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linux/arch/mips/include/asm/mips-r2-to-r6-emul.h

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MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6 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>
2014-12-03 15:47:03 +00:00
/*
* 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) { \
MIPS: math-emu: Make microMIPS branch delay slot emulation work Complement commit 102cedc32a6e ("MIPS: microMIPS: Floating point support.") which introduced microMIPS FPU emulation, but did not adjust the encoding of the BREAK instruction used to terminate the branch delay slot emulation frame. Consequently the execution of any such frame is indeterminate and, depending on CPU configuration, will result in random code execution or an offending program being terminated with SIGILL. This is because the regular MIPS BREAK instruction is encoded with the 0 major and the 0xd minor opcode, however in the microMIPS instruction set this major/minor opcode pair denotes an encoding reserved for the DSP ASE. Instead the microMIPS BREAK instruction is encoded with the 0 major and the 0x7 minor opcode. Use the correct BREAK encoding for microMIPS FPU emulation then. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12174/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-22 05:20:46 +00:00
if (nir == BREAK_MATH(0)) \
MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6 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>
2014-12-03 15:47:03 +00:00
__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);
};
MIPS: traps: Correct the SIGTRAP debug ABI in `do_watch' and `do_trap_or_bp' Follow our own rules set in <asm/siginfo.h> for SIGTRAP signals issued from `do_watch' and `do_trap_or_bp' by setting the signal code to TRAP_HWBKPT and TRAP_BRKPT respectively, for Watch exceptions and for those Breakpoint exceptions whose originating BREAK instruction's code does not have a special meaning. Keep Trap exceptions unaffected as these are not debug events. No existing user software is expected to examine signal codes for these signals as SI_KERNEL has been always used here. This change makes the MIPS port more like other Linux ports, which reduces the complexity and provides for performance improvement in GDB. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Pedro Alves <palves@redhat.com> Cc: Luis Machado <lgustavo@codesourcery.com> Cc: linux-mips@linux-mips.org Cc: gdb@sourceware.org Patchwork: https://patchwork.linux-mips.org/patch/12758/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-03-04 01:44:28 +00:00
extern void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,
MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6 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>
2014-12-03 15:47:03 +00:00
const char *str);
#ifndef CONFIG_MIPSR2_TO_R6_EMULATOR
static int mipsr2_emulation;
MIPS: Set `si_code' for SIGFPE signals sent from emulation too Rework `process_fpemu_return' and move IEEE 754 exception interpretation there, from `do_fpe'. Record the cause bits set in FCSR before they are cleared and pass them through to `process_fpemu_return' so as to set `si_code' correctly too for SIGFPE signals sent from emulation rather than those issued by hardware with the FPE processor exception only. For simplicity `mipsr2_decoder' assumes `*fcr31' has been preinitialised and only sets it to anything if an FPU instruction has been emulated, which in turn is the only case SIGFPE can be issued for here. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9705/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-03 23:27:15 +01:00
static inline int mipsr2_decoder(struct pt_regs *regs, u32 inst,
unsigned long *fcr31)
{
return 0;
};
MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6 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>
2014-12-03 15:47:03 +00:00
#else
/* MIPS R2 Emulator ON/OFF */
extern int mipsr2_emulation;
MIPS: Set `si_code' for SIGFPE signals sent from emulation too Rework `process_fpemu_return' and move IEEE 754 exception interpretation there, from `do_fpe'. Record the cause bits set in FCSR before they are cleared and pass them through to `process_fpemu_return' so as to set `si_code' correctly too for SIGFPE signals sent from emulation rather than those issued by hardware with the FPE processor exception only. For simplicity `mipsr2_decoder' assumes `*fcr31' has been preinitialised and only sets it to anything if an FPU instruction has been emulated, which in turn is the only case SIGFPE can be issued for here. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9705/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-03 23:27:15 +01:00
extern int mipsr2_decoder(struct pt_regs *regs, u32 inst,
unsigned long *fcr31);
MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6 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>
2014-12-03 15:47:03 +00:00
#endif /* CONFIG_MIPSR2_TO_R6_EMULATOR */
#define NO_R6EMU (cpu_has_mips_r6 && !mipsr2_emulation)
#endif /* __ASM_MIPS_R2_TO_R6_EMUL_H */
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