 02b849f761
			
		
	
	
	02b849f761
	
	
	
		
			
			It fails with LTO and probably has always been a fragile. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
		
			
				
	
	
		
			364 lines
		
	
	
	
		
			7.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			364 lines
		
	
	
	
		
			7.3 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) 2003, 04, 07 Ralf Baechle <ralf@linux-mips.org>
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|  * Copyright (C) MIPS Technologies, Inc.
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|  *   written by Ralf Baechle <ralf@linux-mips.org>
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|  */
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| #ifndef _ASM_HAZARDS_H
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| #define _ASM_HAZARDS_H
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| 
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| #include <linux/stringify.h>
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| 
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| #define ___ssnop							\
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| 	sll	$0, $0, 1
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| 
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| #define ___ehb								\
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| 	sll	$0, $0, 3
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| 
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| /*
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|  * TLB hazards
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|  */
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| #if defined(CONFIG_CPU_MIPSR2) && !defined(CONFIG_CPU_CAVIUM_OCTEON)
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| 
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| /*
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|  * MIPSR2 defines ehb for hazard avoidance
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|  */
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| 
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| #define __mtc0_tlbw_hazard						\
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| 	___ehb
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| 
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| #define __tlbw_use_hazard						\
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| 	___ehb
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| 
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| #define __tlb_probe_hazard						\
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| 	___ehb
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| 
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| #define __irq_enable_hazard						\
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| 	___ehb
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| 
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| #define __irq_disable_hazard						\
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| 	___ehb
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| 
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| #define __back_to_back_c0_hazard					\
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| 	___ehb
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| 
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| /*
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|  * gcc has a tradition of misscompiling the previous construct using the
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|  * address of a label as argument to inline assembler.	Gas otoh has the
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|  * annoying difference between la and dla which are only usable for 32-bit
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|  * rsp. 64-bit code, so can't be used without conditional compilation.
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|  * The alterantive is switching the assembler to 64-bit code which happens
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|  * to work right even for 32-bit code ...
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|  */
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| #define instruction_hazard()						\
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| do {									\
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| 	unsigned long tmp;						\
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| 									\
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| 	__asm__ __volatile__(						\
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| 	"	.set	mips64r2				\n"	\
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| 	"	dla	%0, 1f					\n"	\
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| 	"	jr.hb	%0					\n"	\
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| 	"	.set	mips0					\n"	\
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| 	"1:							\n"	\
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| 	: "=r" (tmp));							\
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| } while (0)
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| 
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| #elif (defined(CONFIG_CPU_MIPSR1) && !defined(CONFIG_MIPS_ALCHEMY)) || \
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| 	defined(CONFIG_CPU_BMIPS)
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| 
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| /*
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|  * These are slightly complicated by the fact that we guarantee R1 kernels to
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|  * run fine on R2 processors.
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|  */
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| 
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| #define __mtc0_tlbw_hazard						\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ehb
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| 
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| #define __tlbw_use_hazard						\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ehb
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| 
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| #define __tlb_probe_hazard						\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ehb
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| 
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| #define __irq_enable_hazard						\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ehb
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| 
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| #define __irq_disable_hazard						\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ehb
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| 
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| #define __back_to_back_c0_hazard					\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ehb
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| 
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| /*
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|  * gcc has a tradition of misscompiling the previous construct using the
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|  * address of a label as argument to inline assembler.	Gas otoh has the
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|  * annoying difference between la and dla which are only usable for 32-bit
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|  * rsp. 64-bit code, so can't be used without conditional compilation.
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|  * The alterantive is switching the assembler to 64-bit code which happens
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|  * to work right even for 32-bit code ...
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|  */
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| #define __instruction_hazard()						\
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| do {									\
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| 	unsigned long tmp;						\
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| 									\
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| 	__asm__ __volatile__(						\
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| 	"	.set	mips64r2				\n"	\
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| 	"	dla	%0, 1f					\n"	\
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| 	"	jr.hb	%0					\n"	\
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| 	"	.set	mips0					\n"	\
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| 	"1:							\n"	\
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| 	: "=r" (tmp));							\
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| } while (0)
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| 
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| #define instruction_hazard()						\
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| do {									\
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| 	if (cpu_has_mips_r2)						\
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| 		__instruction_hazard();					\
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| } while (0)
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| 
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| #elif defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_CPU_CAVIUM_OCTEON) || \
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| 	defined(CONFIG_CPU_LOONGSON2) || defined(CONFIG_CPU_R10000) || \
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| 	defined(CONFIG_CPU_R5500) || defined(CONFIG_CPU_XLR)
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| 
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| /*
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|  * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
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|  */
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| 
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| #define __mtc0_tlbw_hazard
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| 
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| #define __tlbw_use_hazard
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| 
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| #define __tlb_probe_hazard
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| 
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| #define __irq_enable_hazard
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| 
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| #define __irq_disable_hazard
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| 
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| #define __back_to_back_c0_hazard
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| 
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| #define instruction_hazard() do { } while (0)
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| 
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| #elif defined(CONFIG_CPU_SB1)
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| 
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| /*
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|  * Mostly like R4000 for historic reasons
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|  */
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| #define __mtc0_tlbw_hazard
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| 
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| #define __tlbw_use_hazard
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| 
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| #define __tlb_probe_hazard
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| 
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| #define __irq_enable_hazard
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| 
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| #define __irq_disable_hazard						\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ssnop
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| 
