* config/tc-mips.c (mips_fix_loongson2f, mips_fix_loongson2f_nop,

mips_fix_loongson2f_jump): New variables.
        (md_longopts): Add New options -mfix-loongson2f-nop/jump,
        -mno-fix-loongson2f-nop/jump.
        (md_parse_option): Initialize variables via above options.
        (options): New enums for the above options.
        (md_begin): Initialize nop_insn from LOONGSON2F_NOP_INSN.
        (fix_loongson2f, fix_loongson2f_nop, fix_loongson2f_jump):
        New functions.
        (append_insn): call fix_loongson2f().
        (mips_handle_align): Replace the implicit nops.
        * config/tc-mips.h (MAX_MEM_FOR_RS_ALIGN_CODE): Modified
        for the new mips_handle_align().
        * doc/c-mips.texi: Document the new options.

        * gas/mips/loongson-2f-2.s: New test of -mfix-loongson2f-nop.
        * gas/mips/loongson-2f-2.d: Likewise.
        * gas/mips/loongson-2f-3.s: New test of -mfix-loongson2f-jump.
        * gas/mips/loongson-2f-3.d: Likewise.
        * gas/mips/mips.exp: Run the new tests.

        * opcode/mips.h (LOONGSON2F_NOP_INSN): New macro.

gas/ChangeLog

@@ -1,3 +1,20 @@
+2010-02-25  Wu Zhangjin <wuzhangjin@gmail.com>
+
+	* config/tc-mips.c (mips_fix_loongson2f, mips_fix_loongson2f_nop,
+	mips_fix_loongson2f_jump): New variables.
+	(md_longopts): Add New options -mfix-loongson2f-nop/jump,
+	-mno-fix-loongson2f-nop/jump.
+	(md_parse_option): Initialize variables via above options.
+	(options): New enums for the above options.
+	(md_begin): Initialize nop_insn from LOONGSON2F_NOP_INSN.
+	(fix_loongson2f, fix_loongson2f_nop, fix_loongson2f_jump):
+	New functions.
+	(append_insn): call fix_loongson2f().
+	(mips_handle_align): Replace the implicit nops.
+	* config/tc-mips.h (MAX_MEM_FOR_RS_ALIGN_CODE): Modified
+	for the new mips_handle_align().
+	* doc/c-mips.texi: Document the new options.
+
 2010-02-23  Daniel Gutson  <dgutson@codesourcery.com>
 
 	* config/tc-arm.c (do_rd_rm_rn): Added warning

gas/config/tc-mips.c

@@ -1,6 +1,7 @@
 /* tc-mips.c -- assemble code for a MIPS chip.
    Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
-   2003, 2004, 2005, 2006, 2007, 2008, 2009  Free Software Foundation, Inc.
+   2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   Free Software Foundation, Inc.
    Contributed by the OSF and Ralph Campbell.
    Written by Keith Knowles and Ralph Campbell, working independently.
    Modified for ECOFF and R4000 support by Ian Lance Taylor of Cygnus
@@ -751,7 +752,8 @@ static const unsigned int mips16_to_32_reg_map[] =
 
 /* Classifies the kind of instructions we're interested in when
    implementing -mfix-vr4120.  */
-enum fix_vr4120_class {
+enum fix_vr4120_class
+{
   FIX_VR4120_MACC,
   FIX_VR4120_DMACC,
   FIX_VR4120_MULT,
@@ -761,6 +763,15 @@ enum fix_vr4120_class {
   NUM_FIX_VR4120_CLASSES
 };
 
+/* ...likewise -mfix-loongson2f-jump.  */
+static bfd_boolean mips_fix_loongson2f_jump;
+
+/* ...likewise -mfix-loongson2f-nop.  */
+static bfd_boolean mips_fix_loongson2f_nop;
+
+/* True if -mfix-loongson2f-nop or -mfix-loongson2f-jump passed.  */
+static bfd_boolean mips_fix_loongson2f;
+
 /* Given two FIX_VR4120_* values X and Y, bit Y of element X is set if
    there must be at least one other instruction between an instruction
    of type X and an instruction of type Y.  */
@@ -1048,8 +1059,9 @@ static struct {
 enum mips_regclass { MIPS_GR_REG, MIPS_FP_REG, MIPS16_REG };
 
