegal(void)
+{
+  math_abort(FPU_info,SIGILL);
+}
+
+
+
+void FPU_printall(void)
+{
+  int i;
+  static const char *tag_desc[] = { "Valid", "Zero", "ERROR", "Empty",
+                              "DeNorm", "Inf", "NaN" };
+  u_char byte1, FPU_modrm;
+  unsigned long address = FPU_ORIG_EIP;
+
+  RE_ENTRANT_CHECK_OFF;
+  /* No need to check access_ok(), we have previously fetched these bytes. */
+  printk("At %p:", (void *) address);
+  if ( FPU_CS == __USER_CS )
+    {
+#define MAX_PRINTED_BYTES 20
+      for ( i = 0; i < MAX_PRINTED_BYTES; i++ )
+        {
+          FPU_get_user(byte1, (u_char __user *) address);
+          if ( (byte1 & 0xf8) == 0xd8 )
+            {
+              printk(" %02x", byte1);
+              break;
+            }
+          printk(" [%02x]", byte1);
+          address++;
+        }
+      if ( i == MAX_PRINTED_BYTES )
+        printk(" [more..]\n");
+      else
+        {
+          FPU_get_user(FPU_modrm, 1 + (u_char __user *) address);
+          
+          if (FPU_modrm >= 0300)
+            printk(" %02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8, FPU_modrm & 7);
+          else
+            printk(" /%d, mod=%d rm=%d\n",
+                   (FPU_modrm >> 3) & 7, (FPU_modrm >> 6) & 3, FPU_modrm & 7);
+        }
+    }
+  else
+    {
+      printk("%04x\n", FPU_CS);
+    }
+
+  partial_status = status_word();
+
+#ifdef DEBUGGING
+if ( partial_status & SW_Backward )    printk("SW: backward compatibility\n");
+if ( partial_status & SW_C3 )          printk("SW: condition bit 3\n");
+if ( partial_status & SW_C2 )          printk("SW: condition bit 2\n");
+if ( partial_status & SW_C1 )          printk("SW: condition bit 1\n");
+if ( partial_status & SW_C0 )          printk("SW: condition bit 0\n");
+if ( partial_status & SW_Summary )     printk("SW: exception summary\n");
+if ( partial_status & SW_Stack_Fault ) printk("SW: stack fault\n");
+if ( partial_status & SW_Precision )   printk("SW: loss of precision\n");
+if ( partial_status & SW_Underflow )   printk("SW: underflow\n");
+if ( partial_status & SW_Overflow )    printk("SW: overflow\n");
+if ( partial_status & SW_Zero_Div )    printk("SW: divide by zero\n");
+if ( partial_status & SW_Denorm_Op )   printk("SW: denormalized operand\n");
+if ( partial_status & SW_Invalid )     printk("SW: invalid operation\n");
+#endif /* DEBUGGING */
+
+  printk(" SW: b=%d st=%ld es=%d sf=%d cc=%d%d%d%d ef=%d%d%d%d%d%d\n",
+         partial_status & 0x8000 ? 1 : 0,   /* busy */
+         (partial_status & 0x3800) >> 11,   /* stack top pointer */
+         partial_status & 0x80 ? 1 : 0,     /* Error summary status */
+         partial_status & 0x40 ? 1 : 0,     /* Stack flag */
+         partial_status & SW_C3?1:0, partial_status & SW_C2?1:0, /* cc */
+         partial_status & SW_C1?1:0, partial_status & SW_C0?1:0, /* cc */
+         partial_status & SW_Precision?1:0, partial_status & SW_Underflow?1:0,
+         partial_status & SW_Overflow?1:0, partial_status & SW_Zero_Div?1:0,
+         partial_status & SW_Denorm_Op?1:0, partial_status & SW_Invalid?1:0);
+  
+printk(" CW: ic=%d rc=%ld%ld pc=%ld%ld iem=%d     ef=%d%d%d%d%d%d\n",
+         control_word & 0x1000 ? 1 : 0,
+         (control_word & 0x800) >> 11, (control_word & 0x400) >> 10,
+         (control_word & 0x200) >> 9, (control_word & 0x100) >> 8,
+         control_word & 0x80 ? 1 : 0,
+         control_word & SW_Precision?1:0, control_word & SW_Underflow?1:0,
+         control_word & SW_Overflow?1:0, control_word & SW_Zero_Div?1:0,
+         control_word & SW_Denorm_Op?1:0, control_word & SW_Invalid?1:0);
+
+  for ( i = 0; i < 8; i++ )
+    {
