MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6
authorLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Wed, 3 Dec 2014 15:47:03 +0000 (15:47 +0000)
committerMarkos Chandras <markos.chandras@imgtec.com>
Tue, 17 Feb 2015 15:37:37 +0000 (15:37 +0000)
MIPS R6 removed quite a few R2 instructions. However, there
is plenty of <R6 userland code so we add an in-kernel emulator
so we can still be able to execute all R2 userland out there.

The emulator comes with a handy debugfs under /mips/ directory
(r2-emul-stats) to provide some basic statistics of the
instructions that are being emulated.

Below are some statistics from booting a minimal buildroot image:

Instruction     Total   BDslot
------------------------------
movs            236969  0
hilo            56686   0
muls            55279   0
divs            10941   0
dsps            0       0
bops            1       0
traps           0       0
fpus            0       0
loads           214981  17
stores          103364  0
llsc            56898   0
dsemul          150418  0
jr              370158
bltzl           43
bgezl           1594
bltzll          0
bgezll          0
bltzal          39
bgezal          39
beql            14503
bnel            138741
blezl           0
bgtzl           3988

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
arch/mips/Kconfig
arch/mips/include/asm/branch.h
arch/mips/include/asm/mips-r2-to-r6-emul.h [new file with mode: 0644]
arch/mips/kernel/Makefile
arch/mips/kernel/branch.c
arch/mips/kernel/mips-r2-to-r6-emul.c [new file with mode: 0644]
arch/mips/kernel/traps.c
arch/mips/math-emu/cp1emu.c

index 883eb3a..afa808a 100644 (file)
@@ -2063,6 +2063,19 @@ config MIPS_MT_FPAFF
        default y
        depends on MIPS_MT_SMP
 
+config MIPSR2_TO_R6_EMULATOR
+       bool "MIPS R2-to-R6 emulator"
+       depends on CPU_MIPSR6 && !SMP
+       default y
+       help
+         Choose this option if you want to run non-R6 MIPS userland code.
+         Even if you say 'Y' here, the emulator will still be disabled by
+         default. You can enable it using the 'mipsr2emul' kernel option.
+         The only reason this is a build-time option is to save ~14K from the
+         final kernel image.
+comment "MIPS R2-to-R6 emulator is only available for UP kernels"
+       depends on SMP && CPU_MIPSR6
+
 config MIPS_VPE_LOADER
        bool "VPE loader support."
        depends on SYS_SUPPORTS_MULTITHREADING && MODULES
index 2894ea5..de781cf 100644 (file)
@@ -13,9 +13,6 @@
 #include <asm/ptrace.h>
 #include <asm/inst.h>
 
-static int mipsr2_emulation = 0;
-#define NO_R6EMU       (cpu_has_mips_r6 && !mipsr2_emulation)
-
 extern int __isa_exception_epc(struct pt_regs *regs);
 extern int __compute_return_epc(struct pt_regs *regs);
 extern int __compute_return_epc_for_insn(struct pt_regs *regs,
diff --git a/arch/mips/include/asm/mips-r2-to-r6-emul.h b/arch/mips/include/asm/mips-r2-to-r6-emul.h
new file mode 100644 (file)
index 0000000..60570f2
--- /dev/null
@@ -0,0 +1,96 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2014 Imagination Technologies Ltd.
+ * Author: Markos Chandras <markos.chandras@imgtec.com>
+ */
+
+#ifndef __ASM_MIPS_R2_TO_R6_EMUL_H
+#define __ASM_MIPS_R2_TO_R6_EMUL_H
+
+struct mips_r2_emulator_stats {
+       u64 movs;
+       u64 hilo;
+       u64 muls;
+       u64 divs;
+       u64 dsps;
+       u64 bops;
+       u64 traps;
+       u64 fpus;
+       u64 loads;
+       u64 stores;
+       u64 llsc;
+       u64 dsemul;
+};
+
+struct mips_r2br_emulator_stats {
+       u64 jrs;
+       u64 bltzl;
+       u64 bgezl;
+       u64 bltzll;
+       u64 bgezll;
+       u64 bltzall;
+       u64 bgezall;
+       u64 bltzal;
+       u64 bgezal;
+       u64 beql;
+       u64 bnel;
+       u64 blezl;
+       u64 bgtzl;
+};
+
+#ifdef CONFIG_DEBUG_FS
+
+#define MIPS_R2_STATS(M)                                               \
+do {                                                                   \
+       u32 nir;                                                        \
+       int err;                                                        \
+                                                                       \
+       preempt_disable();                                              \
+       __this_cpu_inc(mipsr2emustats.M);                               \
+       err = __get_user(nir, (u32 __user *)regs->cp0_epc);             \
+       if (!err) {                                                     \
+               if (nir == BREAK_MATH)                                  \
+                       __this_cpu_inc(mipsr2bdemustats.M);             \
+       }                                                               \
+       preempt_enable();                                               \
+} while (0)
+
+#define MIPS_R2BR_STATS(M)                                     \
+do {                                                           \
+       preempt_disable();                                      \
+       __this_cpu_inc(mipsr2bremustats.M);                     \
+       preempt_enable();                                       \
+} while (0)
+
+#else
+
+#define MIPS_R2_STATS(M)          do { } while (0)
+#define MIPS_R2BR_STATS(M)        do { } while (0)
+
+#endif /* CONFIG_DEBUG_FS */
+
+struct r2_decoder_table {
+       u32     mask;
+       u32     code;
+       int     (*func)(struct pt_regs *regs, u32 inst);
+};
+
+
+extern void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
+                         const char *str);
+
+#ifndef CONFIG_MIPSR2_TO_R6_EMULATOR
+static int mipsr2_emulation;
+static __maybe_unused int mipsr2_decoder(struct pt_regs *regs, u32 inst) { return 0; };
+#else
+/* MIPS R2 Emulator ON/OFF */
+extern int mipsr2_emulation;
+extern int mipsr2_decoder(struct pt_regs *regs, u32 inst);
+#endif /* CONFIG_MIPSR2_TO_R6_EMULATOR */
+
+#define NO_R6EMU       (cpu_has_mips_r6 && !mipsr2_emulation)
+
+#endif /* __ASM_MIPS_R2_TO_R6_EMUL_H */
index de1e653..d3d2ff2 100644 (file)
@@ -90,6 +90,7 @@ obj-$(CONFIG_EARLY_PRINTK)    += early_printk.o
 obj-$(CONFIG_EARLY_PRINTK_8250)        += early_printk_8250.o
 obj-$(CONFIG_SPINLOCK_TEST)    += spinlock_test.o
 obj-$(CONFIG_MIPS_MACHINE)     += mips_machine.o
+obj-$(CONFIG_MIPSR2_TO_R6_EMULATOR)    += mips-r2-to-r6-emul.o
 
 CFLAGS_cpu-bugs64.o    = $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi -c -o /dev/null -x c /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
index 249c61c..c2e0f45 100644 (file)
@@ -16,6 +16,7 @@
 #include <asm/fpu.h>
 #include <asm/fpu_emulator.h>
 #include <asm/inst.h>
+#include <asm/mips-r2-to-r6-emul.h>
 #include <asm/ptrace.h>
 #include <asm/uaccess.h>
 
diff --git a/arch/mips/kernel/mips-r2-to-r6-emul.c b/arch/mips/kernel/mips-r2-to-r6-emul.c
new file mode 100644 (file)
index 0000000..64d17e4
--- /dev/null
@@ -0,0 +1,2378 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2014 Imagination Technologies Ltd.
+ * Author: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
+ * Author: Markos Chandras <markos.chandras@imgtec.com>
+ *
+ *      MIPS R2 user space instruction emulator for MIPS R6
+ *
+ */
+#include <linux/bug.h>
+#include <linux/compiler.h>
+#include <linux/debugfs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/ptrace.h>
+#include <linux/seq_file.h>
+
+#include <asm/asm.h>
+#include <asm/branch.h>
+#include <asm/break.h>
+#include <asm/fpu.h>
+#include <asm/fpu_emulator.h>
+#include <asm/inst.h>
+#include <asm/mips-r2-to-r6-emul.h>
+#include <asm/local.h>
+#include <asm/ptrace.h>
+#include <asm/uaccess.h>
+
+#ifdef CONFIG_64BIT
+#define ADDIU  "daddiu "
+#define INS    "dins "
+#define EXT    "dext "
+#else
+#define ADDIU  "addiu "
+#define INS    "ins "
+#define EXT    "ext "
+#endif /* CONFIG_64BIT */
+
+#define SB     "sb "
+#define LB     "lb "
+#define LL     "ll "
+#define SC     "sc "
+
+DEFINE_PER_CPU(struct mips_r2_emulator_stats, mipsr2emustats);
+DEFINE_PER_CPU(struct mips_r2_emulator_stats, mipsr2bdemustats);
+DEFINE_PER_CPU(struct mips_r2br_emulator_stats, mipsr2bremustats);
+
+extern const unsigned int fpucondbit[8];
+
+#define MIPS_R2_EMUL_TOTAL_PASS        10
+
+int mipsr2_emulation = 0;
+
+static int __init mipsr2emu_enable(char *s)
+{
+       mipsr2_emulation = 1;
+
+       pr_info("MIPS R2-to-R6 Emulator Enabled!");
+
+       return 1;
+}
+__setup("mipsr2emu", mipsr2emu_enable);
+
+/**
+ * mipsr6_emul - Emulate some frequent R2/R5/R6 instructions in delay slot
+ * for performance instead of the traditional way of using a stack trampoline
+ * which is rather slow.
