i386: move math-emu

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 438 insertions, 0 deletions

diff --git a/arch/x86/math-emu/get_address.c b/arch/x86/math-emu/get_address.c
new file mode 100644
index 0000000..2e2c51a
--- /dev/null
+++ b/arch/x86/math-emu/get_address.c
@@ -0,0 +1,438 @@
+/*---------------------------------------------------------------------------+
+ |  get_address.c                                                            |
+ |                                                                           |
+ | Get the effective address from an FPU instruction.                        |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1994,1997                                         |
+ |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
+ |                       Australia.  E-mail   billm@suburbia.net             |
+ |                                                                           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------+
+ | 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/stddef.h>
+
+#include <asm/uaccess.h>
+#include <asm/desc.h>
+
+#include "fpu_system.h"
+#include "exception.h"
+#include "fpu_emu.h"
+
+
+#define FPU_WRITE_BIT 0x10
+
+static int reg_offset[] = {
+	offsetof(struct info,___eax),
+	offsetof(struct info,___ecx),
+	offsetof(struct info,___edx),
+	offsetof(struct info,___ebx),
+	offsetof(struct info,___esp),
+	offsetof(struct info,___ebp),
+	offsetof(struct info,___esi),
+	offsetof(struct info,___edi)
+};
+
+#define REG_(x) (*(long *)(reg_offset[(x)]+(u_char *) FPU_info))
+
+static int reg_offset_vm86[] = {
+	offsetof(struct info,___cs),
+	offsetof(struct info,___vm86_ds),
+	offsetof(struct info,___vm86_es),
+	offsetof(struct info,___vm86_fs),
+	offsetof(struct info,___vm86_gs),
+	offsetof(struct info,___ss),
+	offsetof(struct info,___vm86_ds)
+      };
+
+#define VM86_REG_(x) (*(unsigned short *) \
+		      (reg_offset_vm86[((unsigned)x)]+(u_char *) FPU_info))
+
+/* This dummy, gs is not saved on the stack. */
+#define ___GS ___ds
+
+static int reg_offset_pm[] = {
+	offsetof(struct info,___cs),
+	offsetof(struct info,___ds),
+	offsetof(struct info,___es),
+	offsetof(struct info,___fs),
+	offsetof(struct info,___GS),
+	offsetof(struct info,___ss),
+	offsetof(struct info,___ds)
+      };
+
+#define PM_REG_(x) (*(unsigned short *) \
+		      (reg_offset_pm[((unsigned)x)]+(u_char *) FPU_info))
+
+
+/* Decode the SIB byte. This function assumes mod != 0 */
+static int sib(int mod, unsigned long *fpu_eip)
+{
+  u_char ss,index,base;
+  long offset;
+
+  RE_ENTRANT_CHECK_OFF;
+  FPU_code_access_ok(1);
+  FPU_get_user(base, (u_char __user *) (*fpu_eip));   /* The SIB byte */
+  RE_ENTRANT_CHECK_ON;
+  (*fpu_eip)++;
+  ss = base >> 6;
+  index = (base >> 3) & 7;
+  base &= 7;
+
+  if ((mod == 0) && (base == 5))
+    offset = 0;              /* No base register */
+  else
+    offset = REG_(base);
+
+  if (index == 4)
+    {
+      /* No index register */
+      /* A non-zero ss is illegal */
+      if ( ss )
+	EXCEPTION(EX_Invalid);
+    }
+  else
+    {
+      offset += (REG_(index)) << ss;
+    }
+
+  if (mod == 1)
+    {
+      /* 8 bit signed displacement */
+      long displacement;
+      RE_ENTRANT_CHECK_OFF;
+      FPU_code_access_ok(1);
+      FPU_get_user(displacement, (signed char __user *) (*fpu_eip));
+      offset += displacement;
+      RE_ENTRANT_CHECK_ON;
+      (*fpu_eip)++;
+    }
+  else if (mod == 2 || base == 5) /* The second condition also has mod==0 */
+    {
+      /* 32 bit displacement */
+      long displacement;
+      RE_ENTRANT_CHECK_OFF;
+      FPU_code_access_ok(4);
+      FPU_get_user(displacement, (long __user *) (*fpu_eip));
+      offset += displacement;
+      RE_ENTRANT_CHECK_ON;
+      (*fpu_eip) += 4;
+    }
+
+  return offset;
+}
+
+
+static unsigned long vm86_segment(u_char segment,