+      FPU_REG *r = &st(i);
+      u_char tagi = FPU_gettagi(i);
+      switch (tagi)
+        {
+        case TAG_Empty:
+          continue;
+          break;
+        case TAG_Zero:
+        case TAG_Special:
+          tagi = FPU_Special(r);
+        case TAG_Valid:
+          printk("st(%d)  %c .%04lx %04lx %04lx %04lx e%+-6d ", i,
+                 getsign(r) ? '-' : '+',
+                 (long)(r->sigh >> 16),
+                 (long)(r->sigh & 0xFFFF),
+                 (long)(r->sigl >> 16),
+                 (long)(r->sigl & 0xFFFF),
+                 exponent(r) - EXP_BIAS + 1);
+          break;
+        default:
+          printk("Whoops! Error in errors.c: tag%d is %d ", i, tagi);
+          continue;
+          break;
+        }
+      printk("%s\n", tag_desc[(int) (unsigned) tagi]);
+    }
+
+  RE_ENTRANT_CHECK_ON;
+
+}
+
+static struct {
+  int type;
+  const char *name;
+} exception_names[] = {
+  { EX_StackOver, "stack overflow" },
+  { EX_StackUnder, "stack underflow" },
+  { EX_Precision, "loss of precision" },
+  { EX_Underflow, "underflow" },
+  { EX_Overflow, "overflow" },
+  { EX_ZeroDiv, "divide by zero" },
+  { EX_Denormal, "denormalized operand" },
+  { EX_Invalid, "invalid operation" },
+  { EX_INTERNAL, "INTERNAL BUG in "FPU_VERSION },
+  { 0, NULL }
+};
+
+/*
+ EX_INTERNAL is always given with a code which indicates where the
+ error was detected.
+
+ Internal error types:
+       0x14   in fpu_etc.c
+       0x1nn  in a *.c file:
+              0x101  in reg_add_sub.c
+              0x102  in reg_mul.c
+              0x104  in poly_atan.c
+              0x105  in reg_mul.c
+              0x107  in fpu_trig.c
+              0x108  in reg_compare.c
+              0x109  in reg_compare.c
+              0x110  in reg_add_sub.c
+              0x111  in fpe_entry.c
+              0x112  in fpu_trig.c
+              0x113  in errors.c
+              0x115  in fpu_trig.c
+              0x116  in fpu_trig.c
+              0x117  in fpu_trig.c
+              0x118  in fpu_trig.c
+              0x119  in fpu_trig.c
+              0x120  in poly_atan.c
+              0x121  in reg_compare.c
+              0x122  in reg_compare.c
+              0x123  in reg_compare.c
+              0x125  in fpu_trig.c
+              0x126  in fpu_entry.c
+              0x127  in poly_2xm1.c
+              0x128  in fpu_entry.c
+              0x129  in fpu_entry.c
+              0x130  in get_address.c
+              0x131  in get_address.c
+              0x132  in get_address.c
+              0x133  in get_address.c
+              0x140  in load_store.c
+              0x141  in load_store.c
+              0x150  in poly_sin.c
+              0x151  in poly_sin.c
+              0x160  in reg_ld_str.c
+              0x161  in reg_ld_str.c
+              0x162  in reg_ld_str.c
+              0x163  in reg_ld_str.c
+              0x164  in reg_ld_str.c
+              0x170  in fpu_tags.c
+              0x171  in fpu_tags.c
+              0x172  in fpu_tags.c
+              0x180  in reg_convert.c
+       0x2nn  in an *.S file:
+              0x201  in reg_u_add.S
+              0x202  in reg_u_div.S
+              0x203  in reg_u_div.S
+              0x204  in reg_u_div.S
+              0x205  in reg_u_mul.S
+              0x206  in reg_u_sub.S
+              0x207  in wm_sqrt.S
+              0x208  in reg_div.S
+              0x209  in reg_u_sub.S
+              0x210  in reg_u_sub.S
+              0x211  in reg_u_sub.S
+              0x212  in reg_u_sub.S
+              0x213  in wm_sqrt.S
+              0x214  in wm_sqrt.S
+              0x215  in wm_sqrt.S