+ * @regs: Process register set
+ * @ir: Instruction
+ */
+static inline int mipsr6_emul(struct pt_regs *regs, u32 ir)
+{
+       switch (MIPSInst_OPCODE(ir)) {
+       case addiu_op:
+               if (MIPSInst_RT(ir))
+                       regs->regs[MIPSInst_RT(ir)] =
+                               (s32)regs->regs[MIPSInst_RS(ir)] +
+                               (s32)MIPSInst_SIMM(ir);
+               return 0;
+       case daddiu_op:
+               if (config_enabled(CONFIG_32BIT))
+                       break;
+
+               if (MIPSInst_RT(ir))
+                       regs->regs[MIPSInst_RT(ir)] =
+                               (s64)regs->regs[MIPSInst_RS(ir)] +
+                               (s64)MIPSInst_SIMM(ir);
+               return 0;
+       case lwc1_op:
+       case swc1_op:
+       case cop1_op:
+       case cop1x_op:
+               /* FPU instructions in delay slot */
+               return -SIGFPE;
+       case spec_op:
+               switch (MIPSInst_FUNC(ir)) {
+               case or_op:
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       regs->regs[MIPSInst_RS(ir)] |
+                                       regs->regs[MIPSInst_RT(ir)];
+                       return 0;
+               case sll_op:
+                       if (MIPSInst_RS(ir))
+                               break;
+
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       (s32)(((u32)regs->regs[MIPSInst_RT(ir)]) <<
+                                               MIPSInst_FD(ir));
+                       return 0;
+               case srl_op:
+                       if (MIPSInst_RS(ir))
+                               break;
+
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       (s32)(((u32)regs->regs[MIPSInst_RT(ir)]) >>
+                                               MIPSInst_FD(ir));
+                       return 0;
+               case addu_op:
+                       if (MIPSInst_FD(ir))
+                               break;
+
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       (s32)((u32)regs->regs[MIPSInst_RS(ir)] +
+                                             (u32)regs->regs[MIPSInst_RT(ir)]);
+                       return 0;
+               case subu_op:
+                       if (MIPSInst_FD(ir))
+                               break;
+
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       (s32)((u32)regs->regs[MIPSInst_RS(ir)] -
+                                             (u32)regs->regs[MIPSInst_RT(ir)]);
+                       return 0;
+               case dsll_op:
+                       if (config_enabled(CONFIG_32BIT) || MIPSInst_RS(ir))
+                               break;
+
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       (s64)(((u64)regs->regs[MIPSInst_RT(ir)]) <<
+                                               MIPSInst_FD(ir));
+                       return 0;
+               case dsrl_op:
+                       if (config_enabled(CONFIG_32BIT) || MIPSInst_RS(ir))
+                               break;
+
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       (s64)(((u64)regs->regs[MIPSInst_RT(ir)]) >>
+                                               MIPSInst_FD(ir));
+                       return 0;
+               case daddu_op:
+                       if (config_enabled(CONFIG_32BIT) || MIPSInst_FD(ir))
+                               break;
+
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       (u64)regs->regs[MIPSInst_RS(ir)] +
+                                       (u64)regs->regs[MIPSInst_RT(ir)];
+                       return 0;
+               case dsubu_op:
+                       if (config_enabled(CONFIG_32BIT) || MIPSInst_FD(ir))
+                               break;
+
+                       if (MIPSInst_RD(ir))
+                               regs->regs[MIPSInst_RD(ir)] =
+                                       (s64)((u64)regs->regs[MIPSInst_RS(ir)] -
+                                             (u64)regs->regs[MIPSInst_RT(ir)]);
+                       return 0;
+               }
+               break;
+       default:
+               pr_debug("No fastpath BD emulation for instruction 0x%08x (op: %02x)\n",
+                        ir, MIPSInst_OPCODE(ir));
+       }
+
+       return SIGILL;
+}
+
+/**
+ * movt_func - Emulate a MOVT instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int movf_func(struct pt_regs *regs, u32 ir)
+{
+       u32 csr;
+       u32 cond;
+
+       csr = current->thread.fpu.fcr31;
+       cond = fpucondbit[MIPSInst_RT(ir) >> 2];
+       if (((csr & cond) == 0) && MIPSInst_RD(ir))
+               regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
+       MIPS_R2_STATS(movs);
+       return 0;
+}
+
+/**
+ * movt_func - Emulate a MOVT instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int movt_func(struct pt_regs *regs, u32 ir)
+{
+       u32 csr;
+       u32 cond;
+
+       csr = current->thread.fpu.fcr31;
+       cond = fpucondbit[MIPSInst_RT(ir) >> 2];
+
+       if (((csr & cond) != 0) && MIPSInst_RD(ir))
+               regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
+
+       MIPS_R2_STATS(movs);
+
+       return 0;
+}
+
+/**
+ * jr_func - Emulate a JR instruction.
+ * @pt_regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns SIGILL if JR was in delay slot, SIGEMT if we
+ * can't compute the EPC, SIGSEGV if we can't access the
+ * userland instruction or 0 on success.
+ */
+static int jr_func(struct pt_regs *regs, u32 ir)
+{
+       int err;
+       unsigned long cepc, epc, nepc;
+       u32 nir;
+
+       if (delay_slot(regs))
+               return SIGILL;
+
+       /* EPC after the RI/JR instruction */
+       nepc = regs->cp0_epc;
+       /* Roll back to the reserved R2 JR instruction */
+       regs->cp0_epc -= 4;
+       epc = regs->cp0_epc;
+       err = __compute_return_epc(regs);
+
+       if (err < 0)
+               return SIGEMT;
+
+
+       /* Computed EPC */
+       cepc = regs->cp0_epc;
+
+       /* Get DS instruction */
+       err = __get_user(nir, (u32 __user *)nepc);
+       if (err)
+               return SIGSEGV;
+
+       MIPS_R2BR_STATS(jrs);
+
+       /* If nir == 0(NOP), then nothing else to do */
+       if (nir) {
+               /*
+                * Negative err means FPU instruction in BD-slot,
+                * Zero err means 'BD-slot emulation done'
+                * For anything else we go back to trampoline emulation.
+                */
+               err = mipsr6_emul(regs, nir);
+               if (err > 0) {
+                       regs->cp0_epc = nepc;
+                       err = mips_dsemul(regs, nir, cepc);
+                       if (err == SIGILL)
+                               err = SIGEMT;
+                       MIPS_R2_STATS(dsemul);
+               }
+       }
+
+       return err;
+}
+
+/**
+ * movz_func - Emulate a MOVZ instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int movz_func(struct pt_regs *regs, u32 ir)
+{
+       if (((regs->regs[MIPSInst_RT(ir)]) == 0) && MIPSInst_RD(ir))
+               regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
+       MIPS_R2_STATS(movs);
+
+       return 0;
+}
+
+/**
+ * movn_func - Emulate a MOVZ instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int movn_func(struct pt_regs *regs, u32 ir)
+{
+       if (((regs->regs[MIPSInst_RT(ir)]) != 0) && MIPSInst_RD(ir))
+               regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
+       MIPS_R2_STATS(movs);
+
+       return 0;
+}
+
+/**
+ * mfhi_func - Emulate a MFHI instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int mfhi_func(struct pt_regs *regs, u32 ir)
+{
+       if (MIPSInst_RD(ir))
+               regs->regs[MIPSInst_RD(ir)] = regs->hi;
+
+       MIPS_R2_STATS(hilo);
+
+       return 0;
+}
+
+/**
+ * mthi_func - Emulate a MTHI instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int mthi_func(struct pt_regs *regs, u32 ir)
+{
+       regs->hi = regs->regs[MIPSInst_RS(ir)];
+
+       MIPS_R2_STATS(hilo);
+
+       return 0;
+}
+
+/**
+ * mflo_func - Emulate a MFLO instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int mflo_func(struct pt_regs *regs, u32 ir)
+{
+       if (MIPSInst_RD(ir))
+               regs->regs[MIPSInst_RD(ir)] = regs->lo;
+
+       MIPS_R2_STATS(hilo);
+
+       return 0;
+}
+
+/**
+ * mtlo_func - Emulate a MTLO instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int mtlo_func(struct pt_regs *regs, u32 ir)
+{
+       regs->lo = regs->regs[MIPSInst_RS(ir)];
+
+       MIPS_R2_STATS(hilo);
+
+       return 0;
+}
+
+/**
+ * mult_func - Emulate a MULT instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int mult_func(struct pt_regs *regs, u32 ir)
+{
+       s64 res;
+       s32 rt, rs;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = (s64)rt * (s64)rs;
+
+       rs = res;
+       regs->lo = (s64)rs;
+       rt = res >> 32;
+       res = (s64)rt;
+       regs->hi = res;
+
+       MIPS_R2_STATS(muls);
+
+       return 0;
+}
+
+/**
+ * multu_func - Emulate a MULTU instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int multu_func(struct pt_regs *regs, u32 ir)
+{
+       u64 res;
+       u32 rt, rs;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = (u64)rt * (u64)rs;
+       rt = res;
+       regs->lo = (s64)rt;
+       regs->hi = (s64)(res >> 32);
+
+       MIPS_R2_STATS(muls);
+
+       return 0;
+}
+
+/**
+ * div_func - Emulate a DIV instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int div_func(struct pt_regs *regs, u32 ir)
+{
+       s32 rt, rs;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+
+       regs->lo = (s64)(rs / rt);
+       regs->hi = (s64)(rs % rt);
+
+       MIPS_R2_STATS(divs);
+
+       return 0;
+}
+
+/**
+ * divu_func - Emulate a DIVU instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int divu_func(struct pt_regs *regs, u32 ir)
+{
+       u32 rt, rs;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+
+       regs->lo = (s64)(rs / rt);
+       regs->hi = (s64)(rs % rt);
+
+       MIPS_R2_STATS(divs);
+
+       return 0;
+}
+
+/**
+ * dmult_func - Emulate a DMULT instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 on success or SIGILL for 32-bit kernels.