+				  struct address *addr)
+{
+  segment--;
+#ifdef PARANOID
+  if ( segment > PREFIX_SS_ )
+    {
+      EXCEPTION(EX_INTERNAL|0x130);
+      math_abort(FPU_info,SIGSEGV);
+    }
+#endif /* PARANOID */
+  addr->selector = VM86_REG_(segment);
+  return (unsigned long)VM86_REG_(segment) << 4;
+}
+
+
+/* This should work for 16 and 32 bit protected mode. */
+static long pm_address(u_char FPU_modrm, u_char segment,
+		       struct address *addr, long offset)
+{ 
+  struct desc_struct descriptor;
+  unsigned long base_address, limit, address, seg_top;
+
+  segment--;
+
+#ifdef PARANOID
+  /* segment is unsigned, so this also detects if segment was 0: */
+  if ( segment > PREFIX_SS_ )
+    {
+      EXCEPTION(EX_INTERNAL|0x132);
+      math_abort(FPU_info,SIGSEGV);
+    }
+#endif /* PARANOID */
+
+  switch ( segment )
+    {
+      /* gs isn't used by the kernel, so it still has its
+	 user-space value. */
+    case PREFIX_GS_-1:
+      /* N.B. - movl %seg, mem is a 2 byte write regardless of prefix */
+      savesegment(gs, addr->selector);
+      break;
+    default:
+      addr->selector = PM_REG_(segment);
+    }
+
+  descriptor = LDT_DESCRIPTOR(PM_REG_(segment));
+  base_address = SEG_BASE_ADDR(descriptor);
+  address = base_address + offset;
+  limit = base_address
+	+ (SEG_LIMIT(descriptor)+1) * SEG_GRANULARITY(descriptor) - 1;
+  if ( limit < base_address ) limit = 0xffffffff;
+
+  if ( SEG_EXPAND_DOWN(descriptor) )
+    {
+      if ( SEG_G_BIT(descriptor) )
+	seg_top = 0xffffffff;
+      else
+	{
+	  seg_top = base_address + (1 << 20);
+	  if ( seg_top < base_address ) seg_top = 0xffffffff;
+	}
+      access_limit =
+	(address <= limit) || (address >= seg_top) ? 0 :
+	  ((seg_top-address) >= 255 ? 255 : seg_top-address);
+    }
+  else
+    {
+      access_limit =
+	(address > limit) || (address < base_address) ? 0 :
+	  ((limit-address) >= 254 ? 255 : limit-address+1);
+    }
+  if ( SEG_EXECUTE_ONLY(descriptor) ||
+      (!SEG_WRITE_PERM(descriptor) && (FPU_modrm & FPU_WRITE_BIT)) )
+    {
+      access_limit = 0;
+    }
+  return address;
+}
+
+
+/*
+       MOD R/M byte:  MOD == 3 has a special use for the FPU
+                      SIB byte used iff R/M = 100b
+
+       7   6   5   4   3   2   1   0
+       .....   .........   .........
+        MOD    OPCODE(2)     R/M
+
+
+       SIB byte
+
+       7   6   5   4   3   2   1   0
+       .....   .........   .........
+        SS      INDEX        BASE
+
+*/
+
+void __user *FPU_get_address(u_char FPU_modrm, unsigned long *fpu_eip,
+		  struct address *addr,
+		  fpu_addr_modes addr_modes)
+{
+  u_char mod;
+  unsigned rm = FPU_modrm & 7;
+  long *cpu_reg_ptr;
+  int address = 0;     /* Initialized just to stop compiler warnings. */
+
+  /* Memory accessed via the cs selector is write protected
+     in `non-segmented' 32 bit protected mode. */
+  if ( !addr_modes.default_mode && (FPU_modrm & FPU_WRITE_BIT)
+      && (addr_modes.override.segment == PREFIX_CS_) )
+    {
+      math_abort(FPU_info,SIGSEGV);
+    }
+
+  addr->selector = FPU_DS;   /* Default, for 32 bit non-segmented mode. */
+
+  mod = (FPU_modrm >> 6) & 3;
+
+  if (rm == 4 && mod != 3)
+    {
+      address = sib(mod, fpu_eip);
+    }
+  else
+    {
+      cpu_reg_ptr = & REG_(rm);
+      switch (mod)
+	{
+	case 0:
+	  if (rm == 5)
+	    {
+	      /* Special case: disp32 */
+	      RE_ENTRANT_CHECK_OFF;
+	      FPU_code_access_ok(4);
+	      FPU_get_user(address, (unsigned long __user *) (*fpu_eip));
+	      (*fpu_eip) += 4;
+	      RE_ENTRANT_CHECK_ON;
+	      addr->offset = address;
+	      return (void __user *) address;
+	    }
+	  else
+	    {
+	      address = *cpu_reg_ptr;  /* Just return the contents
+					  of the cpu register */
+	      addr->offset = address;
+	      return (void __user *) address;
+	    }
+	case 1:
+	  /* 8 bit signed displacement */