+              0x220  in reg_norm.S
+              0x221  in reg_norm.S
+              0x230  in reg_round.S
+              0x231  in reg_round.S
+              0x232  in reg_round.S
+              0x233  in reg_round.S
+              0x234  in reg_round.S
+              0x235  in reg_round.S
+              0x236  in reg_round.S
+              0x240  in div_Xsig.S
+              0x241  in div_Xsig.S
+              0x242  in div_Xsig.S
+ */
+
+asmlinkage void FPU_exception(int n)
+{
+  int i, int_type;
+
+  int_type = 0;         /* Needed only to stop compiler warnings */
+  if ( n & EX_INTERNAL )
+    {
+      int_type = n - EX_INTERNAL;
+      n = EX_INTERNAL;
+      /* Set lots of exception bits! */
+      partial_status |= (SW_Exc_Mask | SW_Summary | SW_Backward);
+    }
+  else
+    {
+      /* Extract only the bits which we use to set the status word */
+      n &= (SW_Exc_Mask);
+      /* Set the corresponding exception bit */
+      partial_status |= n;
+      /* Set summary bits iff exception isn't masked */
+      if ( partial_status & ~control_word & CW_Exceptions )
+        partial_status |= (SW_Summary | SW_Backward);
+      if ( n & (SW_Stack_Fault | EX_Precision) )
+        {
+          if ( !(n & SW_C1) )
+            /* This bit distinguishes over- from underflow for a stack fault,
+               and roundup from round-down for precision loss. */
+            partial_status &= ~SW_C1;
+        }
+    }
+
+  RE_ENTRANT_CHECK_OFF;
+  if ( (~control_word & n & CW_Exceptions) || (n == EX_INTERNAL) )
+    {
+#ifdef PRINT_MESSAGES
+      /* My message from the sponsor */
+      printk(FPU_VERSION" "__DATE__" (C) W. Metzenthen.\n");
+#endif /* PRINT_MESSAGES */
+      
+      /* Get a name string for error reporting */
+      for (i=0; exception_names[i].type; i++)
+        if ( (exception_names[i].type & n) == exception_names[i].type )
+          break;
+      
+      if (exception_names[i].type)
+        {
+#ifdef PRINT_MESSAGES
+          printk("FP Exception: %s!\n", exception_names[i].name);
+#endif /* PRINT_MESSAGES */
+        }
+      else
+        printk("FPU emulator: Unknown Exception: 0x%04x!\n", n);
+      
+      if ( n == EX_INTERNAL )
+        {
+          printk("FPU emulator: Internal error type 0x%04x\n", int_type);
+          FPU_printall();
+        }
+#ifdef PRINT_MESSAGES
+      else
+        FPU_printall();
+#endif /* PRINT_MESSAGES */
+
+      /*
+       * The 80486 generates an interrupt on the next non-control FPU
+       * instruction. So we need some means of flagging it.
+       * We use the ES (Error Summary) bit for this.
+       */
+    }
+  RE_ENTRANT_CHECK_ON;
+
+#ifdef __DEBUG__
+  math_abort(FPU_info,SIGFPE);
+#endif /* __DEBUG__ */
+
+}
+
+
+/* Real operation attempted on a NaN. */
+/* Returns < 0 if the exception is unmasked */
+int real_1op_NaN(FPU_REG *a)
+{
+  int signalling, isNaN;
+
+  isNaN = (exponent(a) == EXP_OVER) && (a->sigh & 0x80000000);
+
+  /* The default result for the case of two "equal" NaNs (signs may
+     differ) is chosen to reproduce 80486 behaviour */
+  signalling = isNaN && !(a->sigh & 0x40000000);
+
+  if ( !signalling )
+    {
+      if ( !isNaN )  /* pseudo-NaN, or other unsupported? */
+        {
+          if ( control_word & CW_Invalid )
+            {
+              /* Masked response */
+              reg_copy(&CONST_QNaN, a);
+            }
+          EXCEPTION(EX_Invalid);
+          return (!(control_word & CW_Invalid) ? FPU_Exception : 0) | TAG_Special;
+        }
+      return TAG_Special;
+    }
+
+  if ( control_word & CW_Invalid )
+    {
+      /* The masked response */
+      if ( !(a->sigh & 0x80000000) )  /* pseudo-NaN ? */