+ */
+static int dmult_func(struct pt_regs *regs, u32 ir)
+{
+       s64 res;
+       s64 rt, rs;
+
+       if (config_enabled(CONFIG_32BIT))
+               return SIGILL;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = rt * rs;
+
+       regs->lo = res;
+       __asm__ __volatile__(
+               "dmuh %0, %1, %2\t\n"
+               : "=r"(res)
+               : "r"(rt), "r"(rs));
+
+       regs->hi = res;
+
+       MIPS_R2_STATS(muls);
+
+       return 0;
+}
+
+/**
+ * dmultu_func - Emulate a DMULTU instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 on success or SIGILL for 32-bit kernels.
+ */
+static int dmultu_func(struct pt_regs *regs, u32 ir)
+{
+       u64 res;
+       u64 rt, rs;
+
+       if (config_enabled(CONFIG_32BIT))
+               return SIGILL;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = rt * rs;
+
+       regs->lo = res;
+       __asm__ __volatile__(
+               "dmuhu %0, %1, %2\t\n"
+               : "=r"(res)
+               : "r"(rt), "r"(rs));
+
+       regs->hi = res;
+
+       MIPS_R2_STATS(muls);
+
+       return 0;
+}
+
+/**
+ * ddiv_func - Emulate a DDIV instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 on success or SIGILL for 32-bit kernels.
+ */
+static int ddiv_func(struct pt_regs *regs, u32 ir)
+{
+       s64 rt, rs;
+
+       if (config_enabled(CONFIG_32BIT))
+               return SIGILL;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+
+       regs->lo = rs / rt;
+       regs->hi = rs % rt;
+
+       MIPS_R2_STATS(divs);
+
+       return 0;
+}
+
+/**
+ * ddivu_func - Emulate a DDIVU instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 on success or SIGILL for 32-bit kernels.
+ */
+static int ddivu_func(struct pt_regs *regs, u32 ir)
+{
+       u64 rt, rs;
+
+       if (config_enabled(CONFIG_32BIT))
+               return SIGILL;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+
+       regs->lo = rs / rt;
+       regs->hi = rs % rt;
+
+       MIPS_R2_STATS(divs);
+
+       return 0;
+}
+
+/* R6 removed instructions for the SPECIAL opcode */
+static struct r2_decoder_table spec_op_table[] = {
+       { 0xfc1ff83f, 0x00000008, jr_func },
+       { 0xfc00ffff, 0x00000018, mult_func },
+       { 0xfc00ffff, 0x00000019, multu_func },
+       { 0xfc00ffff, 0x0000001c, dmult_func },
+       { 0xfc00ffff, 0x0000001d, dmultu_func },
+       { 0xffff07ff, 0x00000010, mfhi_func },
+       { 0xfc1fffff, 0x00000011, mthi_func },
+       { 0xffff07ff, 0x00000012, mflo_func },
+       { 0xfc1fffff, 0x00000013, mtlo_func },
+       { 0xfc0307ff, 0x00000001, movf_func },
+       { 0xfc0307ff, 0x00010001, movt_func },
+       { 0xfc0007ff, 0x0000000a, movz_func },
+       { 0xfc0007ff, 0x0000000b, movn_func },
+       { 0xfc00ffff, 0x0000001a, div_func },
+       { 0xfc00ffff, 0x0000001b, divu_func },
+       { 0xfc00ffff, 0x0000001e, ddiv_func },
+       { 0xfc00ffff, 0x0000001f, ddivu_func },
+       {}
+};
+
+/**
+ * madd_func - Emulate a MADD instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int madd_func(struct pt_regs *regs, u32 ir)
+{
+       s64 res;
+       s32 rt, rs;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = (s64)rt * (s64)rs;
+       rt = regs->hi;
+       rs = regs->lo;
+       res += ((((s64)rt) << 32) | (u32)rs);
+
+       rt = res;
+       regs->lo = (s64)rt;
+       rs = res >> 32;
+       regs->hi = (s64)rs;
+
+       MIPS_R2_STATS(dsps);
+
+       return 0;
+}
+
+/**
+ * maddu_func - Emulate a MADDU instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int maddu_func(struct pt_regs *regs, u32 ir)
+{
+       u64 res;
+       u32 rt, rs;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = (u64)rt * (u64)rs;
+       rt = regs->hi;
+       rs = regs->lo;
+       res += ((((s64)rt) << 32) | (u32)rs);
+
+       rt = res;
+       regs->lo = (s64)rt;
+       rs = res >> 32;
+       regs->hi = (s64)rs;
+
+       MIPS_R2_STATS(dsps);
+
+       return 0;
+}
+
+/**
+ * msub_func - Emulate a MSUB instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int msub_func(struct pt_regs *regs, u32 ir)
+{
+       s64 res;
+       s32 rt, rs;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = (s64)rt * (s64)rs;
+       rt = regs->hi;
+       rs = regs->lo;
+       res = ((((s64)rt) << 32) | (u32)rs) - res;
+
+       rt = res;
+       regs->lo = (s64)rt;
+       rs = res >> 32;
+       regs->hi = (s64)rs;
+
+       MIPS_R2_STATS(dsps);
+
+       return 0;
+}
+
+/**
+ * msubu_func - Emulate a MSUBU instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int msubu_func(struct pt_regs *regs, u32 ir)
+{
+       u64 res;
+       u32 rt, rs;
+
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = (u64)rt * (u64)rs;
+       rt = regs->hi;
+       rs = regs->lo;
+       res = ((((s64)rt) << 32) | (u32)rs) - res;
+
+       rt = res;
+       regs->lo = (s64)rt;
+       rs = res >> 32;
+       regs->hi = (s64)rs;
+
+       MIPS_R2_STATS(dsps);
+
+       return 0;
+}
+
+/**
+ * mul_func - Emulate a MUL instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int mul_func(struct pt_regs *regs, u32 ir)
+{
+       s64 res;
+       s32 rt, rs;
+
+       if (!MIPSInst_RD(ir))
+               return 0;
+       rt = regs->regs[MIPSInst_RT(ir)];
+       rs = regs->regs[MIPSInst_RS(ir)];
+       res = (s64)rt * (s64)rs;
+
+       rs = res;
+       regs->regs[MIPSInst_RD(ir)] = (s64)rs;
+
+       MIPS_R2_STATS(muls);
+
+       return 0;
+}
+
+/**
+ * clz_func - Emulate a CLZ instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int clz_func(struct pt_regs *regs, u32 ir)
+{
+       u32 res;
+       u32 rs;
+
+       if (!MIPSInst_RD(ir))
+               return 0;
+
+       rs = regs->regs[MIPSInst_RS(ir)];
+       __asm__ __volatile__("clz %0, %1" : "=r"(res) : "r"(rs));
+       regs->regs[MIPSInst_RD(ir)] = res;
+
+       MIPS_R2_STATS(bops);
+
+       return 0;
+}
+
+/**
+ * clo_func - Emulate a CLO instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+
+static int clo_func(struct pt_regs *regs, u32 ir)
+{
+       u32 res;
+       u32 rs;
+
+       if (!MIPSInst_RD(ir))
+               return 0;
+
+       rs = regs->regs[MIPSInst_RS(ir)];
+       __asm__ __volatile__("clo %0, %1" : "=r"(res) : "r"(rs));
+       regs->regs[MIPSInst_RD(ir)] = res;
+
+       MIPS_R2_STATS(bops);
+
+       return 0;
+}
+
+/**
+ * dclz_func - Emulate a DCLZ instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int dclz_func(struct pt_regs *regs, u32 ir)
+{
+       u64 res;
+       u64 rs;
+
+       if (config_enabled(CONFIG_32BIT))
+               return SIGILL;
+
+       if (!MIPSInst_RD(ir))
+               return 0;
+
+       rs = regs->regs[MIPSInst_RS(ir)];
+       __asm__ __volatile__("dclz %0, %1" : "=r"(res) : "r"(rs));
+       regs->regs[MIPSInst_RD(ir)] = res;
+
+       MIPS_R2_STATS(bops);
+
+       return 0;
+}
+
+/**
+ * dclo_func - Emulate a DCLO instruction
+ * @regs: Process register set
+ * @ir: Instruction
+ *
+ * Returns 0 since it always succeeds.