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| #define __back_to_back_c0_hazard
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| 
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| #define instruction_hazard() do { } while (0)
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| 
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| #else
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| 
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| /*
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|  * Finally the catchall case for all other processors including R4000, R4400,
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|  * R4600, R4700, R5000, RM7000, NEC VR41xx etc.
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|  *
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|  * The taken branch will result in a two cycle penalty for the two killed
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|  * instructions on R4000 / R4400.  Other processors only have a single cycle
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|  * hazard so this is nice trick to have an optimal code for a range of
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|  * processors.
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|  */
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| #define __mtc0_tlbw_hazard						\
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| 	nop;								\
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| 	nop
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| 
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| #define __tlbw_use_hazard						\
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| 	nop;								\
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| 	nop;								\
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| 	nop
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| 
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| #define __tlb_probe_hazard						\
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| 	nop;								\
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| 	nop;								\
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| 	nop
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| 
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| #define __irq_enable_hazard						\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ssnop
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| 
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| #define __irq_disable_hazard						\
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| 	nop;								\
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| 	nop;								\
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| 	nop
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| 
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| #define __back_to_back_c0_hazard					\
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| 	___ssnop;							\
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| 	___ssnop;							\
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| 	___ssnop
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| 
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| #define instruction_hazard() do { } while (0)
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| 
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| #endif
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| 
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| 
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| /* FPU hazards */
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| 
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| #if defined(CONFIG_CPU_SB1)
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| 
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| #define __enable_fpu_hazard						\
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| 	.set	push;							\
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| 	.set	mips64;							\
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| 	.set	noreorder;						\
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| 	___ssnop;							\
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| 	bnezl	$0, .+4;						\
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| 	___ssnop;							\
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| 	.set	pop
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| 
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| #define __disable_fpu_hazard
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| 
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| #elif defined(CONFIG_CPU_MIPSR2)
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| 
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| #define __enable_fpu_hazard						\
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| 	___ehb
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| 
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| #define __disable_fpu_hazard						\
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| 	___ehb
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| 
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| #else
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| 
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| #define __enable_fpu_hazard						\
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| 	nop;								\
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| 	nop;								\
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| 	nop;								\
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| 	nop
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| 
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| #define __disable_fpu_hazard						\
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| 	___ehb
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| 
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| #endif
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| 
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| #ifdef __ASSEMBLY__
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| 
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| #define _ssnop ___ssnop
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| #define	_ehb ___ehb
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| #define mtc0_tlbw_hazard __mtc0_tlbw_hazard
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| #define tlbw_use_hazard __tlbw_use_hazard
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| #define tlb_probe_hazard __tlb_probe_hazard
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| #define irq_enable_hazard __irq_enable_hazard
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| #define irq_disable_hazard __irq_disable_hazard
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| #define back_to_back_c0_hazard __back_to_back_c0_hazard
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| #define enable_fpu_hazard __enable_fpu_hazard
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| #define disable_fpu_hazard __disable_fpu_hazard
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| 
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| #else
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| 
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| #define _ssnop()							\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(___ssnop)						\
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| 	);								\
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| } while (0)
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| 
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| #define	_ehb()								\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(___ehb)						\
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| 	);								\
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| } while (0)
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| 
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| 
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| #define mtc0_tlbw_hazard()						\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(__mtc0_tlbw_hazard)					\
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| 	);								\
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| } while (0)
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| 
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| 
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| #define tlbw_use_hazard()						\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(__tlbw_use_hazard)					\
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| 	);								\
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| } while (0)
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| 
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| 
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| #define tlb_probe_hazard()						\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(__tlb_probe_hazard)					\
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| 	);								\
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| } while (0)
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| 
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| 
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| #define irq_enable_hazard()						\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(__irq_enable_hazard)				\
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| 	);								\
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| } while (0)
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| 
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| 
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| #define irq_disable_hazard()						\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(__irq_disable_hazard)				\
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| 	);								\
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| } while (0)
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| 
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| 
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| #define back_to_back_c0_hazard() 					\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(__back_to_back_c0_hazard)				\
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| 	);								\
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| } while (0)
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| 
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| 
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| #define enable_fpu_hazard()						\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(__enable_fpu_hazard)				\
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| 	);								\
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| } while (0)
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| 
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| 
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| #define disable_fpu_hazard()						\
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| do {									\
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| 	__asm__ __volatile__(						\
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| 	__stringify(__disable_fpu_hazard)				\
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| 	);								\
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| } while (0)
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| 
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| /*
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|  * MIPS R2 instruction hazard barrier.   Needs to be called as a subroutine.
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|  */
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| extern void mips_ihb(void);
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| 
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| #endif /* __ASSEMBLY__  */
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| 
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| #endif /* _ASM_HAZARDS_H */
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