+        {
+          reg_copy(&CONST_QNaN, a);
+        }
+      /* ensure a Quiet NaN */
+      a->sigh |= 0x40000000;
+    }
+
+  EXCEPTION(EX_Invalid);
+
+  return (!(control_word & CW_Invalid) ? FPU_Exception : 0) | TAG_Special;
+}
+
+
+/* Real operation attempted on two operands, one a NaN. */
+/* Returns < 0 if the exception is unmasked */
+int real_2op_NaN(FPU_REG const *b, u_char tagb,
+                 int deststnr,
+                 FPU_REG const *defaultNaN)
+{
+  FPU_REG *dest = &st(deststnr);
+  FPU_REG const *a = dest;
+  u_char taga = FPU_gettagi(deststnr);
+  FPU_REG const *x;
+  int signalling, unsupported;
+
+  if ( taga == TAG_Special )
+    taga = FPU_Special(a);
+  if ( tagb == TAG_Special )
+    tagb = FPU_Special(b);
+
+  /* TW_NaN is also used for unsupported data types. */
+  unsupported = ((taga == TW_NaN)
+                 && !((exponent(a) == EXP_OVER) && (a->sigh & 0x80000000)))
+    || ((tagb == TW_NaN)
+        && !((exponent(b) == EXP_OVER) && (b->sigh & 0x80000000)));
+  if ( unsupported )
+    {
+      if ( control_word & CW_Invalid )
+        {
+          /* Masked response */
+          FPU_copy_to_regi(&CONST_QNaN, TAG_Special, deststnr);
+        }
+      EXCEPTION(EX_Invalid);
+      return (!(control_word & CW_Invalid) ? FPU_Exception : 0) | TAG_Special;
+    }
+
+  if (taga == TW_NaN)
+    {
+      x = a;
+      if (tagb == TW_NaN)
+        {
+          signalling = !(a->sigh & b->sigh & 0x40000000);
+          if ( significand(b) > significand(a) )
+            x = b;
+          else if ( significand(b) == significand(a) )
+            {
+              /* The default result for the case of two "equal" NaNs (signs may
+                 differ) is chosen to reproduce 80486 behaviour */
+              x = defaultNaN;
+            }
+        }
+      else
+        {
+          /* return the quiet version of the NaN in a */
+          signalling = !(a->sigh & 0x40000000);
+        }
+    }
+  else
+#ifdef PARANOID
+    if (tagb == TW_NaN)
+#endif /* PARANOID */
+    {
+      signalling = !(b->sigh & 0x40000000);
+      x = b;
+    }
+#ifdef PARANOID
+  else
+    {
+      signalling = 0;
+      EXCEPTION(EX_INTERNAL|0x113);
+      x = &CONST_QNaN;
+    }
+#endif /* PARANOID */
+
+  if ( (!signalling) || (control_word & CW_Invalid) )
+    {
+      if ( ! x )
+        x = b;
+
+      if ( !(x->sigh & 0x80000000) )  /* pseudo-NaN ? */
+        x = &CONST_QNaN;
+
+      FPU_copy_to_regi(x, TAG_Special, deststnr);
+
+      if ( !signalling )
+        return TAG_Special;
+
+      /* ensure a Quiet NaN */
+      dest->sigh |= 0x40000000;
+    }
+
+  EXCEPTION(EX_Invalid);
+
+  return (!(control_word & CW_Invalid) ? FPU_Exception : 0) | TAG_Special;
+}
+
+
+/* Invalid arith operation on Valid registers */
+/* Returns < 0 if the exception is unmasked */
+asmlinkage int arith_invalid(int deststnr)
+{
+
+  EXCEPTION(EX_Invalid);
+  
+  if ( control_word & CW_Invalid )
+    {
+      /* The masked response */
+      FPU_copy_to_regi(&CONST_QNaN, TAG_Special, deststnr);
+    }
+  
+  return (!(control_word & CW_Invalid) ? FPU_Exception : 0) | TAG_Valid;
+
+}
+
+
+/* Divide a finite number by zero */
+asmlinkage int FPU_divide_by_zero(int deststnr, u_char sign)
+{
+  FPU_REG *dest = &st(deststnr);
+  int tag = TAG_Valid;
+
+  if ( control_word & CW_ZeroDiv )
+    {
+      /* The masked response */
+      FPU_copy_to_regi(&CONST_INF, TAG_Special, deststnr);
+      setsign(dest, sign);
+      tag = TAG_Special;
+    }
+ 
+  EXCEPTION(EX_ZeroDiv);
+
+  return (!(control_word & CW_ZeroDiv) ? FPU_Exception : 0) | tag;
+
+}
+
+