+ */
+static int dclo_func(struct pt_regs *regs, u32 ir)
+{
+       u64 res;
+       u64 rs;
+
+       if (config_enabled(CONFIG_32BIT))
+               return SIGILL;
+
+       if (!MIPSInst_RD(ir))
+               return 0;
+
+       rs = regs->regs[MIPSInst_RS(ir)];
+       __asm__ __volatile__("dclo %0, %1" : "=r"(res) : "r"(rs));
+       regs->regs[MIPSInst_RD(ir)] = res;
+
+       MIPS_R2_STATS(bops);
+
+       return 0;
+}
+
+/* R6 removed instructions for the SPECIAL2 opcode */
+static struct r2_decoder_table spec2_op_table[] = {
+       { 0xfc00ffff, 0x70000000, madd_func },
+       { 0xfc00ffff, 0x70000001, maddu_func },
+       { 0xfc0007ff, 0x70000002, mul_func },
+       { 0xfc00ffff, 0x70000004, msub_func },
+       { 0xfc00ffff, 0x70000005, msubu_func },
+       { 0xfc0007ff, 0x70000020, clz_func },
+       { 0xfc0007ff, 0x70000021, clo_func },
+       { 0xfc0007ff, 0x70000024, dclz_func },
+       { 0xfc0007ff, 0x70000025, dclo_func },
+       { }
+};
+
+static inline int mipsr2_find_op_func(struct pt_regs *regs, u32 inst,
+                                     struct r2_decoder_table *table)
+{
+       struct r2_decoder_table *p;
+       int err;
+
+       for (p = table; p->func; p++) {
+               if ((inst & p->mask) == p->code) {
+                       err = (p->func)(regs, inst);
+                       return err;
+               }
+       }
+       return SIGILL;
+}
+
+/**
+ * mipsr2_decoder: Decode and emulate a MIPS R2 instruction
+ * @regs: Process register set
+ * @inst: Instruction to decode and emulate
+ */
+int mipsr2_decoder(struct pt_regs *regs, u32 inst)
+{
+       int err = 0;
+       unsigned long vaddr;
+       u32 nir;
+       unsigned long cpc, epc, nepc, r31, res, rs, rt;
+
+       void __user *fault_addr = NULL;
+       int pass = 0;
+
+repeat:
+       r31 = regs->regs[31];
+       epc = regs->cp0_epc;
+       err = compute_return_epc(regs);
+       if (err < 0) {
+               BUG();
+               return SIGEMT;
+       }
+       pr_debug("Emulating the 0x%08x R2 instruction @ 0x%08lx (pass=%d))\n",
+                inst, epc, pass);
+
+       switch (MIPSInst_OPCODE(inst)) {
+       case spec_op:
+               err = mipsr2_find_op_func(regs, inst, spec_op_table);
+               if (err < 0) {
+                       /* FPU instruction under JR */
+                       regs->cp0_cause |= CAUSEF_BD;
+                       goto fpu_emul;
+               }
+               break;
+       case spec2_op:
+               err = mipsr2_find_op_func(regs, inst, spec2_op_table);
+               break;
+       case bcond_op:
+               rt = MIPSInst_RT(inst);
+               rs = MIPSInst_RS(inst);
+               switch (rt) {
+               case tgei_op:
+                       if ((long)regs->regs[rs] >= MIPSInst_SIMM(inst))
+                               do_trap_or_bp(regs, 0, "TGEI");
+
+                       MIPS_R2_STATS(traps);
+
+                       break;
+               case tgeiu_op:
+                       if (regs->regs[rs] >= MIPSInst_UIMM(inst))
+                               do_trap_or_bp(regs, 0, "TGEIU");
+
+                       MIPS_R2_STATS(traps);
+
+                       break;
+               case tlti_op:
+                       if ((long)regs->regs[rs] < MIPSInst_SIMM(inst))
+                               do_trap_or_bp(regs, 0, "TLTI");
+
+                       MIPS_R2_STATS(traps);
+
+                       break;
+               case tltiu_op:
+                       if (regs->regs[rs] < MIPSInst_UIMM(inst))
+                               do_trap_or_bp(regs, 0, "TLTIU");
+
+                       MIPS_R2_STATS(traps);
+
+                       break;
+               case teqi_op:
+                       if (regs->regs[rs] == MIPSInst_SIMM(inst))
+                               do_trap_or_bp(regs, 0, "TEQI");
+
+                       MIPS_R2_STATS(traps);
+
+                       break;
+               case tnei_op:
+                       if (regs->regs[rs] != MIPSInst_SIMM(inst))
+                               do_trap_or_bp(regs, 0, "TNEI");
+
+                       MIPS_R2_STATS(traps);
+
+                       break;
+               case bltzl_op:
+               case bgezl_op:
+               case bltzall_op:
+               case bgezall_op:
+                       if (delay_slot(regs)) {
+                               err = SIGILL;
+                               break;
+                       }
+                       regs->regs[31] = r31;
+                       regs->cp0_epc = epc;
+                       err = __compute_return_epc(regs);
+                       if (err < 0)
+                               return SIGEMT;
+                       if (err != BRANCH_LIKELY_TAKEN)
+                               break;
+                       cpc = regs->cp0_epc;
+                       nepc = epc + 4;
+                       err = __get_user(nir, (u32 __user *)nepc);
+                       if (err) {
+                               err = SIGSEGV;
+                               break;
+                       }
+                       /*
+                        * This will probably be optimized away when
+                        * CONFIG_DEBUG_FS is not enabled
+                        */
+                       switch (rt) {
+                       case bltzl_op:
+                               MIPS_R2BR_STATS(bltzl);
+                               break;
+                       case bgezl_op:
+                               MIPS_R2BR_STATS(bgezl);
+                               break;
+                       case bltzall_op:
+                               MIPS_R2BR_STATS(bltzall);
+                               break;
+                       case bgezall_op:
+                               MIPS_R2BR_STATS(bgezall);
+                               break;
+                       }
+
+                       switch (MIPSInst_OPCODE(nir)) {
+                       case cop1_op:
+                       case cop1x_op:
+                       case lwc1_op:
+                       case swc1_op:
+                               regs->cp0_cause |= CAUSEF_BD;
+                               goto fpu_emul;
+                       }
+                       if (nir) {
+                               err = mipsr6_emul(regs, nir);
+                               if (err > 0) {
+                                       err = mips_dsemul(regs, nir, cpc);
+                                       if (err == SIGILL)
+                                               err = SIGEMT;
+                                       MIPS_R2_STATS(dsemul);
+                               }
+                       }
+                       break;
+               case bltzal_op:
+               case bgezal_op:
+                       if (delay_slot(regs)) {
+                               err = SIGILL;
+                               break;
+                       }
+                       regs->regs[31] = r31;
+                       regs->cp0_epc = epc;
+                       err = __compute_return_epc(regs);
+                       if (err < 0)
+                               return SIGEMT;
+                       cpc = regs->cp0_epc;
+                       nepc = epc + 4;
+                       err = __get_user(nir, (u32 __user *)nepc);
+                       if (err) {
+                               err = SIGSEGV;
+                               break;
+                       }
+                       /*
+                        * This will probably be optimized away when
+                        * CONFIG_DEBUG_FS is not enabled
+                        */
+                       switch (rt) {
+                       case bltzal_op:
+                               MIPS_R2BR_STATS(bltzal);
+                               break;
+                       case bgezal_op:
+                               MIPS_R2BR_STATS(bgezal);
+                               break;
+                       }
+
+                       switch (MIPSInst_OPCODE(nir)) {
+                       case cop1_op:
+                       case cop1x_op:
+                       case lwc1_op:
+                       case swc1_op:
+                               regs->cp0_cause |= CAUSEF_BD;
+                               goto fpu_emul;
+                       }
+                       if (nir) {
+                               err = mipsr6_emul(regs, nir);
+                               if (err > 0) {
+                                       err = mips_dsemul(regs, nir, cpc);
+                                       if (err == SIGILL)
+                                               err = SIGEMT;
+                                       MIPS_R2_STATS(dsemul);
+                               }
+                       }
+                       break;
+               default:
+                       regs->regs[31] = r31;
+                       regs->cp0_epc = epc;
+                       err = SIGILL;
+                       break;
+               }
+               break;
+
+       case beql_op:
+       case bnel_op:
+       case blezl_op:
+       case bgtzl_op:
+               if (delay_slot(regs)) {
+                       err = SIGILL;
+                       break;
+               }
+               regs->regs[31] = r31;
+               regs->cp0_epc = epc;
+               err = __compute_return_epc(regs);
+               if (err < 0)
+                       return SIGEMT;
+               if (err != BRANCH_LIKELY_TAKEN)
+                       break;
+               cpc = regs->cp0_epc;
+               nepc = epc + 4;
+               err = __get_user(nir, (u32 __user *)nepc);
+               if (err) {
+                       err = SIGSEGV;
+                       break;
+               }
+               /*
+                * This will probably be optimized away when
+                * CONFIG_DEBUG_FS is not enabled
+                */
+               switch (MIPSInst_OPCODE(inst)) {
+               case beql_op:
+                       MIPS_R2BR_STATS(beql);
+                       break;
+               case bnel_op:
+                       MIPS_R2BR_STATS(bnel);
+                       break;
+               case blezl_op:
+                       MIPS_R2BR_STATS(blezl);
+                       break;
+               case bgtzl_op:
+                       MIPS_R2BR_STATS(bgtzl);
+                       break;
+               }
+
+               switch (MIPSInst_OPCODE(nir)) {
+               case cop1_op:
+               case cop1x_op:
+               case lwc1_op:
+               case swc1_op:
+                       regs->cp0_cause |= CAUSEF_BD;
+                       goto fpu_emul;
+               }
+               if (nir) {
+                       err = mipsr6_emul(regs, nir);
+                       if (err > 0) {
+                               err = mips_dsemul(regs, nir, cpc);
+                               if (err == SIGILL)
+                                       err = SIGEMT;
+                               MIPS_R2_STATS(dsemul);
+                       }
+               }
+               break;
+       case lwc1_op:
+       case swc1_op:
+       case cop1_op:
+       case cop1x_op:
+fpu_emul:
+               regs->regs[31] = r31;
+               regs->cp0_epc = epc;
+               if (!used_math()) {     /* First time FPU user.  */
+                       err = init_fpu();
+                       set_used_math();
+               }
+               lose_fpu(1);    /* Save FPU state for the emulator. */
+
+               err = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
+                                              &fault_addr);
+
+               /*
+                * this is a tricky issue - lose_fpu() uses LL/SC atomics
+                * if FPU is owned and effectively cancels user level LL/SC.