 static void append_insn
-  (struct mips_cl_insn *ip, expressionS *p, bfd_reloc_code_real_type *r);
+  (struct mips_cl_insn *, expressionS *, bfd_reloc_code_real_type *);
 static void mips_no_prev_insn (void);
+static void macro_build (expressionS *, const char *, const char *, ...);
 static void mips16_macro_build
   (expressionS *, const char *, const char *, va_list);
 static void load_register (int, expressionS *, int);
@@ -1918,6 +1930,8 @@ md_begin (void)
 	      if (nop_insn.insn_mo == NULL && strcmp (name, "nop") == 0)
 		{
 		  create_insn (&nop_insn, mips_opcodes + i);
+		  if (mips_fix_loongson2f_nop)
+		    nop_insn.insn_opcode = LOONGSON2F_NOP_INSN;
 		  nop_insn.fixed_p = 1;
 		}
 	    }
@@ -2731,6 +2745,54 @@ nops_for_insn_or_target (const struct mips_cl_insn *hist,
   return nops;
 }
 
+/* Fix NOP issue: Replace nops by "or at,at,zero".  */
+
+static void
+fix_loongson2f_nop (struct mips_cl_insn * ip)
+{
+  if (strcmp (ip->insn_mo->name, "nop") == 0)
+    ip->insn_opcode = LOONGSON2F_NOP_INSN;
+}
+
+/* Fix Jump Issue: Eliminate instruction fetch from outside 256M region
+                   jr target pc &= 'hffff_ffff_cfff_ffff.  */
+
+static void
+fix_loongson2f_jump (struct mips_cl_insn * ip)
+{
+  if (strcmp (ip->insn_mo->name, "j") == 0
+      || strcmp (ip->insn_mo->name, "jr") == 0
+      || strcmp (ip->insn_mo->name, "jalr") == 0)
+    {
+      int sreg;
+      expressionS ep;
+
+      if (! mips_opts.at)
+        return;
+
+      sreg = EXTRACT_OPERAND (RS, *ip);
+      if (sreg == ZERO || sreg == KT0 || sreg == KT1 || sreg == ATREG)
+        return;
+
+      ep.X_op = O_constant;
+      ep.X_add_number = 0xcfff0000;
+      macro_build (&ep, "lui", "t,u", ATREG, BFD_RELOC_HI16);
+      ep.X_add_number = 0xffff;
+      macro_build (&ep, "ori", "t,r,i", ATREG, ATREG, BFD_RELOC_LO16);
+      macro_build (NULL, "and", "d,v,t", sreg, sreg, ATREG);
+    }
+}
+
+static void
+fix_loongson2f (struct mips_cl_insn * ip)
+{
+  if (mips_fix_loongson2f_nop)
+    fix_loongson2f_nop (ip);
+
+  if (mips_fix_loongson2f_jump)
+    fix_loongson2f_jump (ip);
+}
+
 /* Output an instruction.  IP is the instruction information.
    ADDRESS_EXPR is an operand of the instruction to be used with
    RELOC_TYPE.  */
@@ -2744,6 +2806,9 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
   bfd_boolean relaxed_branch = FALSE;
   segment_info_type *si = seg_info (now_seg);
 
+  if (mips_fix_loongson2f)
+    fix_loongson2f (ip);
+
   /* Mark instruction labels in mips16 mode.  */
   mips16_mark_labels ();
 
