 b0a668fb20
			
		
	
	
	b0a668fb20
	
	
	
		
			
			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>
		
			
				
	
	
		
			103 lines
		
	
	
	
		
			2.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			103 lines
		
	
	
	
		
			2.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * This file is subject to the terms and conditions of the GNU General Public
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|  * License.  See the file "COPYING" in the main directory of this archive
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|  * for more details.
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|  *
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|  * Copyright (C) 1996, 1997, 1998, 2001 by Ralf Baechle
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|  */
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| #ifndef _ASM_BRANCH_H
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| #define _ASM_BRANCH_H
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| 
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| #include <asm/cpu-features.h>
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| #include <asm/mipsregs.h>
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| #include <asm/ptrace.h>
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| #include <asm/inst.h>
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| 
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| extern int __isa_exception_epc(struct pt_regs *regs);
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| extern int __compute_return_epc(struct pt_regs *regs);
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| extern int __compute_return_epc_for_insn(struct pt_regs *regs,
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| 					 union mips_instruction insn);
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| extern int __microMIPS_compute_return_epc(struct pt_regs *regs);
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| extern int __MIPS16e_compute_return_epc(struct pt_regs *regs);
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| 
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| /*
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|  * microMIPS bitfields
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|  */
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| #define MM_POOL32A_MINOR_MASK	0x3f
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| #define MM_POOL32A_MINOR_SHIFT	0x6
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| #define MM_MIPS32_COND_FC	0x30
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| 
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| extern int __mm_isBranchInstr(struct pt_regs *regs,
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| 	struct mm_decoded_insn dec_insn, unsigned long *contpc);
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| 
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| static inline int mm_isBranchInstr(struct pt_regs *regs,
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| 	struct mm_decoded_insn dec_insn, unsigned long *contpc)
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| {
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| 	if (!cpu_has_mmips)
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| 		return 0;
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| 
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| 	return __mm_isBranchInstr(regs, dec_insn, contpc);
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| }
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| 
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| static inline int delay_slot(struct pt_regs *regs)
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| {
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| 	return regs->cp0_cause & CAUSEF_BD;
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| }
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| 
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| static inline void clear_delay_slot(struct pt_regs *regs)
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| {
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| 	regs->cp0_cause &= ~CAUSEF_BD;
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| }
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| 
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| static inline void set_delay_slot(struct pt_regs *regs)
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| {
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| 	regs->cp0_cause |= CAUSEF_BD;
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| }
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| 
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| static inline unsigned long exception_epc(struct pt_regs *regs)
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| {
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| 	if (likely(!delay_slot(regs)))
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| 		return regs->cp0_epc;
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| 
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| 	if (get_isa16_mode(regs->cp0_epc))
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| 		return __isa_exception_epc(regs);
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| 
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| 	return regs->cp0_epc + 4;
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| }
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| 
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| #define BRANCH_LIKELY_TAKEN 0x0001
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| 
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| static inline int compute_return_epc(struct pt_regs *regs)
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| {
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| 	if (get_isa16_mode(regs->cp0_epc)) {
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| 		if (cpu_has_mmips)
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| 			return __microMIPS_compute_return_epc(regs);
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| 		if (cpu_has_mips16)
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| 			return __MIPS16e_compute_return_epc(regs);
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| 		return regs->cp0_epc;
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| 	}
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| 
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| 	if (!delay_slot(regs)) {
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| 		regs->cp0_epc += 4;
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| 		return 0;
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| 	}
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| 
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| 	return __compute_return_epc(regs);
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| }
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| 
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| static inline int MIPS16e_compute_return_epc(struct pt_regs *regs,
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| 					     union mips16e_instruction *inst)
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| {
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| 	if (likely(!delay_slot(regs))) {
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| 		if (inst->ri.opcode == MIPS16e_extend_op) {
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| 			regs->cp0_epc += 4;
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| 			return 0;
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| 		}
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| 		regs->cp0_epc += 2;
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| 		return 0;
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| 	}
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| 
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| 	return __MIPS16e_compute_return_epc(regs);
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| }
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| 
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| #endif /* _ASM_BRANCH_H */
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