+                * So, it could be logical to don't restore FPU ownership here.
+                * But the sequence of multiple FPU instructions is much much
+                * more often than LL-FPU-SC and I prefer loop here until
+                * next scheduler cycle cancels FPU ownership
+                */
+               own_fpu(1);     /* Restore FPU state. */
+
+               if (err)
+                       current->thread.cp0_baduaddr = (unsigned long)fault_addr;
+
+               MIPS_R2_STATS(fpus);
+
+               break;
+
+       case lwl_op:
+               rt = regs->regs[MIPSInst_RT(inst)];
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (!access_ok(VERIFY_READ, vaddr, 4)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGSEGV;
+                       break;
+               }
+               __asm__ __volatile__(
+                       "       .set    push\n"
+                       "       .set    reorder\n"
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+                       "1:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 24, 8\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                       "2:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 16, 8\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                       "3:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 8, 8\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                       "4:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 0, 8\n"
+#else /* !CONFIG_CPU_LITTLE_ENDIAN */
+                       "1:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 24, 8\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                       "2:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 16, 8\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                       "3:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 8, 8\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                       "4:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 0, 8\n"
+#endif /* CONFIG_CPU_LITTLE_ENDIAN */
+                       "9:     sll     %0, %0, 0\n"
+                       "10:\n"
+                       "       .insn\n"
+                       "       .section        .fixup,\"ax\"\n"
+                       "8:     li      %3,%4\n"
+                       "       j       10b\n"
+                       "       .previous\n"
+                       "       .section        __ex_table,\"a\"\n"
+                       "       .word   1b,8b\n"
+                       "       .word   2b,8b\n"
+                       "       .word   3b,8b\n"
+                       "       .word   4b,8b\n"
+                       "       .previous\n"
+                       "       .set    pop\n"
+                       : "+&r"(rt), "=&r"(rs),
+                         "+&r"(vaddr), "+&r"(err)
+                       : "i"(SIGSEGV));
+
+               if (MIPSInst_RT(inst) && !err)
+                       regs->regs[MIPSInst_RT(inst)] = rt;
+
+               MIPS_R2_STATS(loads);
+
+               break;
+
+       case lwr_op:
+               rt = regs->regs[MIPSInst_RT(inst)];
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (!access_ok(VERIFY_READ, vaddr, 4)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGSEGV;
+                       break;
+               }
+               __asm__ __volatile__(
+                       "       .set    push\n"
+                       "       .set    reorder\n"
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+                       "1:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 0, 8\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                       "2:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 8, 8\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                       "3:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 16, 8\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                       "4:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 24, 8\n"
+                       "       sll     %0, %0, 0\n"
+#else /* !CONFIG_CPU_LITTLE_ENDIAN */
+                       "1:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 0, 8\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                       "2:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 8, 8\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                       "3:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 16, 8\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                       "4:"    LB      "%1, 0(%2)\n"
+                               INS     "%0, %1, 24, 8\n"
+                       "       sll     %0, %0, 0\n"
+#endif /* CONFIG_CPU_LITTLE_ENDIAN */
+                       "9:\n"
+                       "10:\n"
+                       "       .insn\n"
+                       "       .section        .fixup,\"ax\"\n"
+                       "8:     li      %3,%4\n"
+                       "       j       10b\n"
+                       "       .previous\n"
+                       "       .section        __ex_table,\"a\"\n"
+                       "       .word   1b,8b\n"
+                       "       .word   2b,8b\n"
+                       "       .word   3b,8b\n"
+                       "       .word   4b,8b\n"
+                       "       .previous\n"
+                       "       .set    pop\n"
+                       : "+&r"(rt), "=&r"(rs),
+                         "+&r"(vaddr), "+&r"(err)
+                       : "i"(SIGSEGV));
+               if (MIPSInst_RT(inst) && !err)
+                       regs->regs[MIPSInst_RT(inst)] = rt;
+
+               MIPS_R2_STATS(loads);
+
+               break;
+
+       case swl_op:
+               rt = regs->regs[MIPSInst_RT(inst)];
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGSEGV;
+                       break;
+               }
+               __asm__ __volatile__(
+                       "       .set    push\n"
+                       "       .set    reorder\n"
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+                               EXT     "%1, %0, 24, 8\n"
+                       "1:"    SB      "%1, 0(%2)\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                               EXT     "%1, %0, 16, 8\n"
+                       "2:"    SB      "%1, 0(%2)\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                               EXT     "%1, %0, 8, 8\n"
+                       "3:"    SB      "%1, 0(%2)\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                               EXT     "%1, %0, 0, 8\n"
+                       "4:"    SB      "%1, 0(%2)\n"
+#else /* !CONFIG_CPU_LITTLE_ENDIAN */
+                               EXT     "%1, %0, 24, 8\n"
+                       "1:"    SB      "%1, 0(%2)\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               EXT     "%1, %0, 16, 8\n"
+                       "2:"    SB      "%1, 0(%2)\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               EXT     "%1, %0, 8, 8\n"
+                       "3:"    SB      "%1, 0(%2)\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               EXT     "%1, %0, 0, 8\n"
+                       "4:"    SB      "%1, 0(%2)\n"
+#endif /* CONFIG_CPU_LITTLE_ENDIAN */
+                       "9:\n"
+                       "       .insn\n"
+                       "       .section        .fixup,\"ax\"\n"
+                       "8:     li      %3,%4\n"
+                       "       j       9b\n"
+                       "       .previous\n"
+                       "       .section        __ex_table,\"a\"\n"
+                       "       .word   1b,8b\n"
+                       "       .word   2b,8b\n"
+                       "       .word   3b,8b\n"
+                       "       .word   4b,8b\n"
+                       "       .previous\n"
+                       "       .set    pop\n"
+                       : "+&r"(rt), "=&r"(rs),
+                         "+&r"(vaddr), "+&r"(err)
+                       : "i"(SIGSEGV)
+                       : "memory");
+
+               MIPS_R2_STATS(stores);
+
+               break;
+
+       case swr_op:
+               rt = regs->regs[MIPSInst_RT(inst)];
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGSEGV;
+                       break;
+               }
+               __asm__ __volatile__(
+                       "       .set    push\n"
+                       "       .set    reorder\n"
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+                               EXT     "%1, %0, 0, 8\n"
+                       "1:"    SB      "%1, 0(%2)\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               EXT     "%1, %0, 8, 8\n"
+                       "2:"    SB      "%1, 0(%2)\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               EXT     "%1, %0, 16, 8\n"
+                       "3:"    SB      "%1, 0(%2)\n"
+                               ADDIU   "%2, %2, 1\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               EXT     "%1, %0, 24, 8\n"
+                       "4:"    SB      "%1, 0(%2)\n"
+#else /* !CONFIG_CPU_LITTLE_ENDIAN */
+                               EXT     "%1, %0, 0, 8\n"
+                       "1:"    SB      "%1, 0(%2)\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                               EXT     "%1, %0, 8, 8\n"
+                       "2:"    SB      "%1, 0(%2)\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                               EXT     "%1, %0, 16, 8\n"
+                       "3:"    SB      "%1, 0(%2)\n"
+                       "       andi    %1, %2, 0x3\n"
+                       "       beq     $0, %1, 9f\n"
+                               ADDIU   "%2, %2, -1\n"
+                               EXT     "%1, %0, 24, 8\n"
+                       "4:"    SB      "%1, 0(%2)\n"
+#endif /* CONFIG_CPU_LITTLE_ENDIAN */
+                       "9:\n"
+                       "       .insn\n"
+                       "       .section        .fixup,\"ax\"\n"
+                       "8:     li      %3,%4\n"
+                       "       j       9b\n"
+                       "       .previous\n"
+                       "       .section        __ex_table,\"a\"\n"
+                       "       .word   1b,8b\n"
+                       "       .word   2b,8b\n"
+                       "       .word   3b,8b\n"
+                       "       .word   4b,8b\n"
+                       "       .previous\n"
+                       "       .set    pop\n"
+                       : "+&r"(rt), "=&r"(rs),
+                         "+&r"(vaddr), "+&r"(err)
+                       : "i"(SIGSEGV)
+                       : "memory");
+
+               MIPS_R2_STATS(stores);
+
+               break;
+
+       case ldl_op:
+               if (config_enabled(CONFIG_32BIT)) {
+                   err = SIGILL;
+                   break;
+               }
+
+               rt = regs->regs[MIPSInst_RT(inst)];
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (!access_ok(VERIFY_READ, vaddr, 8)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGSEGV;
+                       break;
+               }
+               __asm__ __volatile__(
+                       "       .set    push\n"
+                       "       .set    reorder\n"
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+                       "1:     lb      %1, 0(%2)\n"