@@ -11216,6 +11281,10 @@ enum options
     OPTION_MNO_7000_HILO_FIX, 
     OPTION_FIX_24K,
     OPTION_NO_FIX_24K,
+    OPTION_FIX_LOONGSON2F_JUMP,
+    OPTION_NO_FIX_LOONGSON2F_JUMP,
+    OPTION_FIX_LOONGSON2F_NOP,
+    OPTION_NO_FIX_LOONGSON2F_NOP,
     OPTION_FIX_VR4120,
     OPTION_NO_FIX_VR4120,
     OPTION_FIX_VR4130,
@@ -11304,6 +11373,10 @@ struct option md_longopts[] =
   {"mfix7000", no_argument, NULL, OPTION_M7000_HILO_FIX},
   {"no-fix-7000", no_argument, NULL, OPTION_MNO_7000_HILO_FIX},
   {"mno-fix7000", no_argument, NULL, OPTION_MNO_7000_HILO_FIX},
+  {"mfix-loongson2f-jump", no_argument, NULL, OPTION_FIX_LOONGSON2F_JUMP},
+  {"mno-fix-loongson2f-jump", no_argument, NULL, OPTION_NO_FIX_LOONGSON2F_JUMP},
+  {"mfix-loongson2f-nop", no_argument, NULL, OPTION_FIX_LOONGSON2F_NOP},
+  {"mno-fix-loongson2f-nop", no_argument, NULL, OPTION_NO_FIX_LOONGSON2F_NOP},
   {"mfix-vr4120",    no_argument, NULL, OPTION_FIX_VR4120},
   {"mno-fix-vr4120", no_argument, NULL, OPTION_NO_FIX_VR4120},
   {"mfix-vr4130",    no_argument, NULL, OPTION_FIX_VR4130},
@@ -11571,6 +11644,22 @@ md_parse_option (int c, char *arg)
       mips_fix_24k = 0;
       break;
 
+    case OPTION_FIX_LOONGSON2F_JUMP:
+      mips_fix_loongson2f_jump = TRUE;
+      break;
+
+    case OPTION_NO_FIX_LOONGSON2F_JUMP:
+      mips_fix_loongson2f_jump = FALSE;
+      break;
+
+    case OPTION_FIX_LOONGSON2F_NOP:
+      mips_fix_loongson2f_nop = TRUE;
+      break;
+
+    case OPTION_NO_FIX_LOONGSON2F_NOP:
+      mips_fix_loongson2f_nop = FALSE;
+      break;
+
     case OPTION_FIX_VR4120:
       mips_fix_vr4120 = 1;
       break;
@@ -11785,6 +11874,8 @@ md_parse_option (int c, char *arg)
       return 0;
     }
 
+    mips_fix_loongson2f = mips_fix_loongson2f_nop || mips_fix_loongson2f_jump;
+
   return 1;
 }
 
@@ -14790,6 +14881,8 @@ void
 mips_handle_align (fragS *fragp)
 {
   char *p;
+  int bytes, size, excess;
+  valueT opcode;
 
   if (fragp->fr_type != rs_align_code)
     return;
@@ -14797,17 +14890,28 @@ mips_handle_align (fragS *fragp)
   p = fragp->fr_literal + fragp->fr_fix;
   if (*p)
     {
-      int bytes;
+      opcode = mips16_nop_insn.insn_opcode;
-
+      size = 2;
-      bytes = fragp->fr_next->fr_address - fragp->fr_address - fragp->fr_fix;
-      if (bytes & 1)
-	{
-	  *p++ = 0;
-	  fragp->fr_fix++;
-	}
-      md_number_to_chars (p, mips16_nop_insn.insn_opcode, 2);
-      fragp->fr_var = 2;
     }
+  else
+    {
+      opcode = nop_insn.insn_opcode;
+      size = 4;
+    }
+
+  bytes = fragp->fr_next->fr_address - fragp->fr_address - fragp->fr_fix;
+  excess = bytes % size;
+  if (excess != 0)
+    {
+      /* If we're not inserting a whole number of instructions,
+	 pad the end of the fixed part of the frag with zeros.  */
+      memset (p, 0, excess);
+      p += excess;
+      fragp->fr_fix += excess;
+    }
+
+  md_number_to_chars (p, opcode, size);
+  fragp->fr_var = size;
 }
 
 static void
@@ -15519,6 +15623,8 @@ MIPS options:\n\
 -mmt			generate MT instructions\n\
 -mno-mt			do not generate MT instructions\n"));
   fprintf (stream, _("\
+-mfix-loongson2f-jump	work around Loongson2F JUMP instructions\n\
+-mfix-loongson2f-nop	work around Loongson2F NOP errata\n\
 -mfix-vr4120		work around certain VR4120 errata\n\
 -mfix-vr4130		work around VR4130 mflo/mfhi errata\n\
 -mfix-24k		insert a nop after ERET and DERET instructions\n\