+	  RE_ENTRANT_CHECK_OFF;
+	  FPU_code_access_ok(1);
+	  FPU_get_user(address, (signed char __user *) (*fpu_eip));
+	  RE_ENTRANT_CHECK_ON;
+	  (*fpu_eip)++;
+	  break;
+	case 2:
+	  /* 32 bit displacement */
+	  RE_ENTRANT_CHECK_OFF;
+	  FPU_code_access_ok(4);
+	  FPU_get_user(address, (long __user *) (*fpu_eip));
+	  (*fpu_eip) += 4;
+	  RE_ENTRANT_CHECK_ON;
+	  break;
+	case 3:
+	  /* Not legal for the FPU */
+	  EXCEPTION(EX_Invalid);
+	}
+      address += *cpu_reg_ptr;
+    }
+
+  addr->offset = address;
+
+  switch ( addr_modes.default_mode )
+    {
+    case 0:
+      break;
+    case VM86:
+      address += vm86_segment(addr_modes.override.segment, addr);
+      break;
+    case PM16:
+    case SEG32:
+      address = pm_address(FPU_modrm, addr_modes.override.segment,
+			   addr, address);
+      break;
+    default:
+      EXCEPTION(EX_INTERNAL|0x133);
+    }
+
+  return (void __user *)address;
+}
+
+
+void __user *FPU_get_address_16(u_char FPU_modrm, unsigned long *fpu_eip,
+		     struct address *addr,
+		     fpu_addr_modes addr_modes)
+{
+  u_char mod;
+  unsigned rm = FPU_modrm & 7;
+  int address = 0;     /* Default used for mod == 0 */
+
+  /* Memory accessed via the cs selector is write protected
+     in `non-segmented' 32 bit protected mode. */
+  if ( !addr_modes.default_mode && (FPU_modrm & FPU_WRITE_BIT)
+      && (addr_modes.override.segment == PREFIX_CS_) )
+    {
+      math_abort(FPU_info,SIGSEGV);
+    }
+
+  addr->selector = FPU_DS;   /* Default, for 32 bit non-segmented mode. */
+
+  mod = (FPU_modrm >> 6) & 3;
+
+  switch (mod)
+    {
+    case 0:
+      if (rm == 6)
+	{
+	  /* Special case: disp16 */
+	  RE_ENTRANT_CHECK_OFF;
+	  FPU_code_access_ok(2);
+	  FPU_get_user(address, (unsigned short __user *) (*fpu_eip));
+	  (*fpu_eip) += 2;
+	  RE_ENTRANT_CHECK_ON;
+	  goto add_segment;
+	}
+      break;
+    case 1:
+      /* 8 bit signed displacement */
+      RE_ENTRANT_CHECK_OFF;
+      FPU_code_access_ok(1);
+      FPU_get_user(address, (signed char __user *) (*fpu_eip));
+      RE_ENTRANT_CHECK_ON;
+      (*fpu_eip)++;
+      break;
+    case 2:
+      /* 16 bit displacement */
+      RE_ENTRANT_CHECK_OFF;
+      FPU_code_access_ok(2);
+      FPU_get_user(address, (unsigned short __user *) (*fpu_eip));
+      (*fpu_eip) += 2;
+      RE_ENTRANT_CHECK_ON;
+      break;
+    case 3:
+      /* Not legal for the FPU */
+      EXCEPTION(EX_Invalid);
+      break;
+    }
+  switch ( rm )
+    {
+    case 0:
+      address += FPU_info->___ebx + FPU_info->___esi;
+      break;
+    case 1:
+      address += FPU_info->___ebx + FPU_info->___edi;
+      break;
+    case 2:
+      address += FPU_info->___ebp + FPU_info->___esi;
+      if ( addr_modes.override.segment == PREFIX_DEFAULT )
+	addr_modes.override.segment = PREFIX_SS_;
+      break;
+    case 3:
+      address += FPU_info->___ebp + FPU_info->___edi;
+      if ( addr_modes.override.segment == PREFIX_DEFAULT )
+	addr_modes.override.segment = PREFIX_SS_;
+      break;
+    case 4:
+      address += FPU_info->___esi;
+      break;
+    case 5:
+      address += FPU_info->___edi;
+      break;
+    case 6:
+      address += FPU_info->___ebp;
+      if ( addr_modes.override.segment == PREFIX_DEFAULT )
+	addr_modes.override.segment = PREFIX_SS_;
+      break;
+    case 7:
+      address += FPU_info->___ebx;
+      break;
+    }
+
+ add_segment:
+  address &= 0xffff;
+
+  addr->offset = address;
+
+  switch ( addr_modes.default_mode )
+    {
+    case 0:
+      break;
+    case VM86:
+      address += vm86_segment(addr_modes.override.segment, addr);
+      break;
+    case PM16:
+    case SEG32:
+      address = pm_address(FPU_modrm, addr_modes.override.segment,
+			   addr, address);
+      break;
+    default:
+      EXCEPTION(EX_INTERNAL|0x131);
+    }
+
+  return (void __user *)address ;
+}