+                       "       dinsu   %0, %1, 56, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "2:     lb      %1, 0(%2)\n"
+                       "       dinsu   %0, %1, 48, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "3:     lb      %1, 0(%2)\n"
+                       "       dinsu   %0, %1, 40, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "4:     lb      %1, 0(%2)\n"
+                       "       dinsu   %0, %1, 32, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "5:     lb      %1, 0(%2)\n"
+                       "       dins    %0, %1, 24, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "6:     lb      %1, 0(%2)\n"
+                       "       dins    %0, %1, 16, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "7:     lb      %1, 0(%2)\n"
+                       "       dins    %0, %1, 8, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "0:     lb      %1, 0(%2)\n"
+                       "       dins    %0, %1, 0, 8\n"
+#else /* !CONFIG_CPU_LITTLE_ENDIAN */
+                       "1:     lb      %1, 0(%2)\n"
+                       "       dinsu   %0, %1, 56, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "2:     lb      %1, 0(%2)\n"
+                       "       dinsu   %0, %1, 48, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "3:     lb      %1, 0(%2)\n"
+                       "       dinsu   %0, %1, 40, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "4:     lb      %1, 0(%2)\n"
+                       "       dinsu   %0, %1, 32, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "5:     lb      %1, 0(%2)\n"
+                       "       dins    %0, %1, 24, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "6:     lb      %1, 0(%2)\n"
+                       "       dins    %0, %1, 16, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "7:     lb      %1, 0(%2)\n"
+                       "       dins    %0, %1, 8, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "0:     lb      %1, 0(%2)\n"
+                       "       dins    %0, %1, 0, 8\n"
+#endif /* CONFIG_CPU_LITTLE_ENDIAN */
+                       "9:\n"
+                       "       .insn\n"
+                       "       .section        .fixup,\"ax\"\n"
+                       "8:     li      %3,%4\n"
+                       "       j       9b\n"
+                       "       .previous\n"
+                       "       .section        __ex_table,\"a\"\n"
+                       "       .word   1b,8b\n"
+                       "       .word   2b,8b\n"
+                       "       .word   3b,8b\n"
+                       "       .word   4b,8b\n"
+                       "       .word   5b,8b\n"
+                       "       .word   6b,8b\n"
+                       "       .word   7b,8b\n"
+                       "       .word   0b,8b\n"
+                       "       .previous\n"
+                       "       .set    pop\n"
+                       : "+&r"(rt), "=&r"(rs),
+                         "+&r"(vaddr), "+&r"(err)
+                       : "i"(SIGSEGV));
+               if (MIPSInst_RT(inst) && !err)
+                       regs->regs[MIPSInst_RT(inst)] = rt;
+
+               MIPS_R2_STATS(loads);
+               break;
+
+       case ldr_op:
+               if (config_enabled(CONFIG_32BIT)) {
+                   err = SIGILL;
+                   break;
+               }
+
+               rt = regs->regs[MIPSInst_RT(inst)];
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (!access_ok(VERIFY_READ, vaddr, 8)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGSEGV;
+                       break;
+               }
+               __asm__ __volatile__(
+                       "       .set    push\n"
+                       "       .set    reorder\n"
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+                       "1:     lb      %1, 0(%2)\n"
+                       "       dins   %0, %1, 0, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "2:     lb      %1, 0(%2)\n"
+                       "       dins   %0, %1, 8, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "3:     lb      %1, 0(%2)\n"
+                       "       dins   %0, %1, 16, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "4:     lb      %1, 0(%2)\n"
+                       "       dins   %0, %1, 24, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "5:     lb      %1, 0(%2)\n"
+                       "       dinsu    %0, %1, 32, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "6:     lb      %1, 0(%2)\n"
+                       "       dinsu    %0, %1, 40, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "7:     lb      %1, 0(%2)\n"
+                       "       dinsu    %0, %1, 48, 8\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "0:     lb      %1, 0(%2)\n"
+                       "       dinsu    %0, %1, 56, 8\n"
+#else /* !CONFIG_CPU_LITTLE_ENDIAN */
+                       "1:     lb      %1, 0(%2)\n"
+                       "       dins   %0, %1, 0, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "2:     lb      %1, 0(%2)\n"
+                       "       dins   %0, %1, 8, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "3:     lb      %1, 0(%2)\n"
+                       "       dins   %0, %1, 16, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "4:     lb      %1, 0(%2)\n"
+                       "       dins   %0, %1, 24, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "5:     lb      %1, 0(%2)\n"
+                       "       dinsu    %0, %1, 32, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "6:     lb      %1, 0(%2)\n"
+                       "       dinsu    %0, %1, 40, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "7:     lb      %1, 0(%2)\n"
+                       "       dinsu    %0, %1, 48, 8\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "0:     lb      %1, 0(%2)\n"
+                       "       dinsu    %0, %1, 56, 8\n"
+#endif /* CONFIG_CPU_LITTLE_ENDIAN */
+                       "9:\n"
+                       "       .insn\n"
+                       "       .section        .fixup,\"ax\"\n"
+                       "8:     li     %3,%4\n"
+                       "       j      9b\n"
+                       "       .previous\n"
+                       "       .section        __ex_table,\"a\"\n"
+                       "       .word  1b,8b\n"
+                       "       .word  2b,8b\n"
+                       "       .word  3b,8b\n"
+                       "       .word  4b,8b\n"
+                       "       .word  5b,8b\n"
+                       "       .word  6b,8b\n"
+                       "       .word  7b,8b\n"
+                       "       .word  0b,8b\n"
+                       "       .previous\n"
+                       "       .set    pop\n"
+                       : "+&r"(rt), "=&r"(rs),
+                         "+&r"(vaddr), "+&r"(err)
+                       : "i"(SIGSEGV));
+               if (MIPSInst_RT(inst) && !err)
+                       regs->regs[MIPSInst_RT(inst)] = rt;
+
+               MIPS_R2_STATS(loads);
+               break;
+
+       case sdl_op:
+               if (config_enabled(CONFIG_32BIT)) {
+                   err = SIGILL;
+                   break;
+               }
+
+               rt = regs->regs[MIPSInst_RT(inst)];
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGSEGV;
+                       break;
+               }
+               __asm__ __volatile__(
+                       "       .set    push\n"
+                       "       .set    reorder\n"
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+                       "       dextu   %1, %0, 56, 8\n"
+                       "1:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dextu   %1, %0, 48, 8\n"
+                       "2:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dextu   %1, %0, 40, 8\n"
+                       "3:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dextu   %1, %0, 32, 8\n"
+                       "4:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dext    %1, %0, 24, 8\n"
+                       "5:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dext    %1, %0, 16, 8\n"
+                       "6:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dext    %1, %0, 8, 8\n"
+                       "7:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dext    %1, %0, 0, 8\n"
+                       "0:     sb      %1, 0(%2)\n"
+#else /* !CONFIG_CPU_LITTLE_ENDIAN */
+                       "       dextu   %1, %0, 56, 8\n"
+                       "1:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dextu   %1, %0, 48, 8\n"
+                       "2:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dextu   %1, %0, 40, 8\n"
+                       "3:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dextu   %1, %0, 32, 8\n"
+                       "4:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dext    %1, %0, 24, 8\n"
+                       "5:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dext    %1, %0, 16, 8\n"
+                       "6:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dext    %1, %0, 8, 8\n"
+                       "7:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dext    %1, %0, 0, 8\n"
+                       "0:     sb      %1, 0(%2)\n"
+#endif /* CONFIG_CPU_LITTLE_ENDIAN */
+                       "9:\n"
+                       "       .insn\n"
+                       "       .section        .fixup,\"ax\"\n"
+                       "8:     li      %3,%4\n"
+                       "       j       9b\n"
+                       "       .previous\n"
+                       "       .section        __ex_table,\"a\"\n"
+                       "       .word   1b,8b\n"
+                       "       .word   2b,8b\n"
+                       "       .word   3b,8b\n"
+                       "       .word   4b,8b\n"
+                       "       .word   5b,8b\n"
+                       "       .word   6b,8b\n"
+                       "       .word   7b,8b\n"
+                       "       .word   0b,8b\n"
+                       "       .previous\n"
+                       "       .set    pop\n"
+                       : "+&r"(rt), "=&r"(rs),
+                         "+&r"(vaddr), "+&r"(err)
+                       : "i"(SIGSEGV)
+                       : "memory");
+
+               MIPS_R2_STATS(stores);
+               break;
+
+       case sdr_op:
+               if (config_enabled(CONFIG_32BIT)) {
+                   err = SIGILL;
+                   break;
+               }
+
+               rt = regs->regs[MIPSInst_RT(inst)];
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGSEGV;
+                       break;
+               }
+               __asm__ __volatile__(
+                       "       .set    push\n"
+                       "       .set    reorder\n"
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+                       "       dext    %1, %0, 0, 8\n"
+                       "1:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dext    %1, %0, 8, 8\n"
+                       "2:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dext    %1, %0, 16, 8\n"
+                       "3:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dext    %1, %0, 24, 8\n"
+                       "4:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dextu   %1, %0, 32, 8\n"