+/* This may be called often, so keep it lean */
+int set_precision_flag(int flags)
+{
+  if ( control_word & CW_Precision )
+    {
+      partial_status &= ~(SW_C1 & flags);
+      partial_status |= flags;   /* The masked response */
+      return 0;
+    }
+  else
+    {
+      EXCEPTION(flags);
+      return 1;
+    }
+}
+
+
+/* This may be called often, so keep it lean */
+asmlinkage void set_precision_flag_up(void)
+{
+  if ( control_word & CW_Precision )
+    partial_status |= (SW_Precision | SW_C1);   /* The masked response */
+  else
+    EXCEPTION(EX_Precision | SW_C1);
+}
+
+
+/* This may be called often, so keep it lean */
+asmlinkage void set_precision_flag_down(void)
+{
+  if ( control_word & CW_Precision )
+    {   /* The masked response */
+      partial_status &= ~SW_C1;
+      partial_status |= SW_Precision;
+    }
+  else
+    EXCEPTION(EX_Precision);
+}
+
+
+asmlinkage int denormal_operand(void)
+{
+  if ( control_word & CW_Denormal )
+    {   /* The masked response */
+      partial_status |= SW_Denorm_Op;
+      return TAG_Special;
+    }
+  else
+    {
+      EXCEPTION(EX_Denormal);
+      return TAG_Special | FPU_Exception;
+    }
+}
+
+
+asmlinkage int arith_overflow(FPU_REG *dest)
+{
+  int tag = TAG_Valid;
+
+  if ( control_word & CW_Overflow )
+    {
+      /* The masked response */
+/* ###### The response here depends upon the rounding mode */
+      reg_copy(&CONST_INF, dest);
+      tag = TAG_Special;
+    }
+  else
+    {
+      /* Subtract the magic number from the exponent */
+      addexponent(dest, (-3 * (1 << 13)));
+    }
+
+  EXCEPTION(EX_Overflow);
+  if ( control_word & CW_Overflow )
+    {
+      /* The overflow exception is masked. */
+      /* By definition, precision is lost.
+         The roundup bit (C1) is also set because we have
+         "rounded" upwards to Infinity. */
+      EXCEPTION(EX_Precision | SW_C1);
+      return tag;
+    }
+
+  return tag;
+
+}
+
+
+asmlinkage int arith_underflow(FPU_REG *dest)
+{
+  int tag = TAG_Valid;
+
+  if ( control_word & CW_Underflow )
+    {
+      /* The masked response */
+      if ( exponent16(dest) <= EXP_UNDER - 63 )
+        {
+          reg_copy(&CONST_Z, dest);
+          partial_status &= ~SW_C1;       /* Round down. */
+          tag = TAG_Zero;
+        }
+      else
+        {
+          stdexp(dest);
+        }
+    }
+  else
+    {
+      /* Add the magic number to the exponent. */
+      addexponent(dest, (3 * (1 << 13)) + EXTENDED_Ebias);
+    }
+
+  EXCEPTION(EX_Underflow);
+  if ( control_word & CW_Underflow )
+    {
+      /* The underflow exception is masked. */
+      EXCEPTION(EX_Precision);
+      return tag;
+    }
+
+  return tag;
+
+}
+
+
+void FPU_stack_overflow(void)
+{
+
+ if ( control_word & CW_Invalid )
+    {
+      /* The masked response */
+      top--;
+      FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
+    }
+
+  EXCEPTION(EX_StackOver);
+
+  return;
+
+}
+
+
+void FPU_stack_underflow(void)
+{
+
+ if ( control_word & CW_Invalid )
+    {
+      /* The masked response */
+      FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
+    }
+
+  EXCEPTION(EX_StackUnder);
+
+  return;
+
+}
+
+
+void FPU_stack_underflow_i(int i)
+{
+
+ if ( control_word & CW_Invalid )
+    {
+      /* The masked response */
+      FPU_copy_to_regi(&CONST_QNaN, TAG_Special, i);
+    }
+
+  EXCEPTION(EX_StackUnder);
+
+  return;
+
+}
+
+
+void FPU_stack_underflow_pop(int i)
+{
+
+ if ( control_word & CW_Invalid )
+    {
+      /* The masked response */
+      FPU_copy_to_regi(&CONST_QNaN, TAG_Special, i);
+      FPU_pop();
+    }
+
+  EXCEPTION(EX_StackUnder);
+
+  return;
+
+}
+