gas/config/tc-mips.h

@@ -1,6 +1,6 @@
 /* tc-mips.h -- header file for tc-mips.c.
    Copyright 1993, 1994, 1995, 1996, 1997, 2000, 2001, 2002, 2003, 2004,
-   2005, 2006, 2007, 2008  Free Software Foundation, Inc.
+   2005, 2006, 2007, 2008, 2009, 2010  Free Software Foundation, Inc.
    Contributed by the OSF and Ralph Campbell.
    Written by Keith Knowles and Ralph Campbell, working independently.
    Modified for ECOFF support by Ian Lance Taylor of Cygnus Support.
@@ -59,7 +59,7 @@ extern char mips_nop_opcode (void);
 extern void mips_handle_align (struct frag *);
 #define HANDLE_ALIGN(fragp)  mips_handle_align (fragp)
 
-#define MAX_MEM_FOR_RS_ALIGN_CODE  (1 + 2)
+#define MAX_MEM_FOR_RS_ALIGN_CODE  (3 + 4)
 
 struct insn_label_list;
 struct mips_segment_info {

gas/doc/c-mips.texi

@@ -1,5 +1,5 @@
 @c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 1999, 2000, 2001,
-@c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+@c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
 @c Free Software Foundation, Inc.
 @c This is part of the GAS manual.
 @c For copying conditions, see the file as.texinfo.
@@ -78,7 +78,7 @@ VxWorks-style position-independent macro expansions.
 @itemx -mips2
 @itemx -mips3
 @itemx -mips4
-@itemx -mips5
+@itemx -mips5xo
 @itemx -mips32
 @itemx -mips32r2
 @itemx -mips64
@@ -172,6 +172,20 @@ This tells the assembler to accept MT instructions.
 Cause nops to be inserted if the read of the destination register
 of an mfhi or mflo instruction occurs in the following two instructions.
 
+@item -mfix-loongson2f-jump
+@itemx -mno-fix-loongson2f-jump
+Eliminate instruction fetch from outside 256M region to work around the
+Loongson2F @samp{jump} instructions.  Without it, under extreme cases,
+the kernel may crash.  The issue has been solved in latest processor
+batches, but this fix has no side effect to them.
+
+@item -mfix-loongson2f-nop
+@itemx -mno-fix-loongson2f-nop
+Replace nops by @code{or at,at,zero} to work around the Loongson2F
+@samp{nop} errata.  Without it, under extreme cases, cpu might
+deadlock.  The issue has been solved in latest loongson2f batches, but
+this fix has no side effect to them.
+
 @item -mfix-vr4120
 @itemx -mno-fix-vr4120
 Insert nops to work around certain VR4120 errata.  This option is

gas/testsuite/ChangeLog

@@ -1,3 +1,11 @@
+2010-02-25  Wu Zhangjin  <wuzhangjin@gmail.com>
+
+	* gas/mips/loongson-2f-2.s: New test of -mfix-loongson2f-nop.
+	* gas/mips/loongson-2f-2.d: Likewise.
+	* gas/mips/loongson-2f-3.s: New test of -mfix-loongson2f-jump.
+	* gas/mips/loongson-2f-3.d: Likewise.
+	* gas/mips/mips.exp: Run the new tests.
+
 2010-02-24  Nick Clifton  <nickc@redhat.com>
 
 	PR binutils/6773

gas/testsuite/gas/mips/loongson-2f-2.d

@@ -0,0 +1,18 @@
+#as: -mfix-loongson2f-nop
+#objdump: -M reg-names=numeric -dr
+#name: ST Microelectronics Loongson-2F workarounds of nop issue 
+
+.*:     file format .*
+
+
+Disassembly of section .text:
+
+00000000 <loongson2f_nop_insn>:
+   0:	00200825 	move	\$1,\$1
+   4:	00200825 	move	\$1,\$1
+   8:	00200825 	move	\$1,\$1
+   c:	00200825 	move	\$1,\$1
+  10:	00200825 	move	\$1,\$1
+  14:	00200825 	move	\$1,\$1
+  18:	00200825 	move	\$1,\$1
+  1c:	00200825 	move	\$1,\$1