+                       "5:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dextu   %1, %0, 40, 8\n"
+                       "6:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dextu   %1, %0, 48, 8\n"
+                       "7:     sb      %1, 0(%2)\n"
+                       "       daddiu  %2, %2, 1\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       dextu   %1, %0, 56, 8\n"
+                       "0:     sb      %1, 0(%2)\n"
+#else /* !CONFIG_CPU_LITTLE_ENDIAN */
+                       "       dext    %1, %0, 0, 8\n"
+                       "1:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dext    %1, %0, 8, 8\n"
+                       "2:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dext    %1, %0, 16, 8\n"
+                       "3:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dext    %1, %0, 24, 8\n"
+                       "4:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dextu   %1, %0, 32, 8\n"
+                       "5:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dextu   %1, %0, 40, 8\n"
+                       "6:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dextu   %1, %0, 48, 8\n"
+                       "7:     sb      %1, 0(%2)\n"
+                       "       andi    %1, %2, 0x7\n"
+                       "       beq     $0, %1, 9f\n"
+                       "       daddiu  %2, %2, -1\n"
+                       "       dextu   %1, %0, 56, 8\n"
+                       "0:     sb      %1, 0(%2)\n"
+#endif /* CONFIG_CPU_LITTLE_ENDIAN */
+                       "9:\n"
+                       "       .insn\n"
+                       "       .section        .fixup,\"ax\"\n"
+                       "8:     li      %3,%4\n"
+                       "       j       9b\n"
+                       "       .previous\n"
+                       "       .section        __ex_table,\"a\"\n"
+                       "       .word   1b,8b\n"
+                       "       .word   2b,8b\n"
+                       "       .word   3b,8b\n"
+                       "       .word   4b,8b\n"
+                       "       .word   5b,8b\n"
+                       "       .word   6b,8b\n"
+                       "       .word   7b,8b\n"
+                       "       .word   0b,8b\n"
+                       "       .previous\n"
+                       "       .set    pop\n"
+                       : "+&r"(rt), "=&r"(rs),
+                         "+&r"(vaddr), "+&r"(err)
+                       : "i"(SIGSEGV)
+                       : "memory");
+
+               MIPS_R2_STATS(stores);
+
+               break;
+       case ll_op:
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (vaddr & 0x3) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGBUS;
+                       break;
+               }
+               if (!access_ok(VERIFY_READ, vaddr, 4)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGBUS;
+                       break;
+               }
+
+               if (!cpu_has_rw_llb) {
+                       /*
+                        * An LL/SC block can't be safely emulated without
+                        * a Config5/LLB availability. So it's probably time to
+                        * kill our process before things get any worse. This is
+                        * because Config5/LLB allows us to use ERETNC so that
+                        * the LLAddr/LLB bit is not cleared when we return from
+                        * an exception. MIPS R2 LL/SC instructions trap with an
+                        * RI exception so once we emulate them here, we return
+                        * back to userland with ERETNC. That preserves the
+                        * LLAddr/LLB so the subsequent SC instruction will
+                        * succeed preserving the atomic semantics of the LL/SC
+                        * block. Without that, there is no safe way to emulate
+                        * an LL/SC block in MIPSR2 userland.
+                        */
+                       pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
+                       err = SIGKILL;
+                       break;
+               }
+
+               __asm__ __volatile__(
+                       "1:\n"
+                       "ll     %0, 0(%2)\n"
+                       "2:\n"
+                       ".insn\n"
+                       ".section        .fixup,\"ax\"\n"
+                       "3:\n"
+                       "li     %1, %3\n"
+                       "j      2b\n"
+                       ".previous\n"
+                       ".section        __ex_table,\"a\"\n"
+                       ".word  1b, 3b\n"
+                       ".previous\n"
+                       : "=&r"(res), "+&r"(err)
+                       : "r"(vaddr), "i"(SIGSEGV)
+                       : "memory");
+
+               if (MIPSInst_RT(inst) && !err)
+                       regs->regs[MIPSInst_RT(inst)] = res;
+               MIPS_R2_STATS(llsc);
+
+               break;
+
+       case sc_op:
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (vaddr & 0x3) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGBUS;
+                       break;
+               }
+               if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGBUS;
+                       break;
+               }
+
+               if (!cpu_has_rw_llb) {
+                       /*
+                        * An LL/SC block can't be safely emulated without
+                        * a Config5/LLB availability. So it's probably time to
+                        * kill our process before things get any worse. This is
+                        * because Config5/LLB allows us to use ERETNC so that
+                        * the LLAddr/LLB bit is not cleared when we return from
+                        * an exception. MIPS R2 LL/SC instructions trap with an
+                        * RI exception so once we emulate them here, we return
+                        * back to userland with ERETNC. That preserves the
+                        * LLAddr/LLB so the subsequent SC instruction will
+                        * succeed preserving the atomic semantics of the LL/SC
+                        * block. Without that, there is no safe way to emulate
+                        * an LL/SC block in MIPSR2 userland.
+                        */
+                       pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
+                       err = SIGKILL;
+                       break;
+               }
+
+               res = regs->regs[MIPSInst_RT(inst)];
+
+               __asm__ __volatile__(
+                       "1:\n"
+                       "sc     %0, 0(%2)\n"
+                       "2:\n"
+                       ".insn\n"
+                       ".section        .fixup,\"ax\"\n"
+                       "3:\n"
+                       "li     %1, %3\n"
+                       "j      2b\n"
+                       ".previous\n"
+                       ".section        __ex_table,\"a\"\n"
+                       ".word  1b, 3b\n"
+                       ".previous\n"
+                       : "+&r"(res), "+&r"(err)
+                       : "r"(vaddr), "i"(SIGSEGV));
+
+               if (MIPSInst_RT(inst) && !err)
+                       regs->regs[MIPSInst_RT(inst)] = res;
+
+               MIPS_R2_STATS(llsc);
+
+               break;
+
+       case lld_op:
+               if (config_enabled(CONFIG_32BIT)) {
+                   err = SIGILL;
+                   break;
+               }
+
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (vaddr & 0x7) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGBUS;
+                       break;
+               }
+               if (!access_ok(VERIFY_READ, vaddr, 8)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGBUS;
+                       break;
+               }
+
+               if (!cpu_has_rw_llb) {
+                       /*
+                        * An LL/SC block can't be safely emulated without
+                        * a Config5/LLB availability. So it's probably time to
+                        * kill our process before things get any worse. This is
+                        * because Config5/LLB allows us to use ERETNC so that
+                        * the LLAddr/LLB bit is not cleared when we return from
+                        * an exception. MIPS R2 LL/SC instructions trap with an
+                        * RI exception so once we emulate them here, we return
+                        * back to userland with ERETNC. That preserves the
+                        * LLAddr/LLB so the subsequent SC instruction will
+                        * succeed preserving the atomic semantics of the LL/SC
+                        * block. Without that, there is no safe way to emulate
+                        * an LL/SC block in MIPSR2 userland.
+                        */
+                       pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
+                       err = SIGKILL;
+                       break;
+               }
+
+               __asm__ __volatile__(
+                       "1:\n"
+                       "lld    %0, 0(%2)\n"
+                       "2:\n"
+                       ".insn\n"
+                       ".section        .fixup,\"ax\"\n"
+                       "3:\n"
+                       "li     %1, %3\n"
+                       "j      2b\n"
+                       ".previous\n"
+                       ".section        __ex_table,\"a\"\n"
+                       ".word  1b, 3b\n"
+                       ".previous\n"
+                       : "=&r"(res), "+&r"(err)
+                       : "r"(vaddr), "i"(SIGSEGV)
+                       : "memory");
+               if (MIPSInst_RT(inst) && !err)
+                       regs->regs[MIPSInst_RT(inst)] = res;
+
+               MIPS_R2_STATS(llsc);
+
+               break;
+
+       case scd_op:
+               if (config_enabled(CONFIG_32BIT)) {
+                   err = SIGILL;
+                   break;
+               }
+
+               vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
+               if (vaddr & 0x7) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGBUS;
+                       break;
+               }
+               if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
+                       current->thread.cp0_baduaddr = vaddr;
+                       err = SIGBUS;
+                       break;
+               }
+
+               if (!cpu_has_rw_llb) {
+                       /*
+                        * An LL/SC block can't be safely emulated without
+                        * a Config5/LLB availability. So it's probably time to
+                        * kill our process before things get any worse. This is
+                        * because Config5/LLB allows us to use ERETNC so that
+                        * the LLAddr/LLB bit is not cleared when we return from
+                        * an exception. MIPS R2 LL/SC instructions trap with an
+                        * RI exception so once we emulate them here, we return
+                        * back to userland with ERETNC. That preserves the
+                        * LLAddr/LLB so the subsequent SC instruction will
+                        * succeed preserving the atomic semantics of the LL/SC
+                        * block. Without that, there is no safe way to emulate
+                        * an LL/SC block in MIPSR2 userland.
+                        */
+                       pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
+                       err = SIGKILL;
+                       break;
+               }
+
+               res = regs->regs[MIPSInst_RT(inst)];
+
+               __asm__ __volatile__(
+                       "1:\n"
+                       "scd    %0, 0(%2)\n"
+                       "2:\n"
+                       ".insn\n"
+                       ".section        .fixup,\"ax\"\n"
+                       "3:\n"
+                       "li     %1, %3\n"
+                       "j      2b\n"
+                       ".previous\n"
+                       ".section        __ex_table,\"a\"\n"
+                       ".word  1b, 3b\n"
+                       ".previous\n"
+                       : "+&r"(res), "+&r"(err)
+                       : "r"(vaddr), "i"(SIGSEGV));
+
+               if (MIPSInst_RT(inst) && !err)
+                       regs->regs[MIPSInst_RT(inst)] = res;
+
+               MIPS_R2_STATS(llsc);
+
+               break;
+       case pref_op:
+               /* skip it */
+               break;
+       default:
+               err = SIGILL;
+       }
+
+       /*
+        * Lets not return to userland just yet. It's constly and
+        * it's likely we have more R2 instructions to emulate
+        */
+       if (!err && (pass++ < MIPS_R2_EMUL_TOTAL_PASS)) {
+               regs->cp0_cause &= ~CAUSEF_BD;
+               err = get_user(inst, (u32 __user *)regs->cp0_epc);
+               if (!err)
+                       goto repeat;
+
+               if (err < 0)
+                       err = SIGSEGV;
+       }
+
+       if (err && (err != SIGEMT)) {
+               regs->regs[31] = r31;
+               regs->cp0_epc = epc;
+       }
+
+       /* Likely a MIPS R6 compatible instruction */
+       if (pass && (err == SIGILL))
+               err = 0;
+
+       return err;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+static int mipsr2_stats_show(struct seq_file *s, void *unused)
+{
+
+       seq_printf(s, "Instruction\tTotal\tBDslot\n------------------------------\n");
+       seq_printf(s, "movs\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.movs),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.movs));
+       seq_printf(s, "hilo\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.hilo),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.hilo));
+       seq_printf(s, "muls\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.muls),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.muls));
+       seq_printf(s, "divs\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.divs),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.divs));
+       seq_printf(s, "dsps\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.dsps),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.dsps));
+       seq_printf(s, "bops\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.bops),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.bops));
+       seq_printf(s, "traps\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.traps),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.traps));
+       seq_printf(s, "fpus\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.fpus),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.fpus));
+       seq_printf(s, "loads\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.loads),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.loads));
+       seq_printf(s, "stores\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.stores),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.stores));
+       seq_printf(s, "llsc\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.llsc),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.llsc));
+       seq_printf(s, "dsemul\t\t%ld\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2emustats.dsemul),
+                  (unsigned long)__this_cpu_read(mipsr2bdemustats.dsemul));
+       seq_printf(s, "jr\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.jrs));
+       seq_printf(s, "bltzl\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.bltzl));
+       seq_printf(s, "bgezl\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.bgezl));
+       seq_printf(s, "bltzll\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.bltzll));
+       seq_printf(s, "bgezll\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.bgezll));
+       seq_printf(s, "bltzal\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.bltzal));
+       seq_printf(s, "bgezal\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.bgezal));
+       seq_printf(s, "beql\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.beql));
+       seq_printf(s, "bnel\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.bnel));
+       seq_printf(s, "blezl\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.blezl));
+       seq_printf(s, "bgtzl\t\t%ld\n",
+                  (unsigned long)__this_cpu_read(mipsr2bremustats.bgtzl));
+
+       return 0;
+}
+
+static int mipsr2_stats_clear_show(struct seq_file *s, void *unused)
+{
+       mipsr2_stats_show(s, unused);
+
+       __this_cpu_write((mipsr2emustats).movs, 0);
+       __this_cpu_write((mipsr2bdemustats).movs, 0);
+       __this_cpu_write((mipsr2emustats).hilo, 0);
+       __this_cpu_write((mipsr2bdemustats).hilo, 0);
+       __this_cpu_write((mipsr2emustats).muls, 0);
+       __this_cpu_write((mipsr2bdemustats).muls, 0);
+       __this_cpu_write((mipsr2emustats).divs, 0);
+       __this_cpu_write((mipsr2bdemustats).divs, 0);
+       __this_cpu_write((mipsr2emustats).dsps, 0);
+       __this_cpu_write((mipsr2bdemustats).dsps, 0);
+       __this_cpu_write((mipsr2emustats).bops, 0);
+       __this_cpu_write((mipsr2bdemustats).bops, 0);
+       __this_cpu_write((mipsr2emustats).traps, 0);
+       __this_cpu_write((mipsr2bdemustats).traps, 0);
+       __this_cpu_write((mipsr2emustats).fpus, 0);
+       __this_cpu_write((mipsr2bdemustats).fpus, 0);
+       __this_cpu_write((mipsr2emustats).loads, 0);
+       __this_cpu_write((mipsr2bdemustats).loads, 0);
+       __this_cpu_write((mipsr2emustats).stores, 0);
+       __this_cpu_write((mipsr2bdemustats).stores, 0);
+       __this_cpu_write((mipsr2emustats).llsc, 0);
+       __this_cpu_write((mipsr2bdemustats).llsc, 0);
+       __this_cpu_write((mipsr2emustats).dsemul, 0);
+       __this_cpu_write((mipsr2bdemustats).dsemul, 0);
+       __this_cpu_write((mipsr2bremustats).jrs, 0);
+       __this_cpu_write((mipsr2bremustats).bltzl, 0);
+       __this_cpu_write((mipsr2bremustats).bgezl, 0);
+       __this_cpu_write((mipsr2bremustats).bltzll, 0);
+       __this_cpu_write((mipsr2bremustats).bgezll, 0);
+       __this_cpu_write((mipsr2bremustats).bltzal, 0);
+       __this_cpu_write((mipsr2bremustats).bgezal, 0);
+       __this_cpu_write((mipsr2bremustats).beql, 0);
+       __this_cpu_write((mipsr2bremustats).bnel, 0);
+       __this_cpu_write((mipsr2bremustats).blezl, 0);
+       __this_cpu_write((mipsr2bremustats).bgtzl, 0);
+
+       return 0;
+}
+
+static int mipsr2_stats_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, mipsr2_stats_show, inode->i_private);
+}
+
+static int mipsr2_stats_clear_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, mipsr2_stats_clear_show, inode->i_private);
+}
+
+static const struct file_operations mipsr2_emul_fops = {
+       .open                   = mipsr2_stats_open,
+       .read                   = seq_read,
+       .llseek                 = seq_lseek,
+       .release                = single_release,
+};
+
+static const struct file_operations mipsr2_clear_fops = {
+       .open                   = mipsr2_stats_clear_open,
+       .read                   = seq_read,
+       .llseek                 = seq_lseek,
+       .release                = single_release,
+};
+
+
+static int __init mipsr2_init_debugfs(void)
+{
+       extern struct dentry    *mips_debugfs_dir;
+       struct dentry           *mipsr2_emul;
+
+       if (!mips_debugfs_dir)
+               return -ENODEV;
+
+       mipsr2_emul = debugfs_create_file("r2_emul_stats", S_IRUGO,
+                                         mips_debugfs_dir, NULL,
+                                         &mipsr2_emul_fops);
+       if (!mipsr2_emul)
+               return -ENOMEM;
+
+       mipsr2_emul = debugfs_create_file("r2_emul_stats_clear", S_IRUGO,
+                                         mips_debugfs_dir, NULL,
+                                         &mipsr2_clear_fops);
+       if (!mipsr2_emul)
+               return -ENOMEM;
+
+       return 0;
+}
+
+device_initcall(mipsr2_init_debugfs);
+
+#endif /* CONFIG_DEBUG_FS */
index 6e9d850..fc15732 100644 (file)
@@ -46,6 +46,7 @@
 #include <asm/fpu.h>
 #include <asm/fpu_emulator.h>
 #include <asm/idle.h>
+#include <asm/mips-r2-to-r6-emul.h>
 #include <asm/mipsregs.h>
 #include <asm/mipsmtregs.h>
 #include <asm/module.h>
@@ -837,7 +838,7 @@ out:
        exception_exit(prev_state);
 }
 
-static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
+void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
        const char *str)
 {
        siginfo_t info;
@@ -1027,7 +1028,32 @@ asmlinkage void do_ri(struct pt_regs *regs)
        unsigned int opcode = 0;
        int status = -1;
 
+       /*
+        * Avoid any kernel code. Just emulate the R2 instruction
+        * as quickly as possible.
+        */
+       if (mipsr2_emulation && cpu_has_mips_r6 &&
+           likely(user_mode(regs))) {
+               if (likely(get_user(opcode, epc) >= 0)) {
+                       status = mipsr2_decoder(regs, opcode);
+                       switch (status) {
+                       case 0:
+                       case SIGEMT:
+                               return;
+                       case SIGILL:
+                               goto no_r2_instr;
+                       default:
+                               process_fpemu_return(status,
+                                                    &current->thread.cp0_baduaddr);
+                               return;
+                       }
+               }
+       }
+
+no_r2_instr:
+
        prev_state = exception_enter();
+
        if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs),
                       SIGILL) == NOTIFY_STOP)
                goto out;
index 6e7920b..3c341b0 100644 (file)
@@ -48,6 +48,7 @@
 #include <asm/processor.h>
 #include <asm/fpu_emulator.h>
 #include <asm/fpu.h>
+#include <asm/mips-r2-to-r6-emul.h>
 
 #include "ieee754.h"
 
@@ -68,7 +69,7 @@ static int fpux_emu(struct pt_regs *,
 #define modeindex(v) ((v) & FPU_CSR_RM)
 
 /* convert condition code register number to csr bit */
-static const unsigned int fpucondbit[8] = {
+const unsigned int fpucondbit[8] = {
        FPU_CSR_COND0,
        FPU_CSR_COND1,
        FPU_CSR_COND2,