gas/testsuite/gas/mips/loongson-2f-2.s

@@ -0,0 +1,10 @@
+# Test the work around of the NOP issue of loongson2F
+	.text
+	.set noreorder
+
+	.align 5	# Test _implicit_ nops
+loongson2f_nop_insn:
+	nop		# Test _explicit_ nops
+
+# align section end to 16-byte boundary for easier testing on multiple targets
+	.p2align 4

gas/testsuite/gas/mips/loongson-2f-3.d

@@ -0,0 +1,35 @@
+#as: -mfix-loongson2f-jump
+#objdump: -M reg-names=numeric -dr
+#name: ST Microelectronics Loongson-2F workarounds of Jump Instruction issue 
+
+.*:     file format .*
+
+
+Disassembly of section .text:
+
+00000000 <.text>:
+   0:	3c01cfff 	lui	\$1,0xcfff
+   4:	3421ffff 	ori	\$1,\$1,0xffff
+   8:	03c1f024 	and	\$30,\$30,\$1
+   c:	03c00008 	jr	\$30
+  10:	00000000 	nop
+
+  14:	3c01cfff 	lui	\$1,0xcfff
+  18:	3421ffff 	ori	\$1,\$1,0xffff
+  1c:	03e1f824 	and	\$31,\$31,\$1
+  20:	03e00008 	jr	\$31
+  24:	00000000 	nop
+
+  28:	3c01cfff 	lui	\$1,0xcfff
+  2c:	3421ffff 	ori	\$1,\$1,0xffff
+  30:	03c1f024 	and	\$30,\$30,\$1
+  34:	03c0f809 	jalr	\$30
+  38:	00000000 	nop
+
+  3c:	00200008 	jr	\$1
+  40:	00000000 	nop
+
+  44:	08000000 	j	0x0
+			44: R_MIPS_26	external_label
+  48:	00000000 	nop
+  4c:	00000000 	nop

gas/testsuite/gas/mips/loongson-2f-3.s

@@ -0,0 +1,23 @@
+# Test the work around of the Jump instruction Issue of Loongson2F
+	.text
+	.set noreorder
+
+	j	$30	# j with register
+	 nop
+
+	jr	$31	# jr
+	 nop
+
+	jalr	$30	# jalr
+	 nop
+
+	.set	noat
+	jr	$1	# jr with at register and .set annotation
+ 	 nop
+	.set	at
+
+	j	external_label	# j with label
+	 nop
+
+# align section end to 16-byte boundary for easier testing on multiple targets
+	.p2align 4

gas/testsuite/gas/mips/mips.exp

@@ -789,6 +789,8 @@ if { [istarget mips*-*-vxworks*] } {
 
     run_dump_test "loongson-2e"
     run_dump_test "loongson-2f"
+    run_dump_test "loongson-2f-2"
+    run_dump_test "loongson-2f-3"
 
     run_dump_test_arches "octeon"	[mips_arch_list_matching octeon]
     run_list_test_arches "octeon-ill" "" \

include/opcode/ChangeLog

@@ -1,3 +1,7 @@
+2010-02-25  Wu Zhangjin  <wuzhangjin@gmail.com>
+
+	* mips.h: (LOONGSON2F_NOP_INSN): New macro.
+
 2010-02-08  Philipp Tomsich  <philipp.tomsich@theobroma-systems.com>
 
 	* opcode/ppc.h (PPC_OPCODE_TITAN): Define.

include/opcode/mips.h

@@ -1,6 +1,6 @@
 /* mips.h.  Mips opcode list for GDB, the GNU debugger.
    Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
-   2003, 2004, 2005, 2008, 2009
+   2003, 2004, 2005, 2008, 2009, 2010
    Free Software Foundation, Inc.
    Contributed by Ralph Campbell and OSF
    Commented and modified by Ian Lance Taylor, Cygnus Support
@@ -1106,4 +1106,8 @@ extern int bfd_mips_num_opcodes;
 extern const struct mips_opcode mips16_opcodes[];
 extern const int bfd_mips16_num_opcodes;
 
+/* A NOP insn impemented as "or at,at,zero".
+   Used to implement -mfix-loongson2f.  */
+#define LOONGSON2F_NOP_INSN	0x00200825
+
 #endif /* _MIPS_H_ */